Wikipedia:Reference desk archive/Science/March 2006

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March 1[edit]

Plants and their production of oxygen[edit]

I was wondering if it was possible for future moon colonization for the colony's oxygen supply to be totally relient on plants? Could the colonists provide the plants with their carbon dioxide while the plants supplied them with oxygen?

Yes, so long as the whole thing is in air tight containers. The Earth's moon can not be teraformed because its gravity is too low to maintain an atmosphere. WAS 4.250 02:04, 1 March 2006 (UTC)
Closed ecological system --Zeizmic 00:30, 1 March 2006 (UTC)

In order for a planet/moon to have an atmosphere it has to generate enough gravity to hold the gases to the surface of the planet. Our moon has a very thin atmosphere because of its relatively small mass. There is also the question of sustaining the plants. At the very minimum, plants need water, sugar, and carbon dioxide to live. If the moon cannot provide this, in the right quanities, then plants cannot survive. In actuallity, what you want to do is put plants on the moon to generate oxygen. Though it sounds like a good idea, if it were possible, the moon would be as green as our planet. It would have already gone through this process, which is an interesting read. --Chris 01:03, 1 March 2006 (UTC)

I have another question the moon may not have the gravitational pull strong enough for this process but does Mars? If the temperture could be raised then could plants be grown on the surface, of course this would require the discovery of a water source, but could it be done? The carbon dioxide is already there.

I think there's already a lot of water (frozen) on Mars. The problem comes in "raising the temperature". I don't think it would be possible to live on Mars in the same way we use Earth because the amount of energy required would be difficult to generate so far from the Sun. Not to mention the lower intensity of natural light required for photosynthesis. Unless there are high quantities of quality radioactive materials available, forget it. --Username132 01:37, 1 March 2006 (UTC)

Mars can be teraformed by crashing into it a large object that has a lot of frozen water. Objects like this are plentiful. There are a lot of interesting details involved, but Mars is do-able, Earth's moon isn't. You do realize we are talking huge amounts of time, right? WAS 4.250 02:04, 1 March 2006 (UTC)

If the caps were melted would the amount of carbon dioxide released be enough to raise the temperture any? Also if the caps were melted then water would be released.

It's difficult to tell, since to this day we still don't know just how much CO2 there is in the martian polar caps. Modelling planetwide climate change is something we can't even do well on our own planet, let alone on a planet we have never been to.
Aside: we have a pretty good article on terraforming. — QuantumEleven | (talk) 11:20, 1 March 2006 (UTC)

Degree symbols on Computers[edit]

Anybody know why there is not a key for a "degree symbol" on computer keyboards? I frquently have need of one and I'm sure many other people do too.

If you need to use the degree symbol "°" regularly, you may be able to configure your word processing program to assign the degree symbol to a keyboard shortcut. --Robert Merkel 03:41, 1 March 2006 (UTC)
I've got it in my GNOME Character Palette. —Keenan Pepper 04:52, 1 March 2006 (UTC)

There's two things here: 1) computer keyboards evolved from Typewriter keyboards. There was no need for a degree sign with typewriters, because you could simply manually move the platen half a row down and type "o" (in otherwords, put a lower case O in superscript), which is all that was needed given the rudimentary font capabilities of typewriters. 2) most computers use a simple key combination to get a degree symbol. I can't recall offhand what it is with PCs, but with Macs "option-shift-8" gives you "°" in most editing and word-processing programs. Grutness...wha? 05:56, 1 March 2006 (UTC)

If you are using an Apple Computer, just press option and K. K for Kelvin.
There is no degree symbol on a standard US QWERTY keyboard. The (IMO much improved, but very rare) US-International layout has the ° accessible by SHIFT-ALTGR-: . The German QWERTZ and French AZERTY layouts also have a ° key (either SHIFT-) or SHIFT-^ ). See keyboard layout - the standard US keyboard is one of the least functional of them all, and useless for languages which use diacritic marks, or for inputting all but the most common of symbols.
If you're using a French keyboard (probably not, but just in case :)), the ° is on a key just to the right of 0 (press shift + that key). If not, you can get it by using it's ASCII key combination, press and hold down ALT, type 0176 on your numerical keypad, and release ALT. (you can use this method to type pretty much any character, find out the different codes by using the Character Map utility, usually in your start menu under Accessories -> System Tools). You can also install a language pack (e.g. French) and change the language when you need various symbols only available on the other language keyboard, if you know its layout. — QuantumEleven | (talk) 08:36, 1 March 2006 (UTC)

Planet spinning[edit]

Can someone tell me why every thing in the Universe spins? Do all stars, planets etc. spin in the same direction? I can understand that a baseball spins because of the friction between the ball and the throwers hand but I'm not sure this would explain why a star spins. Thanks WSC

Something started them spinning a long time ago, and they can't stop because angular momentum is conserved. It would be amazing if the angular momentum randomly happened to be exactly zero. —Keenan Pepper 04:49, 1 March 2006 (UTC)
More specifically, something started them moving a while ago. Then all kinds of gravity happened. Venus and some other orbiting bodies, mainly comets, have retrograde rotations. -LambaJan 07:44, 1 March 2006 (UTC)
Take a simple analogy - water flowing down a drain. In theory, the water could flow straight down the drain without any sort of spin (all that about the draining water spinning the other way in the southern hemisphere is rubbish). But in practice it almost never does, because any slight imbalance (a bit more water on one side, the bowl not being perfectly symmetrical...) will cause the draining water to start spinning.
With stars and other objects it works in a similar way - they are formed when clouds of gas and dusk contract under their own gravity. In theory, the cloud could be perfectly uniform in every direction, and contract perfectly symmetrically. In practice, that's never the case, any small variation will cause the resulting object to start spinning, and in space, as there's no friction, something which starts spinning won't stop.
Because of this, no, not all stars and planets spin the same way, far from it! Their axis and velocity of spin is dependent on how they were formed, and so can be every which way. We have a decent article on axial tilt if you're interested. — QuantumEleven | (talk) 08:27, 1 March 2006 (UTC)
Consider a good-sized chunk of plasticine hanging from a string attached to the ceiling. This is going to be our model of a planet being formed. Assume that it starts out stationary. If you give the lump a little kick–say, by throwing another little chunk of plasticine at it–our lump will start moving. If you hit it dead center, the lump moves sideways: no rotation. If you're even a little bit off center, there will be some movement sideways and some rotation. If you just graze the edge of the lump with a tangential hit, you'll get essentially pure rotation.
When any astronomical body forms, billions of little particles smack into it, and very few strike dead center. It's also very unlikely that the off-center impacts will cancel out perfectly. Consequently, everything spins.
Gravity makes it worse. Like the classic example of a figure skater pulling in her arms, as stars and planets pack their material more densely they spin faster. (Conservation of angular momentum.) TenOfAllTrades(talk) 16:51, 1 March 2006 (UTC)
It may be that the off-centre hits will not cancel each other out perfectly, but with a large number of relatively small hits they will effectively. And they will in time be small because the surviving celestial bodies will be much much bigger than the stuff that hits them. The amount of energy needed to make a planet spin at the speed at which they do would require either a lot of small ones going off-centre on the same side, which would be statistically impossible or a big one, which would either destroy it or knock it so far out of orbit that it will get destroyed in some other way (or flung out into deep space).
I have thought about this too and haven't come up with an answer. It makes me think a bit about the question where structure in the Universe comes from. It can not have formed without already being present before the Big Bang. But we can't explain structure there, so we simply have to accept its existence. Jus like matter and time 'just are' and structure 'just is', maybe rotation is something that simply is. Asking about its origin would be like asking why there is matter.
Now that sounds like a lame answer, so let me try a different one. Maybe it's a matter of starting conditions. Maybe the very first momentum caused by chance will amplify. Chaos theory would probably come in here because we've got am instable system the outcome of which is determined by minute variations in the starting conditions. And I've got a feeling relativity might come in here too, with the initial rotation determining how attracted matter will approach it, but that's no more than a hunch.
I wonder. If one would add up all the rotations in the Universe, would they cancel each other out? DirkvdM 09:08, 2 March 2006 (UTC)

False Embryo Sketchings?[edit]

I've heard some Christians and creationists say that Ernst Haeckel's drawings of embryoes, which he claimed to be scientific evidence for evolution, are fake or flawed.Is that true?Bowei 06:50, 1 March 2006 (UTC)

That can be dismissed without addressing the main question. It's a straw man argument, since a drawing isn't scientific evidence of anything, ever. (at least in the context of biology/medicine) --BluePlatypus 07:38, 1 March 2006 (UTC)
Haeckel drawings.jpg
Yes, Haeckel's sketches are flawed—he gets a bit fanciful with his third row of sketches in the figure at right. Haeckel's Theory of Recapitulation stated that the development of an embryo would follow the evolutionary development of a species. (Often this is condensed down to the catchy slogan 'Ontogeny recapitulates phylogeny'.)
While Haeckel's theory fails in the strictest sense and his drawings sometimes strayed into wishful thinking, it does provide a useful rule of thumb. In the human embryo, features that evolved early (a backbone, for instance) are formed early in embryogenesis, whereas features that evolved recently (the cerebrum) form last. In whales (which evolved from land mammals) the embryo grows and then loses hair during the course of its development.
Certainly if Haeckel's sketches were the only evidence in support of evolution, they would be poor proof indeed. However, there is a wealth of other evidence that supports evolutionary theory quite well; an error made by a zoologist in 1866 doesn't render the theory any less reliable. TenOfAllTrades(talk) 16:33, 1 March 2006 (UTC)
Of course, they are flawed in many ways. Embryos aren't two dimensional, to begin with. deeptrivia (talk) 04:12, 2 March 2006 (UTC)

porn site[edit]

Can anyone give me the best born site in the world?

What are your criteria? JackofOz 12:21, 1 March 2006 (UTC)
why are people so weird these days. they dont know that much, that is why we have very smart scienctist.Because there is no reputable ranking site, I don't think you can say. It all boils down to personal preference. For example, you might like or Proto||type 14:09, 1 March 2006 (UTC)
As of a couple of years ago Usenet literally contained more FREE porn of EVERY category (including illegal) than you could view in a lifetime. I haven't been there in years, so I don't know its current status. WAS 4.250 18:12, 1 March 2006 (UTC)
Our article onit says in one place it currently has a daily volume of "2.00 TB" and in another place says " Commonly omitted from such a newsfeed are foreign-language newsgroups and the alt.binaries hierarchy which largely carries software and erotica and, in the 21st century, accounts for over 99 percent of the article data." So does 2 TB of free porn a day qualify as "best"? WAS 4.250 18:22, 1 March 2006 (UTC)
Sure, but only if you can tell me correctly what the best book ever written and the best movie ever made were (and have *everybody* agree on it). --Robert Merkel 00:25, 2 March 2006 (UTC)
There is only one book that stands out from all others and that is The Bible. There is no moving picture that stands out above all others so the "best" movie that everyone can agree is the "best" is yet to be made. That's not exactly what you asked, but that's what's available in terms of books and movies. What's available in reality-land is fresh bread with cheese and tomato and sausage topping (pizza) with wine (or beer), and an opposite-sex friend (ask around, find a real life babe, beats anything on the internet); or as someone once put it a loaf of bread, a jug of wine, and thou. WAS 4.250 03:11, 2 March 2006 (UTC)
To be fair, the question was the best site, not the best porn, it's more like asking what is the best library than what is the best book. I think it's fair to say that the site containing the largest amount and largest range would be most likely to be agreed on by the most people as the best site. Your milage may vary.
No no no no no! You're saying that 'best' is defined by quantity. That should be quality. Wikipedia is the best site on the Internet because it's structured (and free). The Internet is a huge collection of info, but what was lacking was an easy way to get the right information. Search engines were one solution, but you still usually have to wade through a lot of stuff you're not interrested in. Even though Wikipedia doesn't quite come near the quantity of what these search engines can access (the whole Internet) it is already an equal competitor (I already often search on Wikipedia before I Google a term). When Wikipedia encompasses all information of some importance (a decade from now?) search engines will be out the window. So the best porn site would have all sorts of types of porn, but it would stand out by making it easy to find what you are looking for. And it would be free. That probably doesn't exist yet. So maybe we should start this? Wikiporn anyone? Of course we'd need to have images under gpl, so we'd have to make them ourselves. I suggest you start asking pretty girls (and guys) in your neighbourhood if they'd want to have their photos taken. All in the name of the open source movement of course. It's for a good cause. :) DirkvdM 09:28, 2 March 2006 (UTC)
It's been suggested already. :) I even proposed the "This page is currently softcore. You can help Wikiporn by hardcoring it" template. ;) ☢ Ҡiff 15:12, 2 March 2006 (UTC)
So the best porn site would have all sorts of types of porn, but it would stand out by making it easy to find what you are looking for. And it would be free. That probably doesn't exist yet. Obviously you haven't bothered to look at either usenet nor any of the myriad ways of accessing it. Usenet is free, volumous, contains high quality by any standards mixed in with high quality by every standard (meaning whatever you want is in there somewhere), AND it is divided up into categories as precise as "" (see [1]). To search and sort more thoroughly, you have to find an accessing method (tool, site, provider) that suits your desires/needs whatever that may be. Just cause you don't check something out doesn't mean it doesn't exist. Ever hear about the economist who said there is no such thing as a quarter on the ground because someone would have picked it up according to economic theory? By any standard except trying to get you to pay money for what you can get elsewhere for free, usenet is the best. Usenet has been for a decade well known as the best web porn site period. On slashdot it's been compared to trying to get a drink of water from a firehose. Porn sites flood the place with free pics trying to get customers to come to their specialized sites. Enthusiasts share entire collections with one another. It's also spam city. examples of tame usenet from[2]:
  1. (sources, sample of binaries)
  2. alt.binaries.multimedia.japanese (sources, FAQ, sample of binaries)
  3. finet.binaries.keskustelu (sources, sample of binaries)
  4. (sources, sample of binaries)
  5. (sources, sample of binaries)
  6. (sources, sample of binaries)
  7. (sources, FAQ, sample of binaries)
  8. alt.multimedia.mpeg (sources)
  9. alt.binaries.e-book.flood (sources, sample of binaries)
  10. (sources, sample of binaries)
  11. (sources)
  12. (sources, sample of binaries)
  13. alt.binaries.webstars (sources)
  14. (sources)
  15. alt.binaries.slack (sources, sample of binaries)
  16. (sources, sample of binaries)
  17. (sources, sample of binaries)
  18. alt.binaries.sheet-music (sources, sample of binaries)
  19. (sources, FAQ, sample of binaries)
  20. alt.binaries.cracks (sources, sample of binaries)
  21. alt.binaries.e-book.fantasy (sources, sample of binaries)WAS 4.250 10:32, 2 March 2006 (UTC)

Examples of untame usenet from [3]:

   Pictures of mammalian protruberances

   More than a handful is too much

   A binaries group devoted to British glamour girls

   Erotic pictures of brunettes


   Reposts of erotic photos of brunettes with short hair (on their head!), corrected

   Erotic pictures of women of fractional or full Bulgarian ancestry or close enough

   Erotic butts come into view WAS 4.250 10:57, 2 March 2006 (UTC) p.s. This page is not to be taken seriously :). you people are stupid:p

energy change[edit]

what is the energy change in a pendulum?

Just take the energy change outside the pendulum and subtract! Seriously, check out pendulum, and work it from there.  freshgavinΓΛĿЌ  13:48, 1 March 2006 (UTC)

Where does the EM energy go when the Poynting vector is zero?[edit]

I hope you've guessed that I'm talking about an electromagnetic wave. According to the electromagnetic wave equation, the phase difference between the E and B fields is zero, so the Poynting vector, which is their cross-product, is a cos-squared function of time. This means that the energy in a wavefront oscillates between zero and some value. Where does nature put the energy while the Poynting vector is zero, so that it can magically produce it a quarter-cycle later? I'm not trying to be controversial: I just want to know how I have misunderstood the equations. This stems from a question that someone asked me on my Talk page about why the E and M components in the light-wave.png image are in-phase. --Heron 14:53, 1 March 2006 (UTC)

It means that the energy of the EM wave is zero at that particular point of the wave - however, the wave must have some spatial extent in the longitudinal direction, and the E & H fields are not zero as you move away from the crossing point. So the answer is, the energy is stored in other parts of the wave, and as it propogates, the zero-energy points move along with the rest of it. If you integrate the energy for the whole wave-packet, you'll see that it is conserved as you expect.
Note that this isn't just a mathematical fiction - if you create an EM standing wave, you get no effect from the wave at the nodes (since there is no E or H field there), which can cause unwanted effects in lasers. --Bob Mellish 16:27, 1 March 2006 (UTC)

Thanks Bob, that makes sense. --Heron 18:50, 1 March 2006 (UTC)

telephone usage[edit]

Excluding mobiles which country has the most telphones per head of population? 15:48, 1 March 2006 (UTC)~

You will want an anomoly - extremely small population with high telephone usage. My best guess would be Palau. They have 6,600 wired telephones and 20,000 people. That is 30% of the population with a wired telephone (assuming 1 phone per person and not one person with 6,000 phones). So, look at the micro-nations and look for high telephone use and low population. The Vatican may be a good one. --Kainaw (talk) 16:08, 1 March 2006 (UTC)

Thank you :) much appreciated 19:23, 1 March 2006 (UTC)~

I'd be willing to bet it's the Vatican City - population about 900, but employing a couple of thousand non-resident workers, and in the heart of Western Europe. I can't see them having less than the 300 phones needed to beat Palau's 30%. Grutness...wha? 01:20, 2 March 2006 (UTC)
The Netherlands had 8 million connections in 1995 (if that figure includes mobiles it won't be too many). In 1997 that was 8,8 million (different source). Mobiles will have slowed the increase of wired connections, but if we assume 10 million now, on a population of 16 million that would be 60%. That said, the Netherlands is said to be the most 'connected' country in the world in different respects (highest Internet usage, for one). The main causes for that are probably high GDP combined with socialism (everyone gets to share in the wealth) and a high population density (there is no 'outback' in the Netherlands). Scandinavian countries have the former but not the latter (except maybe Denmark). But indeed smaller countries may score better. Maybe Luxemburg, Hong Kong or Singapore? DirkvdM 09:42, 2 March 2006 (UTC)

Well it's for a radio quiz & it's been going for 8 days now & it's not Vatican City because someone tried that last night - before I got chance to ring in. Belgium, Liechtenstein, France, Guernsey, Jersey, Hong Kong, Singapore, Norway, Sweden, England, Luxemburg, Malta, Republic of Ireland, Spain, Andorra, Afghanistan, New Zealand, Australia, US, Canada, Vatican City, Falkland Islands, Taiwan, Holland, Japan & Korea are the answers given so far. It's just driving me nuts now! Tonight I'm hoping to get on there & try Palua which was Kainaw's guess. Failing that it's back to banging the head on the desk! Will keep eveyone informed

If it is a radio contest, the answer they want is most likely wrong. They read obscure news articles that they don't understand, grab a fact that uses words they don't understand, and then turn it into a questions loosely based on the fact. Your best bet is searching Google News for articles about telephone usage as that is where the question came from. --Kainaw (talk) 14:30, 2 March 2006 (UTC)
Searched Google News... A recent new article claims Monaco has the most telephones per capita (199.4%). --Kainaw (talk) 01:20, 3 March 2006 (UTC)

Thanks Kainaw you've been ever so helpful. I'm new to all this so I do appreciate it :) Only worked out yesterday how to get a user name rather than a number!Devononlyknows

Have you tried using the CIA The World Factbook? However, it doesn't seem to have per capital figure, and you may have to divide the list of number of telephones with population. The Monaco's figure given above seems difficult to beat. Interestingly, the Pitcairn Islands has only one telephone, i wonder if they complain about long-distance charges. --Vsion 09:13, 3 March 2006 (UTC)

I will check that link now thank you Vsion. I wonder if the Pitcairn Islanders do complain about phone charges! Must be a pain in the neck if they need an engineer because the phone isn't working!Devononlyknows

And the answer is....Monaco! It has 1707 telephones per 1000 people. I didn't get through to give the answer. But well you never know when someone may need this information! :o)Devononlyknows 12:46, 7 March 2006 (UTC)

Why haven't I ever even SEEN a B Battery?[edit]

I've seen and used AAA, AA, A, C, D, 9V, and other sizes of batteries, but why haven't I even seen a "B" battery? Why aren't they made? --Shultz III 18:12, 1 March 2006 (UTC)

Hmm... it appears that they are made: [4] [5]. Put the second one appears to be "hand-made". KILO-LIMA 18:26, 1 March 2006 (UTC)
You just weren't looking in the right place. --LarryMac 18:32, 1 March 2006 (UTC)
Obviously, however, C battery (vacuum tubes) is not the same as the consumer C battery originally referenced, so I wouldn't call B battery (vacuum tubes) "the right place". Duracell only lists yours above as "common" (though I've also seen AAAA), so Bs certainly appear to be long gone. I'll keep poking around. — Lomn Talk 19:00, 1 March 2006 (UTC)
Well, I did show him a B battery, even if it came from the wrong family. There is amazingly little to be found on the web about the consumer style. The ANSI standard (referenced below) is C18.1, but NEMA wants $79 to see it. --LarryMac 19:49, 1 March 2006 (UTC)
Here's a quick note on A and B being part of the 1920s ANSI standard for battery sizes (noting simply that those extant today are the ones that caught on commercially) and a chart of standard battery sizes (A is included, but B appears not to be). — Lomn Talk 19:06, 1 March 2006 (UTC)

A related question - is it just my imagination, or did Britain used to have the same betteries but with completely different names? ISTR U-11 batteries as a young kid. Grutness...wha? 01:21, 2 March 2006 (UTC)

They did used to. I can't remember the names either though. I remember figuring out what the equivalents were. 03:11, 2 March 2006 (UTC)
The codes are of the form LR06 = AAA, LR6 = AA, LR20 = D, 6LF22 = 9V, etc., and are still printed on batteries here in the UK. Ojw 20:16, 3 March 2006 (UTC)
Not the codes I'm thinking of - these were definitely U-number, as in U-11, U-5 (I think) and U-22. Grutness...wha? 00:04, 4 March 2006 (UTC)
Good quote from Dan's data on the AAAA cells - "no matter whether you're at the bottom of a five-mile cave system, performing extra-vehicular activity on the International Space Station, or lost in the middle of the Gobi Desert, you at least know you're no further away from a place that sells AAAA cells than you'd be if you were standing in your local shopping centre.". Ojw 20:22, 3 March 2006 (UTC)
I added them as A battery (vacuum tubes), B battery (vacuum tubes), and C battery (vacuum tubes) specifically to avoid confusion with the modern A battery and C battery as the letters used in the vacuum tube batteries refered to usage not specific sizes/packages (all three came in many different sizes/packages). The modern A and C cells are battery sizes/packages. -- RTC 23:46, 4 March 2006 (UTC)
Ha! Found this, which says that U11 is an alternative code for C batteries. Grutness...wha? 00:55, 7 March 2006 (UTC)


What is the estimation of current number of WWW. sites?

By www site, do you mean a unique site or a domain name. Many sites have multiple names all pointing to the same site. Also, some sites have many subsites (like and all the user pages under the domain). So, using "site" is very vague. But, an estimate can be made. Assume 5% of the computers in the world are web servers hosting a web site. If you think that is low, then consider that some web servers host multiple sites. If you think that is high, then use a different percentage. Now, take into account that there are currently around 4 billion IP Addresses in use - meaning there are around 4 billions computers connected to the Internet. Many are printers, switches, and the like. But, we only consider 5% of them to be web servers. So, 5% of 4 billion is... 200 million. That may sound high, but I think it is rather low. Google claims to have indexed well over 9 billion pages. They don't even touch all the "Hi. I learned to make my own webpage!" pages. So, either a lot more of the computers on the Internet are web servers or the web servers are hosting a lot more than one site on average. --Kainaw (talk) 01:38, 2 March 2006 (UTC)
The February 2006 Netcraft survey received responses from 76 184 000 sites, so there are at least 76 million websites out there. --Bowlhover 13:33, 2 March 2006 (UTC)



Little bit of trivia, the mass spectrometers they use for those tests are so sensitive that if you've used cocaine any time in the last 6 months you'll test positive, so if you've haven't done anything recently it doesn't mean that it's a false positive, just a very sensitive spectrometer-- 22:15, 1 March 2006 (UTC)
Please stop yelling. Turn off your caps lock. The logic of your dillemma there is obviously flawwed. If a person has never used drugs, then the person should pass the test, assuming the test was done correctly. Is there a specific person involved? Is it yourself? Did this actually happen or is it a theoretical question? More information is needed. In the mean time, you can take a look at our article on hair drug testing. It might help you out. --Chris 20:07, 1 March 2006 (UTC)
  • In a test, the Mythbusters showed consumption of poppy seeds could cause you to test positive for opiates, but for such things to show up in a hair test, that would require massive amounts of the stuff. - Mgm|(talk) 20:47, 1 March 2006 (UTC)
Few tests are so good that they have NO false positives - what is the accuracy of this test?
  • Actually, there are no false positives, it's the same machine they use to sequence proteins, and is more than capable of telling the difference between cocaine and coca flavored shampoo, LOL-- 05:17, 2 March 2006 (UTC)
    • I don't see how, given that coca-flavored shampoo would actually contain cocaine. --Trovatore 05:20, 2 March 2006 (UTC)

It occurs to me that if you were to use an herbal shampoo containing coca leaf, it could mess you up this way. I've never heard of any such shampoo, but you never know. --Trovatore 03:20, 2 March 2006 (UTC)

The short answer is, it depends. If you have been in the presence of other individuals using cocaine (smoking large amounts of crack, in particular), then it is possible for some cocaine to become attached to your hair. Hair testing protocols call for fairly extensive washing of the hair sample to remove drug that may have been absorbed from the air, but there are studies which suggest that this process may not be 100% effective. Dark-haired individuals may be particularly vulnerable, as there is evidence to suggest that melanin (a pigment in dark hair) can effectively bind cocaine. Modern hair-testing labs should be testing the hair for both cocaine and for its metabolites: compounds like benzoylecgonine. The presence of such compounds is usually taken to be indicative that the drug was ingested, since they are produced as the body processes the drug. (If a lab cuts corners or offers cheap tests, they may not be testing for metabolites.) There is also an off chance that someone screwed up sample handling or labelling somewhere along the line; if someone else's hair was tested in place of yours, then you're going to get incorrect results. I am operating under the assumption that the lab is using a GC/MS (gas chromatography/mass spectrometry) system to run these tests. Such equipment–used properly–is pretty much the gold standard. Other testing protocols may be more prone to false positives. TenOfAllTrades(talk) 05:45, 2 March 2006 (UTC)

I am actually pretty sure I saw in Scientific American that it is possible to detect certain drug usage, and how much a person has been using after they've had enough time to grow their hair out. I don't remember any details, maybe it was crack they talked about. -- Flag of the United States.svg Mac Davisญƛ. 10:18, 2 March 2006 (UTC)

You might get a positive result if the lab is sloppy. If they have cocaine around, the dust can contaminate the room so that test samples could pick up cocaine from air or surfaces. The FBI whistleblowers made just that claim about the FBI labs. They had a lot of cocaine around. I have read that money counted out near drugs will pick up particles of drug. As that money gets passed around, it rubs off on other money in the money drawer. Thus I read that a large percentage of money has detectable drug residue, and could be confiscated under USA forfeiture laws, if the police decide to test YOUR money. GangofOne 08:12, 3 March 2006 (UTC)

Why is Schrondinger's Equation The Way It Is?[edit]

This question might be asking something that isn't very answerable by anyone, or at least answerable without recourse to talking about 11 dimensions and Hilbert Spaces, but why is Schrodinger's Equation what it is? I'm in Intro QM at Uni, and was talking to a friend, trying to describe what wave functions are. I was explaining the infinite-square well potential, and she asked why it was that the stationary states were all sinusoidal. The answer, of course, is that time-independent equation becomes a differential equation for a simple harmonic oscillator in the infinite-square well case, and the rest is boundary conditions. But she wanted to know why the time-independent eq. (and by extension the general eq.) worked out to a harmonic oscillator. I had no answer, was wondering if one existed. A simpler question might be, how did Schrodinger come up with the equation in the first place? It hardly seems as intuitive as f=ma and the like.

  • A particle in an infinite square potential well wouldn't be a harmonic oscillator, you're confusing two entirely different models, so I'm not sure quite what you're asking, and certianly the number of dimensions is irrelevant, if you're asking why is the Schrondinger Equation sinusoidal then the answer is simple, the linear, or in your case angular momentum can be defined as the sum of two exponential functions (in 1 space), representing momentum in both the positive and negative directions, euler allows us to summarize this as a harmonic function, and as far as where the expoential terms come from, you simply apply your Ĥamiltonian over your wavefunction, which gives you a second order differential equation, which in turn gives you your exponential term, it's not only more intuitive than F=ma, it's more accurate as well, although if you replaced your a term for an expression involving an expression of momentum, and your m term for your reduced mass, you could probably construct some sort of rudimentary Fx operator ;)-- 22:03, 1 March 2006 (UTC)
  • Are you asking why the Schrödinger equation is the way it is, or are you asking why the solutions to it are the way they are? The former is physics, the latter is a purely mathematical issue. As for the former, you can't really go by how Schrödinger derived it, because his way was rather ad-hoc. A ground-up approach from basic postulates is given in, for instance, the first three chapters of Landau & Lifschitz book on QM. It's not string theory, but it's not introductory-level stuff either. --BluePlatypus 04:03, 2 March 2006 (UTC)
  • This is – approx – how Schrödinger came by his equation (or how we've been told he did): It was at the time that people had quite agreed that particles are waves, and someone asked Schrödinger: "Now, we have waves, shouldn't we have wave equations?" So Schrödinger went searching. In time before QM, fysicians had constructed Lagrangian and Hamiltonian formalisms (you may know them, though you may not) and there's a formula, saying: energy = kinetic energy + potential energy (though it's stated in a slightly more different way, so as to be so general it can be applied to cases that have nothing to do with energy at all; the "real" formula is in fact: H = pq۟ + V). Now he needed waves, and these go like sin(kx - ωt) or cos(kx - ωt). If you derive them with respect to x, you get k (≈impulse) in front of them, and if you derive them to t, you get ω (≈energy). So you add some constants where needed and you get an equation that certainly looks pretty smart and cool, and it even works. Greetings. David Da Vit 15:28, 2 March 2006 (UTC)

Scientific Journals - where does the money go?[edit]

$20 to download a single article from some journal publishers seems a bit steep (especially for a student). Why do they have to charge so much? Are some of the publishing executives struggling to pay for their second homes? Some day us scientists will raise our conical flasks and petri dishes and revolt! --Username132 16:09, 28 February 2006 (UTC)

It depends on the journal. Some are published by professional societies; in those cases the money ges back into the cost of production of the journals (which are usually subsidised by members dues). In the case of journals that are published by publishers like Elsevier and others - it's all about profit. You charge a library $1000 for a subscription to a journal, charge authors page charges and get peer reviewers to work for free. Guettarda 16:22, 28 February 2006 (UTC)
Do you know how the peer review process works? If peer review is free, would it be possible to set up a free/cheap/donation-based online journal? --Username132 20:24, 28 February 2006 (UTC)
The money certainly isn't paid to the editors: I once applied for a job at a journal produced by a commercial publisher (not a scientific society), but the salary they offered was almost exactly half what I was earning as a university researcher! Physchim62 (talk) 20:33, 28 February 2006 (UTC)
Is an editor the same as a peer-reviewer? If not, how do they differ? --Username132 23:46, 28 February 2006 (UTC)
An editor will edit the content for the journal (spell-check, grammar check, introduce incorrect grammar when they simply don't understand the scientific wording...). A peer-reviewer reads and rates submissions. For example, I primarily work in research on hypertension. When we submit articles to journals, the editor most likely knows nothing about hypertension. So, they send it to peers who know a lot about it. Then, they read it and tell the journal if the article is worth publishing. If you are very lucky, you get the article back with suggestions. You fix it up and resubmit it. Sometimes it can be something rather silly. We had to resubmit one because we used "underpriveleged" to mean "lacking in access to healthcare". In this particular journal, "underpriveleged" is a reserved synonym for "African-American". We changed it to "deprived" and everyone was happy. --Kainaw (talk) 01:36, 1 March 2006 (UTC)
Thanks for the insight. What do peer-reviewers get for their work? Free journal access?
Gratitude --pom 00:11, 2 March 2006 (UTC)
Depends on ethics. Some peer reviewers get into it just to steal ideas. Others are really trying to help. --Kainaw (talk) 01:55, 2 March 2006 (UTC)
You would be better stealing ideas from reviewing grants not papers. Most people (99%) review papers because others have done it for their own papers. David D. (Talk) 08:34, 3 March 2006 (UTC)

Most universities have subscriptions to most journals, including the online versions. If you're a university student, you can inquire with your library for what journal subscriptions they have and how to access them. At my university, merely by being on a university machine (or logging in through a proxy server), I can get free copies of articles from any journals I've ever looked for. I don't know if that helps you or not, but it might be something to check into. -- SCZenz 23:51, 28 February 2006 (UTC)
Yeah we have subscriptions to the most relevant ones. Occasionaly though, I find an article I'd like but can't access. I know people writing some dissertatations are even less well served by the available subscriptions. My main concern is how I keep up between leaving university and getting a research position. --Username132 08:41, 1 March 2006 (UTC)

The scientific journal business has made a large number of scientists rather unhappy; see open access (which is not the most neutral of articles, but anyway) for an alternative approach. --Robert Merkel 22:17, 28 February 2006 (UTC)
Thanks, this is great! I'm actually a representative for my university course to our university library. Is there any way our university library can do more to support open access? I'd like to make the most of my position for the remaining couple of months that I still have it.
Also is research funded by a corporation such GlaxoSmithKline more likely to be published in a traditional journal? When they're close to something, they stop publishing at all so they can patent it first, don't they?
Supposing I had really good eye-site and looked through a GSK window as I passed by and saw the notes jotted by some scientist and then ran to the internet and published "the cure" for HIV before it had been patented... apart from being on GSKs hitlist, would I have comitted a crime, and would people be allowed to use the information published? --Username132 22:56, 28 February 2006 (UTC)
Patenting depends on where you are. If memory serves me, in Europe, you can publish after the application has been sent in, in the US you have to wait for the patent to be approved. And assuming you weren't trespassing, then no, you haven't done anything illegal. This is all kind of moot though, because in reality Pharma companies patent stuff at a very early stage (pretty much as soon as the idea presents itself), far before the years of development and clinical testing (from candidate to approved drug is a process that takes over a decade). So even if you managed to get hold of a not-yet-patented idea, you wouldn't have the resources to turn it into a drug. And even if you did, less than 1 in 1000 candidates make it through all the way to an approved drug. --BluePlatypus 08:20, 1 March 2006 (UTC)
What can an individual library do to help support open access? --Username132 08:29, 3 March 2006 (UTC)

Kinetic Energy and Einstein's Theory of Special Relativity[edit]

Firstly, can someone please verify that the equation for kinetic energy, taking into account Einstein's Theory of Special Relativity is:

Secondly, can someone explain how we get that equation from I think I get it now, although it would still be handy if someone could explain it just in case...

Thirdly, can someone please tell me of a computer program/language that will enable me to perform calculations with this with absolute accuracy. All the software I have at the moment doesn't seem to be able to cope with numbers such 299792458 squared (which isn't surprising I suppose). P.S. I think I'll stick to the Key Stage 3 stuff I'm supposed to be doing... 21:29, 1 March 2006 (UTC)

Once you subtract the rest energy from the total energy , you get the energy of motion .
As for your software, have you looked for a scientific mode? The speed of light should not be stored as an exact integer, but as a floating point value, which usually has a lot more range. —Keenan Pepper 21:41, 1 March 2006 (UTC)
Thanks for the answer Keenan. As for the software, it doesn't have a scientific mode, although I think I will try it with something else I have found. Thanks. 17:30, 2 March 2006 (UTC)

Drug Hair Test[edit]

What causes hair to test positive for cocaine, if one never used it.

You asked that question already. Scroll up a bit. Optichan 22:03, 1 March 2006 (UTC)
Ever get really tweaked on some coke, ask a question, and then, just a few minutes later, forget if you asked it or not already? --Kainaw (talk) 01:11, 2 March 2006 (UTC)
And then the darn test results come in, and you forgot you even took it... --Zeizmic 13:34, 2 March 2006 (UTC)

Drug store?[edit]

Why is a drug store called a drug store instead of a medicine store? (Aidan Age 8)

I don't know, but my guess is that the word "drug" has less syllables than "medicine". --HappyCamper 23:16, 1 March 2006 (UTC)
Hi Aidan. The meaning of words changes over time. When the phrase "drug stores" was invented the word "drugs" was a word that people associated with relief from pain and other good things so it was a good name for a type of store. Today "medicine" means something that you won't go to jail for and make you better; while "drugs" means things people say are bad for you. The words mean the same thing, but the connotation is different. You are trained to feel one way about one word and you are trained to feel a different way about the other word even though the two words mean the same thing. WAS 4.250 23:34, 1 March 2006 (UTC)
When a police officer ask "Are you on medication", such as [6], he is refering to general substance abuse including non-medicinal drug, isn't it? --Vsion 15:05, 2 March 2006 (UTC)

There is a store near me, owned by a person of Middle Eastern descent, whose English leaves quite a bit to be desired. The name of the store ? "The Drug and Party Fair". LOL StuRat 23:55, 1 March 2006 (UTC)

Out on a limb here, but the Dutch word for 'drug store' is 'drogist', which refers to the word 'drogen', which means 'to dry'. And indeed most medicines have in the past been dried plants. Considering the overlap between the Dutch and English languages there is a good chance the English word has a similar origin. And indeed over time the usage has changed when the word is used by itself, but (possibly) retained its original meaning in the term 'drug store'. DirkvdM 09:56, 2 March 2006 (UTC)
The OED says drug-store is originally U.S. The archaic English word druggist has the same meaning as drogist in Dutch, and is also usually traced back to a root meaning 'dry'. --Heron 20:56, 2 March 2006 (UTC)

Note that, at least in American English, "drug" still retains the meaning of "pharmaceutical", as well as "recreational substance". (For that matter, the line between the two is not always entirely clear.) --Trovatore 03:30, 3 March 2006 (UTC)

Well, the definition of the line between the two is in general quite simple; whether it's legal or not. Which, of course, is an upside down way of reasoning; "It is illegal, therefore any use must be recreational". But some drugs are used both pharmaceutically (legally) and recreationally (illegally), such as opium (laudanum) in the past and marihuana (which is literally a dried plant) recently. Interrestingly, heroin was originally devised as a wonder drug against opium addiction (so as a medicinal drug). Now, such a wonder drug is methadon. I wonder how long it will take until that becomes a 'street drug' like heroin. DirkvdM 08:51, 3 March 2006 (UTC)

March 2[edit]

Is it true that the earth wobbles while it spins?[edit]

Yes. --Kainaw (talk) 01:12, 2 March 2006 (UTC)
How much does it wobble? And at what frequency? --HappyCamper 01:13, 2 March 2006 (UTC)
Well, he didn't ask that. Anyway, according to axial tilt, "The Earth's axial tilt varies between 21.5° and 24.5° with a 41,000 year periodicity". --Kainaw (talk) 01:41, 2 March 2006 (UTC)
Oh, I didn't know that was what it was called. Thank you :-) --HappyCamper 01:55, 2 March 2006 (UTC)
The actual wobble is called a precession, the kind of motion you get if you deliver a sideways prod to a spinning top. --BluePlatypus 03:50, 2 March 2006 (UTC)
To be clear, there are two overlapping 'wobbles' at work. The axial tilt changes on a 41,000 year cycle, and the axis precesses on a 26,000 year cycle.
The geophysicist Milutin Milanković looked at the combined effect of these wobbles (as well as a number of other factors) on Earth's climate. He proposed that there would by cyclical variations in climate (resulting in periodic ice ages and the like) on a roughly 100,000 year time scale; these are called Milankovitch cycles. TenOfAllTrades(talk) 05:24, 2 March 2006 (UTC)
I also found something interesting while searching for this. There's another (much) smaller wobble called the Chandler wobble, which has a period of only 435 days. Interesting read; you learn something new every day. EWS23 | (Leave me a message!) 05:35, 2 March 2006 (UTC)

iTunes and storage[edit]

I have MUCH more music than I want to store on my G4 Powerbook. I have some of it on the PB, and a lot, lot more on an external drive that is accessable when the PB is 'docked' on my desk, but not on the road. I want to have a way to easily choose which music stays and which goes, much as I can with my iPod. Anything?

Well, it looks like you've actually got three hard drives: the Powerbook's drive, the external drive and the iPod. So how about you store all the music on the external drive, but manage it using iTunes (make sure iTunes on the PB isn't copying the files to the local drive). Set up a playlist in iTunes of the songs you want to take on the road which you can easily alter. Sync the iPod to that playlist only, and then when you go on the road, plug the iPod into the Powerbook and play the music straight off the iPod through the Powerbook speakers. --Canley 05:02, 2 March 2006 (UTC)

Good idea - thanks. The problem is the iPod is tiny, and the PB has a pretty large drive. I'd really like to have a boat load on the PB. Any other ideas?

I don't understand why you wouldn't just put all the music on the Powerbook. If its too much, just choose what songs go. -- Flag of the United States.svg Mac Davisญƛ. 10:07, 2 March 2006 (UTC)

The reason that I don't put it all on the PB is that the harddrive is too small for the whole collection. What I am looking for is a way to easily manage what songs go on it, and what stays at home. I want to be able to change what is on the PB and what is not on a fairly regular basis.

  1. . iPod - 1 gig. Good for jogging, and other small outings.
  2. . PB - 80 gig. About 20 gig I am willing to use for music. Good for trips out of town.
  3. . External drive - 300 gig. All my music, about 100 gig filled.

So I want to keep everything on the external. I want to put pretty much a random and changing selection on the iPod. I can do this already. I want to put pretty much a random and changing (but bigger) selection on the PB. I can't figure out how to do that.

Nature red in tooth and claw[edit]

What exactly does the phrase "Nature red in tooth and claw" (from Tennyson's "In Memoriam") mean, particularly as used in evolutionary biology? Dawkins makes a reference in it in The Selfish Gene [7], though he doesn't explain it. --JianLi 04:10, 2 March 2006 (UTC)

It is a reminder that animals eat each other without mercy. It is the reality to which "the lion shall lie down with the lamb" is the imaginary antithesis. alteripse 04:15, 2 March 2006 (UTC)


Is it true that earthquakes often occur after a heavy rain during a hot day? --ct

If you find out, why don't you clean up the article earthquake weather? --Trovatore 06:11, 2 March 2006 (UTC)
I can assure you there is absolutely no scientific basis behind that. Geothermal mantle currents have nothing to do with how sunny it is or how wet it is. -- Flag of the United States.svg Mac Davisญƛ. 10:09, 2 March 2006 (UTC)

That would be a handy indication of wheather or not an earthquake is coming. (Ok, that was lame even by my standards). DirkvdM 10:08, 2 March 2006 (UTC)

The phoney concept of 'earthquake weather' was reinforced by Mark Twain. Here is a hilarious quote. [[8]] --Zeizmic 13:29, 2 March 2006 (UTC)

Perhaps you meant that avalanches or landslides often occur after hot days or heavy rains. --Leah

Perhaps this is part of where the misconception comes from, as I imagine earthquakes can cause landslides and avalanches as well. EWS23 | (Leave me a message!) 01:46, 3 March 2006 (UTC)

Chewing gum versus bubblegum[edit]

What exactly is it about bubblegum that allows you to blow larger bubbles than is possible with the same amount of regular chewing gum? Is there some chemical that facilitates bubble blowing? —Keenan Pepper 06:00, 2 March 2006 (UTC)

More gum base (so it holds together better), and softer gum (so it's easier to blow bubbles). It's softened by adding glycerine or vegetable oil. --BluePlatypus 06:28, 2 March 2006 (UTC)

Now that that is answered, if you wish to kick the habit of chewing gum, you might go to a gum producing area. I followed chiclero tracks in Guatemala and saw how the gum is handled. I never touched a chewing gum since (then again I hardly ever did before, so there was no cold turkey :) . DirkvdM 10:15, 2 March 2006 (UTC)

I thought nowadays it's all made of petroleum products. —Keenan Pepper 14:58, 2 March 2006 (UTC)
So you're chewing oil. Which is rotten plant material. You know, that stinking black fluid that drips from a garbage bag if you leave it out too long. That sounds a lot tastier. :) DirkvdM 08:59, 3 March 2006 (UTC)
I thought oil came from dead dinosaurs. User:Zoe|(talk) 16:44, 3 March 2006 (UTC)
If you're going to get squeemish about where your food ultimately comes from, you're in big trouble. For great justice. 19:22, 3 March 2006 (UTC)

cure for wet bed[edit]

(question moved from Wikipedia:Newcomers help page)

clothes line?
clothes dryer?
Someone makes a diaper with an attached alarm that goes off when it gets wet. This is used to train a person to wake up when they have a full bladder. --Kainaw (talk) 16:47, 2 March 2006 (UTC)
Or, at least, moments after having a full bladder. :) kmccoy (talk) 03:27, 3 March 2006 (UTC)

old or used systems[edit]

how to use old or used computers as a firewall

What computers? How old? The preceding unsigned comment was added by (talk • contribs) .
  • You can't use computers as a firewall. A firewall a piece of software. - Mgm|(talk) 09:11, 2 March 2006 (UTC)
A firewall can be software or hardware. You can use an old computer as a demilitarized zone, but I'm not sure if that's what you want to do.--Commander Keane 09:48, 2 March 2006 (UTC)
Maybe the user was trying to turn the old computer into a router, presumably with a firewall software running on it. — QuantumEleven | (talk) 11:23, 2 March 2006 (UTC)
If you have enough old computers, you could weld them together and make a pretty good firewall. It would probably take a good two hours to burn through a wall of old computers. --Kainaw (talk) 16:48, 2 March 2006 (UTC)

Read this for clues. WAS 4.250 11:07, 2 March 2006 (UTC)

Technically, you could put two Ethernet cards in the computer, and run it as a gateway, with some firewall software on it. Thus, using it as a firewall.

if you perform the test for starch and the iodine remains yellow, what does this indicate?[edit]

  • It becomes blue if there's starch. So what do you think you proved if there's no reaction? - Mgm|(talk) 09:12, 2 March 2006 (UTC)
That the raison bread wasn't pregnant!  freshgavinΓΛĿЌ  11:15, 2 March 2006 (UTC)
  • Simple, that the is no starch present in whatever you tested. If you would like to test for other substances, there's a whole category of tests you can use to find different things Obli (Talk)? 16:23, 2 March 2006 (UTC)

Bacteria in our ears!![edit]

I have heard that listening to music with headphones for over an hour multiplies the bacteria present in our this true?? thanks 10:03, 2 March 2006 (UTC)sciencefreak!! 10:03, 2 March 2006 (UTC)

I think so, it increases the humidity and temperature slightly in our ears. But theoretically, every second bacteria are multiplying, or you could look at it like at all times there are bacteria in your ear being born and dying. Don't worry, the bacteria aren't the bad kind either. They won't make you sick. As gross as bacteria's connotation might seem, don't worry about it when you pump up Green Day on your headphones. -- Flag of the United States.svg Mac Davisญƛ. 10:16, 2 March 2006 (UTC)
What music do they prefer then? Wet warm music? DirkvdM 10:18, 2 March 2006 (UTC)
I've no idea, but I bet if you did a study on it you'd have a good shot for an Ig Nobel prize. —Ilmari Karonen (talk) 10:39, 2 March 2006 (UTC)
If you're wearing your earbuds for too long I could see a potential risk of it, they'll improve the conditions for bactera substantially (less light, moist, dark, not to mention dirty - earbuds are never washed). Obli (Talk)? 16:13, 2 March 2006 (UTC)
I read somewhere that bacteria are multiplied in there 700 times! Something to do with anaerobic environments being a major breeding ground. However, your feet are subjected to anaerobic environments for far longer, usually daily, so it multiplies who knows how many times more! I apply Germ-X to my feet at the end of the day to take care of the bacterial build-up. And speaking of ears and bacterial growth, I feel compelled to apply it right now. --Shultz III 00:16, 3 March 2006 (UTC)
You could also regularly ventilate your feet (and then swap socks) like I do. My feet used to give off a horrible stink. This, plus no more soap, solved the problem. A solution by using less is always preferable to one that uses more, I'd say. DirkvdM 09:03, 3 March 2006 (UTC)
Ventilate feet often, fresh clean dry socks at LEAST twice a day, let shoes air out for at least 24 hours between uses (IE at least two pairs of shoes, alternated), and using rubbing alcohol on your feet are all good methods to deal with the fungal problems caused by enclosing feet. WAS 4.250 12:21, 3 March 2006 (UTC)
See obsessive compulsive... --Username132 20:00, 3 March 2006 (UTC)
And which would be that? It often refers to excessive use of soap and it's precisely the fact that I stopped using soap that was probably a major part of my 'cure'. DirkvdM 13:21, 4 March 2006 (UTC)

Head-on auto crash.[edit]

If two autos of equal weight, and each going 50 miles an hour, crash head on, will the impact be 100 miles an hour or just 50 miles an hour? Thank you. Paul Weiss

Assuming both cars are travelling forward, and the earth isn't spinning at a crazy rate, then yes. Err... I mean 100 miles per hour. It's a 2-dimensional collision so you simply subtract the vectors: .  freshgavinΓΛĿЌ  11:17, 2 March 2006 (UTC)
If you're standing on the road watching the crash, you'll see both autos travelling at 50 mph but in opposite directions. If you're sitting in either auto, you'll see the other as approaching at 100 mph. --Bowlhover 16:57, 2 March 2006 (UTC)
The question is what you mean by "will the impact by 100 miles an hour". If you imagine an extremely solid wall of heavy steel or something that you could crash a car into without damaging the wall, then the 50+50 mph collision will damage the cars in the same way that a 50 mph collision into this wall would be, because all of the kinetic energy goes into damaging the cars, and colliding with an identical car will stop a car in the same way that the very solid wall would.
On the other hand, if you imagine the damage from crashing the car into a stationary car of the same kind, then the 50+50 mph collision would be like a crash at 71 mph into a stationary car. Here 71 is 50 times the square root of 2, and that arises because the energy will be distributed equally between the two cars and energy varies as the square of speed.
For some calculations involving collisions you want to consider momentum rather than kinetic energy, but energy is the right measure when you're thinking about the amount of damage.
--Anonymous, 00:57 UTC, March 3, 2006.
Nope, I agree with your first para about the wall, but the 50+50 mph collision is like a crash at 100mph into a stationary car. Yes, the 100mph system has twice the total energy, but only half of that energy goes into destroying the cars. The other half is left as kinetic energy after the collision as the two cars, smashed together, are still trundling along the road at 50mph by conservation of momentum. —Blotwell 05:50, 4 March 2006 (UTC)
Argh dammit. I should have realized that. Sorry. --Anon, 19:30 UTC, March 5.


A friend of mine claims that rubbing cocaine on one's penis before intercourse makes the sex more pleasurable for the woman, but this doesn't sound right. Is it true?

Cocaine, when applied topically, acts as an anesthetic and intense vasoconstrictor. I'd say it has the opposite effect... — TheKMantalk 13:21, 2 March 2006 (UTC)
Rub it on your hair, and you fail the drug test. --Zeizmic 13:36, 2 March 2006 (UTC)

"Because of the extensive processing it undergoes during preparation and its highly addictive nature, cocaine is generally treated as a hard drug, with severe penalties for possession and trafficking." [9]

"After the US helped the Colombian military dismantle the Medellín and Cali cocaine cartels in the '90s, the guerrillas moved in and took over much of the drug trade. By the late '90s, rebels controlled more than a third of the country and had the financial clout to intensify the [civil] war and protect their newfound position as narcotraffickers. It's an extremely lucrative business. The coke habit in the US alone was worth $35 billion in 2000 - about $10 billion more than Microsoft brought in that year." [10]

Sorry, I couldn't help it. -LambaJan 20:39, 2 March 2006 (UTC)
I guess an anasthetic, applied to the male, is likely to reduce his stimulation, so things go on longer than the regulation three minutes. This in turn may appeal to the female, if her tastes run that way. Notinasnaid 21:11, 2 March 2006 (UTC)
I doubt she would appreciate the effect the cocaine would have on her bits =P. — TheKMantalk 21:55, 2 March 2006 (UTC)
Try powdered ginger mixed with honey. She will never look at another man. (Never use chilli powder!) --Anon.
Honey? No thank you. She doesn't need a yeast infection. moink 05:27, 7 March 2006 (UTC)


The concept of "Usenet" has confused me (and yes, I read the article). Is it basically just a huge group of "bins" (like alt.binaries.videos, etc) and people post any message or file they want into the suitable "bin", and when you read it with a client it shows everything posted in that "bin" with the most recent first? - unsigned

Usenet is essentially a newsgroup or forum, however you want to look at it. Its a resource whereby messages very similar to emails are sent into the system and then processed and stored in order, and someone with a reader can come along and read all the stored messages in order. Many people have adapted it for use with files, but its essentially the same strategy as sending files attached to emails. The only thing to remember is that someone has to host those groups, and many places only host the non-space-hogging kind since server disk space isnt exactly cheap. -unsigned
So what's the deal with the readers? I mean, google groups doesn't let you download files AFAIK, or look very far back. Is there some free way to look at and download usenet files and look atp osts from way back (like months ago?) - unsigned
Since its a service that is rather resource-intensive, its access is often subscriber based. Most ISPs will run some form of USEnet relay for their customers, although this is going by the wayside as it's use has shifted from the legitimate, to grey filesharing and piracy. —Preceding unsigned comment added by (talkcontribs) 15:44, 2 March 2006
Google doesn't carry binaries groups, but it does archive old posts (pretty much for ever - the oldest usenet post in Google's archive is from 1981.) Binaries groups are not generally achived and are not carried by as many servers as text groups. -- AJR | Talk 16:50, 2 March 2006 (UTC)
Go here and try out a temporary free reader called Agent. It's highly recommended. Permanent free versions of Agent exist if you look hard enough. To connect the usenet reader to the usenet, ask your ISP for the net address to type into the reader. Its generally not an additional ISP charge so far as I know. (mine isn't - EarthLink) WAS 4.250 16:53, 2 March 2006 (UTC)

First a terminology correction: the original poster referred to "bins", and those are the newsgroups. Each newsgroup is a forum. Usenet is all of the newsgroups taken collectively. Some newsgroups are intended for messages in text form (that was the original idea, back when most of Usenet was carried on 300 or 1200 baud telephone connections); others are intended for binaries, which are encoded in text form. Most newsgroups are "unmoderated" and anyone can post anything, just as they can here; others have a moderator who screens all postings, or variations on this.

The original poster referred to seeing messages "newest first". The order that you see articles in depends on what newsreader (software ) you use. Historically, the original presentation was oldest first; then came oldest first but grouped by subject line; then came threading, which allows people to read a sequence of followups in a sensible tree-traversal order. Good newsreaders allow you a lot of control over what they see and how they see it, and they keep track of what you've already read, which is essential when you're reading oldest-first. Frankly, it's a much more congenial presentation of messages than the massive concatenation of everything into a single web page that we see in Wikipedia talk pages like this.

If you read newsgroups via Google Groups, then in effect you're using Google's newsreader running on their site (which you access via your web browser), where it accesses the postings locally. This contrasts with the traditional newsreader, which runs on your machine (so you can run whichever one you want to install) and accesses the postings you choose from a remote news server. Historically there was a third approach: all postings in all newsgroups you might want to read were stored on your machine, and your newsreader accessed them as local files. ("Your machine" in that case would likely be a big corporate or institutional one, rather than a personal computer. Postings would stay online for a few days or weeks, depending on disk capacity.) --Anonymous, 01:15 UTC, March 3, 2006.

Gagging, vomiting daily through stress[edit]

My girlfriend has recently started teaching at a public school. Over the first couple months the stress was extremely intense and she thought she was going to quit. Recently, the stress has dies down somewhat, but she is still experiencing stomach problems: each morning she dry heaves or vomits, and can't keep any food down until about lunch.

Obviously the problem is mainly psychological, and ought to go away once the stress starts becoming managable. However, is there anything she can take to help the symptoms? Would antacid tablets help? Any other over-the-counter stomach medicine? What is the physical response that is turning stress into an upset stomach?

Thanks in advance.

She should probably consult her physician to be sure that there isn't something physically wrong. If necessary, her doctor can also refer her to an appropriate specialist for help in managing her response to stress.
Whether physical or psychological at its root, cranking out gobs of stomach acid and vomiting every morning isn't a good thing, and warrants medical attention. Depending on the precise cause, antacid tablets (calcium carbonate, e.g. TUMS) may provide some relief. More potent blockers of acid production are also available over the counter (ranitidine, sold under the brand name Zantac in North America). TenOfAllTrades(talk) 15:51, 2 March 2006 (UTC)

This sounds like extreme anxiety. Get the doctor to refer to a specialist. I just read about a drug for extreme stage fright. I just get along with common meds, for my anxiety. --Zeizmic 18:00, 2 March 2006 (UTC)

She needs to go to the doctor (is she pregnant?), but I have noticed ginger and ginger ale help me with nausea. -Ravedave 06:22, 3 March 2006 (UTC)

great pyramids[edit]

It is claimed that even with todays technology the great pyramids could not be built -is this true?

Since most people agree that they were build even without today's technology, I think one could say with great certainty that they could be built with today's technology. See our Great Pyramid of Giza and Egyptian pyramid construction techniques articles for information on how they were built. — Asbestos | Talk (RFC) 20:20, 2 March 2006 (UTC)
Of course, it is impossible, with today's technology, to stack rocks. That is why all those buildings and monuments that look like stacked marble, stone, or steel girders are just illusions. It is a four-inch model that appears big based on your frame of reference. In fact, I think Manhattan is only about three feet wide. --Kainaw (talk) 20:25, 2 March 2006 (UTC)
Actually most buildings that look like large stacked rock slabs are actually illusions, usally they're brick or concrete, and the stone is just a thin outer facade. But that's because it's cheaper of course, not because we can't stack rocks. --BluePlatypus 13:04, 3 March 2006 (UTC)

We couldn't build it the way they did, with today's technology. Just the life insurance on 10,000 expendable slaves would break the bank. --Zeizmic 22:25, 2 March 2006 (UTC)

Whoever is claiming this is trying to prove something; from the way the assertion is worded I suspect that the intent is to demonstrate that extraterrestrials did it. It is of course nonsense; when one considers what can be built with modern construction technology, one realizes that reproducing the Great Pyramid would not be impossible. (Whether anyone today would want to build it is a different question.) —Charles P._(Mirv) 23:47, 2 March 2006 (UTC)

Sure, it could be done. Just need a nice large quarry, the right machinery, a large dedicated workforce, and plenty of cash and time. And would anyone want to do it? Unlikely, when instead you could make a neat looking hollow one made of glass and put a casino inside. — TheKMantalk 03:17, 3 March 2006 (UTC)
Asbestos, you basically say that if something could be done in the past of course we can do it too. You seem to assume that all new knowledge is simply added to the old knowledge. But it can also replace it. A simple example is survival skills of hunters/gatherers as they learn western ways and stop hunting and gathering. Or knowledge of old western trades that has been lost because the need has disappeared. Or take cement. The Romans knew about it. Almost 2000 years later it was re-invented. It is quite possible that a technique was used to build the pyramids that we don't need because we have different solutions. Sure, we could build something similar, but with our technology it would be different in many ways. To make an exacts copy would probably be prohibitively expensive, because we would have to first invent the techniques or adapt ours to get the desired effect. Sorry I said this a bit messy, but the thought behind it is not less valid for it. :) DirkvdM 10:38, 3 March 2006 (UTC)
Another good example of this is Damascus steel (or more specifically Wootz steel.) Reports of weapons made using the technique date back to 30AD, but up until 1980, noone could reproduce the effect. GeeJo (t) (c)  11:06, 3 March 2006 (UTC)
We don't know how to make Greek fire, either. User:Zoe|(talk) 16:47, 3 March 2006 (UTC)
Right - there are two things going on here 1) whether it would be possible, in the abstract, to build a replica of the pyramids, and 2) whether it would be possible in terms of mobilizing the money, time, manpower and other resources to do it. I think we need to clarify which question we're asking. For great justice. 17:56, 3 March 2006 (UTC)
Well the answer to 1) is yes. And the answer to 2) is yes as well. Most modern nations have greater economic and human resources than ancient Egypt. Not that it would be needed, we'd no doubt be able to do it with less (human and economic) expense. The main obstacle is political will. Not many countries today would allow their leaders to spend a large part of their national GDP on building a tomb for themselves. Not that it'd be a large part for most countries, but it's still money most people would rather see erecting schools or something useful. --BluePlatypus 18:08, 3 March 2006 (UTC)
Yes. That's what I meant. For great justice. 19:20, 3 March 2006 (UTC)

March 3[edit]

Dual core CPU questions[edit]

I have an athlon 64 4400 (dual core). I use windows xp.

1) Is there some kind of update that I should get for windows to optimize it for using a dual core cpu? If so, what exact update(s) should I get and where?
2) I've noticed that when running certain games, it goes extremely fast (not at all playable). Is this because I have a dual core?
3) I've also noticed that when playing music and movies and such in windows media player it periodically skips (it sounds similar to how it is when cds skip in old portable cd players) Is this because I have a dual core?
4) Is there some program out there that can make my dual core cpu temporarily run on only one core? Flea110 01:16, 3 March 2006 (UTC)
I don't know all of the answers to your questions, but (1) according to AMD, Windows XP has dual core support; you shouldn't need to do anything special. If you go into Task Manager and look at your CPU usage, you'll see two CPU graphs. (2) It depends on what sort of games you're playing. If they're old DOS games, they were probably designed to run on machines orders of magnitude slower. Look into using something like DOSBox, if that's the case. I don't know about (3), but (4) according to some dude on HardOCP forums, you can disable one core if you add an option with the /onecpu option in boot.ini. If your skippy-media problems go away, then they were probably due to the use of two cores. grendel|khan 15:33, 3 March 2006 (UTC)
Re your skippy music and games, can you try the same media on a different machine? A different media player? Try to isolate the conditions under which it happens and give some more information. For great justice. 18:14, 3 March 2006 (UTC)
Re (4), yes, there is (and probably are) programs that support what you are looking for. A slight variation of what you're describing is called CPU Affinity - locking a process to a particular CPU, after so many associations you can achieve dedication of one CPU (core) to a single process. You would have to lock processes to a particular CPU one at a time and eventually you could achieve this dedicated situation such that only 1 process had affinity to 1 cpu, all others to the other (or any number of other cpus). The only program that I know of is called TaskInfo, if my memory serves. I think this feature was available in 'TaskInfo 2000' and may still be in the latest version. You could only confirm that this was occuring by monitoring Windows Taskmanager once you had assigned all of the running processes. Even then it may be challenging to really know for certain. 16:35, 4 March 2006 (UTC)

Games running too fast are a result of poor programming. Specifically, display updates should have a wait statement in them (that causes a delay) to make the action proceed at a reasonable pace. Games designed to run on very slow computers may have been too slow already, so the programmers didn't feel the need to include wait statements. It would be relatively easy for a programmer to add these statements to most games, when updating them for new hardware. Another problem is if a form of wait based on CPU cycles is used instead of one based on real time. StuRat 02:52, 10 March 2006 (UTC)


In an elliptical orbit,what happens to the distance between the planet and the sun?

As compared to? When what happens? Your question is a bit unclear. --Obli (Talk)? 11:18, 3 March 2006 (UTC)
I think the questioner means how it changes over the course of one orbital period. But since it sounds suspiciously like homework (apols if I am just being hyper-cynical), I'm just going to point 'em at Planetary orbit. --Bth 11:29, 3 March 2006 (UTC)


Why are cells usually small? Ana

The cytoskeleton of a cell is an important, complex, and dynamic cell component made up of microfilaments. It acts to organize and maintain the cell's shape; anchors organelles in place; helps during endocytosis, the uptake of external materials by a cell; and moves parts of the cell in processes of growth and motility. Diffusion does not limit cell size. According to Biology Cell biology Introduction Cell Size which shows cell sizes range from "150-250 nm small bacteria such as Mycoplasma" to "1 mm Diameter of the squid giant nerve cell" the limits to cell size are due to "Prokaryotes - Limited by efficient metabolism Animal Cells (Eukaryotic) - Limited by Surface Area to Volume ratio Plant Cells (Eukaryotic) - Have large sizes due to large central vacuole which is responsible for their growth". Cells have lenghs of meters in some cases, like nerve cells. Multicellualr organisms have out-evolved single cell organisms in the the competive space defined by "large size" because modular structures are a better design. Even things humans build tend to be modular due to the various superiorities of modular over unitary. WAS 4.250 12:57, 3 March 2006 (UTC)

Diffusion is slow. A large spherical cell would not be able to use diffusion to get small molecules into all parts of the cell. Look up Fick's Law of diffusion for more details on the math. David D. (Talk) 08:38, 3 March 2006 (UTC)

I wanted to say "Define small. Compared to what?" But are you now saying that they couldn't be any bigger because diffusion places a limit? In that case, I'd change the question to "Why are cells so big?" If being smaller makes diffusion easier and still they are as big as that permits, then they must have a reason for being so big. DirkvdM 10:44, 3 March 2006 (UTC)
I'd like to rephrase the question to "why aren't cells much larger than they are?"
It's a question of surface area, David D. touched the subject by talking about diffusion. Osmosis (diffusion through a plasma membrane) is not instant, and only a certain amount of osmosis can take place at a give point at the plasma membrane, therefore the area of the plasma membrane limits the volume of the cell, usually to something really small by our standards. Think of the membrane as transport routes in and out of a city, a cell the size of your fist would then be like New York city, with one dirt road connecting it, it just won't work. This problem is remedied in some cells, such as the inner lining of the small intestine by the use of Microvilli.
I hope I answered your questions, you are welcome to drop me a note on my talk page if you need further clarification. --Obli (Talk)? 11:10, 3 March 2006 (UTC)

ova are often pretty big. Gdr 21:57, 3 March 2006 (UTC)

URGENT! - AutoText in MS Word[edit]

Hey I was using MS Word and would like to insert automatic pagenumber, and that never seems to work. I used "Insert", then "AutoText", "Headers and Footers", and selected "-PAGE-", and the only thing that appeared on the screen is "-1-", and never continued (on the second page, there is no "-2-"). How can that be accomplished?

Also, I accidentally deleted the "-PAGE-" AutoText, how can I restore it? I added one in AutoText Settings "-PAGE-", and when I insert it, it is firstly cannot be found in the headers and footers category, and also, turns out to be "-PAGE-" instead of the expected "-1-". Very urgent! Thanks!

Just Love Science

  • Can't you just use "Insert", then "Page numbers" to insert page numbers? - Mgm|(talk) 10:32, 3 March 2006 (UTC)
I've just had a play with my copy of Word and I think you need to make sure you're in the Header/Footer view. (View->Header and Footer) before you do the insert. The "Header/Footer" section under the Autotext menu is just a collection of things that are useful in headers and footers, it doesn't automatically put it into the footer -- when I followed your description of what you'd done I just got a "-1-" at the location of the cursor. It's only when the cursor is in the footer that it'll propagate properly. HTH. HAND. --Bth 11:18, 3 March 2006 (UTC)
As to recreating the deleted autotext entry, you need Fields. Ctrl-F9 will bring up a pair of grey-background curly braces {}. Type "PAGE" in between them and you'll have a page number variable. Select it (and any stuff you want to put round it) and save it as a new bit of autotext (Insert->Autotext->New) and you'll have something that should do the job. It won't work quite as neatly as the original -- you may have to switch to print preview or a different view before it kicks in. See site for more detail than you might want. --Bth 13:08, 3 March 2006 (UTC)
It's possible that you have set it so that the first page has a "different" header and footer than the other pages. This setting should be in document properties or page setup. Skomae 04:14, 4 March 2006 (UTC)

Sharp weapons vs. blunt weapons[edit]

Regarding wounds in pre-modern times, I have two conflicting sources. One tells me that sharp weapons are more lethal because while a broken bone could be set, a cut from a sword might lead to infection, which was a major headache before people learnt to disinfect things. The other source says that broken bones from blunt weapons are more dangerous, because they were difficult at best to treat. Which is correct? 11:51, 3 March 2006 (UTC)

Both statements seem to be correct. A sharp sword will penetrate further and cause more damage to internal organs. A big blunt rock will break more bones. Either can be lethal, depending where they strike and with how much force. --Shantavira 12:28, 3 March 2006 (UTC)
It depends on the exact nature of the weaponery, the defensive gear, the soldier training, and the battle tactics used. Polybius in The Rise of the Roman Empire recounts a battle between Romans with pointy blades fighting against Gauls/Celts who were armed with sharp edges but non-pointy blades and the Roman tactic was to fight so closely packed that the Gauls couldn't swing their weapons, while the Romans were able to thrust theirs. Romans won. WAS 4.250 13:10, 3 March 2006 (UTC)
"The Romans are thought to have shown uncommon skill in this battle; the Tribunes instructing the troops how they were to conduct themselves both collectively and individually. They had learned from former engagements that Gallic tribes were always most formidable at the first onslaught, before their courage was at all damped by a check; and that the swords with which they were furnished, as I have mentioned before, could only give one downward cut with any effect, but that after this the edges got so turned and the blade so bent, that unless they had time to straighten them with their foot against the ground, they could not deliver a second blow. The Tribunes accordingly gave out the spears of the Triarii, who are the last of the three ranks, to the first ranks, or Hastati: and ordering the men to use their swords only, after their spears were done with, they charged the Celts full in front. When the Celts had rendered their swords useless by the first blows delivered on the spears, the Romans close with them, and rendered them quite helpless, by preventing them from raising their hands to strike with their swords, which is their peculiar and only stroke, because their blade has no point. The Romans, on the contrary, having excellent points to their swords, used them not to cut but to thrust: and by thus repeatedly hitting the breasts and faces of the enemy, they eventually killed the greater number of them. And this was due to the foresight of the Tribunes: for the Consul Flaminius is thought to have made a strategic mistake in his arrangements for this battle. By drawing up his men along the very brink of the river, he rendered impossible a manœuvre characteristic of Roman tactics, because he left the lines no room for their deliberate retrograde movements; for if, in the course of the battle, the men had been forced ever so little from their ground, they would have been obliged by this blunder of their leader to throw themselves into the river. However, the valour of the soldiers secured them a brilliant victory, as I have said, and they returned to Rome with abundance of booty of every kind, and of trophies stripped from the enemy." [11] WAS 4.250 13:23, 3 March 2006 (UTC)
Hmm... more complicated than I originally imagined :) Thanks for all your informative replies. 05:47, 4 March 2006 (UTC)

if science is about growing and learning[edit]

then my is the MSM so opposed to people who offer new and better theories? Isn't it true that so called "scineces" are much more of a dogma than anything else, yes, some things may be true, but isn't most sceince usually looked back on as stupid after the fact? Whose to say what's a valid scientific theory and what isn't? Isn't the fact that mainstream scinece won't even investigate certian things because they're so steeped in secularist ideolgies, a sign that scinece is, for lack of a better word "broken"?--Name2354325` 14:17, 3 March 2006 (UTC)

Science is not about growing and learning, it is about performing experiments and doing things that produce results (going to the moon, blowing up cities, fighting H5N1, finding oil in the ground, etc). Science is not a dogma of any kind, it's just "whatever works". Most science is usually looked back on as what worked then, but now we have other additional things that work. "A valid scientific theory" is what works (produces results). Mainstream science investigates everything; it is not broken. Science even has developed to the point that we know what works about theories about what works! The scientific method is all about that. WAS 4.250 14:36, 3 March 2006 (UTC)
The "mainstream media" (MSM) on the other hand includes whatever media outlets are in harmony with the prevailing direction of influence in the culture at large. In the United States, usage of these terms often depends on the connotations the speaker wants to invoke. The term "corporate media" is often used by leftist media critics to imply that the mainstream media is itself composed of large multinational corporations, and promotes those interests (see e.g., Fairness and Accuracy in Reporting; Noam Chomsky's "propaganda model"). This is countered by right-wingers with the term "MSM", the acronym implying that the majority of mass media sources are dominated by leftist powers which are furthering their own agenda (see Conspiracy theory, Media bias in the United States). WAS 4.250 15:20, 3 March 2006 (UTC)
I completely agree with the question. I believe that everything science tells is fact - all we see and feel - is just a persistent imagination of a large purple goat. We are in a goat's dream. Some have talked to the goat and called it God. That bothers him and terrible things happen. So, it is our job to be quiet and let the goat sleep soundly. However, no matter how often I send this to all the mainstream media outlets, they never call me in for an interview. They are just secularist mouthpieces for the science fools. --Kainaw (talk) 15:26, 3 March 2006 (UTC)

Who's opposed to "new and better theories"? The media loves new theories; they don't even have to be better! Claim to invent a perpetual motion machine, hold a press conference, and you'll get written up everywhere. You'll even get written up on slashdot, even though they ought to know better.

Science, on the other hand, does tend to insist that new theories actually be better. That may end up looking like dogma, and sometimes there is a certain amount of dogma, but mostly, what's operating is that science demands things like proof and reproducability, and those take time. —Steve Summit (talk) 18:21, 3 March 2006 (UTC)

It should also be noted that historically it has been difficult for new scientific theories to be immediately accepted (for example, ask Galileo). This has improved in recent years a bit, since scientists are less focused on religion and more focused on proving the facts and reproducibility, but it still often takes new theories a relatively long time to gain acceptance, as old theories are so ingrained into our heads as truth. This isn't necessarily a bad thing, as it keeps us from believing every hoax that comes along, but I can see how it would be frustrating to individuals who don't always subscribe to mainstream theories. EWS23 | (Leave me a message!) 19:11, 3 March 2006 (UTC)

They've hit the high points, so I won't repeat them; how the 'media' is an unreliable way to judge science; how science is only as dogmatic as necessary to prevent hoaxes and mistakes; the fact that most things (electricity, the chemistry that created plastic, sperm) will never be looked back on as stupid; the fact that science's judge is the harsh realities of the natural world; the fact that science investigates more things than you will ever hear of or imagine, and investigates them well... no, I'd like to respond to the message itself. If you ever come back to see the answers to your question, I'd like to ask you a few things, for my own edification:
  • Is your post as indignant as it sounds? Because it sounds like a pet theory of yours (probably religious, based on the references to dogma and secularism) is getting what it deserves, and you're pissed off.
  • Were you just talking, or were you hoping to learn, or were you hoping we'd see the light?
  • Do you have any idea what secular and ideology mean? Do you know what buzzword means?
  • What specific things are you thinking of when you talk about stupid past theories? I ask because it's always fun to hear about a new one. Phlogiston is a classic in that area.
  • Similarly, what specific things are you thinking of when you talk about things science won't investigate? The paranormal? The existence of Jesus? The existence of Jesus's evil twin brother, Billy? The existence of Juan and Cindy? Black Carrot 00:39, 4 March 2006 (UTC)
Good questions. I wonder if we'll get any answers, any more than any of the previous N times questions like this have been asked on the various Reference Desks. —Steve Summit (talk) 15:03, 4 March 2006 (UTC)
  • There are many texts about whether science is inherently dogmatic or not, whether it is conservative or daring, etc. etc. There's no easy answer to it -- scientists will always claim that they are not dogmatic (unless they feel "outside" the mainstream), while historians, sociologists, and philosophers go back and forth over it depending who you are reading. A good starter into thinking about these sorts of things is Thomas Kuhn's The Structure of Scientific Revolutions. If you are feeling very daring you can try tracking down Pierre Bourdieu's "The Specificity of the Scientific Field and the Social Conditions of the Progress of Reason", which I find to be a bit more to-the-point that Kuhn (and discusses Kuhn quite a bit). There's a copy of it, I think, in The Science Studies Reader, ed. Mario Biagioli. You could also check out Paul Feyerabend's work, which by its titles you can judge is a bit more radical: Against Method and Farewell to Reason. --Fastfission 23:24, 5 March 2006 (UTC)

Sound in water[edit]

When we put our hands inside water and clap we don't hear the sound. Why is this so?

Because you didn't clap hard enough for the anything to vibrate. Hit the side of the pool with a rock and vibrations will be created that you can hear even underwater. Sound is your perception of vibration that gets to your ears. WAS 4.250 14:43, 3 March 2006 (UTC)
Because sound waves, at least those in the range audible to human beings, tend to propagate in air, as opposed to water-- 14:29, 3 March 2006 (UTC)
No, audible sound waves can propagate through water just as well. As WAS 4.250 said, you'd have to clap much harder in water to make an audible sound, because the water is more dense so it's harder to push out of the way. Also, the inside of your ear is filled with air, so the difference in density between the two fluids makes a kind of filter, muffling the sounds. —Keenan Pepper 14:53, 3 March 2006 (UTC)
Oh, oh, we are getting silly here. Sound waves are perfectly happy in water, the dolphins carry out excellent conversations about silly humans. But you can't get anything to 'clap' underwater because of the viscosity of the thin film of water. --Zeizmic 16:03, 3 March 2006 (UTC)

Scuba divers have developed a number of ways of using sound to communicate under water too - the most common is to band on the air tank with something metal, which produces a sound that travels well (although it is more difficult to locate direction underwater using sound, I don't really know why). More complex systems use pitch shift devices, or wireless radio comms to circumvent difficulties of propogation in water. For great justice. 19:29, 3 March 2006 (UTC)

Sound does travel really well underwater, and it turns out that's why it's so hard to localize. One way we localize sounds is by (unconsciously) measuring the difference in arrival times between one ear and the other. But since sound travels faster in water, the differences become too quick for our land-evolved brains to measure. —Steve Summit (talk) 20:31, 3 March 2006 (UTC)
There's a type of lobster or something similar that catches its prey by snapping a claw so fast that it produces a shockwave that stuns (or even kills?) the prey. I don't know if this is audible, but it should be. Because of the viscosity of water clapping hands are slowed down too much. The claws cut through the water more easily. I suspect there will be a cavity in the claw where the water is compressed and then jets out. If this is fast enough it should qualify as sound. (So this is a very Zen creature that can clap with one hand (well, claw).) I'm not sure here, but I suppose most sound is a vibration but it can also be one single shockwave, as with clapping hands.
A related question: can one snap one's fingers under water? Probably not. DirkvdM 13:42, 4 March 2006 (UTC)
Actually, yes, you can. A good 'finger snapper' can produce a light sound underwater. Try holding your hand out in front of you and then next to your ear while snapping. Then do it out of water. The volume is greater out of water right next to your ear, and in water it's muffled in both instances and the volume doesn't change much. A good example of the characteristics of sound waves traveling through water vs. air. 16:48, 4 March 2006 (UTC)

I think sound travels fine in both air and water, but doesn't pass through the surface from one to another very well. That is, you need a very loud underwater sound to hear it in the air above or a very loud air sound to hear it underwater. StuRat 03:08, 10 March 2006 (UTC)


It's very cold in Birmingham. Why is it that the coldest and hottest weather usually occurs a good two months after the winter and summer solstices, at least in the UK? I'd expect there to be some time lag with the earth/sea having to heat up and cool down, but two months seems a lot. Is this the norm in other parts of the world? --Shantavira 14:32, 3 March 2006 (UTC)

Yep, this is normal. Where I'm from (Texas) the hottest month is typically August, a good 2 months after the summer solstice. As you suspected this is due to time lag, often referred to as seasonal lag (a page I should probably do some work on). According to this page, the typical lag is about one month for continental areas and about two months for areas near large bodies of water (such as Birmingham and Texas). EWS23 | (Leave me a message!) 19:23, 3 March 2006 (UTC)
In North America people are taught that the winter solstice is the "official first day of winter" and the spring equinox is the "official last day of winter"; some people in Britain also use this terminology (although of course the solstice is also called "midwinter's day" there). The fact that people generally don't see anything wrong with this terminology shows that people find it natural for temperature changes to lag by something like a month and a half behind the changes in the amount of daylight.
Remember that during the period near the solstices, the amount of daylight isn't changing very fast. At latitude 45°N, from December 1 to December 21 the reduction in daylight is only about 16 minutes out of 9 hours, and similarly on the other side of the solstice. The continued short days (and the low-angle sunlight that goes along with them) keep the temperature dropping. Of course if the days remained like that permanently then an equilibrium would be reached, but it does take a while.
--Anonymous, 02:38 UTC, March 4, 2006.

What is Einsteins Theory of Relativity?[edit]

What is Einsteins Theory of Relativity and how do you use it?

See Special relativity and General relativity. —Keenan Pepper 14:47, 3 March 2006 (UTC)

What is a black hole?[edit]

What is a black hole (space) and how does it work?

See Black hole. —Keenan Pepper 14:48, 3 March 2006 (UTC)

What is the difference between black hole and wormhole in space?[edit]

What is the difference between a black hole and a wormhole in space?

For one thing, black holes are probably real and wormholes are still only theoretical (at best). For another, if you get sucked into a black hole you'll just get streched out and then crushed into a point. See Spaghettification. —Keenan Pepper 14:55, 3 March 2006 (UTC)
A black hole is like a huge vacuum cleaner sucking up everything. A wormhole is like a cool subway tunnel between two locations. --Kainaw (talk) 14:59, 3 March 2006 (UTC)
A wormhole connects two parts of the universe, sort of a shortcut. One way this might exist is as a combination of a black hole and a white hole. See Wormhole#Schwarzschild_wormholes. DirkvdM 13:51, 4 March 2006 (UTC)


hi i would like to know 1.why cant we run a vehicle in 2nd or higher gear shifts directly.

2.problems in using diesel in petrol engine and vice virsa

You can start in second and possibly third if you give it enough gas. Gears are used to optimize the horsepower of the engine. As for diesel and petrol (we call it just "gas" in the U.S.), they burn at different rates. Engines are very particular about timing. Put diesel in a non-diesel engine and it will start, but it will make a knocking sound and you won't get much power out of it. I've never put gas in a diesel engine. I figure it is like a 2-stroke. It will start and then die quickly. --Kainaw (talk) 14:57, 3 March 2006 (UTC)

I had a friend, who's daughter put in diesel unaware. Naturally it went nuts and took it to a mechanic who couldn't figure out what was wrong, and they spent a fortune. I think they even replaced the engine. Finally took it to a second mechanic who had a sniff of the gas tank and immediately knew what happened. --Zeizmic 15:38, 3 March 2006 (UTC)

Diesel engines and gas engines work in very different manners. Gas/petrol uses a spark and a relatively flammable fuel while diesel use an less flammable fuel (almost non-flammable) and high compression with a glow plug to ignite the fuel. One will certainly not work in the other - diesel may gum up a gas engine and gas may burn up a diesel. See aslo the "Differences in fuel dispensers" in the Filling station article. Rmhermen 17:09, 3 March 2006 (UTC)
The problem is octane, diesel is much much lower in octane, and much more 'energetic' per volume than typical gasoline (this is my second hand understanding, i am not a chemical engineer). In a normal gasoline engine, diesel fuel will knock due to compression, and the engine will produce very little power and may even become damaged if the operator persists in trying to run it. As for the story about someone doing it on accident, it takes an INCREDIBLY thick-skulled person to do this. Why? The pumps are different, a (larger) diesel nozzle will not fit into the fill hole on a standard gasoline vehicle, which is usually enough of an indication to the operator that something isn't right, since trying to fill it will result in it spilling everywhere.
The pumps here (South Carolina) and back home (Missouri) are the same size for gas and deisel. So, it is very easy to put deisel in a normal engine. The larger pump was for leaded gasoline back when unleaded gasoline was introduced. --Kainaw (talk) 19:14, 3 March 2006 (UTC)
All the ones i've seen in OH are sized this way, it's a small difference but it's enough to stop someone from doing something stupid, I know this first hand after watching my friend try it. I just figured this was standard practice as all major brands seem to do it.
Not literally lower in octane (although probably) - Octane rating is a measurement system for gasoline; for diesel, it is rated by the cetane rating. Rmhermen 00:49, 4 March 2006 (UTC)
In the US there are petrols with an octane level under 90% (as low as 86% even, I believe). I once put a bit of that in an almost empty tank. The car started making very scary clonking noises, so I quickly filled the tank up with a high quality petrol. Why do such petrols exist in the US? Are there engines that can run well on it? Or is it meant for old cars that are just months away from the scrap heap? DirkvdM 13:59, 4 March 2006 (UTC)
Octane is not measured in percent - and it doesn't measure the amount of octane either. Most cars work fine on 86 octane, although 87-88 is the most common in the U.S. - but note that this same fuel is labeled as 91 octane in Europe due to a difference in measurement definitions. This may be part of what you are noticing. Rmhermen 15:58, 4 March 2006 (UTC)
Ah, that's something I had been wondering about for 10 years now. Given that the octane ratings in Europe are usually in the high nineties, 86 sounded ridiculously low. Could we get all our units standardised please (before another Mars lander crashes)? DirkvdM 10:29, 5 March 2006 (UTC)
I've seen 85 octane in the US, measured with the (R+M)/2 method, but agree that 87 is the typical minimum. I always use the cheapest gas available and have never had any trouble with engine knocking. Perhaps additives used in the US make this less likely. StuRat 03:13, 10 March 2006 (UTC)


1. what is the significance of inclination of engine in bikes?

On an inline motor, or a V?
Uh... See V engine, straight engine and inline engine? ☢ Ҡiff 18:05, 3 March 2006 (UTC)
Motorcycles are typically designed to have the lowest possible center of gravity, especially those used for sport riding and racing. This is to allow the bike to turn quicker with less lean angle. To accomplish this, the motor is typically inclined as much as possible, to bring it lower to the ground given that the motor/transmission assembly are the heaviest things on the bike, and by inclining the motor and keeping the transmission in the same spot the overall center of gravity will become lower. -- 19:37, 3 March 2006 (UTC)


why front brakes are stronger than rear in bikes

The same reason they are on cars. When stopping, the force causes the suspension to compress, because the force vector expressed as the relationship between gravity and acceleration causes the realized weight to shift forward. This means much more downward force is on the front tire. For the exact same reason, bikes and cars (preferrably) power themselves via the rear wheel, the forces involved make it the most ideal wheel for the task.
Erm, re rear wheel drive, it's a little more complicated than that for cars... For great justice. 19:33, 3 March 2006 (UTC)
We have pretty good articles on front wheel drive and rear wheel drive. — QuantumEleven | (talk) 12:37, 6 March 2006 (UTC)

Is this monkey a Drill?[edit]

Is this monkey a Drill? I think it is, but I'm not quite certain; I didn't mark down the sign at the zoo at the time. grendel|khan 15:22, 3 March 2006 (UTC)

I doubt it, the facial features suggests it's a prettier monkey than the Drill (lack of mane, no bald forehead) --Obli (Talk)? 16:54, 3 March 2006 (UTC)
Maybe Allen's swamp monkey? I think you took the image at Chicago's Lincoln Park Zoo. Here is a list of [mammals] they have. You can google for images of each species. Rmhermen 17:01, 3 March 2006 (UTC)
Our image in the swamp monkey article doesn't look much like the one on this page though. Rmhermen 17:04, 3 March 2006 (UTC)
Thanks for the link; that helps tremendously. It looks a bit like a De Brazza's Monkey, I think, but the white beard isn't nearly as pronounced, and it doesn't have the weird brow ridge. Maybe an Allen's Swamp Monkey? That looks pretty similar. grendel|khan 21:38, 3 March 2006 (UTC)

No monkeying around here, THIS IS NOT A DRILL! (sorry, couldn't resist that one.) DirkvdM 14:04, 4 March 2006 (UTC)

It's not a De Brazza's Monkey. If you took it at the Chicago Zoo, then it is certainly Allen's Swamp Monkey. It's much better than the image we have on the article, so please feel free to upload it (to and change the image in the taxobox. - UtherSRG (talk) 15:26, 10 April 2006 (UTC)

Right click on words in web textbox[edit]

I'd like to make a website which includes a textbox that users can write in. When the users rightclick on any word in the text box, I want the usual right-click pop-up menu to be replaced by one that allows them to, say, make the text bold or add a link. Is this possible? I know a little JavaScript. Thanks in advance!

Yes it is. Celcius 02:28, 10 March 2006 (UTC)

Text box that doesn't look like a text box[edit]

How would I be able to make a text box that doesn't look like your standard text box? For instance, I could have a thin line around it, instead of the "indented" look of most text boxes (like this one), or maybe have curved corners. Also, could the font be changed, so it's not courier? Thanks in advance (again)!

Take a look at cascading style sheets. --Kainaw (talk) 19:10, 3 March 2006 (UTC)

Li-Ion Batteries (specifically for iPod)[edit]

Hey. I have a few questions about iPod battery life. I have a 5G iPod (which I got 2 days ago).

  1. Is it better to keep the iPod on the charger all the time when not using it, or to take it off when it's charged (even though i'm not using it atm)?
  2. Apple reccomends not charging inside a case, however my case has little holes around the corners that allow the iPod to breathe. Also, it's been on the charger and in the case for at least 12 hours and is still cool to the touch on the outside. On the other hand, the case is made of leather. I am paranoid of leaving it out of its case though because i have a REALLY dusty house. What should I do?

Ilyanep (Talk) 18:41, 3 March 2006 (UTC)

iPod batteries last an optimal amount of time if they maintain a 40% charge. So take it off once its charged. And yeah, I know you are paranoid (I was too) but it is better to charge without the case. They do warm during charging, and its best if the heat can dissapate. pschemp | talk 00:54, 4 March 2006 (UTC)
Oh i almost forgot, a great resource is iLounge [12]. They've tested and dissassembled all the iPods and you can find answers to most iPod questions there. Hope this helps! pschemp | talk 01:02, 4 March 2006 (UTC)

But I can't stand taking it out :P It gets completely covered in dust within 10 seconds :( Oh well. Thanks for the website — Ilyanep (Talk) 01:34, 4 March 2006 (UTC)

I've never understood this...why is it important to keep dust off the iPod? Isn't it completely closed? And isn't it meant to be used, ie, scratched and dropped? Isn't it designed to be robust against such things? --HappyCamper 14:16, 7 March 2006 (UTC)

Can viruses invade a host and creat a zombie?[edit]

Yes. HHV Latency Associated Transcript. WAS 4.250 20:50, 3 March 2006 (UTC)

Viruses invade a host by attaching to a cell and injecting DNA or RND into the cell. This DNA/RND info tells the cell to stop making the product it was and to start making protein coat and viral genetic info. This however will eventually kill the host.

But what would happed if a virus attached to a cell and injected DNA or RND into the cell which did not coda for making protein coat and viral genetic info, instead, made the cell duplicate its self with the new DNA/RND being replicated too. Eventually (7 years or so) the entire body would be a cross breed of the virus and a human… a Zombie! Many problems of reality must be over come such as the inability of the Brain cells to divide … yet this may be untrue as brain tumours exist.

My question is could this be a reality and has anything like it ever been reported?

Um, so you're asking what would happen if a tiny fraction of a viral genome were replicated by the cell and unintentionally incorporated into the host genome?? See Junk DNA for ref, about 60% or so of the human genome doesn't code for anything at all, just tiny bits of viral DNA that replicate themselves, and resplice over and over again, and ultimatly don't code for anything, non-coding DNA, over a few million years these tend to pile up, and it's kind of neat, because if you examine the genomes of several distantly related species, you can find paterns of non-coding DNA vs coding DNA, and you can see where they diverged, but no, no zombies-- 20:23, 3 March 2006 (UTC)
Ok, I just read the articles on Junk DNA and non-coding DNA, and it's prompted me to ask a sub-question:
Why is it that...
...all the science related articles on wikipedia contain creationist counter arguments against whatever the article is about?-- 20:48, 3 March 2006 (UTC)
Because Wikipedia is a Wiki. What did you expect when everyone is allowed to edit something? I'm more concerned with why every page about pop culture includes a list of where it is parodied in The Simpsons. DJ Clayworth 22:51, 7 March 2006 (UTC)
It actually would happen much faster, occuring in 3-4 hours or so. See Shaun of the Dead for more information. --Sam Pointon United FC 18:47, 3 March 2006 (UTC)
No, a virus could not cause a person to become a zombie. Because viruses are so small, they can contain very little genetic information and code only for a few different proteins. There is no way for them to control a person's movements or do anything like you see on TV. I virus especially, cannot re-animate someone who is already dead.
Making cells divide (for which they must be alive to begin with) does not create zombies. If they divide frequently enough, out of control, it creates a cancer.
Furthermore, only certain cells can replicate to form other cells and there is not ONE cell in you body that can replicate and form any differrent type of cell. Some cells, [[stem cells], can be induced to form many different types of cell, but not ANY type of cell. This of course means that you have many different types of stem cell in your body.
Also, you mean RNA, not RND... --Username132 19:42, 3 March 2006 (UTC)
Not true, if I was a virus, I'd want to do some serious Research and Development before turning anyone into a zombie!-- 20:23, 3 March 2006 (UTC)
Hahaha. Kudos. — Ilyanep (Talk) 20:46, 3 March 2006 (UTC)

As mentioned above, it is likely that every cell in your body has bits of DNA from various viruses, and you will pass this amalgam of genetic material on to your children. In fact, it has even been theorized (but not widely accepted by any means) that the eukaryotic cell nucleus arose through incorporation of a DNA virus (a la the endosymbiotic theory). Under most circumstances, neurons cannot divide. Tumors in the brain are due to unrestrained growth of the “helper” cells such as astrocytes or glial cells, not neurons. — Knowledge Seeker 02:00, 4 March 2006 (UTC)

A certain virus(I think tobacco mosaic virus), does what is described above in plants. It can actually bring dead cells back to life by inserting DNA that codes for plant proteins . This can help the virus reproduce itself. However there haven't been any documented cases of this happening in humans.

Long-term Effects of Medication for Attention-Deficit (Stimulants)[edit]

I have searched and come across very little about what science knows about the longe-range effects of stimulant medications used to treat Attention Deficit Disorder, such as Adderall and Ritalin. Is it fair to thus compare the changes amphetamine (which Adderall is, I believe) and cocaine create in the brain to such medications? The studies I read were linked to in the Wiki ADHD article; yet they were only two and themselves admitted further research is necessary. Are such long-term studies being done? - C

Probably. I might be able to hook you up if you can be more specific about what studies you're after (how about; "Review of ritalin (methylphenidate) medication use in children, in British Columbia, Canada"?). What level of study are you at? I've got access to a lot of journal articles, but you have to be well versed in the area to understand them. What year were the studies that you read conducted? --Username132 19:53, 3 March 2006 (UTC)

Anything relating to evidence for/against/concerning permanent changes in the brain as a result of amphetamine or methylphenidate, as prescribed for Attention Deficit. I have no medical training to speak of. The studies were both from 2005, one June, the other November. I confess only a vague awareness of what they are discussing. They can be found here and here. - C

occuring in 3-4 hours or so? What ?[edit]

occuring in 3-4 hours or so? What ?

Come again? --Obli (Talk)? 18:59, 3 March 2006 (UTC)
In 3-4 hours from now, I'll be ending my workday, headed out to run some errands, maybe stop for a beer. --LarryMac 19:05, 3 March 2006 (UTC)
Hopefully in 3-4 hours I'll be done with homework. — Ilyanep (Talk) 19:13, 3 March 2006 (UTC)
I think this is referring to the virus/zombie question above. — Ilyanep (Talk) 19:26, 3 March 2006 (UTC)

Doesn't this refer to the zombie virus question above? For great justice. 19:34, 3 March 2006 (UTC)

Gues what? I think this refers to the zombie virus question above. DirkvdM 14:19, 4 March 2006 (UTC)

Are you sure it refers to the zombie virus question above? Kilo-Lima Vous pouvez parler 14:43, 5 March 2006 (UTC)


As one who has been coughing for about a week now, and is just now starting to feel better, what component of phlegm makes it green? User:Zoe|(talk) 19:57, 3 March 2006 (UTC)

I could have gone all day without reading that... --Username132 20:17, 3 March 2006 (UTC)
I know that green phlegm is a sign of bacterial infection, but I couldn't tell you precisely why--might be that the bacterial mass itself is green. grendel|khan 21:53, 3 March 2006 (UTC)
Yes, but what pigment is responsible? It couldn't be chlorophyll, could it? —Keenan Pepper 23:06, 3 March 2006 (UTC)
Thanks, Keenan, that was really what I was trying to ask. Is there any copper involved? User:Zoe|(talk) 23:32, 3 March 2006 (UTC)
I doubt there would be copper, but I'm no biologist or doctor. I think of Cu2+ ions, which are blue. I suppose it would look green if some copper compounds were somehow mixed in with some yellow pigments in the phlegm, but I really have no idea. --HappyCamper 13:31, 4 March 2006 (UTC)
Iron, not copper. Myeloperoxidase is the culprit, which has a ferric (Fe(II)) heme iron, which makes it green. --BluePlatypus 13:54, 4 March 2006 (UTC)
<phew> Thank God it is iron! --HappyCamper 13:56, 4 March 2006 (UTC)
Wow. Thanks! I'd really been wondering about that. Color me impressed. And green. grendel|khan 14:49, 4 March 2006 (UTC)
Awesome! Thanks, Blue. User:Zoe|(talk) 19:43, 4 March 2006 (UTC)

Titanium dioxide as a sunscreen in cosmetics[edit]

I know that titanium dioxide is a sunscreen and is currently used as such in products. I make my own lip balm and recently some people who like to use my product asked if I could make it with sunscreen properties. I have titanium doixed in powder form, but as stated in its fact sheet, it is insoluable. How do go about using titanium dioxed in my lip balm so that it will act as a sunscreen without the product feeling gritty? Thanks for your help. Debbie Bliss

In suntan creams it is a suspenion of tiny particles, not a solution. You need to grind the powder more finely if it feels gritty. For great justice. 22:18, 3 March 2006 (UTC)
Titanium dioxide is in sunscreens because of how immensely white it is, in fact either zinc or titanium di/oxide is the whitest thing known to man. Black as you probably know is hotter to wear on a sunny day than a bright color, because light is absorbed into black, whereas white reflects most of the light. Long and medium wave ultraviolet rays from the sun are what cause sunburn, more of these are reflected off with the addition of zinc or titanium di/oxide You're not going to be able to add the titanium in, unless you can make it finer than a dust, the kind of dust you see in the light floating around in the air. -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 04:31, 6 March 2006 (UTC)

There seems to be another issue here: any lip balm with sufficient titanium dioxide to have sunscreen effects will be white. Do people really want white lips ? If not, perhaps you are considering angel dusting ? StuRat 03:29, 10 March 2006 (UTC)

March 4[edit]

Maple program[edit]

How does one factor polynomials in Maple?

Have you tried using factor(whatever)? expand() and factor() should do what you need. grendel|khan 01:45, 4 March 2006 (UTC)

Moved from my user talk page. grendel|khan 14:55, 4 March 2006 (UTC)

Thanks, but how do I factor equations in the form ax+bx+c. It doesn't work out well in Maple.

You mean ? Like quadratic equations? You should be able to enter, for instance, factor(x^2-5*x+6) and have it return to you . I've never actually used Maple; I Googled up an instructional page about it, which might be of more help to you. grendel|khan 14:55, 4 March 2006 (UTC)
If you enter "factor(x^2+5*x+6);" then you will get the answer "(x+3)*(x+2)". However if you try to enter something that doesn't factorize then you will just get the original expression as the answer. If you don't get the answer I recommend asking it again here. DJ Clayworth 22:36, 7 March 2006 (UTC)

Detecting the "days-without-a-shower" smell[edit]

In a club meeting one night, when we were all asked to tell the club some of our greatest pet peeves, one of the leaders of the club said that hers was the "days-without-a-shower" smell, and that she could detect the difference between the "after-a-heavy-workout" smell, and the "days-without-a-shower" smell. (Apparently, a lot of smelly people she's encountered tried the "after-a-heavy-workout" excuse if their days-without-a-shower smell was brought to their attention.) Can most (if not all) girls detect a difference between the after-a-heavy-exercise smell and the days-without-a-shower smell, or can only some?

I read in a Maxim magazine a long time ago that a female's sense of smell is 100x (yes, one-hundred times) more sensitive than a male's. I do have my doubts, however. How much more sensitive is the female sense of smell really? Also, how much sooner can a female detect a negative odor than a male?

What hints would typical college girls give, directly or indirectly, that she's detecting this kind of smell from you? (Or otherwise in each other's vicinity, if not you?) I know that in Elementary, Middle, and sometimes High School, people were more direct about what odors they sensed. In college, we're more polite and tactful, so oftentimes hints are given so subtly we may not even decipher them when we need to.

Finally, when a guy who hasn't had a shower in a few days decides to apply deodorant more thoroughly (beyond the armpits; onto the torso, back, legs, arms, et al.) and spray himself some cologne, can it successfully "camouflage" the bad smell or can one still sense the odor "underneath" the deodorant and cologne? --Shultz III 00:39, 4 March 2006 (UTC)

From personal experience, I've had the days-without-a-shower smell mistaken for the just-worked-out smell. Do you live on Arrakis? All this seems a bit much work to avoid washing. (Though I shouldn't really throw stones here.) The method I preferred for the thirty second scrub at work was to take a paper towel in the work restroom, wet it, throw some soap on it, scrub under the armpits and down the shorts. Worked quite well, much better than throwing on a ton of cheap cologne, which, trust me, even guys can detect. As for the women's sense of smell being better than men's, that sounds way fishy to me. If that were true, wine tasters and perfume testers would all be women, because their performance would be so superior to men's that they'd take over the trade. Which they haven't. grendel|khan 01:35, 4 March 2006 (UTC)
I guess this heightened sense of smell only applies to some women, based on what you say about wine and perfume testing. --Shultz III 01:58, 4 March 2006 (UTC)
According to, "A US study showed women of reproductive age are far better at identifying odours than men after repeated exposure to the source of the smell". Females were able to improve their sensitivity to the smell of benzaldehyde after smelling it multiple times, while males did not improve. This means that there is no significant difference in the sensitivity of males and females to smell, if the test subjects are only allowed to smell something for an instant.
There was no significant gender differences in people older than 45 years. There was also no significant difference in "young" boys/girls. (I think "young" means younger than the reproductive age, i.e. before puberty begins.)
Nobody can detect a bad smell "underneath" deodorant, if the deodorant is 100% effective. A person smells bad after a few days without a shower because of bacteria, and if a deodorant can kill all the bacteria, the smell will disappear. Cologne (Eau de Cologne?) is just a perfume, and perfumes do nothing but provide a pleasant smell, so it is possible to smell bad odour underneath cologne.
Finally, for the question "Can most (if not all) girls detect a difference between the after-a-heavy-exercise smell and the days-without-a-shower smell, or can only some?" Obviously some people are more sensitive to smell than others. Those with anosmia cannot smell anything. My guess is that if most girls you know can detect a difference between a specific after-a-heavy-exercise smell and a specific days-without-a-shower smell, than most girls can detect that difference. --Bowlhover 02:17, 4 March 2006 (UTC)
I have anosmia and it suck! I had to learn the hard way exactly how often you need to shower and how much deodorant to use without killing your houseplants. Ye, when you can't smell it's not immediately obvious that you can be dirty without looking dirty. In my now-paranoid state of mind I shower minimum once a day. As for people letting you know you stink - well, they don't. Trust me on this - even your best life long friends won't do it. They'll make fun of your receding harline, mismatching clothes and weight gains - but they'll certainly never risk hurting your feelings by commenting on your oder. Don't worry though, girls tend to let you know right before intimacy "Honey - could you... go disinfect yourself?" It's mostly a drag but it's not all bad. I never tasted another persons gassified feces for instance - I guess there's some bright spots to everything. Celcius 02:52, 10 March 2006 (UTC)

What material is best to make something leap over 20m?[edit]

What sort of material will work best for designing an A4 sized object to leap (or jump) over 20m from the ground? The object must not expel gas/liquid, and not require any other external devise to make it leap. Another thing is that all energy must come from the person supplying the force for the leap. Thank you for your help.

Designing? Or making? A4 is a two-dimensional size, so how tall can it be?
Slumgum 01:48, 4 March 2006 (UTC)
I am not completely sure that this is the best material for this application, but the Titanium-Nickel alloy used in braces is exceptionally springy and generally only retains shapes that it is formed in when heated. Skomae 04:30, 4 March 2006 (UTC)
How about a big rubber band? GangofOne 04:58, 4 March 2006 (UTC)
Making an A4 sized object with a height limit of say 1m. Are springs and rubber bands the only materials possible? Thanks.
Does the entire object need to get to 20m or can it propel an object into the air? Celcius 03:00, 10 March 2006 (UTC)


I was reading the Klinefelter's Syndrome article and noticed that one of the symptoms mentioned was "affectedness." I'm no doctor, but I'm pretty sure that "affectedness" is not a medical condition. Does anyone know more about this? --JianLi 01:04, 4 March 2006 (UTC)

I think it's just "creative" writing. What they mean by "signs of affectedness"(!) is "symptom". JackofOz 01:41, 4 March 2006 (UTC)
Oh, I see. --JianLi 02:47, 4 March 2006 (UTC)

Microphone Query[edit]

My microphone will make a low hum when recording unless I blow loudly into it. The hum is recorded as unchanging. Why does this happen? What can I do? Thanks. M@$+@ Ju ~ 01:42, 4 March 2006 (UTC)

Are you near a fluorescent tube? Does the hum get louder or quieter if you move it closer or further from a piece of equipment? If someone is running a microwave or a fluorescent light (among other things), it can emit radio interference that the mic will pick up. grendel|khan 01:49, 4 March 2006 (UTC)
Nah, it goes away only if I blow loudly into it, like overloading then it resets. M@$+@ Ju ~ 03:48, 4 March 2006 (UTC)
A constant low hum is most likely (IME) to be either: (1) interference from mains electricity (50Hz/60Hz depending on what country you're in) which will be at its worst if your mic cable is running alongside mains power cabling, or (2) a ground loop, which can happen if you are using an unbalanced line (if you don't know, you probably are) between two powered devices. I've heard examples of the latter where the hum is unnoticable when there's a signal on the line but imensely distracting when the source is muted. -- AJR | Talk 20:41, 7 March 2006 (UTC)
I can attest to the fact of a hum from mains power in a PA system, which was resolved by using an adapter to remove the ground connection on all the electronics (amplifiers, mixers, etc.). -- WhiteDragon 15:23, 10 March 2006 (UTC)

Your microphone may also be too close to your speakers.-- 03:27, 11 March 2006 (UTC)

Type of thermoplastic polyurethane fro making soles/shoes[edit]

The soles of the shoes are made of thermoplastic polyurethane or NON thermoplastic polyurethane.

The P... article tells us that there are different kinds ; some foams can be moulded.
Thermoplastic means "mouldable with the action of heat". If a substance is not thermoplastic, its use is quite different : varnishes are layered rather than moulded. Moulding leaves sometimes marks and allows to design textures that you would not want to draw mechanically. Also, my shoes' soles are leather. Can you decide by yourself now ? --DLL 21:49, 4 March 2006 (UTC)

mysql password[edit]

I've just installed mysql on my computer, and following some online post-installation configuration instructions, I guess I accidentally set the password to something I don't know. Can you tell me how to recover it? -lethe talk + 05:47, 4 March 2006 (UTC)

I found some instructions, which tells you to start mysql with an initfile containing instructions to change the passowrd. However, it didn't work, I got the error
ERROR: 1133  Can't find any matching row in the user table
So I guess I need to also tell the init file to add a user named root? How do I do that? -lethe talk + 06:26, 4 March 2006 (UTC)

OK, so I've started mysql with

/usr/local/mysql/bin/mysqld_safe --init-file=~/mysqlpass

and the file contains this:

use mysql;
INSERT INTO user (host, user, password, select_priv, insert_priv, update_ priv) VALUES ('localhost', 'root',
PASSWORD('somepassword'), 'Y', 'Y', 'Y');

which I believe should create a root user with a specified password. Nevertheless, when I try to connect using

/usr/local/mysql/bin/mysql -u root -p

I get the delightfully uninformative error:

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

So I guess what I really need to know is: is there a way I can see which accounts are defined without being able to connect? -lethe talk + 07:13, 4 March 2006 (UTC)

OK, well I figured it out. If you read the file data/mysql/user.MYD, it's a binary file, but you can still see some text in there with all the crud, and I saw the names of all the accounts. So now I can connect and should be able to fix. -lethe talk + 07:21, 4 March 2006 (UTC)
When you first install MySQL, root has no password. You start it without using any password option so you can set a password for root. --Kainaw (talk) 01:22, 5 March 2006 (UTC)
That's true. But maybe other stuff also happens. -lethe talk + 15:03, 5 March 2006 (UTC)

Shortcut keys[edit]

I use Windows XP. I know that I can type Alt+0147, for instance, to type a left double quotation mark (“). Is there any way I can assign a keyboard shortcut to type characters like this (and for instance, different dashes)? I'd like to be able to do this in all programs, not just Microsoft Word. I know there are some programs available to download that let you create complex macros, but is there any way within Windows XP to do this? Or alternately, does anyone have a suggestion for a simple, light program that I can use to accomplish this? I'd rather not have a memory hog running all the time, if possible. Thanks for any assistance! — Knowledge Seeker 06:22, 4 March 2006 (UTC)

Try AutoIt (website). It's a scripting language that can do almost anything, including Window recognisation and manipulation, mouse moving, clicking, keyboard typing, and even complex actions like COM object manipulation and ability to call DLL functions. It should be simple to do what you want to do in AutoIt; it's easy to create a keyboard shortcut to do anything. For example, you could assign "Ctrl-Alt-Q" to insert a quotation mark. AutoIt can send keys from ASCII codes, by something like "{ASC 0147}". If you'd like me to make the program for you, just ask. -- Daverocks (talk) 10:37, 8 March 2006 (UTC)

I need help for my science assignment.[edit]

I'm doing my assignment on ALLOYS. I just want to know who invented the idea. PLease answer as soon as possible or maybe you can give me some advice about where to look it up. Thank you guys.

I'm really desperate.


For general information, alloy is a good place to start. However, as for the first creation of alloys, this page seems like a good jumping-off point. It doesn't say who or what civilization started alloys, but it says that bronze was the first intentional alloy created by man. It also mentions brass which, according to our article on it, has been known to man since prehistoric times, so there seems to be slightly conflicting reports on this. I really don't know much about the topic, but hopefully this gets the ball rolling, or hopefully someone more knowledgable will come along to help. EWS23 | (Leave me a message!) 07:14, 4 March 2006 (UTC)
I suppose it largely depends on your definition of "prehistoric" whether that's conflicting information. After all, the discovery of the alloy bronze is the reason for the age known as the "Bronze Age" Prior to that Iron was the principal metal in use (hence "Iron Age"). Bronze Age culture is often (perhaps questionably) described as prehistoric, simply because so little of its history was preserved. As far as the initial question is concerned, although the first alloys may be difficult to track down the original creators of, some later innovators of processes for creating alloys are far easier to trace (one of the most famous is Henry Bessemer, who revolutionised the production of steel). Actually, the article on steel might give you several pointers, since that is still one of the most widely used alloys and historically has been around for a long time. Grutness...wha? 13:26, 4 March 2006 (UTC)
Asking who invented alloys is like asking who invented salt water. It predates life itself. WAS 4.250 16:02, 4 March 2006 (UTC)
True? Do alloys occur in nature with no human involvement? JackofOz 07:53, 5 March 2006 (UTC)
Depends on your definition; 16 Psyche if apparently one enormous lump of iron, nickel, and probably a collection of various platinum group metals. But it gets into whether you assert that by definition an alloy must be artificial. --Robert Merkel 09:20, 5 March 2006 (UTC)
There exist very few metals (and they're all the very unreactive ones) in the Earth's crust which exist as the metals themselves, rather than as compounds, or ores. But there is no reason, I suppose, why two such metals, eg silver and gold, could not alloy themselves "with no human involvement".G N Frykman 09:19, 5 March 2006 (UTC)


Light waves bend when they move from one medium to other. So does sound or radio waves ben when they move from one medium to other?why?

Yes, they do. --HappyCamper 08:23, 4 March 2006 (UTC)
As do water waves as they go from one depth to another. It's because they change thier speed. Theresa Knott | Taste the Korn 08:41, 4 March 2006 (UTC)
You might find our article on refraction interesting. --HappyCamper 08:43, 4 March 2006 (UTC)
Also, light waves and radio waves are both forms of electromagnetic radiation. Light waves are electromagnetic waves with a wavelength range of 400 nm to 700 nm, whilst radio waves are electromagnetic waves with a wavelength of 1mm to 100 000km. So they behave in the same way. - Akamad 13:35, 4 March 2006 (UTC)
Sound waves refract by changing their speed. Electromagnetic waves can't do this, since their speed is fixed at the value c. So they change their wavelength.G N Frykman 09:22, 5 March 2006 (UTC)
That's not true. When an electromagnetic wave is refracted, both its speed and its wavelength changes (but the frequency doesn't change), just like with sound waves. – b_jonas 22:09, 6 March 2006 (UTC)
Yeah, c is just the speed of light in vacuum. When it's traveling through a medium, its speed is reduced. Black Carrot 23:43, 6 March 2006 (UTC)
Actually, the reason that light (and radio, etc. see Electromagnetic Radiation) bends is because its speed of propagation changes. The index of refraction links these two ideas.Jburt1 23:05, 8 March 2006 (UTC)


Is it possible for genes to overlap one another? --HappyCamper 08:46, 4 March 2006 (UTC)

It is called "alternate open reading frame".Google for details, we lack an article on it. H5N1 has one one these. Our article on that states: "PB1 codes for the PB1 protein and the PB1-F2 protein.* The PB1 protein is a critical component of the viral polymerase.* The PB1-F2 protein is encoded by an alternative open reading frame of the PB1 RNA segment and "interacts with 2 components of the mitochondrial permeability transition pore complex, ANT3 and VDCA1, [sensitizing] cells to apoptosis. [...] PB1-F2 likely contributes to viral pathogenicity and might have an important role in determining the severity of pandemic influenza."[22] This was discovered by Chen et. al. and reported in Nature[23]." WAS 4.250 15:46, 4 March 2006 (UTC)
In a way, yes. See Alternative splicing. Basically if several proteins share parts of their amino-acid sequence, that part can be encoded in a single exon and both proteins can be created by the same gene as splice variants. --BluePlatypus 09:47, 4 March 2006 (UTC)

In that way yes, but not in the sense that you can imagine two meaningful encyclopedia articles that overlap, with the last page of one constituting the first page of the next-- for exactly the reasons the metaphor implies: starts and stops of genes are defined by special signals, and it is hard to imagine an instance where it would be useful to have the tail of one protein constitute the tail of another in reversed attachment. alteripse 12:55, 4 March 2006 (UTC)

Oh, I see. How about in smaller examples, like plasmids? Are there examples where the overlapping is much more significant? --HappyCamper 13:26, 4 March 2006 (UTC)

Language question about anencephaly[edit]

It's a question about norms of english language: how may the notion "anencephalic person" be expressed by a single word? In russian it's "anacephal" -- a person born without brains. Does anything similar exist in English? Thank you. ellol 10:03, 4 March 2006 (UTC)

I suppose if it had to be shortened to one word, you'd use anencephalic, in the same way that diabetic can be used as a noun. Though strictly speaking a person with the condition is only missing the forebrain, not the whole brain.GeeJo (t) (c)  10:17, 4 March 2006 (UTC)
Thank you, GeeJo! ellol 12:04, 4 March 2006 (UTC)

Many doctors avoid using a disease adjective as a noun, especially in formal or public speech. Person with diabetes is preferred over diabetic. One never wants to forget that a person is not a disease. This distinction was introduced publicly in the 1970s in an era of PC speech that often degraded accuracy and enshrined ignorance, and much of it (fortunately) has not survived, but this distinction is both functional and accurate, as well as sensitive. The people who use the term diabetic as a noun most freely are people with diabetes. Anencephaly and anencephalic is a special case, however, as you may be aware, because there has long been debate about the personhood of a body born without a brain. Anencephalic is sometimes used as a noun in a medical context. alteripse 12:50, 4 March 2006 (UTC)

Thank you. It's interesting. Actually, i wondered why does the word that must exist seem to be non-existing. The concept of political correctness is not common here. ellol 17:46, 4 March 2006 (UTC)
Is it likely that AA will become Persons With Alcoholism Anonymous? JackofOz 07:50, 5 March 2006 (UTC)

water potential[edit]

hello, I'm doing biology coursework on osmosis in potato tissue and there is one criteria i'm slightly confused on how to achieve. I have to say why is it better to use water potential instead of molarity.can you help? thank you

There is a hint in the article water potential which you might find useful. Also, check out molarity (and possibly molality). Note how the former takes something very important into account... --HappyCamper 14:21, 4 March 2006 (UTC)

ssh -X and ssh -Y[edit]

What is the difference between the -X and -Y options for ssh? I've read the man pages over and over, and I still don't understand what it means. Thanks for your help! --HappyCamper 14:49, 4 March 2006 (UTC)

Judging by this mailing list message, it's to do with whether or not you trust the applications running using X forwarding (ie what permissions they have on your machine you're SSHing from). -X runs them as untrusted, which can cause some things to break. -Y runs them as trusted. But you shouldn't notice any difference if you're not using an application sensitive to whether or not it's trusted. --Bth 15:20, 4 March 2006 (UTC)

Plugged Ears feeling after running in cold weather[edit]

Why do my ears feel like they're all plugged up during and after I go running/jogging in the cold weather (see your breath kind of cold)? It seems I have to 'pop' my ears after each breath once I go indoors. It's horrible if I have a stuffy nose. 17:04, 4 March 2006 (UTC)

If your Eustachian tubes get plugged up with a bit of mucous, the pressure on the inside of your eardrum will be higher than that outside. Your hearing will be distorted, and 'popping' your ears will clear it. TenOfAllTrades(talk) 21:47, 4 March 2006 (UTC)

Its possible that you have an Ear Infection. I have had it on multiple occasions and its symptoms include plugging on the ears and that popping of the ears is the ears trying to adjust the the pressure changes within your ear to the outisde pressure but somehting is blocking it making it more noticeable. Ear infection is caused by fluid entering the Eusachan tube in the ear and bacteria getting in there and infecting it. See a physician for more of an explanation. This is usually remided with common medicines. I hope this helps. :-) 5aret 00:55, 5 March 2006 (UTC)

Perhaps I just have overproductive mucous membranes in the area of my eustachian tubes since it occurs everytime I exercise in the cold and feel quite healthy. Thanks for the info. But is there a reason why these membranes would produce mucous while Im exercising and not when Im just sitting around out in the cold? 16:38, 5 March 2006 (UTC)


Does OpenID provide a way to link different identities? For example, let's say I have a Livejournal OpenID and a DeadJournal (or experimental MediaWiki) OpenID. Is there any way I can tell the servers that these are one and the same person? — Ilyanep (Talk) 19:48, 4 March 2006 (UTC)

If you have full control over one of the URLs you can delegate it to the other URL, but if it's LiveJournal or MediaWiki, then no. Ashibaka tock 06:09, 5 March 2006 (UTC)
You'll probably have do decide which one you prefer more and just stick with that one. Use your favorite OpenID to log into sites that support it. Why did you create more than one OpenID anyway? --Optichan 19:48, 6 March 2006 (UTC)

Java loading code[edit]

Does anyone know how I could make a program that reads in java code from a text file and executes it. I think I can do it by reading in a class, using the "load"[13] command and doing somthing similar to the code on this [14] page. I'm lost though. Could someone give me an overview of what has to be done? I know I'll have to cast the class after reading it... but how do I get it in the first place? Is this even possible. BrokenSegue 22:11, 4 March 2006 (UTC)

By "java code" I'm assuming you mean "compiled bytecode stored in a .class" file (and not "java sourcecode"). The easy way is to make sure the class file is in the classpath, and then invoke Class.forName (an example is here). If it isn't, you have to create your own classloader (i.e a class that extends ClassLoader), which is what that example you quote does. The important line is the call to defineClass (which is in ClassLoader) which takes a byte array (containing the same stuff as a .class file) and loads it. That will give you a java.lang.Class object. Now, if memory serves, you can't just cast that to something (like an interface) and just go using it (unless they've added some clever stuff to do that after I stopped doing so much java). Instead you have to call the Class object's newInstance method. Note that if your constructor (for that class) has arguments, you'll have to use java.lang.reflect to build the arglist for newInstance (discussed here). One last thing (it's obvious, probably): your compiled class has to implement an interface which your hosting code knows about (and was compiled with) so that you can have something meaningful to cast the result of newinstance to. Here is a rather basic AppletClassLoader (the Sun one is rather more complete) which uses a classloader that comes with the system (NetworkClassLoader). Don't worry if this all seems rather excessive - this is probably the hardest, yet most infomative, part of Java. Once you get this you'll understand how security really works, how reflection works, and how stuff like JINI and Javabeans work. -- Finlay McWalter | Talk 22:37, 4 March 2006 (UTC)
Thanks man. BrokenSegue 12:50, 5 March 2006 (UTC)

mac OS finder windows[edit]

Since this seems to have become the computing reference desk....

I'm running Mac OS 10.4.4. I like to apple-tab between applications. But something very frustrating happens with the Finder. When I apple-tab to the finder, it doesn't bring the last finder window I was working with to the front. The focus seems to go there, because I can apparently navigate directory structures with the arrow keys, but the window itself doesn't come to the front, so I usually can't see what's going on. I have to either somehow find it with the mouse, or apple-tilde until the right window shows up. Extremely annoying. I don't think it behaved like this on older OSes. Does anyone know how to fix this? Thanks... Dmharvey 22:18, 4 March 2006 (UTC)

Not really a fix, but I tend to use Exposé (F9 or F10) to pick the Finder window I want. Sum0 22:52, 4 March 2006 (UTC)
I think it's always been for computing. Its description is "To ask questions about science, medicine, computing, and technology". — Knowledge Seeker 23:29, 4 March 2006 (UTC)
I think it might be worthwhile to split off into a Reference desk/Technology. — Ilyanep (Talk) 23:30, 4 March 2006 (UTC)
I don't think you can get what you want, you're going to need to use the exposé feature, F9 or F10.
Apple-backtick cycles between windows in the same application, e.g. between different finder windows. Ojw 12:21, 5 March 2006 (UTC)
(Oops, when I said apple-tilde I meant apple-backtick.) Well, it's very strange, after behaving like this for several months, as soon as I ask a question on the reference desk, the problem goes away. Now it does what it's supposed to do. I don't think I changed any settings. Very mysterious. Thanks guys! (I guess!) Dmharvey 12:31, 5 March 2006 (UTC)

Science fiction weapon[edit]

I had an idea for a fancy futuristic weapon: Ordinary rifled barrel, magnetic/magnetised bullet. Behind the bullet is a powerful (as powerful as necessary/possible) electromagnet with an opposite charge to the bullet. When the electromagnet switches on, the bullet is repelled straight out of the gun at a high speed. So, sort of like a coilgun but with no coil. Plausible, or fatally flawed? Thanks y'all. Sum0 23:04, 4 March 2006 (UTC)

Doesn't sound very likely to me. By the way you don't really mean "charge"; no one has been able to prove experimentally the existence of magnetic charge, though there is theoretical work about how it would behave if it did exist. If it did exist, you wouldn't want opposite magnetic charge, but rather the same (opposites attract, like charges repel). So what you're really talking about is a magnetic dipole. Dipole forces fall off very quickly with distance. My guess is you'd be lucky to get the bullet to go ten feet. --Trovatore 23:16, 4 March 2006 (UTC)
Oh yeah, I meant same charge. Also, I must have not explained it very well: the idea isn't for the magnetic force to keep "pushing" the bullet as it goes along, but to accelerate it very quickly to a high speed before it leaves the magnetic field. Would that work, or does physics get in the way? Thanks for the replies, anyhow. Sum0 23:32, 4 March 2006 (UTC)
It'd make a nice pistol-like weapon. But what real advantage would it have? — Ilyanep (Talk) 23:26, 4 March 2006 (UTC)
I think the magnet-at-the-back design is just wrong. Why don't you want the coil along the barrel? I haven't worked the numbers or anything, but my intuition is you'll get a much higher muzzle velocity with the latter design. --Trovatore 23:36, 4 March 2006 (UTC)
This is called a rail gun. It isn't science fiction. Working models have been made. The problem is that the power supply is about the size of a VW Bug - so it isn't very portable. --Kainaw (talk) 01:18, 5 March 2006 (UTC)
Some fellow pupils made one of these (under supervision) when I was at school in Oxford in the 1970s. They used the properties of the 3-phase supply to induce huge eddy currents in a metal bolt and to shoot it out of a tube. When it was first tried out, it was just as well that sand-bags had been placed at both ends of the tube, because the connections had been made the wrong way round, and the bolt shot out backwards with huge force... Do not try this at home, is the motto!G N Frykman 09:31, 5 March 2006 (UTC)
One problem is that the bullet will want to turn around, which will cause a lot of friction and make it come out of the barrel at a slight angle. Btw, I came up with the rail gun principle as a kid and asked the physics teacher about it and he hadn't a clue what I meant. Only later did I find out that some trains use this principle. Someone else stole my idea again. :( DirkvdM 10:38, 5 March 2006 (UTC)
The most successful one I've seen (Texas A&M) used a little caddy to carry the bullet down the rails. It was a little bullet-sized bucket with two wings that rode along the rails. This meant that the bullet could be uncharged - instead the wings of the caddy were charged. Then, you can set it up so they try to turn into each other - cancelling out that problem. The new problem is that the wings will easily weld themselves to the rails due to the high amount of electricity travelling through the system. When that happens, you get big sparks and a very expensive paper weight. --Kainaw (talk) 17:58, 5 March 2006 (UTC)
But from what I can tell, this isn't a railgun. There are no rails, for a start, and it's just one magnet behind the bullet. Sum0 20:37, 5 March 2006 (UTC)
Sounds very much like a Gauss gun, but with only a single electromagnet. BTW, you can make a handheld gaussian gun with 5 (magnetic) ball bearings and some similiarly sized neodymium magnets. Connect 4 bearings and the magnets in series, then let the fifth bearing roll towards the exposed magnets. The impact velocity is transferred to the farthest bearing, which by not being in as strong a magnetic field, is propelled away at high velocity. It's more of a toy, since neodymium magnets are too brittle for large-scale versions. PS - I credit MechWarrior 2 for introducing the topic to me - the Gauss Cannon rocked faces. Tzarius 07:54, 6 March 2006 (UTC)
Basically what everyone's saying, Sum0, is that it's not really plausible. A single magnet behind the bullet wouldn't have nearly enough power to project the bullet at any great distance (because the magnetic repulsion would only be effective for a very short distance), something that a rail gun does much more elegantly.  freshgavinΓΛĿЌ  04:52, 8 March 2006 (UTC)

March 5[edit]

Thermostat 7 to 5 wire[edit]

I have a 7-wire thermostat. I went through every thermostat at Lowes and Home Depot. The most connections any have is 5. I tried to use one by connecting the 5 matching colors and leaving the two odd colors (Cyan and Orange) disconnected. The heater runs non-stop. I've been searching and searching on the Internet for information, but I can't find anything about how to connect a 7-wire system to a 5-wire thermostat. Are there any AC experts here? --Kainaw (talk) 00:47, 5 March 2006 (UTC)

Well, I'm not an expert, but I have here the instruction sheet for the Lux TX 1500 thermostat I installed in my house a couple of weeks ago, and it accepts up to 7 wires. (I can't imagine what they're all for; my heating system has only two.) —Steve Summit (talk) 04:35, 5 March 2006 (UTC)
Stopped by an AC supply shop today. They were closed (Sunday), but some guys were there putting in extra hours. It turns out that my "7-wire" is technically called a "C-wire". It is considered commercial, not residential, so I had to get a commercial thermostat. The only ones they carry are from Rite-Temp, which are cheap, but function. They showed me why it is was impossible to use a C-wire heat pump with a 5-wire thermostat. The relay for the fan and heater gets voltage on one side, but not the other. So, no matter what the thermostat says, it always thinks it is supposed to be running the heat. --Kainaw (talk) 17:54, 5 March 2006 (UTC)

some compound[edit]

I mixt (chlorine) bleach with (household) ammonia and put a 1989 canadian 1 cent into it. 2 days later, the mixture is blue. i'm wondering what it's chemical formula is and why it turned blue. -- 04:01, 5 March 2006 (UTC)

Gah! Please, don't try this again, and nobody try this at home. Mixing chlorine bleach and aqueous ammonia will result in the formation of chloramine, a highly toxic compound that is being used in many cities as a substitute for chlorine in water purification. Nasty stuff. TenOfAllTrades(talk) 04:26, 5 March 2006 (UTC)

Did you actually do it or is it just a nicely phrased homework question? deeptrivia (talk) 04:41, 5 March 2006 (UTC)

I'm kind of hoping that a homework question wouldn't encourage a student to do something so blindingly dumb, actually. There's a reason why household bleach and ammonia bottles both have dire warnings on their labels not to mix the two of them together. *grumbles* What are they teaching kids in school these days? *grumbles*
To answer your question, Canadian pennies before 1997 were almost (98%) pure copper. Taking stock of what's present in your beaker, you have copper, sodium hypochlorite (from the bleach) and ammonia (from the ammonia). Now just do some research and find out which combination of those is vividly blue. TenOfAllTrades(talk) 04:57, 5 March 2006 (UTC)
According to a very old book I read, old coins can be cleaned by putting them in ammonia, which will leave the coin clean and the liquid blue. Given the age of the book, I'd assume they presumed most coins are made from copper, which would suggest that ammonia was the only ingredient doing the cleaning in the experiment you described. --Aramգուտանգ 20:23, 5 March 2006 (UTC)

As mentioned above on this page (in some discussion about phlegm) Cu2+ ions are blue. So if you can get some copper to ionize, for instance by putting it in an acid, you'll end up with a blue solution. I think. My memory of high school chemistry is poor. moink 23:40, 5 March 2006 (UTC)

Unless the ammonia is redoxed, the only negative ion available would be hypochlorite, ClO-. Seahen 22:36, 7 March 2006 (UTC)

Okay! Thanks. It's not homework, I was just bored so i wanted to see what would happen if i mixt stuff that it says i shouldn't mix. I really dont care what the compound is called anymore, i just wanted to know why it's blue. PS: I realize it would produce poisonous gas, so i first poured some bleach into a plastic cola bottle and then pushed in a water balloon filled with ammonia, and then popped the balloon while it was inside. there anyway i can make the mixture blow up, or fizzle or some cool reaction by adding more household chemicals? --

Look, just mixing random stuff together is just dumb alchemy. Go find a book on chemistry experiments you can do at home and try some of the stuff in that. Some of it can involve explosions, fizzing, and so on, you may actually learn some interesting stuff in the process, and you run a far lesser chance of killing or injuring yourself and your family in the process. --Robert Merkel 03:39, 6 March 2006 (UTC)

Incidentally, the blue may well be the complex "cuprammonium" ion, which is a deeper blue than copper. Hyperman 42 00:29, 6 March 2006 (UTC)

Australia's First Triple Transplant[edit]

I'm requesting information on the details of Jason Grey's transplant, which was Australia's first triple transplant (heart, lung and liver).

I would specifically like to know the date that the 14 hour operation was done on.

(I have tried using Google, but am not getting much luck.)

Thanks for the help.

05:40, 5 March 2006 (UTC)

I'm not having much luck with Google either. I can't get an exact date, but I've narrowed it down to the last week of July or the first week of August 2003. According to [15] Jason's surgery was performed sometime during the week prior to August 8. This is confirmed by [16] [17], which gives Jason's post-op condition as of August 5. --David Iberri (talk) 16:28, 5 March 2006 (UTC)


i bought some software from e bay about 3 month ago and ive looked at it a few times with no trouble. today i done a avg test on my pc and this software had a virus in it. the virus was

           Trojan horse psw. Banker. wzp
ive looked up a few types of virus but could not find this one

is it very dangerous for my pc and files or not --Titanicful 08:56, 5 March 2006 (UTC)

  • What software did you buy? Some anti virus programs label stuff as trojan by accident, but you can't be too careful. I would look up the trojan's name on symantec's website and download a patch to get rid of it. - Mgm|(talk) 14:01, 5 March 2006 (UTC)
What antivirus software are you using?
The question says AVG.
Slumgum 20:18, 5 March 2006 (UTC)
Oh you're quite right... Are you sure the virus defs are up to date?

Hello everyone, it happened to me too. AVG found some time ago the Trojan Horse PSW.Banker.WZP in 2 files I downloaded during Christmas promotions. The rest of the files were ok, now, after some weeks, another AVG scan found some more files infected with this PSW.Banker.WZP. These files had been scanned several times before and they were ok. I update the definitions every day. I have scanned the same files with other antiviruses: Norton on my pc, and online: f-secure, Panda and BitDefender, they found no problems. Really strange. Kind regards, Irene

Is it possible to change a Yahoo username?[edit]

Is it possible to change a Yahoo username? —Masatran 12:28, 5 March 2006 (UTC)

  • Did you try asking it at Yahoo first? They are the people who are supposed to know this. - Mgm|(talk) 14:02, 5 March 2006 (UTC)
No. But, you can just create a new Yahoo account and stop using the old one. --Kainaw (talk) 15:05, 5 March 2006 (UTC)


Can anyone recommend good free software to recover files from my old NTFS hard drive? I'm running Windows XP. The freeware I've found has found and recovered some of the deleted files I need, but not all. A shareware program I've found (called WinUndelete [18]) detects the remaining files and tells me they're in "good" condition, but the shareware version won't actually recover them. Seahen 14:12, 5 March 2006 (UTC)

What is the freeware you have used already?
It is found at and The latter always gives me an error message. 22:29, 7 March 2006 (UTC)
There isn't a lot of free data-recovery software, but Directory Snoop is a shareware program that you can try for free. It can recover files instead of just telling you they're in good condition. I used it back in May/June 2005, but unfortunately it couldn't help me out.
Good luck! --Bowlhover 20:59, 5 March 2006 (UTC)
Works, but won't recover a folder all at once if it has subfolders?! Seahen 23:28, 9 March 2006 (UTC)
I've had good results using "PC Inspector". It's free, but not Free. - mako 05:08, 8 March 2006 (UTC)
Try Microsoft's recover from the command line. Don't know how well it works, but I know it's there. :) -- Daverocks (talk) 02:35, 11 March 2006 (UTC)

Food allergy?[edit]

I've noticed repeatedly and quite predictably that these two situations will cause 1 episode of diarrhea for me (almost without fail) within 30 minutes after finishing: 1) having large quantities (1/4 teaspoon) of nutmeg in 1 8-12 oz cappuccino, 2) an Italian dinner from a respectable American-Italian restaraunt (e.g. The Olive Garden, Romano's Macaroni Grill). Obviously, I know what the cure is, but i was wondering if anyone knows why this happens? Is this a food allergy? Male, I have an unusually high metabolism, have weighed 150 lbs for more than the last 5 years, and am generally healthy. 17:04, 5 March 2006 (UTC)

Nutmeg is a common cure for diarrhea, not a cause of it. Also, a person with a high metabolism usually has a very low weight as a high metabolism requires more calories to maintain muscle and fat than a normal metabolism. 150-180 pounds is an average weight for a normal male. In our modern obese time, 200-250 is considered normal, but that is normally obese, not normal. So, if you are maintaining 150 pounds without trouble, you probably have a normal metabolism. --Kainaw (talk) 17:50, 5 March 2006 (UTC)
Bloody hell, over 100 kg normal? For someone 2,5 m tall maybe. DirkvdM 07:11, 6 March 2006 (UTC)
Interesting point about my metabolism - you're probably right. 05:14, 6 March 2006 (UTC)
When I and my friends were, how you say, "experimenting" with nutmeg, we had problems with nausea, but not diarrhea. —Keenan Pepper 17:59, 5 March 2006 (UTC)
I once 'experimented' with nutmeg, but remembered incorrectly and put a tablespoon of cinnamon in my mouth. Which instantly sucked my mouth dry and made it almost impossible to spit it out. That cured me from any desire for further experimentation. :) DirkvdM 07:16, 6 March 2006 (UTC)

Could it be coffee? That does it for me in large enough quantities.

Nutmeg is extremely poisonous if inject instantaneously! Kilo-Lima Vous pouvez parler 16:31, 6 March 2006 (UTC)
Inject? You mean intravenously? Don't start giving people ideas. :) But wouldn't the same go for any solid (spice or not)? DirkvdM 11:24, 7 March 2006 (UTC)
Oops! :-) Kilo-Lima Vous pouvez parler 21:03, 8 March 2006 (UTC)

Don't know about the nutmeg, but you may have lactose intolerance. - Taxman Talk 19:41, 6 March 2006 (UTC)

Why do objects appear smaller with distance?[edit]

Why do objects appear smaller as the distance between the object and the eye increases? Consider a square object that is smaller than the eye lens and is lined up perfectly with the center of the lens some distance away. Now the parallel rays of photons/lightwaves coming from the top edge and the bottom edge of the object will hit the eye lens at exactly the same spot no matter how far the object is. So why should the object appear smaller with distance? I once brought this up with my physics teacher back when I was still in high school and he wasn't able to give a satisfactory explanation, and suggested that the post-processing of the optical signal in the brain is what makes the object appear smaller, referring to the Moon illusion as an example. Is that explanation valid? Thanks, this has been bothering me for ages. --Aramգուտանգ 20:37, 5 March 2006 (UTC)

Objects do not appear smaller because of the "post-processing of the optical signal in the brain". If you measure the Sun's angular diameter at 1 AU, and measure it again at 50 million kilometres, you'll find that it is much larger at 50 million kilometres than at 1 AU. But if you measure the Moon's angular diameter when it's high in the sky, and measure it again just before it sets, you'll notice that the angular diameter doesn't change.
Let's say you have an object that's bigger than your eyes. As you move farther away from the object, light rays from the top and bottom of the object will gradually become more parallel. If you measure the angle they form when they intersect (at your eyes), you'll get the angular distance between the top and bottom of the object. The angular distance is what determines how big or small an object appears to be, and as the light rays become more parallel to each other, the angular distance will shrink. This is why objects appear smaller when you move farther away from them--it's not because of an optical illusion like the Moon illusion is. --Bowlhover 21:23, 5 March 2006 (UTC)
Well said, Bowlhover. Objects subtend a smaller angle on your visual sphere the farther away they are. —Keenan Pepper 21:36, 5 March 2006 (UTC)
To address your specific query about parallel rays, you're right that those will not change as the object moves away; however, they are not the only relevant ones (otherwise, you wouldn't be able to see anything larger than the diameter of your lenses. Image:Lens3.png gives an illustration of what's involved in focusing a point of the image. One could imagine moving the object father back. The top ray would remain the same, as it is parallel to the axis of the lens, as you have noted. But the slope of the middle one would decrease and it is easy to see that it would now intersect the top ray further to the left of the original intersection; calculations will show that the other rays will do the same. Of course, the new image is also more ot the left of the original and wouldn't be focused on the retina, but even as the lens adjusted the new image would still be smaller. If you'd like to go through the specific calculations, let me know. Post-processing is not involved in the phenomenon as you have described it. — Knowledge Seeker 21:55, 5 March 2006 (UTC)
Ah, thanks a lot Knowlegde Seeker, the Image:Lens3.png diagram really got the point through. I'm surprised at the incompetency of my old teacher now, I recall he wasn't able to explain why mass increases with velocity in general relativity either, but that's not a question that bothers me a lot. Oh and thanks to Bowlhover too, although I was really looking for an exlanation that would go into ray bending in the eye lens. --Aramգուտանգ 05:16, 6 March 2006 (UTC)

Vinyl Cancer[edit]

Now that they have whimped out in using the killer plasticizers in Polyvinyl chloride, something very bizarre has happened. I have a vinyl insulated cover on my hot-tub (I use it all year up in Canada). It's santized with Bromine. The last couple of months, the underside started bubbling in the middle, and quickly spread. I finally had to rip it off today. It was as hard and as brittle as original PVC. Has anybody seen this happening. Is this a new thing? Many thanks. --Zeizmic 21:37, 5 March 2006 (UTC)

It *sounds* like the plasticizer which is used to keep the plastic flexible has simply left the polymer. How old is it? --HappyCamper 05:16, 6 March 2006 (UTC)
Sounds like it could be water causing seperation of layers, which is something that could happen if the thing is made from a laminate. --BluePlatypus 09:51, 6 March 2006 (UTC)

Only about 2 years old. It was a funny vinyl, without the usual cloth backing. It happened so fast, and now the bottom is tissue paper. I just ripped it out, and there's another type of plastic underneath. Maybe that was the original backing. --Zeizmic 12:54, 6 March 2006 (UTC)

How much do we cost?[edit]

If we were to deconstruct our body to elementary segments, and then convert the cost of each quantity to monetary units, how much would we cost? Now, we all know we are priceless, but...just for the sake of this question.

It all depends on what you mean by "elementary segments". If that means atoms, we're almost worthless. —Keenan Pepper 22:43, 5 March 2006 (UTC)
Here's our percentage makeup of the elements, I guess you'll have to do the maths and some stoichiometry from there, find a chemicals supplier and see how much they charge for the elements, I didn't manage to find any such supplier, though. --Obli (Talk)? 22:56, 5 March 2006 (UTC)

If we were to deconstruct a canon DSLR camera EOS 1Ds mark II body to elementary segments, and then convert the cost of each quantity to monetary units, how much would the canon DSLR camera cost? Now, we all know Canon Camera are expensive, but...just for the sake of this question.

You see the problem. A canon camera cost more than the sum of its parts. A human being cost more than the sum of the chemical components. What about the cost of the skills in a human being if that human is a olympic gold medalist? Ohanian 03:14, 6 March 2006 (UTC)

It would be interesting to try to make a breakdown of how much value is added at each level of complexity. The raw elements are worth some small amount of money; the molecules are worth a different, higher amount, the living cells even more, and so on. —Keenan Pepper 03:29, 6 March 2006 (UTC)
But value depends on supply, which means the means of production, which vary greatly. Producing 1 gram of a single protein in pure form is a *lot* more expensive than producing 1 gram of cultivatable cells. Producing 1 gram of copies of a single DNA is rather cheap, thanks to PCR. The cost of synthesizing organic substances varies enormously depending on what precursors you need, and what reactions yuo can use. And so on. --BluePlatypus 19:32, 6 March 2006 (UTC)
Also, I guess the cost of the deconstruction would probably be larger than the price of the atoms you get. – b_jonas 21:53, 6 March 2006 (UTC)
It depends on what you would count as an 'elementary' segment. If you separate someone down into their constituent atoms and sell those for their bulk market prices, you probably don't get very much—erhaps as much as ten or fifteen dollars worth of raw material.
On the other hand, certain parts have a much higher value when not divided down quite so small. You could probably sell a kidney for five or ten thousand dollars—at least if it weren't illegal to do so. (Some other organs would fetch even higher prices.) Women could sell eggs for quite a chunk of money, too.
Then there's all the useful hormones. You're full of steroids and growth hormones and cell signalling factors and all kinds of other handy biomolecules. If you could collect and purify all of those, then you'd probably be worth hundreds of thousands of dollars. TenOfAllTrades(talk) 00:42, 7 March 2006 (UTC)
I'd estimate about $847.63 --JianLi 05:30, 7 March 2006 (UTC)
Why don't you put yourself on ebay as "spares only", and see how much you get? --Heron 20:57, 7 March 2006 (UTC)
Question is - should he post a picture with it or would that ruin the experiment? Celcius 03:07, 10 March 2006 (UTC)
"Includes bonus Keratin (long hair and nails, extra body and facial hair), Perfumes (may not be suitable for human olfactory centres) and now with 25% extra body mass!" Tzarius 07:16, 10 March 2006 (UTC)

histogram equalization stretch[edit]

when modifying a satellite image, in what situation should the histogram equalization stretch be used, should it be used to enhance a rare feature on an image?

Try it and see if it works for you. GangofOne 02:36, 6 March 2006 (UTC)
What does 'histogram equalisation stretch' mean? Is that some preset for a program? If so, which one and could you describe it's function? I suppose it means reducing the overall contrast. What effect this has on a specific feature depends on that feature. You should increase the contrast between the important parts of the image (and thus 'stretch' the rest?). In Photoshop or the Gimp, play around with 'curves' (don't know what that's called in other programs). DirkvdM 07:33, 6 March 2006 (UTC)
Check your textbook. If you don't have one, go to the library and find one on satellite image processing. --Robert Merkel 00:42, 9 March 2006 (UTC)

Christmas lights fiasco[edit]

I did something stupid the other day: I used a string of Christmas lights as an extension cord for a vaccum cleaner. (Don't ask why. Yes, it was stupid. Yes, I probably could have guessed what would happen.) The lights of course went off and won't come back on, and electricity no longer seems to pass through the cord at all. What's the probable extent of the damage -- is it a light or two that blew needs to be replaced, or is the whole string dead? --Fastfission 23:16, 5 March 2006 (UTC)

Do you happen to know if the lights are strung in series or in parallel? When were they made approximately (and in what country)? moink 23:22, 5 March 2006 (UTC)
From looking at User:Fastfission/About me, you're in the US and youngish. So unless you inherited these from your parents when they were young, they're most likely in parallel. If none of them are working, replacing one won't cause the rest to work. I don't know what's wrong with them. moink 23:29, 5 March 2006 (UTC)
If I am not mistaken, most strings of Christmas lights produced for use in the US in the recent past have a fuse within the plug. (see the fourth major paragraph here); check to see if there seems to be a latch or cover of some kind in the plug. And yeah, don't try that again! --LarryMac 23:40, 5 March 2006 (UTC)

I had a recent set of those tiny lights, and the cord broke. No problem, I thought, I would just solder it together. Well, they are soooo cheap that there is no wire! It just looks like thread wound into string! I think it must be silvered string, or somehow they get it to conduct the little bit that is necessary. This stuff cannot be rejoined, and if you put a bolt through it, I'm sure you get a lot of burnt string! Puts new meaning to a 'string of lights'. --Zeizmic 02:27, 6 March 2006 (UTC)

The tiny lights are actually in series, but if one goes out the whole string doesn't go out because the blown light is designed to short itself. These are low voltage blubs, the voltage of the mains is divided among the either string. The wire is small, you probably burnout the wire somewhere due to too much current. But maybe the bulbs can be used as replacements on your next string. GangofOne 02:41, 6 March 2006 (UTC)

March 6[edit]

March 6? But can you be more specific in your question? For great justice. 05:24, 6 March 2006 (UTC)

You made my day! I think it was referring to the actual date of questions to be asked :) --Ali K 05:29, 6 March 2006 (UTC)
Hey, if you go up a bit, there's another header saying 'March 5' and a bit further up there's a 'March 4'. And so on. Maybe these are not questions at all. Now what might they be for? DirkvdM 07:37, 6 March 2006 (UTC)
It's the Wikipedia fitness regime. Yesterday we were supposed to march five miles and today it's six. --Bth 08:15, 6 March 2006 (UTC)
Actually, I think it's a typo. Today we are supposed to answer questions at Mach 6. - EWS23 | (Leave me a message!) 16:58, 6 March 2006 (UTC)
Aren't you US'ers a bit too tough on yourselves? Switch to kilometres and you only need to march 2/3 the distance. DirkvdM 11:30, 7 March 2006 (UTC)
  • To whoever forgets: Remember Wikipedia uses UTC time and may switch to the next day, when you're still a few hours behind. - Mgm|(talk) 09:32, 6 March 2006 (UTC)
Thanks - it was actually just a silly joke, but the Mach comment made me wonder - if Mach is the ratio of the speed of a thing to the speed of sound in the same medium, what happens as a plane gets higher into the atmosphere and eventually into the vacuum of space, where the speed of sound is, presumably, zero, because there is nothing for it to transmit through in that medium? For great justice. 19:21, 6 March 2006 (UTC)
If the speed of an object in space is refereed to as a Mach number, then the speed of sound at sea level at room temperature was used. Also, airplanes cannot get into the vacuum of space, because they need air to provide lift to counter gravity, and because fuel for the engines cannot burn without oxygen. --Bowlhover 21:00, 6 March 2006 (UTC)
I believe you are incorrect - the Mach number of, say, a plane, is always relative to the local speed of sound (ie the speed of sound at the altitude at which the plane is flying), which, are you pointed out, does change with height. The reason for this is that Mach number is a critical design factor in aerodynamics - air does very funny things when you get to high, subsonic Mach numbers (above about 0.8), everything goes haywire close to Mach 1 (speed of sound), and many things suddenly work the wrong way around above Mach 1 (for instance, above Mach 1, the flow speed in an expanding duct actually increases, which is counter-intuitive and not how things work below Mach 1, see de Laval nozzle). This is why flying at high altitude is a difficult design challenge, as unless you are specifically designing a supersonic airplane, you have to be careful not to fly at too high a Mach number - but, at altitude, the absolute (relative to the Earth's surface) speed of sound decreases, so you can't fly as fast at altitude without getting to the 'dangerous' regions around Mach 1. See compressibility and Mach number. — QuantumEleven | (talk) 07:14, 7 March 2006 (UTC)
Yes, the Mach number is the speed relative to the speed of sound. It's also true that space isn't really a vacuum, just something close to it. But aren't the particles in space so far apart (compared to their size) that no sound can propagate? --Bowlhover 04:49, 8 March 2006 (UTC)
Space isn't actually a vacuum... it's just very low density. The speed of sound up there is therefore very low (has to do with the large mean free path of a molecule) so it's easy to get to a very high Mach number without actually going very fast. moink
Thnaks - yes, I realise that airplanes can't go into space, and that space isn't a perfect vacuum, I was just doing the thought experiment of what happens to the Mach number as a useful indicator of speed as you approach a vacuum. I guess for any sort of real world case you just wouldn't use it? For great justice. 21:54, 6 March 2006 (UTC)
It is used for very high altitude flight occasionally - the re-entry speed of spacecraft such as the Space Shuttle is occasionally given in terms of Mach number (something around Mach 30, IIRC). However, Monik is right, because of the very rarified air, Mach 30 up there is a lot slower than Mach 30 at sea level (it's still ludicrously fast, though!). I would say that Mach number is used whenever there is aerodynamics involved, and therefore starts to be less meaningful at very high altitude, where aerodynamics are less and less involved in controlling a vehicle as there just isn't enough air around to make a difference! — QuantumEleven | (talk) 07:14, 7 March 2006 (UTC)

Pang tree?[edit]

Please see Pang (color). What is a pang tree? User:Zoe|(talk) 18:19, 6 March 2006 (UTC)

Hmm, good question. That article has only been edited by one person, who hasn't edited anything else.. --BluePlatypus 19:26, 6 March 2006 (UTC)
I'm not altogether convinced that there is such a thing... For great justice. 19:28, 6 March 2006 (UTC)
I don't think it exists. --User:Mac_Davis
This is a fairly typical article on a color. That is, it has no references. If Wikipedia standards were applied properly, almost all color articles would be deleted tomorrow. Notinasnaid 23:24, 6 March 2006 (UTC)
Google Image gives a result for "pang tree": a sculpture. For -pang tree- without quotes, it leads to the pangkuna tree, which as far as I can tell doesn't have flowers, but there's not much about it. It could just be a tree most people haven't heard of. Black Carrot 23:34, 6 March 2006 (UTC)

rotational equilibrium[edit]

Is "rotational equilibrium with constant angular velocity" dynamic rotational equilibrium?, analogous to the dynamic equilibrium with constant linear velocity

I think you're confusing dynamic equilibrium with mechanical equilibrium. They are substantially different. If you need more help, you'll have to clarify your question. —Keenan Pepper 18:12, 7 March 2006 (UTC)

Dripping Faucets[edit]

This has been bugging be for quite some time now. Turn on your faucet so that it produces a continuous stream of water. Then slowly nudge it closed until the stream is as thin as it can be without turning into drops. Now place your finger under the stream and move it up towards the faucet. As your finger approaches it, the stream turns into drops. But — and this is the weird part — the faucet stays dripping even after you remove your finger. You would think that it would go back to being a continuous stream, considering that the conditions are exactly the same as before and you have not adjusted the faucet. Does anyone know why this happens? --BrainInAVat 20:35, 6 March 2006 (UTC)

It's to do with surface tension on the water stream. The surface tension on the stream keeps it as a stream. When you interupt it, it colapses, causing a drip to form - the surface tension on the drip 'sucks' more water into it, causing it to fall, etc. You could coax it back into a stream if you were careful. For great justice. 20:47, 6 March 2006 (UTC)
Wow, that was fast :-). So do you mean each drop causes another drop to form? --BrainInAVat 21:01, 6 March 2006 (UTC)
I think it does because when the first drop forms, its a shorter stream, and it is easier to collapse the stream. -- User:Mac_Davis Now, 6, March
Yes, water 'wants' to form into a shape that has the lowest energy. Depending on the volume and surface tension issues that might be a stream, or it might be a drop. For great justice. 21:54, 6 March 2006 (UTC)
You've found a bistable configuration. —Keenan Pepper 23:01, 6 March 2006 (UTC)

Interesting. Thanks people. --BrainInAVat 01:32, 7 March 2006 (UTC)

There's even more; the dripping of a leaky faucet exhibits chaotic behavior under the right circumstances, including period-doubling cascades (with respect to flow rate) and boundary crises. Physicists have studied these phenomena with Ford carburetor valves, among more advanced components. Check out this link and don't forget to click on "Citations to the Article (39)"! Melchoir 06:38, 7 March 2006 (UTC)
Everyone loves the dripping faucet. :) --Optichan 14:16, 7 March 2006 (UTC)
My first two science fair projects were on that. Black Carrot 23:41, 7 March 2006 (UTC)
Yea, you gotta love a strobe light on a dripping faucet (that appears to make the water drip upwards). StuRat 04:12, 10 March 2006 (UTC)


Is it possible to estimate the weight of the earth? and does the weight of the earth change through the burning of materials and what effect will this have on the earth?

The mass of the Earth is about 6×1024 kilograms, so its weight in the gravitational field of the Sun is about 3.5×1022 newtons. Burning materials does not change the mass or weight of the Earth because the mass of the ash and smoke is equal to the mass of the burned material and oxygen. That's called conservation of mass. —Keenan Pepper 22:47, 6 March 2006 (UTC)
Burn anything : won't some gases leave the atmosphere after an unpredictable period of time ? --DLL 22:51, 6 March 2006 (UTC)
On the other hand, meteors tend to add their mass to that of the Earth (either as atmospheric debris or physical bolides). — Lomn Talk 23:28, 6 March 2006 (UTC)

There is some seapage of gas into space, but for practical purposes it's not a big deal. For great justice. 22:54, 6 March 2006 (UTC)

Seepage is the wrong word. The atmosphere is completely open to the vacuum of space, so why doesn't space suck all the air out? Answer: Gravity. To overcome gravity, anything, such as any molecule, has to exceed the escape velocity to leave the earth. At the top of te atmosphere, the lightest molecules, H2 and He, have velocites that sometimes exceed the escape velocity, and they indeed escape. That's why Helium doesn't accumulate in the atmosphere, although it is constantly being produced due to alpha decays in the earth. GangofOne 03:29, 8 March 2006 (UTC)
Yes, according to A Shite History of Nearly Everything (ISBN 1-84317-138-4 ; printed 2005), the Earth is 6.6 sextillion tons. And this makes me want to write more; here are nine other facts about planet earth:
  1. Our planet was formed from a ball of dust and hot gases about 4,5000,000,000 years ago (if you believe in the Big Bang).
  2. The Earth is not flat, nor is it round - it's an ellipsoid.
  3. Nearly one-eigth of the land on Earth is desert, while almost one-fifth is mountaneous.
  4. About one-tenth opf the Earth's surface is permanently covered with ice.
  5. The circumference of the Earth is 40,000km (25,000 miles).
  6. Oxygen is the most abundant element on the Earth's crust, waters and atmosphere (about 19.5%).
  7. The Earth travels at around 107,000 km (66,500 miles) per hour. Luckily there are no speed camers in space. Yet.
  8. This fact is the one I wrote above.
  9. It is estimated that sunlight takes eight minutes and 20 seconds to reach the Earth at 299,792km/sec (186,282 miles/sec).
Hope this helps! Kilo-Lima Vous pouvez parler 21:20, 8 March 2006 (UTC)
About you first pointyou don't have to believe in the Big Bang for that. That our solar system, and the Earth along with it, was created about 5 million years ago is pretty much accepted (I don't think anyone questions that), but the Big Bang is really just a theory to explain certain observations (most notably the expanding universe). But there are big holes in that theory, so that is indeed rather like a belief. Earth's age isn't. (For my alternative to the Big Bang theory see User:DirkvdM#Alternative to the Big Bang theory.)
About your sixth point: I assume that's volume-percentage, not weight. And one should realise that the crust is just a minute fraction of the total size of the Earth (both in weight and volume). DirkvdM 13:15, 9 March 2006 (UTC)
There are a lot of people who don't think Earth and the solar system formed 4.5 billion years ago. See young earth creationism. --Bowlhover 16:56, 9 March 2006 (UTC)
And a lot of people think the earth is flat - a lot of people believe a lot of things. Celcius 03:18, 10 March 2006 (UTC)

Weight of the Earth[edit]

I have a number of points/questions related to the previous post, about the \"weight of the Earth\". They turned out to be so long that I decided to make them a separate post. I\'d be grateful is anybody could answer them:

  1. I guess \"weight\" could mean attraction in relation to whatever gravitational field an object is in (so, like Keenan Pepper said, the attraction between the Earth and the Sun would suffice).
  2. However, in general usage \"weight\" means \"weight in relation to the Earth.\" The weight of a rock is calculated GMM/r-squared, where the first M is the mass of the rock and the second M is the mass of the Earth \'\'minus the weight of the rock\'\', because the rock is not attracted to itself. But usually we do not minus the latter value, because the difference is negligible. However, if we were to measure the Earth in relation to itself, the latter value would be zero, since the Earth is not attracted to itself, so \'\'\'\'\'the weight of the Earth relative to itself would be zero\'\'\'\'\'. Am I right?
  3. But wait, the Earth \'\'is\'\' attracted to itself, as in, there is attraction between the different layers of the Earth. Isn\'t this how a black hole is formed, when a star has a gravitational collapse caused by self-attraction? So how would one calculate self-attraction for the Earth?
  4. Googling \"weight of the Earth,\" I got [20]. It says that the Earth \"weighs in at 5.972 sextillion (5,972,000,000,000,000,000,000) metric tons,\" but this is just the \'\'mass\'\' of the Earth (6E21 metric tons = 6E24 kilograms). Isn\'t this a misuse of \"weight,\" incorrectly substituted for \"mass\"?
--JianLi 00:57, 7 March 2006 (UTC)
2. I would say this is closer to being undefined than zero. Don\'t ask why I say that though, just my intuition.
3. I would argue that there is no single value for that. The outer crust layer for example would weigh in relation to the earth, but the mantle would weigh less.
4. This is an incorrect use of the word weight. But this is a common occurrance, for example, people always say I weigh 80kg, when they meant to say I have a mass of 80kg.
- Akamad 02:17, 7 March 2006 (UTC)
2. That formula only works when the two masses do not overlap. It is meaningless when they are the same object.
3. The particles of the Earth attract each other, just like any other particles, but you\'ll have to define more clearly what you mean by \"self-attraction for the Earth\". —Keenan Pepper 03:31, 7 March 2006 (UTC)
2. Right, Keenan, that is exactly my point. That\'s why I have to subtract the mass of the rock from the mass of the earth, so that the rock and the earth (as it is now defined) don\'t overlap --JianLi 05:20, 7 March 2006 (UTC)

We can easily state the mass of the Earth because it is an absolute quantity. It is true that in general usage \"weight\" means \"weight in relation to the Earth\", but when the thing you\'re weighing is the Earth itself, that breaks down. You cannot use the Earth as its own reference point, but would need to choose a celestial body with a known gravitational effect on the Earth. And the answer would be different depending on which body you chose (eg. the Moon, the Sun, a planet, or a distant star). Dividing the Earth up into the crust and other parts is no longer talking about the Earth per se, so this is getting into a different question altogether. JackofOz 04:24, 7 March 2006 (UTC)

The fact is that outside of physics courses, the word \"weight\" very often means \"mass\". It\'s normal for people to interpret the word that way when mass is what makes sense, and when you ask for the weight of the Earth, \"mass\" is what makes sense. --Anonymous, 06:13 UTC, March 7, 2006.

I guess an easy way to answer this question is to think of one particle of matter, which can\'t have any weight because there is nothing attracting it/nothing to attract to. Add in a second particle and you have double the mass, but the weight stays the same (zero) because the weight of each particle relative to the other is the same (only in a negative direction) and they cancel out. Add a gazillion more particles and you have the earth, and it still weighs nothing.  freshgavinΓΛĿЌ  06:50, 7 March 2006 (UTC)

You might want to look at shell theorem, which states that a spherically symmetric object acts like a point mass at its centre to objects outside the sphere, and has zero total gravity at any point within the sphere. moink 18:54, 7 March 2006 (UTC)

Which means that, if want to calculate how much a hunk of rock within the Earth weighs in Earth gravity, it\'s F = GMm/r^2 - 0, where r is the distance from the center to the rock, M is the amount of Earth\'s mass that lies within that radius, m is the mass of the rock, and 0 is the net effect that all mass beyond that radius has. If the earth is a sphere, which it isn\'t quite, and if its mass is evenly distributed, which it isn\'t quite. Black Carrot 23:34, 7 March 2006 (UTC)
So is there a way to integrate the attraction of the Earth (taking into account the shell theorem, of course) on each bit of the Earth? Would the result have any significance? --JianLi 01:20, 8 March 2006 (UTC)

I guess I should better explain my second point, to explain my reasoning that the weight of the Earth would be zero. If you were to calculate the weight of a mountain using GMM/r-squared, the first M would be the Mountain as expected, but the second M would be the mass of the Earth \'\'minus the mass of the mountain\'\' since the attraction is between the mountain the the \'\'rest\'\' of the Earth. So if you were to \"weigh\" a third of the Earth, the first M would equal 1/3 the mass of the Earth, while the second M would equal the remainder, 2/3 the mass of the Earth. And if you proceed along this path, by the time that you get weighing the entire Earth, the second \"M\" in GMM/r-squared would be equal to zero, making the \"weight of the Earth\" equal to zero. --JianLi 01:36, 8 March 2006 (UTC)

I like that process better than mine. Easier to write on paper.  freshgavinΓΛĿЌ  02:05, 8 March 2006 (UTC)
I don\'t think that\'s quite right. It seems like a more in-depth answer would be more helpful than a two-body formula where, by the time you\'re done, one of the bodies doesn\'t exist. I mean, essentially what you\'re saying is that if the earth\'s all there is, there\'s nothing else to pull on it.
The main problem is that your question just doesn\'t mean anything. Now, if it\'s \"how much inward force, in pounds, is exerted on a layer of the earth by the rest of the earth,\" that has an answer. If it\'s \"what\'s the sum of all those values moving outwards from the center to the surface and including the atmosphere,\" once again, that has an answer, and that is probably the closest thing to what you mean that you\'ll find. To give you an idea what that is, it would take just a bit more than that amount of force, outward in all directions from the center, to form a small bubble in the earth\'s core. And it would have to be a sustained force, because of course everything would fall back down as soon as you stopped pushing. Black Carrot 22:27, 8 March 2006 (UTC)
I think that would be ( being density), assuming a perfect sphere with evenly distributed mass. I don't think that would be very accurate, though, since the rock at the core is a whole lot denser, and therefore a whole lot more massive, than the rock at the crust, which is again a whole lot denser than air or water. Black Carrot 23:20, 8 March 2006 (UTC)
I fixed the math symbols above, by taking out the extra slashes. Did I get it right ? StuRat 04:51, 10 March 2006 (UTC)

Vegans and meat[edit]

I've heard that after going without meat for so long, vegans (and vegetarians) can acquire a sensitivity to meat that is so great that they become nauseous after unknowingly consuming food with meat. Is there any scientific name for this acquired "distaste"? (And since it involves unknowingly consuming it, we can rule out a psychosomatic cause.) --JianLi 23:44, 6 March 2006 (UTC)

I've heard that vegetarians stop producing certain enzymes required to digest meat, so that if we were to eat it, our bodies wouldn't be able to break it down and we'd throw it up. But I don't know if it's true or not. moink 04:11, 7 March 2006 (UTC)
hmm, interesting. can anyone confirm that? --JianLi 05:34, 7 March 2006 (UTC)
As a vegetarian of 30 years, I think the above suggestions are unlikely. I used to fancy seafood for a while after I gave up meat, but now I no longer like it. I don't know of a word for this disacquisition of the taste for meat; will that one do? No doubt the many links from the vegetarianism article would provide more info. Some vegetarians do need to eat a small amount of meat for medical reasons, but I don't know the details. --Shantavira 09:38, 7 March 2006 (UTC)
I've been vegan for 12 years, and I tried meat a couple of times during that period. I can say that after a while, it does seem really thick, chewy and heavy, and after eating it you really do feel lethargic and slow. It seems to be that after a while on veganism, your mind gets lighter and you feel more energetic in general, mentally and physically.
I've been vegetarian all my life, and any dead meat within a radius of 100m makes me nauseate. deeptrivia (talk) 01:29, 12 March 2006 (UTC)

Abilify VS Risperdal[edit]

I'm bipolar. I'm being treated for bipolar mania.Right now I'm switching over from Risperdal to Abilify. Now, I'm pretty well versed on these two medications. I know that I needed to be on Risperdal first before they switched me over to Ablify because Abilify would have probably made me worse if I started it first. Also, Risperdal acts fast and pretty much numbs your mind by blocking all the dopamine. I noticed that, while on Risperdal, my creativity was not what it used to be. I could barely come up with new ideas for stories, and the ones I did come up with aren't great, and my drawings now suck. They, really, really suck. Before my drawings were awesome. And it wasn't because I was delusional, everyone told me they were. My question is, once I'm on Abilify, will my creativity and drawing skills return? Or is it gone forever now?

If requesting medical advice, please consider asking a doctor instead. --Canley 02:12, 7 March 2006 (UTC)
Doesn't really seem like they're requesting medical advice, but rather information on the lasting side-effects of the drugs they're taking. First of all, check out the articles on Aripiprazole (Abilify) and Risperidone (Risperdal) if you haven't already. Although the articles don't seem to be that comprehensive, they do give the impression that Risperdal has a lot more side-effects than Abilify, though there is no mention of a high-risk of long-term effects.
I would like to assume that a return of your creativity would merely be a return of your motivation and will, something that may be being affected by your consumption of Risperdal. It's not very productive to think of Abilify as the drug that gave you your skills, when I'm sure it had really nothing to do with Abilify in the first place. I don't see any reason why some change in your lifestyle (or medication) could bring back your prior creativity, unless Risperdal is known to cause long-term (permanent) mental deficiencies.  freshgavinΓΛĿЌ  06:46, 7 March 2006 (UTC)
Risperdal blocks (antagonizes) all of the dopamine, like you said. On the other hand, aripiprazole is a partial agonist of the dopamine receptor. A partial agonist will block dopamine where there is too much of it, but it will also act as dopamine where there is too little of it.
In support of your experience with blocking dopamine, PMID 16254989 suggests that creative drive & output may be due to dopamine, but not necessarily creative skill. But then, it says "drive correlates better with successful creative output than skill does."
Anyways, back to your concern about whether your creative skills will return after switching from Risperdal to Abilify: I haven't been able to find studies done on the long-term cognitive effects. As a pharmacy student, I'd be interested in hearing your experience switching between the two drugs. Feel free to leave me a message at my talk page. --Uthbrian (talk) 12:50, 7 March 2006 (UTC)
Being marginal bipolar, and from my experience, great creative bouts are a symptom of the disease. The other side being descent into hell. Many famous bipolars were unmedicated or on drugs and booze. They had short lives. If you are stable, and feel good, you have to work harder for creativity. Try lucid dreams, etc. --Zeizmic 14:22, 7 March 2006 (UTC)
Agreed. The meds may, unfortunately, diminish these positive side effects as well as the main condition. StuRat 10:52, 10 March 2006 (UTC)

Goethe's Theory of Colours[edit]

What exactly is the verdict on Goethe's Theory of Colours? The article on Goethe says it is his "weakest work," while the article on the Theory of Colours itself is considerably more sympathetic. --JianLi 01:36, 7 March 2006 (UTC)

I think it's safest to defer to the most specialized article on a given topic; i.e., Johann Wolfgang von Goethe should be changed to reflect Theory of Colours. In fact, Johann Wolfgang von Goethe cites the description of a book that is considerably more sympathetic than the article suggests. You may want to raise this issue on the talk pages... Melchoir 06:27, 7 March 2006 (UTC)
Thanks, I just did. --JianLi 01:15, 8 March 2006 (UTC)

March 7[edit]

annoying keystroke shortcut in Outlook[edit]

I'm a poor typist. Too often in Outlook, while composing a message, my left fingers slip on the shift & ctrl keys while hitting another key with my right hand, and the message is immediately sent automatically. What keys am I hitting? If I knew, maybe I could avoid the problem. BTW, the Fn key is also in that area on my laptop. I believe that CRTL is the key (no pun intended) to the problem, the gateway to many unintended destinations. But in combination with what? --Halcatalyst 03:29, 7 March 2006 (UTC)

Are you sure the message is only sent, and nothing else is done? According to, the keyboard shortcut for sending emails is Alt+S. One way to fix the problem is to leave out the "To:" field until you're ready to send. --Bowlhover 05:17, 7 March 2006 (UTC)
I don't use Microsoft products, but isn't Ctrl-W the MS shortcut for "Close everything right away without giving me any sort of warning of any kind." I get a lot of people who apparently hit it while in Word, Excel, IE, and Outlook and complain that the window just closes. For me, it is Nano's "where is" shortcut. --Kainaw (talk) 13:29, 7 March 2006 (UTC)
For mine it's "ask if you want to save, then close". It could be irritating if hit accidentally but it shouldn't be disastrous except for users who don't believe in reading the boxes they click on. I realize that's a large segment of the population, but I can't find much sympathy. — Lomn Talk 14:32, 7 March 2006 (UTC)
Ctrl+Enter in Outlook means "instantly send this message that I haven't finished typing". Bowlhover's suggestion (leaving the To: field empty until the last minute) is the only defence I know of. --Heron 20:49, 7 March 2006 (UTC)
I know of another defence, at least on Thunderbird: tell it to encrypt emails by default, and it will complain when trying to send if you don't have the public key for the person you are sending to. At the last moment, turn off encryption for that particular message. I don't know if it works on Outlook, since I never used it, but I do know it has encryption support. --cesarb 21:17, 7 March 2006 (UTC)
I found a registry hack that disables this shortcut. See Outlook Daily Tips, Tip 333: Prevent Accidental Sending. It worked for me on Outlook 2002/XP. --Heron 11:16, 25 May 2006 (UTC)

Nazi human experimentation[edit]

Did any of those awful non-consensual experiments make any significant or lasting contributions to medical knowledge? moink 04:13, 7 March 2006 (UTC)

This question is addressed at Talk:Nazi human experimentation. Short answer, no. Melchoir 06:19, 7 March 2006 (UTC)
The U.S. made a secret deal with Shiro Ishii, Unit 731, and Unit Ei 1644 leaders that germ warfare data based on human experimentation would be offered in exchange for immunity from war-crimes prosecution in 1948. The US also made secret deals with Nazis. How many have not been since unclassified is unknown. WAS 4.250 16:02, 7 March 2006 (UTC)
Untrue, I recall reading in Hans Rudel's book, Stuka Pilot, there was a discovery about how pilots could survive in freezing water. This was discovered using human experimentation. The preceding unsigned comment was added by (talk • contribs) 15:00, 7 March 2006.
Ah. That deserves checking on, if anyone has access to the book. I'll copy this discussion to the talk page. Melchoir 02:14, 8 March 2006 (UTC)
Does our hypothermia article mention it ? StuRat 02:17, 10 March 2006 (UTC)
I heard this mentioned several times as the one single piece of useful knowledge that came out of the experiments. Celcius 03:23, 10 March 2006 (UTC)

Development of Artificial Chemical Expert system[edit]

Sirs, I am doing research on data mining. My application area is the development of artificial expert based systems based on quantum mechanics. If anybody is doing research in that area, please provide me with information concerning the latest developments in this area. Thank you. I am an Assistant Professor in Computer Science in ISTAR, Anand, India.

Interesting topic, but this is the wrong place to look for such information. Try something like a scientific journal instead. —Keenan Pepper 18:07, 7 March 2006 (UTC)
I think you meant scientific journal. Black Carrot 23:37, 7 March 2006 (UTC)

Lorenzo's oil[edit]

I was searching the internet to purchase Lorenzo's oil and your website came up, although I couldn't find anywhere to purchase it. Any suggestions? Thanks (Email removed to avoid @spam) 06:01, 7 March 2006 (UTC)

I'll say it again, it's not my website, and there is NO cabal. I found this on the first link that google gave me:
In the U.S., Lorenzo’s Oil is currently only available to patients taking part in a clinical trial under the direction of Dr. Hugo Moser of the Kennedy Krieger Institute. He can be reached at (800) 873-3377. We are working with Dr. Moser and the FDA to obtain approval of Lorenzo's Oil as a drug, so that it can be widely available. The oil is jointly manufactured by Croda International of Britain and SHS International (Scientific Hospital Supply). SHS is also the worldwide distributor of the oil; for a list of international offices, please refer to their website. SHS North America can be reached at (800) 365-7354.
In the U.S., Lorenzo's Oil can be obtained through prescription only by Kennedy Krieger authorized physicians. A 500ml bottle costs $56.00. Some insurance companies will provide coverage for the oil, but others do not because it is still considered an experimental drug by the FDA. Parties residing outside the U.S. should contact Scientific Hospital Supply directly at + 1 (301) 795-2300, to obtain pricing and shipping information.
 freshgavinΓΛĿЌ  06:33, 7 March 2006 (UTC)
Silly question, but we are sure that isn't just looking for a DVD of the movie, right? Grutness...wha? 12:59, 7 March 2006 (UTC)
Actually, I would think that more likely. I'm not advocating any single seller, but typing "Lorenzo's Oil" into and eBay seem to get enough results for the 1993 VHS release and the 2004 DVD release. EWS23 | (Leave me a message!) 18:04, 7 March 2006 (UTC)
How silly of me. But still I doubt that. This is the science page and there are quite a few people asking where to buy difficult to find industrial and medical substances here.  freshgavinΓΛĿЌ  02:09, 8 March 2006 (UTC)

External fertilization[edit]

Is this possible in humans? If yes how and if no why?--Suraj vas

In vitro fertilisation?  freshgavinΓΛĿЌ  06:35, 7 March 2006 (UTC)
Its not possible, sperm has to get to the egg, probably only possible through the vagina. -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 04:28, 8 March 2006 (UTC)
I take it you haven't heard of in vitro fertilisation either then.  freshgavinΓΛĿЌ  04:34, 8 March 2006 (UTC)
Ask Louise Brown - she may have an opinion on the matter. Grutness...wha? 06:51, 8 March 2006 (UTC)

Portable document readers[edit]

I am curious: are there devices on the market whose function is primarily to act as a portable document reader? I was envisaging something about A5 sized, which could store and read documents, perhaps annotate them with a stylus. I know PDAs currently perform these functions, but I was thinking of a more purpose-built device, essentially a form of electronic paper. I know these things were talked about over ten years ago, but I don't think I have really seen them available yet. Or what have I missed? Does anyone know more about such things? — QuantumEleven | (talk) 13:30, 7 March 2006 (UTC)

Sony Reader is one. It uses e-paper, a few megabytes of storage, and can handle special books and PDFs. -- Ec5618 13:34, 7 March 2006 (UTC)
Thanks, Ec - yes, I had seen the Sony reader, it just surprises me that someone has only come up with an item like this recently, or have there been other examples in the past (but which failed commercially, for whatever reason?) — QuantumEleven | (talk) 14:19, 7 March 2006 (UTC)
Weight / battery life / ease of use / reasonable cost have been a difficult combo to achieve. I don't think it's so much been a case of past failure as past lack of a feasible design. — Lomn Talk 14:35, 7 March 2006 (UTC)
  • I have one called Paper. Features: Inexpensive. Requires no batteries. Lightweight. Durable. Disposable. Environmentally-friendly. Handles all text formats. Easier to read than LCD displays. (does require an external light source). Supports annotation and underlining. Etc. I'm serious here.. there aren't many benefits that justify spending $300 on a e-book reader (or even much less) when you can get a used paperback for $0.50. Looking at Amazon, it appears a new paperback is cheaper than the e-book. And that's if it's available as an e-book. I don't have to worry about dropping a paperback either. It's the classical case of a solution in search of a problem. --BluePlatypus 15:36, 7 March 2006 (UTC)
It depends a lot on what you what to read, and where. I do scientific research for a living. I'd love to have a lightweight, portable device that I could store, read, and annotate papers in. Something light, easy on batteries, maybe solid state storage, durable, touch screen for would be sweet. I can imagine that someone travelling to a non-English-speaking country might want someplace to keep his novels—putting a month of reading in a backpack would be far too heavy. University students would be thrilled not to have to cart textbooks around.
Though the solution doesn't solve any of your problems, it's a bit hasty to suggest that it's useless. Presumably since the questioner is asking, he has a purpose in mind. TenOfAllTrades(talk) 16:19, 7 March 2006 (UTC)
The question was "Why aren't there any e-book readers?" or "Why aren't e-book readers more common?", and my answer was that they're simply not useful for most people and purposes. Especially compared to the hype they were getting 10 years ago. I didn't say they were useless. --BluePlatypus 16:58, 7 March 2006 (UTC)
When I have to wait for something, and I'm totally bored, I read classic novels on my Blackberry. It's good enough for reading and it's convenient. Proper e-books will never sell if the publishers want to price it the same as paper books. This is the same thing with the record collusions. --Zeizmic 18:13, 7 March 2006 (UTC)

How to categorize inventions?[edit]

There are branches of industries such as light/heavy industry, chemical, biological, information, medical, aerospace industries. How do I categorize patents using their U.S. class numbers or internaptional class numbers (IPC)? In my opinion, the U.S. class system is quite unstructuralized. Its class codes are not grouped by their technological features. Here are some U.S. class codes:

Are there tools that enanles us to quickly categorize U.S. or other countries' patents? -- Toytoy 16:02, 7 March 2006 (UTC)

Banned Gases[edit]

Hi there, can anyone remember the banned gases becuase it deterioated the Ozone layer. I was think carbon dioxide, but that seems too extreme as we breathe it out. Wasn't it that one that was originally put in fridges? Thanks. Kilo-Lima Vous pouvez parler 17:49, 7 March 2006 (UTC)

It was CFC. --cesarb 17:54, 7 March 2006 (UTC)
You're probably thinking of Freon, which is in the article on haloalkanes. —Keenan Pepper 18:00, 7 March 2006 (UTC)
That'd suck if they banned carbon dioxide.  freshgavinΓΛĿЌ  02:12, 8 March 2006 (UTC)

While carbon dioxide does not damage the ozone layer, it is a greenhouse gas, and, as such, excess levels of may contribute to global warming. Thus, there have been attempts, such as the Kyoto Protocol, at limiting releases. Ironically, ozone itself is also a greenhouse gas. StuRat 01:00, 10 March 2006 (UTC)

Health question[edit]

I'm trying to find out and a rash on my sons face, stomach,arms and legs, and he looks a little pale in his face.I want to know if maybe allergic or something? Moved by me from the Newcomers help page. --Chachu207 18:14, 7 March 2006 (UTC)

If benadryl clears up the problem, then it is probably an allergy. --Kainaw (talk) 18:43, 7 March 2006 (UTC)
Or a self-limited problem. alteripse 01:04, 8 March 2006 (UTC)
This sounds like a question that should be answered with: You should probably go to a family doctor and have your son checked out, especially if he is very young.  freshgavinΓΛĿЌ  02:15, 8 March 2006 (UTC)
Well, do that then, if you are so inclined. I, however, prefer not to bother people with the blatantly obvious. (This, of course, should itself have been a blatantly obvious remark, but given the amount of people who blurt out these disclaimers, apparently it is not.) DirkvdM 13:24, 9 March 2006 (UTC)
I don't know, I didn't think that giving a child benadryl was an obvious solution. I've actually never seen benadryl before, and I don't know (yet) how powerful or safe it is, though I'll surely check it up now. I also said that because it seemed like a pretty serious rash (spreading over the face, stomach, arms, and legs) and I thought it might be an indication of something else.  freshgavinΓΛĿЌ  07:32, 10 March 2006 (UTC)
A rash could be a zillion things - of course it's a case for a doctor! If he had a headache, fine, aspirin, but a rash over the kids entire body isn't something to just diagnose yourself or over an internet "forum"!! Do people in America have to pay to see a GP? --Username132 17:12, 12 March 2006 (UTC)

drug screen[edit]

Two weeks ago I took a random drug screen at work, no problems with that but I was wondering what the intials of the drugs that they tested for were and what they meant. The letters were,"THC,COC,PCP,OPI,AMP". Any idea?

I'm at a loss on the first, but I'd go with cocaine, PCP, opiates like heroin, and amphetamines. — Lomn Talk 18:29, 7 March 2006 (UTC)
Upon searching "THC drug" here at WP, it's tetrahydrocannabinol, the active chemical in marijuana. — Lomn Talk 18:32, 7 March 2006 (UTC)
I believe one tests positive on such tests for THC for years after the last usage, which makes the tests rather useless, I suppose. Depending on what one wants to know of course, but who would want to know you once had a joint as a kid? DirkvdM 13:27, 9 March 2006 (UTC)
THC (marijuana), COCaine, PCP, OPIates (heroin), AMPhetamines (ecstacy).

You were tested for the NIDA Five. NIDA is the U.S. National Institute on Drug Abuse. The five drugs tested are marijuana, cocaine, PCP, or phencyclidine (angel dust, Love Boat, "embalming fluid"), opiates (heroin, morphine, and other painkillers derived from Opium), and amphetamine. Methyldioxymethamphetamine (MDMA) or Extasy, is covered under the amphetamine test. There's also a more comprehensive panel of ten drugs including the former drugs plus barbiturates, benzodiazepines, propoxyphene (Darvocet) and methadone which are similar chemically, lysergic acid diethylamide (LSD), and methaqualone (Quaalude).

Marijuana is not detectable in blood or urine after 7 to 37 days. Over-the-counter decongestants can cause a positive result for amphetamines, and poppy seeds can cause a false positive for opiates. Brian G. Crawford 19:47, 14 March 2006 (UTC)

Impacted wisdom tooth[edit]

Here's one for the dentists out there: If you've got a wisdom tooth impacted against your rearmost molar, why remove the wisdom tooth? Wouldn't it be possible (and perhaps easier) to remove the molar and let the wisdom tooth replace it? Seems a bit of a waste to throw out a brand new tooth just because it doesn't fit. --BluePlatypus 20:04, 7 March 2006 (UTC)

i'm not a denstist, but common sense says that you should remove the tooth that is causing trouble and leave the tooth that works. why would you want a crooked, troublesome tooth to be left in there? --Chris 00:28, 8 March 2006 (UTC)

Did you see the recent discussion of this very topic on the Wisdom teeth talk page? At least one of the participants seems to be a dental student. --LarryMac 00:50, 8 March 2006 (UTC)

A wisdom tooth should optimally be extracted when doing so confers some benefit to the patient (I won't discount the possibility that it is sometimes done for the benefit of the dentist, but that is the stuff of another discussion). In other words, the extraction of a wisdom tooth should address some problem without causing a worse problem. And there are many situations where the presentation of the wisdom tooth or the health profile of the patient makes an extraction too risky to justify. At the same time, an impacted wisdom tooth will often happily co-exist with the other teeth without any harm to its owner. As is the case in all diagnosis and treatment planning, a dentist must assess the current and future risk posed by the impacted tooth, and compare it to the risk of intervention, which usually takes the form of extraction of the wisdom tooth. In the situation posed by the original poster, the removal of the second molar may indeed be justified if it is in poor repair and there is reasonable expectation, based on the position and orientation of the wisdom tooth, that it will erupt into the space left by the extraction. However, wisdom teeth only occasionally meet the criteria for this expectation. Also, wisdom teeth often have aberrant shapes that may detract from their functionality. Each situation must be considered on its own individual merits.--Mark Bornfeld DDS 18:01, 8 March 2006 (UTC)
Interesting! Thanks for the reply. --BluePlatypus 19:47, 8 March 2006 (UTC)

Survey Question (Curiosity)[edit]

What kind of thing have you bought on eBay recently? Black Carrot 23:22, 7 March 2006 (UTC)

Records, a mouse, a New Folder icon (just kidding).  freshgavinΓΛĿЌ  02:19, 8 March 2006 (UTC)
I\'ve only bought ferrofluid, neodynium magnets, and planning to buy 205x4 foot sheet of mylar. —Preceding unsigned comment added by Mac Davis (talkcontribs)
A New England Patriots shirt, camo trousers, and a pair of Doc Martens. Not all at once, obviously. Sum0 16:44, 8 March 2006 (UTC)
Books, and some Frankoma pottery. User:Zoe|(talk) 16:45, 8 March 2006 (UTC)
Nothing. Does that count? DirkvdM 13:30, 9 March 2006 (UTC)
Not really. I\'m trying to learn the market. You may have heard of the misspelling thing on eBay? Well, I\'m trying to see if I can make any money off that, but it requires knowing what will sell in the first place. Black Carrot 20:31, 9 March 2006 (UTC)
I have a total hatred for "spoof" sites (that use misspellings of common web URLs) which will prevent me from ever buying anything from them. From eBay I've bought a board game (King Oil) and a book ("North By Northwest" - The Alfred Hitchcock movie). StuRat 00:53, 10 March 2006 (UTC)

World's largest desert...[edit]

The current revisions of Antarctica and Sahara both state that each is the world's largest desert. Which is correct? --Robert Harrisontalk contrib 23:56, 7 March 2006 (UTC)

Antarctica appears to be bigger than the Sahara. [21] The Sahara is only the biggest (at least in its category) if you separate it like so: [22]. And another source with a nice map: [23]. EWS23 | (Leave me a message!) 00:34, 8 March 2006 (UTC)
Answer - it depends. If you define a desert as having less than a certain amount of precipitation per year, antarctica (which actually gets very little rain or snow) qualifies as a desert and thus is the largest desert in the world. If you define desert in terms of present ambient water, Antarctica (which contains a lot of permanently frozen water) does not qualify and thus the sahara is the largest. Raul654 03:15, 8 March 2006 (UTC)
Yes, it depends on what answer you want. For the largest dry desert, it is Antarctica, for the largest hot desert, it is the Sahara.
You appear to be rather proud you have an answer on that, that you advertise it so boldly. :) DirkvdM 13:32, 9 March 2006 (UTC)

Kind of similar, the article for Easter Island claims it's the most isolated inhabited island, while some reliable sources (namely Bill Bryson) give the honour to Tristan da Cunha. I've left a comment on the Easter Island page but there's been no response yet.  freshgavinΓΛĿЌ  02:22, 8 March 2006 (UTC)

Hm. That honour (?) often goes to Pitcairn Island. As to deserts, it's a little known fact that the Sahara contains so much sand that - if it was spread out - it could cover all of North Africa. Grutness...wha? 06:57, 8 March 2006 (UTC)
  • Yes, Antarctica is definitely a bigger desert. The problem is that a lot of people don't define desert correctly. Hopefully, desert states correctly a desert is an extreme environment (not just a hot and/or dry one), but adjusting Sahara to say "hot desert" and Antarctica to say something else would fix this inaccuracy. - Mgm|(talk) 09:39, 8 March 2006 (UTC)

Scientific Misconduct[edit]

Earlier this year, there were news stories Boston Globe NYTimes about how the editors of scientific journals, most notably The Journal of Cell Biology, have had to become more vigilant in response to photo manipulation by researchers. The editor of that journal is quoted, "In 1 percent of the cases we find authors have engaged in fraud." Who exactly are the kinds of scientists who engage in this? I'm not familiar at all with how scientific research is conducted, so I would like to know: Is there be some kind of mechanism for penalizing these scientists, similar to how lawyers are disbarred or doctors lose their license? It seems that these scientists get off scot-free. In fact, according to the Boston Globe Article, some just re-submit their fraudulent papers in other magazines and get published. --JianLi 01:03, 8 March 2006 (UTC)

See Scientific misconduct. -- Toytoy 08:17, 8 March 2006 (UTC)
In the US, the method mentioned for penalizing lawyers by disbarrment is mostly theoretical. An attorney can violate law (eg, in knowingly misrepresenting the identity and criminal status of a witness in a criminal trial) and suffer no penalty whatsoever. Not from employer (local district attorny's office), not from the courts, not from any agency charged to police crime -- perjury and subornation of justice would seem to be crimes to which attention ought to be paid by police, ... Even when the conduct is admitted under oath in another coart and in an affidavit given under penalty of perjury. The police are not interested, the FBI is not, and the courts ruled that no further filings would be accepted in matters relateing to the trial and alleged perjury during it.
The local Bar Association took nearly a year to even appoint an investigating attorney, he took several years to 'gather' evidence, and in the end the Bar Association Disciplinary Committee decided there was nothing to discipline. Actually happened in the 80s in King County Washington, believe it or not. Justice is not a word I'd apply with a straight face to such a system. An attempt at it perhaps. The theory's good, though. ww 12:15, 8 March 2006 (UTC)
Yes, there usually is one or even two ways of policing research fraud. First is that most (reputable) universities will appoint, if an accusation of fraud occurs, a review board to scrutinize in detail the research in question. If it's found to be fraudulent the researcher can face suspension or termination from their position. And there will be notices of this in the journals who published the papers. Secondly, the people issuing grants almost always have independent reviewers and auditors of the research conducted for their grant money (They don't just give the money away without checking that you're doing what you said!). For serious research fraud, it almost certainly means your career as a scientist is over, because you'll have little hope of getting a new job, or getting grants.
As for what kinds of scientists get involved in it.. I think it depends on the fraud. Ideally, a scientist is supposed to have an open mind, and be prepared to drop any idea as soon as there's convincing evidence for the opposite. In practice, this can be harder to do. How do you not get emotional about something you've worked hard on for years? Also, there's an entire spectrum of dishonest behaviour, and it's not always clear when you're in the wrong. Some of the main things reviewers encounter are whether you've investigated alternative explanations enough, and whether your conclusions are supported by the actual results. It's pretty much accepted that people will often draw conclusions as large as can possibly be supported. Then you've got leaving out things which may cast doubt on your results. It could be something insignificant, but it could also be something which you're fooled yourself into believing is insignificant. At the far end, you've got folks who systematically fabricate results without even doing the experiments. I guess they're motivated by careers. I wouldn't really know, though. --BluePlatypus 19:19, 8 March 2006 (UTC)

March 8[edit]

Composite Spacecraft[edit]

I was wondering how much a cubed foot of spacecraft worthy composite material would wiegh?

I would have to say it would depend on the specific composite material. Have anything specific in mind? — TheKMantalk 02:18, 8 March 2006 (UTC)

Would about kevlar?

The Sea as the Largest Desert[edit]

I think the sea is the largest desert on earth if desert only means a place unhabitable to life.

Let's say if I capture a salt water fish from its natural habitat, I think I can easily find a place in the high seas of similar temperature but without any food. The fish will starve to death before seeing any edible thing. Not even a tuna or a mackrel.

Am I wrong? -- Toytoy 02:13, 8 March 2006 (UTC)

If you capture an American from its natural habitat and displace it to someplace faraway (let's say, Northern China) there's a good chance it'd die of starvation before seeing anything considered "edible" to an American.  freshgavinΓΛĿЌ  02:26, 8 March 2006 (UTC)
According to Chambers

desert: noun; an arid area of land where rainfall is less than potential evaporation, vegetation is scarce or non-existent, and which is characterized by extremely high or low temperatures. Also as adj.

And I agree.
Slumgum 02:45, 8 March 2006 (UTC)
And Wikipedia's desert. As for habitability, the sea is absolutely filthy with life, historically and presently. Melchoir 02:47, 8 March 2006 (UTC)

As to microscopic life, I think the ocean surface (plenty of sunshine, water, CO2, ...) can support planktons. However, I have heard a theory stating that most sea surface lacks iron so lives cannot grow. You need wind over land to carry dust (rich in Fe2O3) to the sea so lives can grow. -- Toytoy 02:57, 8 March 2006 (UTC)

Basically, in many ways the upper regions of deep seas are very similar to a desert, but because it's not land, it's not a real desert. If you were doing a report on it you could coin the term "sea desert".  freshgavinΓΛĿЌ  04:28, 8 March 2006 (UTC)

Is natural selection inherently "intelligent?"[edit]

There's been a lot of nonsense recently regarding "Intelligent Design," so to start off, just to set the record straight, I am not advocating any theological explanations.

Here is what I am saying: Scientifically speaking, humans are merely very complex machines, made of the same types of elements as anything else. However, their organization leads to extraordinary emergent properties such as intelligence. So if humans, who are merely machines, can be intelligent, can't the process of natural selection itself, by some definitions of "intelligent," be considered that?

Natural selection in effect "distinguishes" between good and bad traits, and then allows the good ones to continue.Take trees for example. "Within any one species, the taller the tree, the relatively larger the buttresses. It is widely accepted that the shape and size of these buttresses are close to the economic optimum for keeping the tree errect, although an engineer would require quite sophisticated mathematics to demonstrate this." (Dawkins, Selfish Gene) So, in effect, even though it does not do any mathematical calculations, natural selection is solving an optimization problem.

The difference between natural selection and the engineer is that the engineer uses mathematical calculations, while natural selection relies exclusively on trial-and-error (not to mention the considerable difference in time taken to solve the problem).

So, just as the human body is a complex piece of machinery whose emergent properties make it intelligent, why can't the biosphere, which is the complex machinery engaged in natural selection, have emergent properties which give it "intelligence?" --JianLi 02:17, 8 March 2006 (UTC)

I think you first gotta define what intelligence is. What do you consider to be intelligence here? One could argue it's about conciousness. You think the biosphere is self-aware? ☢ Ҡiff 02:23, 8 March 2006 (UTC)
If intelligence is the ability to come to conclusions without resorting to trial-and-error, then I don't see why this wouldn't be a significant benefit in terms of evolutionary gain. While it is often said that intelligence is not expected from evolution, it is certainly probably because of the possible benifits towards survival that it allows. If an ancient ancestor of a tree (a pre-tree organism) had been able to estimate an efficient size-ratio for a tree through the use of basic mathematics, they would have saved a lot of evolutionary time that could be spent evolving on other benificial things (like walking trees, talking trees, cocktails manufactured for tree-like sensibilities). POV: I don't believe evolution constitutes intelligent design because it doesn't have this ability to make a logical choice without significant stimulus. By some definitions of intelligence, though, it could be interpreted that way. You'd be pushing it though.  freshgavinΓΛĿЌ  02:37, 8 March 2006 (UTC)
Regarding the definition of intelligence: I agree that the biosphere doesn't fulfill the requirement of self-awareness or consciousness, but why should that be a prerequisite of intelligence? Consciousness is "the most profound mystery facing modern biology" (also Dawkins). If we do not even understand it fully, I think this allows us some latitude in defining intelligence. I think it's unfair (as in anthropocentric) to have such a narrow definition of intelligence as the one commonly accepted, with the restrictions imposed on it by both Kieff (conciousness) and freshgavin (a non-trial-and-error thought process). It seems as if we define intelligence for the express purpose of excluding all non-human entities from having it! --JianLi 02:40, 8 March 2006 (UTC)
If you use the definition "The capacity to acquire and apply knowledge" and you fudge a bit by considering encoded information to be "knowledge", then you could say that a biological system exhibits intelligence through the use of DNA and natural selection. If, however, you use the definition "The faculty of thought and reason", I don't think it would apply. Even in the first case, though, it's a bit of a stretch, semantically. Kaldari 02:53, 8 March 2006 (UTC)
I didn't mean to imply that a "non-trial-and-error thought process" equals intelligence, but merely that it's probably a subset of a few processes that when combined form a complete definition of intelligence. I agree that stating intelligence is conciousness or self-awareness is very presumptuous given our understanding, and it's inherent difficulty to justify, and I think it's more useful to define intelligence as a combination of ... abilities? which can each be (relatively) easily defined. You could liken it to Wikipedia, which is much easier to define accurately in WP:NOT than in Wikipedia:What Wikipedia is.  freshgavinΓΛĿЌ  04:23, 8 March 2006 (UTC)
I am not quite certain that humans have a non-trial-and-error though process. Certainly, we do not manifest every erroneous creation. But it is quite possible that we making leaps of imagination, we are simulating trial and error in our heads, and combining it with a processing engine that processes the consequences of each assumption - something really fairly identical to natural selection. -User:Fangz (not logged in)

One of the significant ways in which evolution is not intelligent is that while it's very good at blindly finding its way to a local optimum or maximum, it's very bad at stepping back, getting the "big picture", and trying a completely different approach that would let it reach some other, and much higher, optimum or maximum. (Although on the other hand, us supposedly intelligent humans aren't always so hot at doing this, either.) —Steve Summit (talk) 05:51, 8 March 2006 (UTC)

  • Very true, and a point raised too seldom in these discussions. There's an huge amount of stuff which simply isn't 'intelligent' at all. For instance, vestigial traits like wisdom teeth and appendixes (appendices?). Another point not often raised is how evolution isn't just macroscopic traits. It's something which is visible on every single level of structure, down to the molecular level. So while we don't have very many vestigial organs, we've got plenty of vestigial genes that are never expressed. --BluePlatypus 13:03, 8 March 2006 (UTC)

The universe is a computer running an Evolutionary computation program. If humans running this program call it intelligent, why not call nature running it intelligent? WAS 4.250 07:10, 8 March 2006 (UTC)

You've asked "why not" without first considering "why".  freshgavinΓΛĿЌ  07:27, 8 March 2006 (UTC)
See Gaia theory (science). User:Zoe|(talk) 16:48, 8 March 2006 (UTC)
BluePlatypus, I don't think vestigial organs or genes immediately disqualify the process that created it from being intelligent. Intelligent animals do many irrational things (for example, things which are done more out of habit than because of utility, and which may actually detract from utility). Yet, in the sense that I am talking about, people who are highly irrational are still "intelligent beings." Of course, you may call them "unintelligent" or "stupid" in the sense of "what a stupid/unintelligent person!", but of course that's a different usage of "intelligence." JianLi 23:26, 8 March 2006 (UTC)
'Intelligent' is a subjective term, and it's pretty useless to discuss what constitutes an 'intelligent' process or not. Do you want a semantic discussion or a biological one? My point is/was that it obviously costs energy to produce and maintain those vestigal traits and since they provide no benefit to the organism, they're a burden. That doesn't mean they're 'mistakes'. Vestigal traits are an unavoidable consequence of how evolution works. - It's an illustration of Steve's point, that evolution does not work towards a 'global' optimum, but towards the best it can do "working with what it has". --BluePlatypus 12:37, 9 March 2006 (UTC)
I feel I should add that even though the question won't be resolved here, it's a really beautiful idea, JianLi, and lots of fun to think about. Thanks for bringing it up.Adambrowne666 02:54, 14 March 2006 (UTC)
thanks :) JianLi 03:47, 14 March 2006 (UTC)

Big Bang[edit]

If the big bang theory states that the universe began in an enormous explosion, and a law of science states that "you can't get something from nothing", then how could such an explosion occur?

The question assumes facts that are not in evidence (and which are, frankly, false). All the matter/energy present in our current universe was, to the bset of our knowledge, present at the moment of the big bang some 13 billion years ago. So it is not a case of "something from nothing", it's a case of something from itself. Raul654 03:13, 8 March 2006 (UTC)

Antimatter? --JianLi 03:07, 8 March 2006 (UTC)

It is quite possible to create "something from nothing" - ie, ex nihilo, viz. quantum field fluctuations and such. Of course, this in itself raises a lot of peculiar issues. As for the original question, I think it is too general for it to be answered with any precision. I would like to see someday, someone publish a paper linking evolution and nonextensivity. Now that would be most wonderful. --HappyCamper 04:47, 8 March 2006 (UTC)
While it is quite possible to "create something from nothing," due to quantum effects, a common misconception of what the big bang theory presents is that all matter today came out of one point in time in a huge explosion. This is incorrect. The big bang theory presents that at some point billions of years ago, spacetime suddenly began expanding, greatening the distance between things, but without moving them. The big bang theory breaks no laws of thermodynamics.
A recent Gallop poll showed roughly 50% of Americans believe in creationism over evolution. People don’t generally reject evolution because of little or no evidence in support of it, they reject it because of their religious convictions, and because it’s not obviously intuitive, there is an illusion of design which people find hard to comprehend, so why bother with scientific evidence showing evolution to be wrong when you can simply refuse to believe in it out of a rigid mindset which rejects the possibility of accepting design without a creator? Evolution's illusion of design misleads even very smart, educated people. Lots of engineers, for example, will quote you the eye as something that is "obviously designed". Werner von Braun, father of both Hitler's and Kennedy's rocket programs, was of this opinion and was not shy about saying so. -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 04:54, 8 March 2006 (UTC)
Since the nazis believed they were a "master race" of eveolved supermen, wouldn't that actually make them histories strongest supporters of darwin?--Somebodye6436346 05:15, 8 March 2006 (UTC)
Now that this topic has been Godwinned, can we pretend it's gone? Melchoir 05:23, 8 March 2006 (UTC)
I think so, but read my answer first. -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 06:43, 8 March 2006 (UTC)
Re the Nazi's, I think that would merely classify them as people who have incorrectly applied Darwin's theory. Evolution has no "goal" (but if it did, I guess that would prove my argument ;-) ), so the supposed "Master Race" is just an accident of evolution. In addition, humans aren't the epitome of evolution anyway. Just the fact that both humans and cockroaches exist today puts us on about equal footing, I think. And if there were a nuclear holocaust, cockroaches would probably have a better chance of surviving. So, in that case, the "master race" would more likely be cockroaches than Aryans. JianLi 23:41, 8 March 2006 (UTC)
Or if you read Kafka, it could be both ;) 23:47, 8 March 2006 (UTC)
Haha JianLi 00:10, 9 March 2006 (UTC)
Some points of clarification since we seem to have gone off track:
  • The Big Bang is not an explosion. It is an inflation of space. Space itself expanded - not just a ball of matter within it.
  • We don't know what there was before the big bang. In fact, it is fairly absurd to talk about such a notion. Theories about the origin of the big bang are currently really only just speculations, because we have no measurements whatsoever from such a time. In particular, it cannot be asserted that there was nothing before the big bang.
  • Nothing itself is hard to define. Empty space is filled with all sorts of quantum weirdness. And even without that, we have the curvature of space to consider and so on. The big bang may simply break all laws of science, because these laws only came into existence with the big bang.
-User:Fangz (not logged in)

Sand ridges[edit]

I noticed in the article Sand that the whenever the ridges split, it always splits in twos, not threes or fours. Why is this? Is there a reason why this is the case? --HappyCamper 03:43, 8 March 2006 (UTC)

  • The answer is antimatter, it makes sand split in twos, because everyone knows antimatter doesn't split into fours-- 03:52, 8 March 2006 (UTC)
Well, a 3-split would quickly become two 2-splits when one of the three daughter ridges shifts a little. Then there's probably an effective repulsive force between ridges, which would in turn move the 2-splits away from each other until they don't coincide visually. Of course, I'm just making this up. Melchoir 04:05, 8 March 2006 (UTC)
I'm looking for an answer possibly related to fluid dynamics and criticality... --HappyCamper 04:32, 8 March 2006 (UTC)
Perhaps it's the other way 'round - two ridges approach each other and meld into one. hydnjo talk 04:48, 8 March 2006 (UTC)
Okay, I've done some research (try searching for "aeolian" on arXiv), and the ripples do tend to merge over time. There is little known about the two-dimensional dynamics, particularly the evolution of defects, but I found at least one reference:
See "Two-dimensional ripple fields" towads the bottom. Melchoir 05:10, 8 March 2006 (UTC)
How did you know to search "aeolian"? This was a key word that I was not aware of. --HappyCamper 17:20, 8 March 2006 (UTC)
The fifth paragraph in the Sand article starts with, "The study of sand is called arenology", an article which was started only a couple of days before HC started this section! A Google search of "Sand ripples" gets you this interesting study. hydnjo talk 19:46, 8 March 2006 (UTC)
Oh, I tried searching arXiv for more obvious words like "sand" first, which led me to the magic jargon. Melchoir 20:14, 8 March 2006 (UTC)

Chemical Engineering[edit]

Give the binary as well as ternary azeotropic data for the following system>

Ethanol - Water - Ethyl Acrylate

If possible then also give the phase diagram and residue curve map data

If you're going to post your homework, could you at least not phrase it as a command? Melchoir 07:45, 8 March 2006 (UTC)
People who aren't creative enough to do their own homework also aren't creative enough to rephrase it when they type it into a reference desk service like this and "ask" someone else to do it for them. But don't complain; the blatant problem-set diction is a useful marker: it reminds us not to answer. —Steve Summit (talk) 15:49, 8 March 2006 (UTC)
Indeed. Melchoir 20:18, 8 March 2006 (UTC)
Good point JianLi 00:14, 9 March 2006 (UTC)
  • I'm sure they asked you the question with the intention of teaching you how to look it up yourself. Either try the course book, or use a library reference like the "Handbook of Chemistry and Physics" or some "Physical chemistry" book. - Mgm|(talk) 09:44, 8 March 2006 (UTC)

nuclear reaction[edit]

E=mc2,in this equation m stands for mass lost. But the law of conservation of mass states that mass cannot be created nor distroyed. why is this so? Suraj ThanksSuraj

In a nutshell, the law of conservation of mass was superseded (it's no longer a strictly accurate "law") when Einstein discovered e = mc².
Our article on conservation of mass is a bit short, but might be of help to you. In brief, the principle of conservation of mass is an approximation - in chemical reactions, some mass is lost/gained, but the quantities are so infinitessimally small that they can be safely ignored, leading to the "mass is constant" rule, which for these works perfectly well. For nuclear reactions (such as nuclear fission or nuclear fusion), the mass gain/loss starts to become measurable, and so must be taken into account. The extreme case is matter-antimatter annihilation, where all mass is converted to energy, and so "mass is conserved" is obviously incorrect.
More accurately, energy is always conserved, if, by using E=mc² , you equate mass to its equivalent in energy. — QuantumEleven | (talk) 08:36, 8 March 2006 (UTC)
  • With nuclear reactions the mass isn't lost either. It's just converted into energy. - Mgm|(talk) 09:45, 8 March 2006 (UTC)
  • The conservation of mass and conservation of energy laws must just be combined to say "the total of the mass and energy of a system is preserved, with respect to the equation E=mc²". This can be described by the following equation:
initial energy of the system
final energy of the system
initial mass of the system
final mass of the system
speed of light
StuRat 20:46, 9 March 2006 (UTC)
StuRat, your terminology is... shall we say, nonstandard. What you call "energy" is really kinetic energy; what you call "total of mass and energy" is really energy. Melchoir 01:07, 10 March 2006 (UTC)
"Energy" would not just be kinetic energy, but would also include other forms of energy such as heat and gravitational potential energy. The equation I listed does convert everything (including mass) into energy for a quantity comparison. However, you could just as well divide by to convert everything into mass for a quantity comparison:
StuRat 01:54, 10 March 2006 (UTC)
Okay, yes, if you want to include those kinds of energy without calling them kinetic; I was thinking of simpler systems. My point is that in relativistic contexts, the symbol E and the word "energy" already include mass. So either you're using symbols in a way contrary to everyone else, or you're counting the mass twice. Melchoir 02:03, 10 March 2006 (UTC)
Well, I doubt if most people, including the person posing the question, are thinking in those "relativistic terms", thus the need for my explanation. StuRat 02:08, 10 March 2006 (UTC)
If most people think of the speed of light and mass-energy equivalence in nonrelativistic terms, then they're wrong, and we do them a disservice to perpetuate their ignorance. Energy is conserved, period. Melchoir 02:18, 10 March 2006 (UTC)
Using the term "energy" to include mass is just a linguistic choice, thus there is no right or wrong answer, only "more common" and "less common" usages. What exactly do you call energy excluding mass, then ? StuRat 02:28, 10 March 2006 (UTC)
It is, in fact, a linguistic choice that was made decades ago. For a single particle, energy minus mass is the definition of kinetic energy; for a complex system it's more complex. Melchoir 02:41, 10 March 2006 (UTC)
There is no body that "decides" what a word will mean in the English language, it means whatever people use it to mean. Dictionaries only report what it means, they don't chose what it will mean. StuRat 04:35, 10 March 2006 (UTC)

Why is there no footage of moon astronauts jumping really high?[edit]

We\\\'re always told that on the Moon your gravity is something like 1/6th of its weight on Earth and you could effortlessly jump three metres high (or something like that). So why is it that in existing moon footage all the astronauts do is pussyfoot around with those tiny skip-hops? If I ever landed on the moon the FIRST thing I\\\'d do is jump around like I was on a trampoline. So why didn\\\'t they? Professional discipline? Risk of damaging the suits? Or is it proof the landings were faked? —Preceding unsigned comment added by (talkcontribs)

Some reasons include:
  • the suit had a mass of 180 pounds [24]
  • the soles of the boots were (I think entirely) stiff, depriving the astronaut of all of the jumping power of his foot and ankle - try putting on a pair of snowboarding boots and see how high you can jump.
  • I guess they\\\'d also be worried that, if they fell, they couldn\\\'t get up.
--Finlay McWalter | Talk 12:05, 8 March 2006 (UTC)
I\\\'d assume they\\\'d also be worried about landing badly and ripping the suit on a rock or something, which would ruin one\\\'s day rather. Sum0 16:40, 8 March 2006 (UTC)

Also, the legs of the spacesuits were rather stiff - they would have trouble bending their knees very far. You try jumping very high if you\\\'re only allowed to bend your knees a little way (and barely using your arms for balance and momentum). — QuantumEleven | (talk) 12:40, 8 March 2006 (UTC)
You may also be interested in reading our article on the moon landing hoax. In a nutshell, most \\\"hoax\\\" arguments are the result of drastic simplifications or sheer ignorance. — Lomn Talk 15:08, 8 March 2006 (UTC)
I read once that in addition to all the other hinderances of the suit, it was nearly impossible to bend at the waist considering the suit stiffness and pressures involved, so they had to use a pulley mechanism just to lean over. Think of it this way, you are bound in nearly every way except the ability to wiggle your arms and legs a minimal amount. The fact that they got around as much as they did is amazing in itself.

I\\\'d certainly be a lot more worried about the air-less space of death 5 centimeters from my skin than I would be about jumping around like an idiot, but that\\\'s just me.  freshgavinΓΛĿЌ 

LOLZ!!1!1 onely noobs r \\\'fraid of xpl0siV d-comPr3ssi0n!1!1!! NOOB! rofl Black Carrot 20:00, 9 March 2006 (UTC)
They would have needed thicker wires in the studio for higher jumps. For great justice. 21:58, 9 March 2006 (UTC)

Why are computers so flaky?[edit]

Most people I know want reliability rather than extra bells and whistles in their computers, so why are the things still so prone to self-destruction? It is not technically possible to create hard drives which won't crash, and circuit boards which won't burn out? Or is it because we're too stupid to buy a safe, reliable computer rather than a sexy one with new features? Markyour words 13:00, 8 March 2006 (UTC)

I blame the parents.
Slumgum 13:03, 8 March 2006 (UTC)
Did you buy a cheap computer, or look for a highly reliable one? For example, most hard disk manufacturers sell premium lines that go into servers and have a much higher MTBF. In fact, hard disks are the only thing I've seen much of failing, and they inherently will fail one day: reliable computers are designed to accept this and make sure it does not matter. But people don't look for reliable computers, by and large: they look for the cheapest one with the list of features that they think they need. Notinasnaid 13:07, 8 March 2006 (UTC)
Computers are seen as consumer products, and are sold to the masses who, by and large, have absolutely no idea what they're buying. They look at a few of the numbers in the spec (speed, HD space, RAM...), then buy the cheapest one for a given spec. This drives the PC manufacturers to build cheaper and cheaper components - they can't sacrifice performance, so they sacrifice quality, especially knowing as computers become obsolete so fast anyway that they often don't even reach component failure.
It's certainly possible to build computers that are tough and durable - look at the computers on deep-space probes, those things are designed to run for decades in a radiation-filled environment, extreme cold with no maintenance whatsoever. They're ridiculously tough. And, of course, ridiculously expensive, for the same reason.
Bottom line - if you know what you're buying, you can certainly buy a computer which is much less likely to die (for whatever reason) than that $899 super-deal PC at the local supermarket. But you'll pay for it. — QuantumEleven | (talk) 15:22, 8 March 2006 (UTC)

Basically, you're right: we're too stupid. For one thing, even though we say we don't care about bells and whistles, we can almost always be goaded (by salesmen and advertising) into buying something fancier over something plain. In other words, the bells and whistles sell, so we get them even though we don't need them.

More significantly, we're suckers for bargains. By and large, in the mass market, cheaper sells better -- very few people are actually willing to pay significantly more for something that's incrementally better. Disk drives are a perfect example: they're ridiculously cheap, but this economy comes at a cost: they're not nearly as reliable as they used to be. A few years ago, many if not most disk drives came with 3-year warranties; now they're all 1-year (or 90 day). Venerable manufacturers like IBM have gotten out of the disk drive market because they can't make money in it; price competition is too fierce.

At the risk of sounding like an ad, Seagate hard drives still all have 5 year warranties WhiteDragon 17:08, 10 March 2006 (UTC)

Price competition tends to bifurcate a market in a very cruel way. You end up with stuff that's cheap but lower-quality, but it's very cheap, because it enjoys the economies of scale of highly optimized mass production. High-quality but more expensive stuff gets marginalized, and though you can usually find it somewhere, it tends to be a niche, luxury market, and you can end up paying a lot more for it. Also, since it's a niche and "expensive" market, it tends to end up pandering to people with more money than they know what to do with, who like to spend money on "prestigious" items. So if you resolve not to be a bargain hunter, if you decide to put your money where your mouth is and pay more for higher-quality items, you often find that the widget that's (say) twice as reliable costs five times as much, because it's also leather-padded and diamond-studded with gold-plated mounting hardware and a designer name on the front.

Steve Summit (talk) 15:43, 8 March 2006 (UTC)

I gather Apple computers are robust both in terms of hardware and software. They cost a little more but they look nice and don't crash so often. --Username132 18:29, 8 March 2006 (UTC)

Righty-o. I've never EVER had any hardware problems with my last three Apple computers. Well, one time I dropped my Apple Pro mouse on the tile floor too many times. :| -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 07:35, 10 March 2006 (UTC)
  • Personal computers are consumer products, and as such they're made to be as cheap as possible, even if that means occassional hardware failures. For applications where failure is more important there are correspondingly Workstation machines and at the top end, there are Mainframes. Mainframes are almost invunerable to hardware failure, because there are backup systems for just about every component. --BluePlatypus 19:54, 8 March 2006 (UTC)

So if I were trying to find a (not ridiculously expensive) reliable hard drive, for example, how could I tell which one is least likely to die on me? Would it be reasonable to assume that the more expensive it is, the more reliable? Markyour words 20:43, 8 March 2006 (UTC)

I think this question suggests the wrong approach. Hard drives will fail, and unless you prepare for it, then it will be a nuisance in a week, or a nuisance in 2 years: still a nuisance. You should be looking for ways to avoid hard drive failure being a big deal. Backups, of course, but restoring can still be an annoying waste of a day, so why not add mirroring. Not a hugely expensive option, and I tend to specify it on any computer I value. Notinasnaid 21:09, 8 March 2006 (UTC)
Hmm, what is a mirroring option? hydnjo talk 21:59, 8 March 2006 (UTC)
Mirroring is basically installing two identical hard drives, and setting up either a hardware or software solution that makes sure that every disk write goes immediately to both drives. If one drive fails, the other drive is used - nominally automatically, but especially with IDE drives a failed drive may lock up the PC so you might still need to disconnect it. Then you put in a replacement as quickly as possible and resynchronise. Key thing to watch out for: if you don't have a system for checking whether one mirror has failed, you might as well not have bothered! I use a hardware solution from Promise, preinstalled by Dell. Monitoring options are poor: you have to do it manually. Notinasnaid 22:13, 8 March 2006 (UTC)
Emphasize what Notinasnaid said about monitoring! There is nothing so embarrassing as losing all your data because your backup drive fails also (i.e. when a second drive fails after you failed to notice that the first had failed). It's like discovering that your spare tire, when you need it, is flat, or that your fire extinguisher is empty, or that your UPS doesn't work. —Steve Summit (talk) 03:51, 9 March 2006 (UTC)
I'd say the basic answer to this question is that computers are based on principles that were invented 100 years ago. The basic structure of a computer has hardly changed at all in the last 30 years (or even 50). We just keep on inventing cooler parts, and adding them to a very old model (that works pretty well). The computer industry would benefit hugely from a completely re-thought computer model, one that didn't have you navigating through things like the BIOS, valence/integrity checking, memory permission errors, priority issues in IDA ports, and peanut butter on your CD-ROM tray. They've got a lot of new principles (like true plug-and-play and modular systems), but since they're all based on really old structures that weren't initially intended for such fancy shmancy gidjits, there's always going to be weird errors popping up, backdoors, and headaches.  freshgavinΓΛĿЌ  01:42, 9 March 2006 (UTC)

I can't believe this hasn't been mentioned yet. A major difference between computers and just about any other product is that the technology develops at a very rapid pace; double the capacity and speed every year and a half (for decades now). So if you buy a computer at half the price that lasts half as long then after it's 'dead' you buy another and after that's 'dead' too you'll have spent the same amount of money but half the time you've been working on a much bigger and faster computer. But what's more, excepting hard disks, people don't even 'use up' their computer. I've got three computers, all three functional, except that I only use one of them. I might use the middle one as a dedicated machine for simple stuff, but the oldest one is a 80286 - software for that hasn't even been written for a decade now. So there's no point in making them more robust - even at the 'low quality' we get now, they're obsolete before they die.

Another thing that matters, though, is software. Now if they'd do a decent job of making robust software (ie Linux in stead of ms bloody Windows) that would make me a much happier person. Having said that, neither OS uses my graphics card/monitor combination well (the monitor is a wide-screen and the card is pretty non-standard too), but when a friend connected a Mac (a mini-Mac!) to it, it used the full width after a few simple clicks, without any special drivers needed. So if you're willing to spend a little more for quality, go for a Mac.

About the mirroring thing, is that the same as RAID? DirkvdM 18:54, 9 March 2006 (UTC)

Yes, mirroring is one particular type of RAID, specifically RAID 1. --WhiteDragon 17:14, 10 March 2006 (UTC)
Going back to the discussion of software, that is where I find most of the trouble. I rarely have hardware fail but on a daily basis run into an "illegal operation" type error. The basic concept of a PC, that many programs will run simultaneously, some originating locally and some from over the Internet, and that they will each work together nicely, is flawed. This allows one program, whether maliciously or accidentally, to mess up all the other programs and bring the computer down. Each program should run in total isolation, with no ability to affect the others. I envision a parallel computer with, say 32, old, dirt-cheap processors, each with it's own old, dirt cheap hard drive. These programs could run independently so that even the most virulent could not possibly affect anything beyond it's processor and hard disk. One of the 32 processors would run a master control program which would kick off the others and control which programs have control of the monitor and accept input from the keyboard and mouse. Too bad we can't convince Bill Gates to come out with something like this (he prefers coming out with "new and improved" versions of windows with "new and improved" bugs, since each new O/S of his is based on the same flawed model of programs "cooperating nicely"). StuRat 20:26, 9 March 2006 (UTC)
This would be possible if somebody went back and thought about how to build a computer from scratch, and build it in a way that programmers wouldn't have to worry about system specs and fidgities. I don't even think we need to bother with the concept of a conventional "processor".  freshgavinΓΛĿЌ  07:25, 10 March 2006 (UTC)
To answer your questoin - yes, for people who are willing to pay for it, you can get a computer that has extra reliability. A blade server, for example - you can literally rip pieces out of it while it's running and it will keep on humming fine. On the other hand, it's going to cost you a pretty penny. If you want to insulate yourself from hard drive crashes, you can pay for full drive mirroring (Raid level 1, I think -- two hard drives doing exactly the same actions in paralllel - if one of them fails, you have a perfect copy already handy without worrying about data loss).
As to your more general - why are they prone to destructoin question - it depends on what you mean. Hardware destructon is relatively rare - certainly much less so than an automobile, for example. Software screwups are quite a bit more common, owing to the huge general purposes for which computers are applied, and the number of possible bad interactions increases in proportion to the factorial of the number of tasks a computer is running. Raul654 07:31, 10 March 2006 (UTC)
BTW if using mirroring or raid it may be worth mixing the makes/models. You will like lose in performance and waste some capacity (as the drives will never be exactly the same size) but you will protect yourself from batch faults. Plugwash 01:34, 14 March 2006 (UTC)

Searching For Research Groups[edit]

I'm hoping to go into research when I leave uni, in the feild of engineered zinc finger protein transcription factors (preferably mammalian) - I was wondering how I could find all the relevant research groups in the UK and Netherlands? Is there some kind of central database I could use? --Username132 18:25, 8 March 2006 (UTC)

Nope. I'd suggest you either A) Just ask someone in the field. They should know. B) Check some review papers on the subject and check the reference list for such groups or C) Look for representatives from those places in conference schedules on the subject. --BluePlatypus 18:53, 8 March 2006 (UTC)
As BluePlatypus said, check existing papers on the subject. Most will be written by professors at other universities. One problem I've found about working in research for the past fifteen years is that it is very hard to get into if you aren't either a professor or a student. So, I decided to get my PhD and become a professor so I can keep doing research easily. --Kainaw (talk) 19:03, 8 March 2006 (UTC)

Conservation Of Momentum In Time-Demension[edit]

Does the conservation of momentum apply to the dimension of time? --Username132 18:26, 8 March 2006 (UTC)

  • It depends, what does that question mean??-- 20:17, 8 March 2006 (UTC)
Oh, you're going to love this. Check out Noether's theorem. Symmetry under translations in space leads to conservation of momentum, and symmetry under translations in time leads to conservation of energy. —Keenan Pepper 20:22, 8 March 2006 (UTC)
Dang, beaten to it! Well, also check out the article Four-momentum. Melchoir 20:25, 8 March 2006 (UTC)
well, 2 edit conflicts later, all I have left to offer is fourth dimension, I feel so inadequate ); 20:30, 8 March 2006 (UTC)
Thirteen minutes to post a sub-adequate reply, that must be a record!  freshgavinΓΛĿЌ  01:36, 9 March 2006 (UTC)
So if something explodes, the products of the masses and the amounts they are accelerated through time will equal those of the particles deccelerated and/or sent back in time? --Username132 02:31, 9 March 2006 (UTC)
If you interpret "acceleration through time" as a change in the Lorentz factor of a body, and you carefully also take into account changes in mass, then yes: you can make this into a meaningful, true statement. Ultimately it's still just conservation of energy. Melchoir 02:44, 9 March 2006 (UTC)

Cold shock and free radicals[edit]

Why does cold shock cause free radical release (in potatoes if possible)? Thanks --Nick123 (t/c)<;/sup> 22:51, 8 March 2006 (UTC)

  • It's not just cold shock. *Any sort of stress causes cells to release free radicals. Reactive oxygen species should have more info on the issue and a lot of those radicals come from the mitochondrion. - Mgm|(talk) 10:11, 9 March 2006 (UTC)
  • To elaborate just a bit, freezing a food product such as a potato can cause the formation of ice crystals that puncture cell membranes, leading to stress. Edgar181 22:12, 9 March 2006 (UTC)
Thanks for your help! --Nick123 (t/c) 21:35, 11 March 2006 (UTC)

March 9[edit]

animals that are consumers and producers[edit]

Is a grey seal and lion considered a consumer or predator and why

A grey seal and a grey lion? Or a lion and a grey seal? Or possibly a grey seal and a sea lion?  freshgavinΓΛĿЌ  01:33, 9 March 2006 (UTC)
It depends. If they are middle class, they are consumers. If they are upper class, they are predators. If they are lower class, they are a safety net for the middle class and the source of all society\'s problems for the upper class. Wait... isn\'t this your sociology homework? --Kainaw (talk) 01:44, 9 March 2006 (UTC)
Following the link in Consumer to the biological form of the word, I get Heterotroph, which links to Autotroph, the scientific word for producers. Those go into comfortable detail about what each is and isn\'t. In case you actually meant to include the word \"predator\" and it wasn\'t a typo, you might try Predator and Prey as well. Black Carrot 13:05, 9 March 2006 (UTC)

Chewing Gum (CareFree)[edit]

What is florason?

She's the Roman goddess of Spring dad. Grutness...wha? 07:17, 9 March 2006 (UTC)
Floraison is the French word for "flowering." My guess is that it is artificial fragrance in the gum. -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 10:10, 9 March 2006 (UTC)

The Moon[edit]

Why is the flag waving if theirs no gravity.

  • Cuz they obviously faked the moon landing, and you've discovered the one long lost bit of proof that we've been looking for ever since 1894 when the aliens first landed in the hills of MT.BOGATAWOGASFEILD, at last we can expose their secret, moon-landing-faking, alien agenda, and the MT.BOGATAWOGASFEILD aliens will be defeated forever!-- 00:38, 9 March 2006 (UTC)
  • See moon landing hoax. Also, the reason why the flag is waving is because there's an atmosphere in the sound stage where they faked the landing. Both Earth and the Moon have gravity—which is necessary for the flag to hang properly. TenOfAllTrades(talk) 00:40, 9 March 2006 (UTC)
There is gravity on the Moon, but little wind. If you're talking about Image:Buzz Aldrin with U.S. flag.jpg, I can only assume that when you jostle a hanging piece of cloth in the absence of air resistance, it doesn't settle down until its internal friction absorbs the energy, which will take a while.
Also, it's a fake. Melchoir 00:44, 9 March 2006 (UTC)
Dang, TenOfAllTrades' link kicks my ass. Melchoir 00:47, 9 March 2006 (UTC)
Has anyone considered that the Moon Landing hoax goes even deeper? What if the Moon itself is a hoax? The Moon Landing was just there to reinforce the propoganda that there is a Moon and not a huge spy satellite floating around above our heads. --Kainaw (talk) 01:41, 9 March 2006 (UTC)
No, don't be crazy, it was the aliens-- 01:44, 9 March 2006 (UTC)
The 'Moon Landing Hoax' was itself a hoax. They wanted to prove to the Russians that they could do a really good hoax, and have them quiver in their vodka. Unfortunately, they couldn't make convincing enough and actually had to go to the moon for the pictures, while still saying it was done in a sound studio. --Zeizmic 02:40, 9 March 2006 (UTC)

There is no real moon, we all just have this huge cataract on one of our eyes and wen we look into the sky its visible.--Im_in_ur_house 01:30, 9 March 2006 (UTC)

Actually, there is no Earth, and those who live on the moon discuss the Earth landing hoax. EWS23 | (Leave me a message!) 06:35, 9 March 2006 (UTC)

Sigh. The flag had wire sewn into it along the top. It was deliberately put there because it was known that - with no wind - the flag would otherwise have just hung limply and made for lousy photographs. Grutness...wha? 07:17, 9 March 2006 (UTC)

BTW, have you ever wondered who creates all these conspiracy theories? Have they a motive for doing so? There must be a reason for it... perhaps they're trying to divert our intention from the truth... Perhaps the Moon landing was fake - as fake as Christ of the Andes! Grutness...wha? 07:22, 9 March 2006 (UTC)

Right. Stop this. This section has gotten entirely too silly. The whole premise is silly and the answers are badly written. Move along. --The Colonel 08:47, 9 March 2006 (UTC)

Gravity doesn't make the flag wave, wind does (and it doesn't wave), it is rigid. -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 10:12, 9 March 2006 (UTC)
  • Here's why the flag was moving:
  1. There is gravity on the moon, just less than on earth.
  2. There was something sewn in the top to keep it up.
  3. No gravity doesn't mean no wind.
Why people are so hell-bent on claiming anything to be a hoax, I'll never know. - Mgm|(talk) 10:18, 9 March 2006 (UTC)
Well one reason they keep on huffing about is because a lot of the explanations given are a little bit weak. There's some flaws in the way you worded it. a) The flag was moving because there's gravity on the moon. If you think of from the perspective of a human being, gravity is the thing that causes everything to STOP moving (when it hits the ground). An absense of gravity causes things to coninue moving forever (from a relative position) and so this doesn't make sense as an argument. b) It moves because there's something on the top to keep it up. Again, something stiff on the top was put there to keep it from moving (e.g. keep it up) so it sounds strange to use this as a reason. c) No gravity doesn't mean no wind. Actually, it does. Without any gravity, particles will not gather together in one place (let's say, the atmosphere) and thus there will be no substance around to create any wind, just empty space. What I think you meant to say was: 1) The gravity on the moon caused the flag to ruffle as it was being set. 2) There is a bar sewn at the top of the flag to keep it from falling down. #3 doesn't really need to be said.  freshgavinΓΛĿЌ  07:18, 10 March 2006 (UTC)
OK, since it seems people want every T dotted and every eye crossed, let's put it this way. The wire at the top of the flag kept the top rigid. The flag would therefore have been stretched to its full length from hoist to fly, rather than hanging limply. Since the flag would need to have been moved into position in order for it to have been erected on the lunar surface, it would have been in motion to get it to that position. The bottom edge of the flag was not wired, and was hanging freely. Due to inertia, it would not have automatically been in direct position below the upper edge of the flag the second the flag was erected. Thus, the bottom edge would have acted very much like a pendulum - it would have moved backwards and forwards until it came to rest due to gravity at its lowest possible point. Due to the lower gravity of the moon (as compared to the Earth) and the lack of air resistance to the flag, this slight motion would have taken quite a long time to subside. What was seen as the "flapping" of the flag was nothing more than this - the bottom edge of the flag acting as a pendulum beneath the rigid upper edge. Happy? Grutness...wha? 10:09, 10 March 2006 (UTC)

For a very detailed debunking of this, see the article on Clavius. And thank you for all the sarcasm above - it certainly made me grin! — QuantumEleven | (talk) 11:12, 9 March 2006 (UTC)

Very simply put: See Newton's laws of motion. Whenever the flag fluttered, an astronaut had placed, fixed, or bumped it. Prove me wrong. Here7ic 20:55, 10 March 2006 (UTC)


How can an environment affect a phenotype of an organism so that that organism is able to pass on altered traits to its offspring? If that isn't even part of evolution and I'm on the complete wrong track tell me. RENTASTRAWBERRY FOR LET? röck 02:06, 9 March 2006 (UTC)

See Lamarckianism and Lysenkoism for the simple versions, now refuted. alteripse 02:31, 9 March 2006 (UTC)

The phenotype of an organism is determined basicly by the genotype. The genotype has variations within a population (which produce variations in the traits of the organism including variatins in phenotype). Some of these genotypes produce more offspring, thus increasing the proportion of their related phenotype. Most phenotypes go extinct. WAS 4.250 02:42, 9 March 2006 (UTC)

Basically the answer is, organisms aren't able to pass on altered traits to their offspring. So, in fact, that isn't part of Darwinian evolution. Like Alterprise wrote, what you described is part of the now-discredited Lamarckian evolution, not Darwinian evolution JianLi 03:14, 9 March 2006 (UTC)

God created the universe! —Preceding unsigned comment added by Im in ur house (talkcontribs) 05:25, March 9, 2006 (UTC)

If G-d lived on Earth, people would break all His windows. (according to Yiddish proverb) GangofOne 08:27, 9 March 2006 (UTC)

The way the enviroment affects a phenotype is to either kill it ( or otherwise prevent it from reproducing) or not. Those that reproduce dominate the next generation. That's evolution. GangofOne 08:27, 9 March 2006 (UTC)

Yeah. As far as classical evolution is concerned, environment cannot have such a direct effect. On the other hand, there are exceptions to such a rule. For example, exposure of some organisms to stress can cause a faster rate of mutation - not exactly the same, but close. Some research may also be concerned with feedback effects between organisms and their habitats - as an organism's phenotype changes, it may cause changes to its environment that continuate its own phenotype. (If we use rather broad definitions, we can speak of human society and education in particular as an example of this) - User:Fangz (not logged in)
There's still an ongoing debate on directed mutation (which might need an article), as Fangz noted. I seem to recall that there was a study involving exposing fruitflies to high heat. This may be it, the various references on this are also interesting.
Supporters indicate that there is experimental evidence of certain cellular mechanisms for repairing 'damage' mutations which may be suppressed under environmental stress; this is posited to be a fitness trait of another order which allows a species to 'speed up' selection by increasing mutations when there is high environmental stress. Detractors usually mis-identify directed mutation with Lysenkoism by defining it as "the hypothesis that mutations that are useful under particular circumstances are more likely to happen if the organism is actually in those circumstances."[25] However, there is some very interesting experimental evidence that the cell may be able to "choose" the mutation.[26]
I also browsed a science fiction book called Darwin's Radio by Greg Bear which seemed to have a plotline along this angle. KWH 17:42, 9 March 2006 (UTC)
The gender ratio of offspring can be affected by the environment, such as the average temperature of the father's testicles. StuRat 19:53, 9 March 2006 (UTC)

There was an account of an interesting evolution-environment link in Orson Card's Ender's Game series, I think he mentions a Chinese philosopher, but I'm not sure if it was a reference to a real person or not.

The basic gist of it was that there's a planet completely covered with only one species, a sturdy little flower; let's call it a daisy, and assume it's yellow. When the environment of the planet begins to heat (hot cycle) the portion of the planet's plants that had evolved (by random traits) to have slightly darker petals would die because of the absorbtion of too much heat, leaving the lighter colored daisies to multiply and thus lightening the surface of the planet, reflecting greater amounts of light and cooling the atmosphere. If the planet were to suddenly cool down, it would have the opposite effect and the surface would darken causing the atmosphere to warm up again.

I realize this has little to do with the question but it's such a pretty story about cute little yellow flowers, and I wanted to share it with everyone!  freshgavinΓΛĿЌ  05:40, 10 March 2006 (UTC)

The oscillation is interesting, but there are cases where life has changed the Earth in a negative way for it's own survival. Early plants gave off oxygen and thus filled the air with it. However, free oxygen was toxic to these early plants, so later plants, and then animals, needed to develop a defense against free oxygen. Our layer of dead skin on the surface protects us nicely. A current example might be global warming, which may be disastrous for human life. StuRat 10:29, 10 March 2006 (UTC)
I haven't read Ender's Game, but that sounds a lot like the Daisyworld simulation of James Lovelock's Gaia hypothesis. KWH 14:59, 10 March 2006 (UTC)
Yes, yes that's it! So they were daisies after all. I highly recommend the books, anyway. Mostly written in the 1980s, they're not perfect sci-fi books (Card is not a scientist, but a religious man), but if you can imagine it as an adventure series they can be quite inspiring.  freshgavinΓΛĿЌ  05:51, 13 March 2006 (UTC)

Effect of bodies of water on surrounding areas[edit]

I was wondering what the name of the phenomenon might be where proximity to a large body of water regulates the climate and weather of the land directly adjacent to said body of water. For example, the way in which the climate of the coast of British Columbia remains so temperate due to its proximity to the Pacific Ocean. If I could just get the name of the phenomenon or concept, I could go from there. Thanks.

See continentality, which is the opposite of oceanity or oceanicity, which is something like what you're talking about. If you do a google search for "climate", "body of water", and "specific heat" you'll find more. —Steve Summit (talk) 06:20, 9 March 2006 (UTC)
Moderation. The water moderates the climate. --Anonymous, 08:48 UTC, March 9.
I looked around. There's a little bit on microclimate. Googlize and you find a bit more. --Zeizmic 12:36, 9 March 2006 (UTC)
Lake effect snow, Orographic lift, , WAS 4.250 14:55, 9 March 2006 (UTC)

Parabolic hotdog cooker[edit]

Hello friends! My friends and I building a solar hot dog cooker. We are looking for a way to make the parabolic dish shape and for a good reflective material (that doesn't diffuse). Any searching I do lands pizza-box or traugh level work, but we're looking for something a little more kick-but. Any help appreciated. --orphan frequently 05:31, 9 March 2006 (UTC)

May I suggest the Solar death ray? :) --Obli (Talk)? 06:40, 9 March 2006 (UTC)
Did you see solar cooker? And there are some interesting links from there. --Shantavira 08:25, 9 March 2006 (UTC)
I remember when I did that in 8th grade, I shared my two hotdogs with my friends. *tear* A Frensel lens off Ebay is what you want to do. You can find directions for building the box and doing the right math (if you are doing this for school). Have fun! Also try cooking other things, and things that aren't food. (Shotgun shells don't work well). Ow. -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 10:05, 9 March 2006 (UTC)
I believe you meant to say a Fresnel lens. StuRat 19:45, 9 March 2006 (UTC)


How long does it take for the effects of this to wear off? I took a 40mg dose ~36 hrs ago and while it's had the desired effect on my symptoms, I'm getting a bit concerned that it's been too effective. (Apologies for TMI.) --Bth 08:21, 9 March 2006 (UTC)

  • What did the packaging say about dosage? - Mgm|(talk) 10:19, 9 March 2006 (UTC)
To intially take two 20mg pills and then another one every time I had a loose bowel movement (which I haven't had so the initial dose was the only one). Looking at the infobox in the article, the elimination halflife is ~10 hours so I should still have about 5mg floating around my system, which makes me a bit less worried. (And my stomach just rumbled, which makes me thinks might be coming back to life.) --Bth 10:29, 9 March 2006 (UTC)
By the way, don't take anti-diarrheals if you think it's being caused by an infection. Diarrhea is a good thing since it flushes out the organisms. Just be sure to stay well-hydrated with an oral rehydration solution preferably or a sports drink like Gatorade. --Uthbrian (talk) 19:21, 9 March 2006 (UTC)

PC catastrophe[edit]

I bought a graphics card from, marked Used. " used stock has been price discounted because there’s a minor problem with it. For example, the packaging could be damaged, or there might be something missing such as the software or its user manual. Alternatively, it may have been opened, used and simply returned to us."

I installed it, with no problems that I could notice during my installation. Then my problems began. Windows booted, I tried installing drivers for my card, but the screen went black and my PC hanged in the middle. When I tried to restart, Windows rebooted before the login screen. Safe mode got stuck at amdagp.sys. I took the new graphics card out and put my old one back in, but the problems remained. I tracked the reboot problem down to one of the nVidia drivers, so I deleted them in Ubuntu Linux, but alas I got another error. I finally got Windows to boot by using "Last Known Good Configuration", but then I got a blue screen a few minutes later. This morning the PC seemed to be up and running again, so cautiously I rebooted and scheduled a CHKDSK. I came back to find the error "Windows cannot start because the HAL.sys file is missing" (or something similar) and a very worrying smell of burning. Opening the case, I found the smell was coming from my processor.

So, two queries: 1) Has anyone any ideas at all what the problem might be? I think it might be something to do with the PSU... but would that explain my hard drive/Windows problems as well?

2) Is there any way I can get compensation from Dabs for selling me a product that could end up costing me my whole PC?

Thanks. I think I have burning plastic fumes in my lungs. Sum0 12:20, 9 March 2006 (UTC)

Wow! I just got a mirror delivered by UPS. It was dropped on my porch (I think they waited for me to go away a few minutes). It looked liked it had bullet holes through it. The box was falling apart, so it looked like the guy tipped it to stop glass shards from falling out. Does this answer the question? No -- shit happens. --Zeizmic 12:38, 9 March 2006 (UTC)
I had a server delivered by FedEx about 10 years ago. It was in fine condition if you ignored the steel rod going through the package (and server). I brought this to the delivery guy's attention and he replied, "So, you're saying the rod isn't yours?" Does that answer the question? No. But, an answer could be: The card is apparently an AGP card. Windows failed on an AGP library. A hard reboot was apparently done, which messes up the Windows files. A reinstall is required. See if you can disable AGP in the BIOS and use the card like it is a PCI card. If you have an LCD display, ensure you are using a resolution it can display - otherwise you will get a blank screen even when the card is working perfectly. Expect 90% of what you purchase through cheap discount dealers to be garbage. If it was actually a great deal, someone would have bought it before you saw it. --Kainaw (talk) 13:22, 9 March 2006 (UTC)
Is it possible that you might have inadvertently loosened the heat sink on your CPU when you swapped graphics cards? Poor contact between the CPU and heat sink will result in inefficient cooling; a processor that's running hot will cause the PC to behave erratically and hang periodically (whenever the CPU warms up). Running for extended periods with a poorly-attached heat sink will eventually cook your CPU (possibly leading to the smell of burning and the release of the magic smoke.) TenOfAllTrades(talk) 13:55, 9 March 2006 (UTC)
What is the material that actually burns to produce this smoke? --Username132 22:28, 9 March 2006 (UTC)
The smoke is installed when the chip is produced. We can only speculate as to what it's actually made of.  freshgavinΓΛĿЌ  03:50, 10 March 2006 (UTC)
 :D I assume it's actually the plastic casing of the chip melting. Sum0 09:21, 10 March 2006 (UTC)
Good thinking, TenOfAllTrades. The heat sink appears to be fine, but the CPU fan isn't spinning. I think what has happened is that when I was putting the new card in I invadventantly damaged the connection between the CPU fan speed controller (a knob on the back) and the fan. So... sorry Dabs, seems like it was my fault all along. Just need to get a new fan. Either way, thanks to everyone for the replies. Sum0 16:07, 10 March 2006 (UTC)
Hopefully you just need a new fan! You may need a new motherboard and processor too! I mean you smelled the thing burning... Good luck anyway. --Username132 17:15, 12 March 2006 (UTC)
Thanks for your concern! I installed a new fan yesterday and everything is now working swimmingly. I'll be sending the card back, incidentally. Sum0 23:03, 12 March 2006 (UTC)
I'd imagine the burning smell was dust or something. You get it all the time when something gets hotter than normal but not hot enough to destroy itself or when stuff that normally runs hot has been in storage for a while. I can't imagine a fan failure alone killing any modern chip (most have protection systems and whilst they are sometimes a bit slow to deal with complete heatsink removal fan failure is a much more gradual overheat).


Can anyone please explain the following to me: Engine Horsepower (EHP), Thrust Horsepower (THP) and how do I explain it to a student?

Confused pilot?

EHP is the horsepower that the engine produces, equal to torque times angular speed. THP is the horsepower required to push the aircraft along, and is equal to drag times speed (assuming constant speed). The difference between the two is due to losses such as heating of the air [27]. --Heron 21:33, 9 March 2006 (UTC)
Wow, that should be in an article (if it isn't already). - Cybergoth 21:52, 16 March 2006 (UTC)

should the distance between eyes and monitor vary with the size of the monitor?[edit]

How close is too close to watch a computer monitor? It is a well known fact that while viewing a 15 inch monitor, we should keep a distance of 25 to 27 inches between the monitor and the eyes. Should the same distance be maintained while viewing a 10 inch monitor? (Please note here that the area of a 10 inch monitor is approximately half that of a 15 inch monitor). Can I use small fonts in the 10 inch monitor and sit closer than what distance I keep with a 15 inch monitor? Generally, should the distance between eyes and monitor vary with the size of the monitor?

If 27 inches is okay to 15 inch monitor, whats ok for 10 inch?

Eyes are unique to each person. So, distance to a monitor is unique to each person. If your monitor position makes your eyes hurt, movie it. If your neck hurts, the monitor is usually too far away or too low. There is no "well known fact" about specific monitor distance. There are only assumptions based on poor science. --Kainaw (talk) 15:46, 9 March 2006 (UTC)
I can tell you that the top of your monitor should be roughly at eye level, so you never have to look up to read pages.
If I do that, I get severe migranes. I keep the bottom of my monitor at eye level. As I stated before, monitor position is dependent on the person looking at the monitor. Any "rule" can, at most, be applied to most people, not all people. --Kainaw (talk) 17:26, 9 March 2006 (UTC)
In my iMac's manual I think it said I should have my eye level a few inches above the bottom of the monitor. -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 07:29, 10 March 2006 (UTC)
  • Further on this point, the desirable height may be different for people who use bifocal/multifocal glasses, or have (say) neck problems affecting what position they can hold their head in. --Anonymous, 23:33 UTC, March 9.
I think you need to invest in a larger monitor, 10 inches is pathetically small. I use a 19 inch monitor, so almost 4 times the area, and wish I had a larger one. Also, I would avoid traditional cathode ray tube monitors and go with a plasma screen. That technology can produce a bright, high contrast image with a minimum of electromagnetic radiation, unlike a CRT. The size, brightness, and contrast of the screen are more critical to preventing eyestrain than your distance from it. StuRat 19:15, 9 March 2006 (UTC)
I don't think radiation is an issue in modern monitors. I'd go for a 17-19 inch CRT off ebay or something. If you're using a 10" monitor, you probably havn't got money to spend on a plasma anything. I certainly don't. Vive le CRT! --Username132 22:20, 9 March 2006 (UTC)
Well, that's the reason it's called a "plasma" screen, you need to sell blood plasma until you can afford it ! :-) StuRat 10:20, 10 March 2006 (UTC)
Only in America... The UK (at least) blood service don't pay for blood products. --Username132 13:36, 10 March 2006 (UTC)

Possible allergy?[edit]

I'd never had Tasty Food Product (hereafter referred to as TFP) until about a year ago. When I eat it after abstaining for a while, I get mild stomach pains and moderate diarreah. After that, I can eat it daily with no troubles -- but if I go a few days or a week or two without it, then try it again, I get the diarreah. Is this an allergy or what?

First, a disclaimer: Wikipedia is not a medical doctor. All responses should be treated as random hearsay. Anyway, I've had similar stuff (in my case, red meat, which I didn't eat as a poor college student) where my tolerance could fluxuate. However, in my case, it was simply said tolerance and the need to develop one. — Lomn Talk 16:27, 9 March 2006 (UTC)
I can think of a possible mechanism for this observation: perhaps a helpful bacteria exists in the digestive system initially in insufficient quantities to digest large quantities of that food. However, the bacteria quickly multiplies by eating that food, and thus the numbers become sufficient to properly digest the food after a few days. Then, when you abstain from eating the food for a long period they are flushed from the system. The appendix seems to serve the function of allowing at least a few of the bacteria to stay in that pouch and not be flushed out. I would be interested to know if you each still have your appendices. Four possible solutions are:
  • Avoid that food entirely.
  • Eat the food more continuously to avoid flushing out the good bacteria.
  • When you start eating it after a gap, only eat a small amount the first few days.
  • Consume the needed bacteria with the food (much as lactase is taken by the lactose intolerant).
StuRat 19:00, 9 March 2006 (UTC)
Did you just invent a function of the appendix? Or did I miss a new discovery? And what is TFP? Is it some food brand or fatfood chain? Suitly emphazi (there, now I'm talking in riddles too, for those not native to this ref desk :) ). DirkvdM 19:16, 9 March 2006 (UTC)
No, I've heard that theory before, especially with respect to storing bacteria necessary for the digestion of raw meat by cave men, who would likely go for long periods betweens "kills" and thus need a way to preserve the helpful bacteria. If our appendix article omits this info, that's just one of Wikipedia's shortcomings, I guess. Also, they were using TFP to refer to any food which causes the problem in question, not any specific food. StuRat 19:32, 9 March 2006 (UTC)
Appendix intact and in place here, and "TFP" is just a catch-all for "whatever food is responsible here". — Lomn Talk 19:33, 9 March 2006 (UTC)
Thanks for the advice. I still have my appendix, and the food in question is soymilk. --Original Poster

acute renal failure[edit]

Can acute renal failure be caused by Ptomaine poisioning? Any information would be helpful. Thank you in advance.

Where did you pull Ptomaine from? "Ptomaine poisoning" is a rather old term for "food-born bacteria poisoning". In the area of food-born bacteria, you will find E.Coli, which is known to cause renal failure. --Kainaw (talk) 17:56, 9 March 2006 (UTC)

operational amplifiers[edit]

why level shifting is necessary in operational amplifiers?--- 18:31, 9 March 2006 (UTC)

This looks like a good reason to do your own homework, but you might also check out operational amplifier and search for "level shift". — Lomn Talk 19:39, 9 March 2006 (UTC)


My son was working in a crawl space under a residence, he saw mold, mouse droppings and smelled sewage, the man working above him was drilling holes in the floor boards for elec. wires. The debris rained on him. His employer provided no protective gear. My son soon therafter came down with acute renal failure. The workmen's comp doctor says my son must have had Ptomaine poisioning. My doctor feels he came in contact with a number of toxic items, and even feels he may have contacted a virus such as hunta virus. I want to know can Ptomaine poisoning cause renal failure. We all had the same lunch my son ate. Dry Salami and no one got sick? My son almost died, he has now recovered and has never had any renal problem before.

I think your analysis is correct, and they are just trying to protect themselves from a costly lawsuit. If you have samples of the materials he was exposed to, say from those could be analyzed to find the toxic agent. StuRat 18:50, 9 March 2006 (UTC)
Wow! Two people with renal failure caused by ptomaine poisoning in the same day! --Kainaw (talk) 19:10, 9 March 2006 (UTC)
I bet they both had salami too, without getting sick with a question mark. DirkvdM 19:21, 9 March 2006 (UTC)
I don't understand what either of you are saying? Only one person got poisoned - his son? And why did Dirkvdm verbalise his question mark? --Username132 22:12, 9 March 2006 (UTC)
The question got asked twice, both times unsigned. Of course it's obvious that it was the same person who asked it but we were just having a bit of fun. And this version of the question had an oddly placed question mark; "Dry Salami and no one got sick?" so I made a little 'joke' about that? Aren't we having a lot of fun here! (in case you wonder about the misplaced exclamation mark - it's intentional?). DirkvdM 12:42, 10 March 2006 (UTC)
StuRat is right, you should probably consult a lawyer; if your son is in a union he should probably speak to the union people as well. --Robert Merkel 01:48, 10 March 2006 (UTC)
That would be hantavirus, btw, not hunta virus. - Nunh-huh 09:36, 10 March 2006 (UTC)
Well, if you don't know where a virus is, you need to hunta virus, right ? :-) StuRat 10:17, 10 March 2006 (UTC)

Well, yes I am hunting the cause and I am his mother, since he has no medical insurance.(Of course the medical bill is enormous and I am on SS) And we can't find a lawyer to take the case because it is a workmen's comp. case. and my son was out of work for 3 weeks, so there is no money to speak of for an attorney to get motived to take the case. Since we are not allowed to hire an attorney and pay him out of our own pocket. We are very "nicely" aced out of legal representation. Thanks anyway. Francesca

The solution to your problem is publicity. This is a human interest story. Newspapers make money from circulation, and get circulation from interesting and alarming stories. Trying to help your son all by your self against the only-profit-matters corporations makes a great story. Further people who read it will offer to help. Some will send a dollar. A law student might decide your publicity could be his publicity and offer free legal help. But to get the ball rolling, you have to talk to reporters, church groups, neighbors, etc. Set up a web site with photos and a way to donate. WAS 4.250 18:56, 10 March 2006 (UTC)

You need to find lawyers who are willing to do the work for free (pro bono). See our Legal Aid article, and follow the links at the bottom for specific contacts. StuRat 03:04, 14 March 2006 (UTC)

analogy of rotational equilibrium[edit]

I want to know that Is "rotational equilibrium with constant angular velocity" a dynamic rotational equilibrium?, since "Translational equilibrium with constant linear velocity" is Dynamic Equilibrium

It is, I'd say. deeptrivia (talk) 20:13, 9 March 2006 (UTC)

I'd say you're confusing dynamic equilibrium with mechanical equilibrium. —Keenan Pepper 22:01, 9 March 2006 (UTC)

Fiber in Tropicana "Lots of pulp" juice[edit]

How come there is 0 grams of fiber in Tropicana "Lots of pulp" juice? Isn't the pulp fiber? What's the benefit of pulp in juice if it's not fiber? deeptrivia (talk) 20:13, 9 March 2006 (UTC)

The pulp does contain fiber, and other carbohydrates, but probably the pulp makes up a small enough proportion of the total juice that one serving contains less than a gram of fiber. (0 grams, really means less than one gram per serving). What's the benefit of pulp? Maybe some people just like the pulp because it makes the juice seem more like fresh squeezed, rather than processed, juice. Edgar181 21:59, 9 March 2006 (UTC)
Have you ever poured a jug of Tropicana into a sieve just to see how much pulp there actually was? There's lots of it, a lot more than 1 gram per serving. By your logic, it should at least get a "traces" rating for fiber. I'd say the answer to this Tropicana mystery is that the company figures that people don't really care about the fiber content, and rather just like getting their faces sloppy, and it puts the same specs on the box for "Homestyle" and "Original". I personally prefer the pulp.  freshgavinΓΛĿЌ  07:07, 10 March 2006 (UTC)
I'm confident that if you filtered a serving of juice, collecting the pulp, and then completely removed all the water, the remaining dried solid would weigh less than a gram. Edgar181 13:24, 10 March 2006 (UTC)
I hate those chunks of pulp that stick between my teeth. I once bought "homestyle", not knowing that apparently means "nothing but pulp" ! StuRat 08:57, 10 March 2006 (UTC)

The pulp is low in fiber, as most of it is digestible. Only a small portion of the pulp goes through the system undigested (and thus can be called fiber). StuRat 09:02, 10 March 2006 (UTC)

Well there you go. Gotta give it to fruits. They really know how to be eaten.  freshgavinΓΛĿЌ  05:47, 13 March 2006 (UTC)

Hard disk[edit]

If you save data on hard disk and remove the hard disk from CPU ? you will lose the data

if you removed hardisk too much this remove will effect on hard disk?

Generally, hard disks can be unplugged, removed, placed in another computer, etc. without damaging data. Doing it too much shouldn't be dangerous, but it increases the chance that something might go wrong. Hope this helps! Sum0 20:51, 9 March 2006 (UTC)
As long as you treat your HD with care as you do this, there shouldn't be any problems. — TheKMantalk 21:15, 9 March 2006 (UTC)
It may go without saying, but I'm going to say it anyway—don't remove the hard disk while the computer is running. This will often result in data loss, and may result in physical damage to the drive.
On a practical note, IDE connectors have a lot of fiddly little pins that don't like being repeatedly plugged and unplugged. Moving a hard drive between computers too often may result in premature failure of these pins. TenOfAllTrades(talk) 21:20, 9 March 2006 (UTC)
External USB harddisks maybe a better solution. Theresa Knott | Taste the Korn 21:43, 9 March 2006 (UTC)
Treating with care includes full anti-static precautions. The vulnerable part of a hard disk (unless you drop it) is that circuitry on the outside. Consider an external hard disk, though, may be much easier, or a memory key. Notinasnaid 09:14, 10 March 2006 (UTC)
Oh yes, and make sure the computer was shut down normally before you take the disk out, NOT just crashed or switched off. That can reduce the chances of damage. Notinasnaid 09:15, 10 March 2006 (UTC)
That's a tricky one - in my experience, shutting down 'normally' is not normal for msWindows. DirkvdM 12:45, 10 March 2006 (UTC)
And sing to it - and care for it - and love it. Celcius 11:39, 10 March 2006 (UTC)
At the risk of being pedantic, SATA hard drives (as well as external USB or FireWire ones) are hot-swappable. However, the operating system needs to be aware of this capability, so for instance in linux, be sure to umount the hard drive first. In Windows, SATA drives don't seem to be considered removable storage, so you don't have the handy safely remove hardware icon for it, so you must shut down windows before removing or reconnecting the drive. --WhiteDragon 17:33, 10 March 2006 (UTC)

I like my apples waxy... or not[edit]

I took an apple out of the pack and it felt really waxy, and then so did the others. What's this weird waxy coating... it's not conveinient to wash them before eating... --Username132 13:34, 10 March 2006 (UTC)

Take a look here. Hope this helps — TheKMantalk 21:16, 9 March 2006 (UTC)
Oh thanks. Perfect. :) --Username132 22:21, 9 March 2006 (UTC)
In future, if you ever come across a mystery waxy or oily substance that you're not sure if you're supposed to eat or not, I recommend you eat it. Not because I wish any harm on you, but because waxy and oily substances are hydrophobic, and will (generally) cluster (more or less) in your stomache, and won't cause any damage (probably, if you're lucky). On second thought...  freshgavinΓΛĿЌ  03:06, 10 March 2006 (UTC)
lol, that's the best advice I've ever heard. =P —Keenan Pepper 04:52, 10 March 2006 (UTC)
Bile salts may emulsify the wax... Plus being hydrophobic/lipid soluble, they should be able to freely cross cell membranes into the blood. --Username132 13:34, 10 March 2006 (UTC)


What did this have to do with the formation of the internet? Just wondering??Do any of you know?-- 06:32, 24 February 2006 (UTC)

The preamble at the beginning of this bit has something on "It's quicker just to do your own search rather than bother people". You can type 'darpa' into the magic box, and find something wonderful. --Zeizmic 22:28, 9 March 2006 (UTC)

March 10[edit]

Evil Gene Patenting[edit]

I was reading about gene patenting. What was it the Netherlands was trying to do? Did they want the patenting stopped? --Username132 03:18, 10 March 2006 (UTC)

The evil gene cannot be patented; for national security reasons it is subject to a government monopoly. --Trovatore 03:21, 10 March 2006 (UTC)
Patenting genes is patent nonsense - so a lot of countries want it stopped. Celcius 03:35, 10 March 2006 (UTC)
Then why did the legislation get passed in the first place? --Username132 04:08, 10 March 2006 (UTC)

Wait so what happens if someone patents a gene and my child is born with it? :\ — Ilyanep (Talk) 04:09, 10 March 2006 (UTC)

You get payed a penny every time your kid repeats the company slogan in front of strangers. Or, if your kid is ugly, you have to pay a penny.  freshgavinΓΛĿЌ  05:12, 10 March 2006 (UTC)

Or you can't actually claim anything over natural expression of the gene. But that's not the point. The point is, some corporation discovers the gene involved in, say, I don't know, some kind of cancer. The fat business executives who couldn't care less about people's welfare (they studied business and finance, not biomedical science) can then charge anyone who tries to distribute a treatment for that disease. --Username132 13:32, 10 March 2006 (UTC)
The businessman would say, "Listen, this isn't about people's welfare. I have a big company and spend a huge amount of private money in searching for genes related to disease. Of course I try to make a profit off of this once I've discovered something useful -- if I didn't, how would I ever get the money to look for genes in the first place? Sure, it'd be great if governments ponied up the dough for this, but we all know that it doesn't always work out. We'll try to set things at a fair price, to guarantee our future research abilities. And hey -- we all know that most of the money from these treatments is paid by insurance anyway, so what's the big deal?" I'm not saying that's the last word on the subject, but viewing it as just about "fat business executives" is a very one-sided and unfair approach. --Fastfission 01:52, 11 March 2006 (UTC)
Sounds like something a fat business executive would say... I'm in this gig for the people and what do I get? Exploited. It's fine to make money to cover future expense etc. but they're in it for their flash cars, homes and swimming pools. When my mum was younger she had to boil her asthma cartridges (to pressurise any remaining medicine) SO SHE COULD BREATHE. --Username132 16:57, 12 March 2006 (UTC)
Again, I think that's an overly narrow view of things. While I agree that there is much to be wary about in the big pharma industry, it is important not to mistakenly collapse things down into simple categories of "good guys" and "bad guys" because in most cases that's simply not how the world works. --Fastfission 03:33, 17 March 2006 (UTC)

Computer program equation input[edit]

If I want users to enter an equation into a program I write, and then want the program to use the equation, I only seem to have two options, neither of which seem very good:

1) Parse the equation in the program, allowing for every possible combination of functions, like trig functions, absolute value, hyperbolic functions, log functions, etc. This seems like a lot of work to redo what the program could already do had the equation just been hardcoded in.

2) Write the entire program out to a file, including the equation supplied by the user, then recompile and relink the program, and run it. This requires that anyone running the program also have a compiler.

The language I am using is FORTRAN and the application is a graphing program, but this seems like a more general issue to me. An example would be, if the user enters Y = X^(pi^e) + abs(sin(X^3))/log(1/sqrt(X)), I would then graph that equation. Are there any languages where a user supplied equation can just be used directly by the program ? Does anyone have any other ideas for how to do this in FORTRAN ? StuRat 05:04, 10 March 2006 (UTC)

Yay procedural programming! Not specific to FORTRAN but I learned a little about this in compiler theory (which I didn't enjoy too much), so you might want to check out a book on that. It's possible that someone has made a library that can recieve code as a parameter and parses it into instructions, but they probably did the exact same thing that you said in (1), though likely with a low-level language. High level langauges aren't very good at analysing their own code, which is why many of them have their own scripting languages (I assume FORTRAN doesn't). Does FORTRAN have Assembly commands?  freshgavinΓΛĿЌ  05:25, 10 March 2006 (UTC)
Not that I'm aware of, but it can make system calls, so if assembly language commands are available at the O/S level they could be accessed via a system call. StuRat 08:43, 10 March 2006 (UTC)
This would be relatively trivial in Matlab, but whether that's a real language or not is open to debate.
It wouldn't just be trivial, it wouldn't require any programming at all!  freshgavinΓΛĿЌ  07:01, 10 March 2006 (UTC)
Just look for almost any interpreted language. These tend to show off by having a function like "eval" which takes a string in the same language and execute it. They may be slower than compiled code, but this sort of thing is cute. Believe me, writing an expression parser is not simple, especially if you've never studied formal grammars and parsing techniques. Actually executing the functions is the trivial part. Notinasnaid 09:12, 10 March 2006 (UTC)
Yea, it looks like a lot of work to me. I was actually leaning towards option 2, which requires that the code be recompiled and linked after the user enters the equation to graph. StuRat 10:12, 10 March 2006 (UTC)

I can attest that it is a lot of work because I've written a parser and interpreter that does that; it's not that difficult (recursive descent parser), it just takes forever. You might consider C# which can compile code on the fly without the need for the user to have the SDK on the computer. enochlau (talk) 14:43, 10 March 2006 (UTC)

Expanding on what enochlau said: yes, option 1 is straightforward, though a certain amount of work. But you don't have to do all the work yourself; there are libraries which can do it for you. The C FAQ list mentions a few, although they're pretty dated. And if you know what you're doing, an expression evaluatior really isn't that much work, after all; you can write a simple one in an hour or two. Here's a condensed, mildly obfuscated one I coughed out once: eval.c.
Back in about 1987 I was thinking about precisely the problem you describe -- I wanted the user of a graphing program to be able to enter expressions using FORTRAN-like syntax. I wrote an expression parser and evaluator which I'm still using for various things. Like so many personal projects, it's not quite packaged and documented well enough for others to use easily, but you might take a look at . That package includes the expression evaluation library and a command-line tool to exercise it. I just entered the expression
 c1**(pi**e) + abs(sin(X**3))/log(1/sqrt(c1))
into that tool (where I substituted the FORTRAN ** for your ^, and c1 -- meaning "column 1" -- for X) and it worked fine. Your function blows up pretty fast:
0 divide by 0
1 divide by 0
2 5.76607e+06
3 5.19687e+10
4 3.32476e+13
5 4.99203e+15
Finally, a few more words about your option 2. You don't need to write the entire program out to a file and recompile it; typically you just need to write and compile a stub function containing the user-entered expression, then use dynamic linking to call the just-compiled code from the main program. The C FAQ list talks about this, too. (You didn't say you're using C, but both of the links I mentioned contain information that might be useful no matter what language you're using. Oh: you did say you're using FORTRAN. Hmm. I don't know how much of this stuff even a modern FORTRAN compiler would let you do.)
Steve Summit (talk) 16:06, 10 March 2006 (UTC)
Wow, what a fortunate coincidence ! That math editor function looks quite useful. A few questions:
  • The documentation says "in some versions" repeatedly. Do you have any documentation on what the version you are offering specifically does ?
  • Do you have a FORTRAN stub that calls the function ? This would be useful to overcome all those silly FORTRAN-C function compatibility issues.
  • Is there any support for +/- ? For example, if I give it Y = +/-sqrt(4), I want to get both +2 and -2 as output.
Thanks a lot for your help ! StuRat 20:30, 10 March 2006 (UTC)
Answering these on your talk page. —Steve Summit (talk) 16:45, 11 March 2006 (UTC)
I would like to note that most of these suggestions are good if you're only using the program yourself, maybe if only for a department of a few dozen users, but the concept of using eval statements or open ended compiling is a Really Bad Idea from an information security perspective, if the program is destined to become a software product or mission critical system in any sense. Best case is that an errant user could enter an equation that could crash or drag the processor to a halt, worst case is that you give a malicious hacker the keys to the kingdom (by letting them compile and run any code they want on your system). This of course depends highly on the systems environment you are in, but it is a word to the wise.
If you want to do this in any serious environment (where money or lives are on the line), you will want to know the appropriate compiler theory to parse the equation and build the code yourself, with appropriate boundary checks. KWH 19:11, 10 March 2006 (UTC)
It's just for my own use. I saw many glaring deficiencies in most graphing programs that I wanted to fix:
  • Can only graph an equation in Y = f(X) form. Mine handles Y = f(X), X = f(Y) and equations in neither form.
  • Can only use constant X increments for point sampling. Mine allows constant X increments, constant Y increments, or both.
  • Can't handle inequalities. Mine does.
  • Can't handle Boolean operations on multiple equations. Mine can handle unions, intersections, subtractions, etc.
  • Limited size output. Mine can create a graph any size up to the memory limit of the computer.
  • Can't handle polar equations. Mine can, in R = f(theta), theta = f(R), and general forms.
  • Limited grid lines. Mine can create up to 5 levels of rectangular or polar grid lines.
  • Can't do 3D graphs. My program can.
  • Can't do derivatives and integrals. Mine will do these using numerical methods, although I haven't written this code yet.
I've already created several graphs with this program that are used in Wikipedia [28], but must edit and recompile the program each time I change the formula. This is annoying. StuRat 20:20, 10 March 2006 (UTC)
Look at free software that already does equation parsing. No need to write your own (although you may be the type who likes to DIY) PARI-GP computer algebra system, Euler, YACAS (Yet another computer algebra system) come to mind. Probably others. List of computer algebra systems , Category:Free mathematics software --GangofOne 21:33, 10 March 2006 (UTC)

BIN and CUE files[edit]

I have a .bin and a .cue file which I have downloaded (possibly illegally ;) and contain a computer game. How do I get it to open? --AMorris (talk)(contribs) 07:34, 10 March 2006 (UTC)

Let's hope it's not illegal then. BIN and CUE files can be opened using a "virtual drive". This is a program which emulates a CD drive on your computer. Of course you could just burn the files onto a CD for same effect but it is easier to use the CD drive emulator method. I usually use Daemon Tools - which you can download here - but that's a religious choice - there are many simulators out there. Celcius 11:14, 10 March 2006 (UTC)
An alternative to Daemon Tools is the equally popular Alcohol 120%.
I hope it is one of the many .bin files I've put my remote desktop server hack in. I can always use another bot! --Kainaw (talk) 13:52, 10 March 2006 (UTC)
I highly recommend Alcohol 120% over Daemon Tools, it's much more user friendly I think. Once you got Daemon Tools or Alcohol 120% just mount and unmount the image file(.ISO,.BIN). It's not a very good ideo to have a virtual drive on at all time because it will really slow down your computer, use it only when neccesary. If you want to use the image file constantly just burn the image file to CD using Alcohol 120% but if it's illegal, which i'm guessing it is, it may detect emulation and that you've stolen software, just hope that your OS doesn't send a report.-- 21:16, 12 March 2006 (UTC)


I've heard that some little telescopes can follow the stars so I don't have to turn it all the time. How is that possible? Thank you!! :) Blueiris 11:21, 10 March 2006 (UTC)

I don't know anything about telescopes - but I do know something about computers. It seems like a fairly simple job to hook up a computer and a small motor to a telescope and let it follow the stars automatically. Technically it wouldn't be very difficult. Celcius 11:36, 10 March 2006 (UTC)
The basic principle is that the sky appears to rotate around the pole (north or south). You have a wheel axis pointing to the pole, and have the telescope turn very slowly on it. These days, this can be coupled with a starfinder computer, which knows the location of celestial objects and will automatically use the motor to track to find them, before settling down to following the stars around. It is less expensive than I would have feared. I've been tempted to upgrade my old telescope with one of these. Notinasnaid 11:40, 10 March 2006 (UTC)
Okay. Thanks for both answers! Blueiris 11:46, 10 March 2006 (UTC)
This is very common for all except the smallest and cheapest telescopes, and is called an equatorial mount - for a simple version, all you need to do is set one of these up with the right ascension (also called polar) axis pointing at the celestial north pole, lock the declination axis, and rotate the polar axis so that it makes one revolution every 24 hours. Pretty much every equatorial mount comes with a little motor that does this job for you.
Fancier telescopes with star-tracking software often use a simpler kind of mounting (an altazimuth mount, you've seen them on most binocular tripods), but with motors linked to a computer controlling both axes. This kind of mount is harder to follow stars with manually (as you need to constantly adjust both axes), but the computer does that job for you, while also automatically pointing itself at any object you particularly want to see. — QuantumEleven | (talk) 12:34, 10 March 2006 (UTC)
I think two things get mixed up here. The question was about a little telescope and that may refer to the little one that is often attached to a big one to get the bigger picture. First you roughly aim the telescope, then you look through the small telescope for more precision and only the do you start looking through the big one (sort of like looking up from binoculars to get the bigger picture). Afaik automated star-tracking doesn't use such small telescopes (don't know the ins and out, though) and it will only be used for the more expensive (bigger) telescopes because the mount isn't really cheap (I guess). DirkvdM 12:57, 10 March 2006 (UTC)
(not directly related to the original question, but still) No, you're right, Dirk, automatic star tracking doesn't use the small telescope (often called a finder scope) - how it works is that the computer knows where every star is at any point in time (a very easy thing to store, as stars don't move relatively to each other, and the Earth's rotation is very well known). You set up the telescope by pointing it at a particular star (the computer can't really do this... yet... :)), and from that and the current time and latitude, the computer knows where every star is and will be at any point in time. Therefore, it can control the two motors controlling the axes, and point the scope at anything you want, as well as keep it in the field of view as the Earth rotates. — QuantumEleven | (talk) 15:52, 10 March 2006 (UTC)
By "little" I actually meant a hobbyist's telescope. Equatorial mount was maybe the thing I was looking for, because sometimes telescopes are said to be star-tracking and there's no computer nearby. But I thought it had something to do with gyroscopes because they keep pointing at the same star, too. Blueiris 13:15, 10 March 2006 (UTC)
Yup, I think you probably got that right - a "star tracking" telescope without a computer is most likely one on an equatorial mount with a small drive motor. It takes advantage of the fact that, because the Earth rotates, from the Earth it seems that the stars are spinning around a point in the sky directly above the north pole called the "celestial north pole" (you can see a nice photo of this at Astronomy Picture of the Day - the camera shutter was left open for a few hours, and the streaks you see are the stars apparently moving). If you have a telescope with one of its mount axes pointed directly at this north celestial pole, and you lock the other axis, by spinning the first at the correct rate your telescope will follow a star as it seems to spin around the celestial north pole. Have fun observing! — QuantumEleven | (talk) 15:52, 10 March 2006 (UTC)

I would also think a computer could take video input from a static telescope and compensate for the Earth's rotation. However, this system would only work for small time periods, after which the celestial object being tracked would move out of the field of view. Such a system would have the advantage of eliminating any vibrations that might be introduced by a motor, especially a cheap one. StuRat 19:09, 10 March 2006 (UTC)

Wouldn't a cheap fast spinning motor with a succession of gear-wheels eliminate the vibrations? DirkvdM 07:37, 12 March 2006 (UTC)
I would expect that any moving parts during operation would have to introduce some vibrations. Those vibrations may, or may not, be significant depending on their magnitude and the magnification factor used. StuRat 03:21, 14 March 2006 (UTC)
My thought was that actively moving parts vibrate, so passively moving parts should eliminate that. Not quite sure, though. Another thought would be to use several little motors which cancel out each other's irregularities. I believe that's how record players eliminate motor vibration. Hey, that would be a good one. Use an old record player drive. Oh, of course, a belt drive. There, problem solved. :) DirkvdM 07:31, 14 March 2006 (UTC)
Those things might well reduce the vibrations caused by movement, but none would eliminate them entirely. StuRat 01:29, 15 March 2006 (UTC)
Equatorial mounts with a clockwork drive were around many years before computers came along. --Shantavira 19:50, 13 March 2006 (UTC)


We know that like charges repel(coulombs law) and two wires carrying current in the same direction attract. Suppose there were two independent like charges moving with same velocity parallel to each other in the same direction then what would the force acting on them??? 12:55, 10 March 2006 (UTC)

You appear to be asking: If you take two negative (or positive) ions, put them side-by-side, and send them flying down the road, what will happen? They repel. It doesn't matter how fast they travel. --Kainaw (talk) 13:50, 10 March 2006 (UTC)
To explain this you really need relativistic electromagnetism (electromagnetism in the context of special relativity). The electric repulsion dominates the magnetic attraction until the charges are moving at a substantial fraction of the speed of light, and then relativistic effects like length contraction and time dilation kick in, so that the force in a comoving reference frame is always that due to the electric repulsion alone (because the charges are at rest in that frame). —Keenan Pepper 13:53, 10 March 2006 (UTC)
"two independent like charges moving with same velocity parallel to each other in the same direction" if so, then there's no movement relative to eachother, and no magnetic force. ☢ Ҡiff 18:11, 10 March 2006 (UTC)
Well, yes, but if you're in a second frame of reference that observes the particles zooming off somewhere, you would see the force between them divided into magnetic and electrostatic, but the combined force would be equivalent to the electrostatic force between them in their frame of reference. In other words, it's an "everybody's right" kind of answer :) Confusing Manifestation 13:01, 11 March 2006 (UTC)

Well was wondering if i included relativity,may i now ask that the two electrons would feel repulsion if viewed on the particles,but attracton if viewed ouside the particles??

Earth Orbiter[edit]

What is the minimum speed and altitude a large sattelite would have to be to be in solarsynchronous orbit around the Earth without being torn apart.

Before our resident astronomer comes along, Roche limit might help. Sum0 20:20, 10 March 2006 (UTC)
In particular, note that the "without being torn apart" requirement depends on what the satellite is made of, as described in that article. The Roche limit is usually considered in relation to natural bodies that are held together by their own gravity. Sun-synchronous orbits, on the other hand, are a very specific category of orbits, and are usually considered only in relation to artificial satellites that might be deliberately launched into those orbits. (See Polar Sun Synchronous Orbit and heliosynchronous orbit.) So the question is somewhat odd. --Anonymous, 21:15 UTC, March 10.

Processor spead[edit]

I want to buy computer processor , what is the hieghest spead of processor until now ? have more than 3000 Mhz.

I am ill-aware of the highest processor speed, but the higher the speed does not necessary mean a quicker computer. Kilo-Lima Vous pouvez parler 20:26, 10 March 2006 (UTC)
From your question I take it you are not a computer person? It is not trivial to replace an old processor by a new one, unless you are fairly experienced. In most cases if you simply bought a different processor, it wouldn't fit in the slot, or wouldn't work with other components in your computer. It's also really easy to destroy the processor or other parts (like motherboard) during installation. So if you really want to buy a processor, you need to tell us what kind you have now, what's you motherboard model, memory, etc. --Ornil 20:31, 10 March 2006 (UTC)

Electrical Cost Calculations[edit]

If my utility charges $.1098 KWH how can I figure out what a 5 amp device costs to use?

This might be good to discuss generally. I beleieve people are curious.

Thanks, John

Well, the first step is to figure out the wattage, do you know how to do that ? StuRat 21:02, 10 March 2006 (UTC)
Not to mention how long the device in question will be working for. Here7ic 22:41, 10 March 2006 (UTC)
Like StuRat mentioned, the power consumption is best to go by. Power (Watts) = voltage x current, but the problem is many devices give their current reading as the maximum instead of average, so the 5A could well be the peak current load on the device. - Akamad 23:20, 10 March 2006 (UTC)
Rule of thumb - electricity costs (approximately) $1/watt-year. A 5 AMP device running continiously for one year would consume: 5 amps * 120 volts -> $600 in one year. (5 amps is *a lot* of current). This is the reason, in my field, that supercomputers cost more in the long term due to energy usage than it costs to build them. Raul654 23:27, 10 March 2006 (UTC)
Well, your rule of thumb isn't too far off, assuming a few things about the question. The voltage of the questioner isn't specified, which makes quite a bit of difference. Assuming he's in the US (probably a good guess, based on his use of a dollar sign), this device will draw about 600 watts. Given John's cost, that results in a cost of $0.06588 per hour. This assumes that the device draws a constant 5 amps. So, with all these assumptions, this device running all year would cost $577.1088. kmccoy (talk) 03:21, 11 March 2006 (UTC)
You only report the total to the hundredth of a cent ? What kind of accuracy is that ? Spock would be appalled. StuRat 03:33, 14 March 2006 (UTC)

Space Based Radio Telescope[edit]

Would it be possible to built an enormous radio telescope in GEO above Earth? I'm talking bigger than Arecibo. If possible, what are the cheapest viable construction resources that could be used? Polymers? Here7ic 21:58, 10 March 2006 (UTC)

Sure, but why would you want to? -- Finlay McWalter | Talk 22:01, 10 March 2006 (UTC)
A) Self indulgance, B) A better, clearer, and cheaper grasp of our universe, C) Wouldn't it just look cool? Here7ic 22:36, 10 March 2006 (UTC)
Edit: plus, it'd help to make the Earth a more peaceful place. Here7ic 22:39, 10 March 2006 (UTC)
How's so? ☢ Ҡiff 23:39, 10 March 2006 (UTC)
I think such a project would result in one of two outcomes. 1: The Earth governments would control it as a whole, and it would be one more step towards peace. 2: The Earth governments quibble about spying, good ole' cold war fears are back, and our home world buries itself deeper into political unrest. Here7ic 04:35, 11 March 2006 (UTC)
Arecibo is a radio telescope, placing a single radio telescope that size in space would not yield better results than the Earth-bound arrays we already use. In fact it would probably not be better than Arecibo itself as radio waves aren't as distorted by the atmosphere as visible light. Rmhermen 23:57, 10 March 2006 (UTC)
What if you set up an array of satellite receivers? i.e. VLA but with a diameter of the Earth itself? --Fastfission 02:20, 11 March 2006 (UTC)
Why use the diameter of the Earth ? If you put them in geosynchronous orbit you would have a much larger diameter and would avoid much of the local radio interference on Earth. StuRat 02:51, 11 March 2006 (UTC)
Indeed, there already is a VLA-type array on Earth that's thousands of miles across: the VLBA. The VLA looks cool because of all the dishes being close together, but the VLBA does way better on resolution. According to the NRAO web site, it "has an ability to see fine detail equivalent to being able to stand in New York and read a newspaper in Los Angeles." Of course, as StuRat says, a high orbit in space would do even better. On the other hand, there is the downside that you'd need a radiotelescope to receive the signals from your radiotelescope... --Anonymous, 03:57 UTC, March 11.
What if the Voyagers would have been used for this? That would have given a rather long baseline. DirkvdM 09:08, 11 March 2006 (UTC)
One problem with that is the speed with which technology advances. In the amount of time it took Voyager to get there, its capability is outstripped by new local deployable technologies. Who would invest in a long term scheme when new technology might surpass it before it started it work? Already adaptive optic technology rivals the Hubble Space Telescope. Rmhermen 15:37, 11 March 2006 (UTC)
A radio telescope isn't all that high tech. Actually, it's pretty low tech I believe. So that isn't a problem and they would have known then that that technology wouldn't improve much. But, not knowing that space exploration budgets would collapse, they might indeed have thought that later faster satelites would overtake them.
The precision of Hubble can't compensate for a lack of diameter (which is what this is about). And anyway, Hubble isn't a radio telescope. It wouldn't make sense to put a radio telescope in space because that radiation reaches Earth's surface almost unperturbed. And the corrections were needed to compensate for errors, not to improve on an already good system. DirkvdM 07:47, 12 March 2006 (UTC)

March 11[edit]

Combustion chamber[edit]

1) Is the flame ignited in a car engine's motor cylinder a premixed flame- being more efficient, and kinda bluish- thanks to the premixture of fuel and oxidizer?

Since question 2 is not really related, I split it off into a separate question just below. --Anonymous, 04:10 UTC, March 11, 2006.

Color of overcast sky[edit]

2) Why does a cloudy overcast day have a hot color temperature as indicated by its bluish tint when it is usually cooler (what amkes it color hot)?

First, color temperature is related to actual temperature only when you're talking about objects that are actually incandescent, like the Sun or a light bulb. That doesn't apply to sky light.
I think the answer is that sky light on a cloudy day is only bluish in comparison to direct sunlight. On a clear day, scattering in the atmosphere affects high-frequency light more than low, so the sky is bluish while the direct light from the Sun is depleted of blue and therefore is slightly yellow. On a cloudy day, all the light is further scattered in the clouds and as much of it as gets through also gets mixed back together. So it's bluer than direct sunlight, but less blue than the sky light you get in a shadow on a sunny day. --Anonymous, 04:10 UTC, March 11, 2006.
I would suggest taking a look at the article Rayleigh scattering 01:15, 18 March 2006 (UTC)

Earths Atmosphere[edit]

What are two different theories on the origins of life and what is the evidence that supports these two theories?

Try origins of life

Only two? Organic molecules may have formed in several differrent ways and that may have happened in different locations, such as in water, in rocks and in space. And then there are the oldest 'theories', from before the emergence of proper science, that some 'superbeings' created it, but that is of course begging the question because where did those 'superbeings' come from then? DirkvdM 09:17, 11 March 2006 (UTC)

I agree that there are many theories on the origins of life but synthetic theory of evolution is followed.Suraj vas 11:39, 11 March 2006 (UTC)

Search for life on other worlds[edit]

Does anybody out there have any worries on how NASA is actively trying to search for life in other worlds? I am all for exploration, but I am seriously afraid of a scenario in which we make contact with an alien civilization. Stephen Hawkins himself made a statement that basically stated that if we contacted an alien civilization that was far more advanced then we, then there was a chance that they would not come in peace. Does anyone know if the U.S. government or the military has any plans of dealing with such a situation?

I can understand on why some people may be afraid of a situation in which we make contact with an alien civilization. History on this planet shows us that when a more advanced civilization interacts with a lesser civilization, death and destruction follows. This was the case when Europeans first came to the Americas with their superior guns and wiped out much of the native Indian population. I do not know if the government or military has any plans for this. One would assume that if aliens ever came here they would be possesing some serious technology since they would have traveled many ligh years. I don't think aliens that may be a million years more advanced than we, would have any trouble dealing with "primative" human defense capabalities.
Actually, guns didn't do a great deal of damage to Native American populations. Smallpox and measles did. - MPF 21:53, 11 March 2006 (UTC)
Although we have sent some signals, most searches for extraterrestrial intelligence are passive. If we do find a radio signal, the aliens won't know that we know. As for dealing with them, there are other things that we might actually need to defend Earth against; see our stub on Planetary defense. It'd be sad if we spent our anxiety on aliens and then got creamed by a rock. Melchoir 05:27, 11 March 2006 (UTC)
The Earth has been blaring out radio transmissions to this sector of the galaxy for a century now - anyone looking for signs of civilisation that's within 100 light years could have picked us up. So if there are any alien civilisations out there, they may well know we're here. To be actively looking for alien life means meeting it on our terms, rather than have it suddenly arrive on our doorstep, enabling us to be just that little bit more prepared. If there are intelligent belligerent aliens out there, then whether we're seeking it or not is irrelevant, since it could easily find us (we're a very loud species) - but seeking it out at least gives us a chance of finding it and maybe parlaying with it rather than just have it move in. Mind you, the vast majority of the search for extraterrestrial life is simply looking for any form of life, intelligent or not. Just discovering primitive extraterrestrial life - even monocellular - would be one of the biggest discoveries in scientific history. Grutness...wha? 07:29, 11 March 2006 (UTC)
Then again, a 100 lightyears radius is nothing compared to the size of the universe, the edge of which is said to be at 78 billion lightyears away. And our won galaxy is about 100 thousand lightyears wide. A main reason it is assumed there is life somewhere else is that there are so incredibly many stars that it would be statistically unlikely that something that happened here will not have happened somewhere else. The nearest star is about 5 lightyears away. Does anyone know how many stars there are in a 100 lightyear radius around us?
Why would the aliens be interrested in the US alone? Or rather, why should the US alone prepare for this?
Our intellectual and technological levels would likely be so far apart that they wouldn't be interrested in us. Look at animals in nature. They either compete, eat each other or ignore each other, with the last option being by far the most popular. Animals generally only eat what they know. Something from a different ecosystem (in this case Earth) might not go down well and would be avoided. Humans compete (such as in America) because they are so similar and use up each other's sources (land, food). But we pretty much ignore ants (as long as they don't come in our houses) and the aliens would likely be so totally different from us that they'd probably treat us in the same way. They might not even notice our presence and we'd be able to live here side by side. And we might not even notice them. Maybe they're too minute (hey, maybe ants are aliens) or maybe they take a from we don't recognise as intelligent. Maybe they're made of some gas. Hey, maybe they're already here and that's where ghost stories come from. :) DirkvdM 09:35, 11 March 2006 (UTC)
There have been any number of theories advanced by science fiction writers and SETI researchers (who sometimes are one and the same) about what contact with an alien species might mean. here's an interesting discussion of the various possibilities, though the signal-to-noise ratio in the discussion occasionally gets a bit low. You might also have a look at SETI, Fermi Paradox, Drake equation, CETI, and First contact. The short version is that a) unless they're travelling faster than light it's not going to be our problem, b) if their technology is sufficiently advanced to permit interstellar travel, they're probably going to have kick-arse military abilities as well, c) we're already transmitting unintentionally, d) even if their intentions are benign, real contact with aliens could possibly cause all manner of societal ructions, as it has when more technologically advanced cultures have run into less technologically advanced ones, and e) as an actual threat goes, there are plenty of other things higher up the priority list than aliens, for instance near-Earth objects and random long-period comets heading our way. --Robert Merkel 12:00, 11 March 2006 (UTC)
Don't know how many stars are within 100 ly, I too would be interested in knowing. Our List of nearest stars only goes out to 16 ly. Rmhermen 15:30, 11 March 2006 (UTC)
Hold the horses people - why would aliens want to wipe us out? Earth dosn't contain anything of particular value to a space faring civilzation. All of our ressources could be mined more easily from the Kuiper Belt rather than the gravity well that is planet earth. Our planet will most likely not suit their living needs as they evolved in an entirely different enviroment - so what would they want with earth? Celcius 22:58, 11 March 2006 (UTC)
I think usually (in popular science fiction) the aliens want land. Let's face it: Earth is a sweet ride. Melchoir 00:50, 12 March 2006 (UTC)
They might want to eradicate the cancer called 'mankind' before it spreads into space (as it's starting to do now). This isn't eco-negativism but just a conjecture of what alien minds might work. When it comes to alien thinking I consider myself an expert. :) DirkvdM 07:54, 12 March 2006 (UTC)
The reasons for wars just between different human societies are not always about rational reasons like resources, and for an alien civilization, who knows? Maybe they are like Nazis and want to exterminate 'inferior' life? Maybe they are mutant ant men and want to eliminate anyone existing contrary to their regimented existance? Maybe they are an ambulatory plant species, which has an imprinted hostility to animals (who preyed upon them until the plants learned to fight back)?
Even the Nazis only bothered to kill people who got in their way. They weren't about to send out an army to murder people on Easter Island, for example. StuRat 01:04, 15 March 2006 (UTC)
Ummm, no, they went out of their way. HighInBC 21:27, 18 March 2006 (UTC)
Here on Earth some plants (and fungi) have started to fight back by producing poisons. And then we fought back by starting to like some of those poisons (I recommend the fungi - no not Danish Blue, although that's good too). DirkvdM 07:37, 14 March 2006 (UTC)
What are the chances of intelligent life? I used to believe that there were "aliens" out there that are at least as intelligent as us, but a certain documentary[29] changed my mind. :P Even if you ignore the mention of "God" near the end of the video, the scientific and statisical evidence against extraterrestrial intelligent life is staggering. —OneofThem 20:09, 15 March 2006 (UTC)
We don't know. Melchoir 20:11, 15 March 2006 (UTC)


The area of the collector region in a transistor is greater than that of the emitter region. Why it is so?(Detail answer please).

Thank you

Mani reformatted from original all caps

Drawing too much attention to yourself makes me ignore you. For that reason I haven't read your question. DirkvdM 09:37, 11 March 2006 (UTC)

I don't mean to be rude, but if you can't say anything useful... Sorry, it's nothing personal. Sum0 09:52, 11 March 2006 (UTC)
Well, my remark looks a bit silly now that someone has cleaned up the question. Fyi, it was all capitals and indented to draw a box around it. So my point was that it was the questioneer who was being rude. DirkvdM 07:56, 12 March 2006 (UTC)
You are forgiven, my child. Sum0 15:11, 12 March 2006 (UTC)

Nah, nah, Dirk got the 'rude' slam! ...But really, this is a true 'suitly emphazi' homework question. --Zeizmic 12:21, 11 March 2006 (UTC)

The answer is in bipolar junction transistor, with a nice picture too. --Heron 13:56, 11 March 2006 (UTC)

Can anyone tell me the purpose of this page?[edit]

Adambrowne666 11:13, 11 March 2006 (UTC)

My eyeballs are behaving like the tumblers of a one-armed bandit after reading some of the pages on this site. Either it's the work of manic surrealists or someone is trying to reproduce Finnegan's Wake. I've no idea what it is, but I've bookmarked it. Actually, it does bear some resemblance to the sort of weird things you get in some spam mail, so perhaps there's a connection there. Many of the links are like that, too, as are the upper level pages (e.g., On the offchance that it is spam related, I'd be wary of doing too many clicks on it, though... Grutness...wha? 11:30, 11 March 2006 (UTC)
Looks like an example of Markovian Parallax Denigrate to me. GeeJo (t) (c)  11:53, 11 March 2006 (UTC)
It is a randomly created website used to harass search engines and programs that search websites for email addresses. There is no specific name for it (yet). Some call it a quicksand pit. Some shorten that to sandpit. Some call it a stinger site. Others call it a honeypot. Regardless of the name, it is simply designed to appear like a real website to a program that automatically goes from link to link in search of content. Because it cross-links to itself with random links, the program gets stuck and never leaves. --Kainaw (talk) 15:15, 11 March 2006 (UTC)
In fact cf. Honeypot (computing).--Dell Adams 06:54, 12 March 2006 (UTC)
Is that to battle the likes of Google or spammers? Also, wikipedia links to itself, right? --Username132 21:50, 11 March 2006 (UTC)
Google is smart enough to leave one of those sites. Spammers write clumsy programs to harvest email addresses from web pages. Those could spend weeks on a randomized site going round and round and round... --Kainaw (talk) 22:43, 11 March 2006 (UTC)
I see. And how is wikipedia different from one of those sites? --Username132 07:40, 12 March 2006 (UTC)
In that it doesn't go around in circles linking to itself, I suppose.
Are all those English words? DirkvdM 08:01, 12 March 2006 (UTC)
What are you talking about? Of course it links to itself. Cheese > Cheddar > Cheese > Cheddar... --Username132 16:58, 12 March 2006 (UTC)
Trawlers are usually smart enough not to grab files that they have already grabbed.--Fangz 18:51, 12 March 2006 (UTC)
So you're saying the page in question doesn't actually hold on to the programs spammers use? --Username132 00:29, 13 March 2006 (UTC)
You're feeding the trolls again aren't you - now git you trolls and you kids come home right now! hydnjo talk 00:35, 13 March 2006 (UTC)
Well, it is apparent that the word "random" is not in the troll dictionary. Otherwise, it would be rather obvious what the difference is between Wikipedia and a site that randomly creates web pages with random links to more randomly created pages. --Kainaw (talk) 13:49, 13 March 2006 (UTC)
Who's trolling? It doesn't matter whether these links are "random" or not. The facts are

a) these website link to themselves "randomly" b) wikipedia links to itself, albeit usually according to some form of logic - how does a trawler differentiate between "random" links and links which are appropriate in their context? My guess is it doesn't. So again, I propose that either a) these websites don't confuse trawlers OR b) wikipedia confuses trawlers in exactly the same way

If your answer is a), please explain why this is so, beyond the fact that the links are much more "random". --Username132 19:33, 14 March 2006 (UTC)

It is apparent that the point is not getting across. Wikipedia is editable, but it is fairly static. There are a certain number of pages. A handful are added each day. Less are removed. A handful of pages have major changes, but most pages just have minor changes or vandalism reverts. The website mentioned in the question here is as close to infinite as a URL will allow. Try
The page is randomly created. It does not actually exist. So, no matter how long a spider spends trying to index that site, it will never ever finish (well, if it outlived the Sun and increased indexing speed by 200% every year, it may have a shot at it). Wikipedia, on the other hand, is finite. It can be indexed in a single day. Wow! That fast! Yes - it is mirrored constantly. Just copy the site (an hour at most) and then run a keyword indexer (less than a day will suffice). But, going back to the random page... you will never ever be able to mirror it. You will never ever be able to index it. Why? It is random. So, to repeat once again... Wikipedia is a set of real finite files on a server. The site mentioned in this question is a infinite product of a random page generator. --Kainaw (talk) 00:19, 15 March 2006 (UTC)

Ohhhh, I get it now. That's clever. Thanks! --Username132 (talk) 16:58, 15 March 2006 (UTC)

Raw rice[edit]

My friends told me that eating raw rice is harmful to our health. Is it true?If so how?Suraj vas 11:36, 11 March 2006 (UTC)

Well, first off remember the conditions that rice is usually grown in. If it's left completely untreated and eaten shortly after harvesting, it's likely to harbour all sorts of nasties. I also seem to recall reading about a form of torture involving raw rice, in which the torturers would force a victim to eat as much of the stuff as they could, and then force them to drink a portion of water. The rice would take up the water and expand, stretching the stomach and causing extreme pain. I'm not sure on how apocryphal that story is though, and in any case, the stuff bought in supermarkets won't cause you any harm if eaten raw. GeeJo (t) (c)  11:59, 11 March 2006 (UTC)
Apocryphal. When rice soaks up water, it doesn't expand to more than the volume that the water and unsoaked rice occupied in the first place. - MPF 21:57, 11 March 2006 (UTC)
Could be an urban legend but I heard its fairly common that you can't throw rice at some churches because birds eat it and subsequently "explode" - which is to say their stomachs crack open under the pressure of the expanding rice. Does anybody know if this is an urban legend? Does anyone have some birds and some rice and a keen mind to find out? Celcius 22:47, 11 March 2006 (UTC) says this isn't true. User:Zoe|(talk) 23:21, 11 March 2006 (UTC)
Birds probably know quite well how much raw grain they can eat because that's what they normally eat. Right? Not sure about raw rice, though, because it may be dried. Is it?
Anyway, if you drink plenty of water it passes through your stomach. If that is filled with dry rice ,that will absorb it. And then you can keep on adding water with at least part of it being absorbed. So the riceball would expand to several times its original size. Then again, wouldn't that go down the digestive tract and come out before we get a Monty Python restaurant scene? DirkvdM 08:08, 12 March 2006 (UTC)
The version of this story I heard is the birds do not get enough stones in their crop to grind up the rice and have problems because of it.
Meanwhile rice farmers have too many stones in their crops and have problems because of it, how ironic. StuRat 00:57, 15 March 2006 (UTC)


Recently NASA launched its mission to Pluto. So whats the use? They might discover more moons, water,life etc. So what? I mean they spend millions of dollars for this mission which could be used for the support of millions of poor people in the world. Isn't my point right? You might feel that I am not interested in astronomy at all but I really love this. This question was asked by my friend too me. I just couldnt answer him.Suraj vas 11:46, 11 March 2006 (UTC)

They don't know what they'll find, so they won't know the point until they find it. In general terms, however, investigating the outer regions of the solar system may help us understand the process by which the solar system was formed, which is a good thing. That can help us with issues such as how life arose, and where else it might have arisen. In any case, the amount of money spent is trivial compared to the amount spent on buying bombs for the army, or the amount of money spent on chewing gum each year. You can bet that if the money wasn't being spent on this mission, it wouldn't be spent on relieving world poverty. Markyour words 12:02, 11 March 2006 (UTC)
Yes, and what tells you that the money would have been spent to support poor people, or anything useful at all? It's at least as likely that it would have been used to drop a few more bombs on random countries with difficult to pronounce names, so the Pluto mission might actually have saved innocent lives :p dab () 12:11, 11 March 2006 (UTC)
Tell your friend they are committing the logical fallacy of false choice which is a correlative based fallacy in which options are presented as being exclusive when they may not be. It is often used to obscure the likelihood of one option or to reframe an argument on the user's terms. There is nothing to prevent the government from doing both. This fallacy is also known as Morton's Fork. WAS 4.250 14:52, 11 March 2006 (UTC)
So, your friend's argument is to fire everyone at NASA, make them poor, and give their money to poor people? How is that a more intelligent thing to do than sending a probe to Pluto? --Kainaw (talk) 22:41, 11 March 2006 (UTC)
There's this silly idea that feeding the hunger is something terribly important for mankind, as if no money can be spend anywhere else until everyone is chubby. People just try too hard to "do a good thing" (and "feeding the hunger" is the stock "I care" idea) and forget there are other things that are also good for mankind, even on a higher level, such as scientific research. The issue with the poor people shouldn't be solved taking money from these other areas, but by correctly allocating resources and disappearing with corruption and white collar thieves. ☢ Ҡiff 22:49, 11 March 2006 (UTC)
In about 200 years, when the Earth is uninhabitable, these probes will have given NASA or whatever other agencies which succeed it (and those in other countries) enough information to help to transport humanity into space, where they can survive instead of dying out. User:Zoe|(talk) 23:18, 11 March 2006 (UTC)
Now that's just rubbish. The Earth will still be habitable in 200 years. In any case it's the most likely probability. The "last perfect day" is a good several billions of years from now. At least that's the general consensus. Here7ic 05:06, 12 March 2006 (UTC)
You guys seem to have crystal balls (no pun). One far-sighted, one short-sighted. DirkvdM 08:42, 12 March 2006 (UTC)
I don't need a crystal ball. My contribution is based on the observed age of our sun and it's predicted life. I'd really like to see his sources... Here7ic 18:31, 12 March 2006 (UTC)
I'm not talking about the sun burning out, I'm talking about the lack of energy sources and the soup of pollution. User:Zoe|(talk) 00:20, 13 March 2006 (UTC)
Ever heard of expansion? Earth won't be our only home forever. Here7ic 04:12, 13 March 2006 (UTC)
That's my whole point. If we don't explore the solar system/galaxy, how will we ever be able to expand? User:Zoe|(talk) 17:16, 13 March 2006 (UTC)
It is expected that a large amount of money will be spent on space exploration within the next decades. Here7ic 01:32, 14 March 2006 (UTC)

I am one of those who supports the pursuit of knowledge as its own end (obviously, since I’m a knowledge seeker). Yet experience has repeatedly shown that the pursuit of science provides practical benefits. Obviously, without a space program, we would not have satellites for weather, commmunication, television, and so on. If not for this tendency to push our limits and to explore, humanity might have remained hunter-gatherers still confined to a small region of Africa. And while local sea transport certainly helped with coastal trade and so on, the deep-sea voyages of several centuries ago were extremely risky and expensive, with no clear knowledge of what lay beyond, to use an approximate analogy. — Knowledge Seeker 06:01, 12 March 2006 (UTC)

Relatively speaking, these explorations are very cheap. Space exploration brings up the same argument and counter-argues that "space exploration itself receives a very small percentage of total government spending (nearly always under 0.5%)". And most countries don't even have any space program at all. A mistake often made is to just look at the cost and not at how often that cost is made. Space programs are expensive but rare. New Horizons (the project) says it costs 650 million US$ over 15 years. That's 40 million per year. A comparison with military cost is obvious, but let's take something closer to home. The US has 220 million cars. The total cost of driving a car is a few thousand $ per year. Say that comes to 400 billion per year. That would then be 10.000 times the cost of the program. So maybe if people would do more ride sharing that would save loads of money that could be spent elsewhere. You yourself can donate the money you save with this. Share a ride and save a life. That's something you can do yourself, so you don't have to bitch about the government not doing things right. DirkvdM 08:42, 12 March 2006 (UTC)

World hunger is not as simple as just not having enough food for poor people, the reasons it exists are complex. For instance, a country may have a dictator who uses collective farming techniques to force the farmers to raise cash crops like strawberries to generate revenue to buy weapons. Another problem is like the situation in Iraq where the UN was drawing off resources intended to provide food and medicine to the people. Also, just giving people food does not teach them how to feed themselves.

Suraj, you might like to think about why your own country is doing things like a) building the BrahMos cruise missile, buying (and building, I believe) Su-30 fighter jets, and hosting the 2010 Commonwealth Games, all of which are considerably more expensive than the New Horizons mission? Are they really more important than the 300-million odd Indians who still live in absolute poverty? And would cancelling any of them help those people? --Robert Merkel 00:48, 14 March 2006 (UTC)
How does collective farming promote poverty? Or did you just throw that one in for good measure? DirkvdM 07:41, 14 March 2006 (UTC)
Well, I do not want to turn this into a collective farming rant, so just presume collective farming=command economy and do the math.
Wait, communitarianism and collectivism is not necessarily by a command economy...there are gift economies and anarcho-syndicalist communes, for instance... Elle vécut heureuse à jamais (Be eudaimonic!) 22:58, 14 March 2006 (UTC)
I did not want to get into an extended discussion of collective farming and command economies. For the example stated above, the dictator uses a collective farming techniques in it's command economy sense to starve the people.

Origin of life[edit]

In wikipedias article about this there is no mention about Synthetic theory of evolution. But my science book(CBSE, class 10) says its the currently accepted theory of evolution. So which is right?

Modern evolutionary synthesis? Markyour words 12:04, 11 March 2006 (UTC)


what is rotational friction.while a bicycle is running how is the frictions act on the tyres?--Mufleeh 12:27, 11 March 2006 (UTC)

  • See rolling friction. Is "rotational friction" another name for it? --jpgordon∇∆∇∆ 16:59, 11 March 2006 (UTC)
    • That's probably what the question was looking for, but in general, from a google search, "rotational friction" seems to mean any damping torque in general. Melchoir 19:29, 11 March 2006 (UTC)

Pre-heat/warm oven?[edit]

Why do we pre-heat/warm ovens?

Regards, Reelstreets.

Are you talking about an oven you would have in your kitchen? If so, to pre-heat the oven just means to turn the oven on a few minutes before you are going to need to use it so that the oven is up to the desired temperature before you put the food into it. Dismas|(talk) 15:22, 11 March 2006 (UTC)
It's because foods cook differently at different temperatures. Let's say you were baking a cake. Cooking it for 10 minutes at 300 degrees(F) is not the same as cooking it for 20 minutes at 150 degrees(F) (twice as long at half the temp). All things are cooked at a specific temperature to achieve the best results. We preheat ovens so that from the moment we put the food in there, it is cooking at just the right temperature. A good example of how things cook can be found in pretzels. Hard pretzels are the result of high temperatures and short cook times. Soft pretzels are the result of low temperatures and long cook times. See how much of a differene it makes? --Chris 15:59, 11 March 2006 (UTC)

Oh! Right. Thank you so much for the information. Reelstreets.

I don't always preheat the oven, let me explain why I sometimes do and sometimes don't:

  • Preheating is useful if you are cooking something based strictly on time, for example, at 300 degrees for an hour. That is, without it you don't exactly know how long it takes for the oven to get up to temp and how much cooking was done while at the lower temps.
  • Cooking based strictly on time and temp is akin to "dead reckoning", however, which is finding a location by moving a certain amount in a certain direction with no regard for landmarks. If you use landmarks, you can navigate much more closely to your target. Imagine the difference between driving home with your eyes closed and with them open ! In cooking, you can look for browning, use a thermometer, stick a fork in the food, use smell, etc., to gauge when the food is ready. This is much more reliable than going strictly by time and temp, which may vary by altitude, oven design, humidity, slight differences in proportions of ingredients, age of ingredients, how much of your yeast is alive, etc.
  • I prefer to put food into the oven and take it out, when the oven is cool, to prevent accidental burns. Yes, you can use pot holders, but one slip and it's easy to severely burn yourself. I also like to open the oven door and let it cool down before removing the food. Most food needs a cool-down period before it's served anyway, so this is not a problem.

StuRat 20:47, 11 March 2006 (UTC)

You're odd. Everybody knows that the best way to prevent accidental burns is to first burn yourself on purpose so that you develop large calluses on your hands and all the nerves die. You can't grow up to be a respectable old lady with cared-for dove-soft hands.  freshgavinΓΛĿЌ  05:44, 13 March 2006 (UTC)
I don't want to be a respectable old lady. I was rather hoping to be a dirty old man. StuRat 04:01, 14 March 2006 (UTC)

multilingual webpage[edit]

What's the right way to make a page multilingual? Like, so that the right language gets selected automatically according to the clients language preference? -lethe talk + 17:59, 11 March 2006 (UTC)

You have to set up your web server to serve them a different page based on the "Accept-Language" field sent by the browser. Exactly how to do it depends on which web server you're using. —Keenan Pepper 18:33, 11 March 2006 (UTC)
Well, what if I don't have access to the server configuration? I was hoping for something I could include in the page. Basically I'm looking to replace a front page that says "choose your language". You know that wikipedia error page that you get when the site goes down? It's a single page, but it includes 5 or so different languages, which you can switch between (without loading a different page). Like, maybe it's Javascript? How do I see that page when wikipedia is not offline? -lethe talk + 18:40, 11 March 2006 (UTC)
So does the webserver have to know what translations to use for every single page it's going to serve? Seems a bit inefficient, doesn't it? Every time you add a page, you have to update the server config? -lethe talk + 18:50, 11 March 2006 (UTC)
The multilingual portal for wikipedia should appear here, and this page seems to address your 'automatic language selection' needs. Tzarius 01:25, 12 March 2006 (UTC)

Tracking Addresses[edit]

Hi is it possible for people to find out my location from posting on Wikipedia, cos people get your I.P address? Also can people do the same from emails, i have a hotmail account can they find my address? thanks Kingstonjr 18:07, 11 March 2006 (UTC)

Short answer: in principle, yes, your IP address tells your physical location, but in practice, no, no one can find out your address. Yes in principle because your IP address is just that, an address. Packets on the internet use it to get to and from your computer, and if internet packets can do it, then so can people. Only, most people don't have access to all the routing information of the internet, so in practice, it's very hard.
On Wikipedia, if you have a user account, no one can get your IP address without developer or m:CheckUser access. Thus having a user account actually makes you more anonymous. If you edit wikipedia "anonymously", then anyone who cares to can see your IP address.
With email, email headers generally contain the fully qualified domain name (FQDN) of the machine they originated from, which is equivalent to the IP address. Emails from webmail services do not actually originate on your machine, they originate on the webserver, although the webserver can choose to add the client's IP address to the headers. Hotmail does this, gmail does not.
So what can people find out from your IP address? It depends on the address. When I'm in my office at university, my FQDN contains my last name, the department I work for, and the name of my uni. That's a lot of information; with that information, someone can look up my full name, see my picture, get my phone number, and my mailing address from the university's online directory. When I'm at home, my IP address contains the name of my internet service provider (ISP) and an abbreviation for the city, province and country that I live in. If I were using AOL instead, the IP address would contain less information; just the name of the ISP (AOL). It might also say whether I'm a broadband or a dialup user. In no case does your IP address contain information about your actual mailing address, though in some cases it can be almost as good.
Your ISP does know your mailing address, that's how they send you bills and do maintainence on the connection, etc. So people who work for your ISP can figure out your address if they know your IP address. This also applies to people who can break into your ISP's database or people who can get a judge to issue a court order to the ISP to release that information. -lethe talk + 18:27, 11 March 2006 (UTC)
In films people sometimes hide their location by being connected through several times (or something like that - I don't understand how that works either). But I suppose that is just to make it difficult to locate them, even for intelligence agencies. By the time the location is found they're gone. I suppose. DirkvdM 08:50, 12 March 2006 (UTC)
Lethe makes a good point, though I would like to point out that to track somebody you need both their IP and the time they were using it. This is because many ISP's give the same IP to many people over the course of time. As for DirkvdM's comment about connecting through other computers, perhaps the article on proxy servers should be consulted for one method of doing this. HighInBC 21:40, 18 March 2006 (UTC)
A lot depends on the internet connection in question. Here in the uk with dialup or DSL connections all you could find out without the ISPs cooperation is that someone is in the uk. With cable you can generally figure out what area of the uk they are in from the reverse dns (e.g. would mean basingstoke. If your on a corprate or academic network it may be much easier to get a physical location though (e.g. is a dead giveaway as to someones location right down to room number!). Sometimes its more cryptic but easilly figured out at least down to site level with some local knowlage (e.g. Plugwash 22:18, 18 March 2006 (UTC)

Antibiotic Sensitivity Testing (Antibiotic Discs)[edit]

Antibiotic sensitivity is tested with impregnated discs. The discs are available at a different antibiotic concentrations from the same company (e.g. Nofloxacin (10 mcg)-NF, Cefuroxime (30 mcg)-CR, Ciprofloxacin (5 mcg)-CI). Now is it fair to normalise the size of the clearance to the concentration of antibiotic on the disc - I mean is a clearance of 30 mm for 10 mcg of antibiotic A supposed to make it an equaly good choice as 30 mm 10 mcg antibiotic B? I mean antibiotic B could be lethal at a concentration of 10 mcg... do they impregnate the discs at physiologically meaningful concentrations? Different companies even do different concentrations for the same antibiotics... how confusing! How does one decide what to give a patient? --Username132 20:05, 11 March 2006 (UTC)

Different disks are used for different purposes, or are used with appropriate variations of method. Obviously, the concentrations need to be clinically relevant. Patterns of infection and resistance in a hospital are closely watched and if the sensitivity testing results were not correlating with clinical responses to infections, it would be noticed and investigated. The sensitivity report is only one of the pieces of information considered in choosing an antibiotic. I suspect you could pay a visit to the microbiology lab of your local hospital and one of the lab techs would be happy to show you how it is done and answer your specfic questions. alteripse 03:05, 12 March 2006 (UTC)
In clinical use, you have to consider a number of things aside from antibiotic sensitivity, although it is definitely a good starting point. The antibiotic has to be able to reach the site of infection in an active form at adequate concentrations, and you have to consider possible side effects, contraindications, and drug interactions. For instance, tetracycline antibiotics may bind to a number of different metals such as magnesium, aluminium, iron, and calcium-- this will inactivate the tetracycline. Hence, they should not be taken with antacids or milk. Also, since they bind to calcium, they can also cause permanent stains in children's growing teeth, and the tetracyclines may also affect their bones.
Some bacteria may not show resistance at low concentrations; however, when you test at higher concentrations, genes for antibiotic resistance may be activated, and the bacteria is then resistant. This is known as "inducible resistance", and is associated with the SPICE organisms (Serratia marcescens, Pseudomonas, Indole-positive Proteus, Citrobacter, Enterobacter). In these cases, the disc method might not pick up on this form of antibiotic resistance, and you may have to resort to other techniques [30].
Additionally, some bacteria may form biofilms, which are aggregates of micro-organisms that can resist antibiotics-- this makes treatment of replacement joint infections difficult. Also, when you take broad-spectrum antibiotics, you usually end up killing a multitude of microbial species in your gut (i.e. gut flora). This may allow Clostridium difficile to take over, and you can get Pseudomembranous colitis as a result.
Hopefully, I haven't overwhelmed you! But as you can see, there are a number of factors that go into choosing the most appropriate antibiotic aside from antibiotic disc sensitivity. --Uthbrian (talk) 06:01, 13 March 2006 (UTC)

Thank you! That's really helpul! Incidentally, that tetracycline thing is quite relavent. My dissertation involves its use as a controller of gene expression but I guess you wouldn't want to do this with children. Is the stain permenant? I mean bones are dynamic and constantly being rebuilt - surely this would also make adults susceptible? --Username132 19:38, 14 March 2006 (UTC)

visual acuity testing using the stars[edit]

I am preparing a talk to ophthalmalogy residents. It has been said that a test for keen visual acuity in ancient times was to be able to see the "double" star of the second star from the end of the Big Dipper- Mizor and Alcor. This separation is 12 minutes of arc. 12 minutes of arc is equivalent to what in Snellen Vision Acuity about 20/50 or 20/200? Thank you, George Bohigian MD Washington University School of Medicine St. Louis, Mo

Hmm... Visual acuity and Zeta Ursae Majoris don't provide an immediate answer. It doesn't seem as if groups of dots are standard optotypes... Melchoir 21:02, 11 March 2006 (UTC)
I know that answering this question is futile, but I can't help it. :-\ The letters on the Snellen chart are based on a 5x5 grid. At 20/20, each letter subtends 5 minutes of arc, so each grid cell subtends 1 minute. Recklessly assume that resolving two stars is the same as perceiving a single black cell between two single white cells (which of course is not what happens in a real Snellen test). At 20/20, the centres of the two white cells are separated by 2 minutes of arc. 12 minutes of arc is six times bigger than this, so the Snellen fraction would be 20/120. However, with star-spotting, you are violating the standard illumination conditions of the Snellen test just a teensy bit, so I doubt that this result is meaningful. The only true way to equate the Snellen scale with the star-seeing test would be by experiment, which would be an interesting exercise. I wonder if anyone has done it. --Heron 18:32, 12 March 2006 (UTC)
Good response Heron. I think it would also the same as discerning 3 black cells in a row from two black cells separated by one white cell. I would guess that 20/120 would correlate quite well (at the very least it would be a rough estimate) with the star-example although it is true that experiment is the only way to tell. George, I'm wondering where you read about that being an acient test? Just curious, thanks. -Snpoj 07:08, 13 March 2006 (UTC)


How do you add foreign language support in mozilla firefox? I tried tools/options/edit languages/add language, but this did not work -Anonymous

Depends on what you mean by "foreign language support". If you want to read pages in other languages, it should just work automatically as long as you have the right fonts. If you want the browser interface to be in a different language, you have to download a regionalized build here: Pepper 23:40, 11 March 2006 (UTC)
I meant the former, so I guess I don't have the right fonts...But there is nothing that automatically asks me to download the required fonts, like in Internet Explorer. For example, I can't read [31] -Anonymous
It doesn't have to be any particular font, just one that includes the required characters. For example, if you install Microsoft Office, it includes a version of Arial with characters for a wide variety of languages. If you don't have Office, you may be able to find a freeware font with the same characters, such as Code2000, but I haven't tried any of those.
By the way, that "Add Language" dialog is for something completely different. The list you enter there is sent to web servers, which can then decide which language version of a page to send you in case they have more than one of the same page. I don't think it's used much any more. —David Wahler (talk) 15:16, 12 March 2006 (UTC)
That's strange...I already have Microsoft Office. I even went to Microsoft Office Tools/Microsoft Language Settings and added the language (Chinese) but i still couldn't read [32] -Anonymous
Oh, wait, it works now. Thanks! -Anonymous

Problem with my mouse[edit]

I have a problem with my mouse (computer): It seems to jump across the screen, move up and down at random intervals, completely stop responding but then responds a few seconds later, and sometimes go into a slow, sticky movement (if you know what I mean, it's a bit abstract to explain). The connection from computer tower is fine; and I am using a ball mouse. Can anyone help me out on how to resolve the problem? Thank you very, very much. Kilo-Lima Vous pouvez parler 23:01, 11 March 2006 (UTC)

If you haven't already done so, cleaning your mouse is a good idea. Take out the ball and scrape the grey gunk off the rollers (most mouseseses have three). If it's an old mouse, then the problem may be with the cable - if it's worn internally, it may not send a good signal to your computer. And of course, check the connection!
Slumgum 23:10, 11 March 2006 (UTC)
I'd suggest you to just go get an optical mouse instead. They're pretty cheap nowdays and they're just too much better than ball mouses. ☢ Ҡiff 00:58, 12 March 2006 (UTC)
Alas you specified that it is about a computer mouse. Without that the question would have been a lot funnier. Especially the 'ball mouse' bit. DirkvdM 08:53, 12 March 2006 (UTC)
More seriously, it sounds like your graphical system is overloaded. In that case you should have other graphical problems as well, such as when switching between windows being slow. Having too many windows open (say, over 20) could be a cause. I also once had something like this with a mouse-pad, althogh I can't remember the details. I think I had both a normal mouse and the mouse pad connected and when I disconnected the latter all was fine. Does the problem persist when you use a normal mouse? DirkvdM 08:59, 12 March 2006 (UTC)
What about mice with a tracking ball - are they nice to use? --Username132 17:02, 12 March 2006 (UTC)
If you don't mind people making fun of you, and if you can get used to doing everything backwards.  freshgavinΓΛĿЌ  05:39, 13 March 2006 (UTC)
I use a digitizing tablet and pen. Never needs cleaning to get it to work and I don't have to decide if more than one computer mouse are "mice" or not, LOL. StuRat 04:11, 14 March 2006 (UTC)

Download freezing my PC[edit]

I tried to download an .exe to upgrade one of the downloaded programs I have on my PC, and the download froze the computer right at the very end. I had to literally turn the computer off and back on again to get out of it. Now the mostly-downloaded file is sitting on my desktop, and every time I even touch it, either by clicking on the icon on the desktop or clicking on the file name in Windows Explorer, the PC freezes again. Any ideas on how to delete this file? User:Zoe|(talk) 23:08, 11 March 2006 (UTC)

I am assuming you use Microsoft Windows, and if so, then you could try their Malicious Software remover. I have not yet downloaded this, so, unfortunately, I am unable eto give you a mini rave-review. It's available here. Hope this helps. However, after reading a few details on the page, it appears it scans your ccomputer, so I doubt the file will come up becuase every .exe file will come up. Kilo-Lima Vous pouvez parler 23:20, 11 March 2006 (UTC)
(added after edit conflict) First off, a few specifics. What program were you trying to update? What was the name of the exe file? From where did you download it? It might be some sort of spyware mucking up your OS, so it'd be helpful to know what something about it.
Other than that, it sounds like there was a problem with your browser downloading it. Since it froze before it was even finished, it seems like it doesn't have very much to do with the exe itself, other than it got malformed during download. Have you tried simply downloading the file again?
As for deleting it, you may wanna try deleting it using the command line, instead of using Windows Explorer. Does this work? That is, open Run, type "cmd" browse to the correct folder using "cd", and typing "del [filename]". Hope this helps Oskar 23:23, 11 March 2006 (UTC)
It was an update to IrfanView. It isn't a .exe file, it's a .part file, because the download didn't finish. I can't delete it, that's the problem, the minute I single-click on the file name or the icon, the computer freezes. Maybe I'll try re-downloading it, see what happens there. User:Zoe|(talk) 23:44, 11 March 2006 (UTC)
So, what you're saying is, probably not spyware? :P Try downloading again and/or deleting it using the command line, those should work. Oskar 23:48, 11 March 2006 (UTC)
Having more than one OS installed can often help in such situations. Preferably two different ones, so if you use msWindows, install Linux (takes about half an hour with a modern distro and you'll have all sorts of programs coming with it - unlike with msWindows). Then, from there, it should be no problem to remove the file (linux can access just about any file system, although ntfs is problematic). And then you can use Linux to download the program. That's what Linux is best at - internet stuff. And if things go wrong it won't freeze (well, extremely unlikely). DirkvdM 09:04, 12 March 2006 (UTC)
I find Ubuntu Linux useful because the Live CD enables complete access to Windows folders without having to go to the trouble of installing it all. Sum0 15:07, 12 March 2006 (UTC)
Have fun trying to mount it though. The wiki will come in handy if you decide to go the Ubuntu route. --Optichan 18:47, 14 March 2006 (UTC)

Attempting to download it did the same thing -- download froze at 1 second left, and I had to turn off the PC. And Start/Run/cmd doesn't work, it says it can't find the program (I've never tried to get into MS-DOS from this computer, this is the first time I've tried the cmd command). User:Zoe|(talk) 00:04, 13 March 2006 (UTC)

Which version of Windows are you using? Try Start/Programs/MS-DOS Prompt or Start/Programs/Accessories/Command Prompt. --Optichan 18:49, 14 March 2006 (UTC)
You say the half-downloaded file was a *.part file, so I assume you're using Firefox. Firefox has frozen for me before at the end of downloads for no reason. Also, have you configured Windows so that a double click opens a file or a single click? If you're configured in the default way so that single clicks just select, and your computer freezes on merely selecting the file, that's not good. When you select a file in Windows Explorer, it finds out a bit more information about the file such as date created, modified, accessed, and information on its place in the file system. The file's gotta be pretty corrupted if it freezes like that. Also, it would be advisable not to run an incomplete *.exe file. It tends to hang, do nothing, you have to end its process and even then, it doesn't let you delete it except in Safe Mode (hold F8 while booting). -- Daverocks (talk) 03:01, 15 March 2006 (UTC)

March 12[edit]

aromatic oils in citrus[edit]

What is the purpose of the aromatic oils in citrus zest? Are they an insect repellent, or what? —Charles P._(Mirv) 00:44, 12 March 2006 (UTC)

Does the word purpose mean you support intelligent design, or are you really asking why the citrus tree evolved the genes to make those oils? —Keenan Pepper 01:23, 12 March 2006 (UTC)
the latter. sorry if that wasn't clear. —Charles P._(Mirv) 02:21, 12 March 2006 (UTC)
Many fruits are "designed" (the parentheses are there to keep that anti-Intelligent Design guy from chiming in again) to be eaten, then the well fertilized seeds grow into a new plant. Having a bright color and fragrance makes it easier for animals, including us, to find and eat the fruit. StuRat 06:51, 12 March 2006 (UTC)
Also, some of them might be chemical signals in the flowers, to bees or whatever pollinates them, that happen to remain in the fruit. —Keenan Pepper 07:04, 12 March 2006 (UTC)
Your comment on intelligent design was way out-of-order and I expect you to bow deeply and resign from your post. It doesn't matter if it was an intelligent purpose or not, it still functions in the same way and achieves the same results no matter what you think of evolution.  freshgavinΓΛĿЌ  05:38, 13 March 2006 (UTC)
Um...I leave orange peels and lemon peels on the grass so that the racoons and cats don't visit my place... --HappyCamper 03:17, 14 March 2006 (UTC)
Be honest. You just put them there because you don't want to have to explain to people that racoons and cats don't want to visit your place!  freshgavinΓΛĿЌ  03:41, 14 March 2006 (UTC)
I disagree with bringing ID vs Evolution into this question, but one might argue that they'd give different reasons for why the citrus has those oils. (Presumably, the former would say they are mainly for the benefit of humankind, the latter, that they are mainly for the benefit of the tree. However, some forms of creation might say that God made the tree to benefit itself (to become fruitful - pardon the pun - and multiply itself), that the fact that it benefits other species is simply good design. Circle of life and whatnot.)
Either way, a lot of fruit actually "wants" to be eaten and goes out of its way to attract animals. About the insect repellant idea - I don't know if it helps in the tree, but citrus juice is used to handle insects outside: Bryce 14:06, 19 March 2006 (UTC)

Mustard oil[edit]

Mustard oil is being used in India for cooking for thousands of years.IBut I think it is banned in most of the countries including USA and Europe.Is it really hazardous to health? If it is so why is it hazardous?

Have you read the article on mustard oil? —Keenan Pepper 01:18, 12 March 2006 (UTC)
Mustard oil is the best! deeptrivia (talk) 01:21, 12 March 2006 (UTC)

Moment in a bimetallic strip[edit]

When we heat a bimetallic strip, differential expansion causes an induced moment in the strip, from where the curvature of the beam can be calculated (see Eqn. 4 on this page.) This page says: "Derivation of equation (4) is not particularly complex, but need not concern us (see Clyne T W, Key Engineering Materials, vol.116/117 (1996) p.307-330). It is based on the balancing of the bending moment generated by the misfit strain against the opposing moment offered by the beam." I don't have this reference, but since it says this derivation is not complex, I was wondering if someone has ideas on how to go about it. Any help would be highly appreciated. deeptrivia (talk) 03:26, 12 March 2006 (UTC)

I have posted an usatisfying answer on his talk page Vicarious 20:58, 13 March 2006 (UTC)

what's a good common mesh/model file format with enough features?[edit]

I've been looking up mesh/model file formats, but I can't find any open ones with easily-found documentation for a format whose specification allows for not just regular static meshes but also animation channels (weighted or not) and UV texture coordinates.

The closest one I could find have been the .MD3 and .MD5mesh/.MD5anim file formats used in John Carmack's game engines, but I'm not sure if he wants royalties for using those formats. And even if the MD2/MD3/MD5 formats are free to use, exporters for Blender (the only 3D suite I can afford) for that format are only partially functional in that they don't export everything they ought to export.

The only mesh format I've become somewhat comfortable with has been the Wavefront .obj format -- being text based, it's easy to figure out a lot of it just by looking at it and I've written a flat-shaded model viewer for .obj files, but the specifications I've found so far do not indicate that it supports animation information or multiple texture channels.

Do I have to come up with my very own model format and write my own Blender exporter for it, all from scratch, if I want to write anything resembling a graphics engine? That seems to be what many videogame companies do anyway, using an in-house format that they no doubt wrote custom exporters for, but I really don't have time for that. Or is there some open-specification, well-documented, royalty-free, and pretty-much-fully-featured model/mesh file format out there supported by the majority of 3D modeling+animation programs that I haven't noticed yet? It's just frustrating that the only thing holding me back from writing an engine that does more than render flat-shaded, static models is the lack of information and availability of utility. -- 08:06, 12 March 2006 (UTC)

Wow! Do you want to get a real name and work for us? The pay is lousy, but you get to make fun of people. As for your question, you'll have to go to newsgroups, or advanced graphic forums. Since programmers are very mobile, I am sure that somebody has solved the problem, and is no longer tied in-house. --Zeizmic 17:42, 12 March 2006 (UTC)


are there any specific programs that can turn .m4a songs to the format of .wma of .mp3 format songs? urgent!

iTunes can. Melchoir 10:30, 12 March 2006 (UTC)
To turn m4a into mp3, use iTunes. To do this go to prefrences, and make sure you are importing to mp3, with the bps of your choice (128 is CD quality), and right click (control-click on a mac) on the song(s) you want to change and select "convert to mp3." I am pretty sure you can't convert from m4a to wma, because of codec issues. If you want to convert from wma to mp3 or m4a, then you would want to use Easy WMA. Love, -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 11:20, 12 March 2006 (UTC)
It's certainly possible to convert from m4a to wma. If nothing else, you could convert the m4a file to a wav file, then convert the wav file to wma. However any transcoding between lossy formats is going to do damage to the quality of the file, so should be avoided if at all possible. Markyour words 11:39, 12 March 2006 (UTC)

I presume that you are using a PC, since you want .wma, but what are you trying to do? A clearer idea of your purpose would help. For great justice. 02:51, 13 March 2006 (UTC)

Audio Conversion[edit]

How can I convert audio files from a CD into .mp3 files, for free?

Use any CD ripping program. ITunes is popular but very bad; EAC is harder to use, but gives the best quality. Markyour words 12:28, 12 March 2006 (UTC)
Can't Windows Media Player simply do it? Kilo-Lima Vous pouvez parler 12:42, 12 March 2006 (UTC)
Newer versions can, but they're no better than iTunes. Markyour words 13:02, 12 March 2006 (UTC)
Winamp Pro can. This costs $20. You can try this piece of freeware. Though, it doesn't look perfect. Computerjoe's talk</span> 15:34, 12 March 2006 (UTC)
I use FreeRIP, my sisters use EasyCD-DA Extractor. In my opinion, they're both better than all these suggested so far. FreeRIP is the faster I know, too. ☢ Ҡiff 01:12, 13 March 2006 (UTC)
There is a LAME plugin for iTunes that replaces iTunes crappy codex with a kick ass mp3 encoder. For great justice. 02:52, 13 March 2006 (UTC)
I've always used CDEX for ripping. Just another reliable option. It's small and freeware, allows plugins.  freshgavinΓΛĿЌ  05:33, 13 March 2006 (UTC)
I like to use DeepRipper. Its completely free and very easy to use. Try it out. You can download it from or from the official website. If you use the official website, make sure you get DeepRipper and not DeepBurner. I suggest though. Latest version is 1.1 for both sites. --Chris 16:14, 13 March 2006 (UTC)

Blood circulatory system[edit]

How long does it take for sugar in a can of cola to diffuse throughout the body? I need this info for a project im doing involving the "healthiness" of different canned drinks


Well, even although I don't have a specific andwer for this question, bu if coca-cola contains roughly the smae amount of sugar in honey, then it iwll take about 20 seconds for the suagr to get into the bloodstream. (Source: The Book of Useless Information.) Kilo-Lima Vous pouvez parler 14:52, 12 March 2006 (UTC)
Note this is probably the first appearance of sugar from honey in the portal blood, not full absorption or "diffusion" into the systemic circulation. alteripse 18:47, 12 March 2006 (UTC)

Ingested sugar does not normally "diffuse throughout the body" as sugar in normal healthy, non-fasting people. Most is absorbed from the duodenum in less than 15 minutes, triggers insulin and incretins, is carried by portal vein blood directly to the liver, where it is further metabolized. Most is stored in the liver as glycogen, and some is used to make triglycerides or other molecules. A significant amount of sugar is passed to the systemic circulation to "diffuse throughout the body" only when insulin effect is low, which occurs mainly in the following circumstances:

  1. a person has gone a prolonged period without eating carbohydrates (usually more than 16 hours), or
  2. a person has a low blood glucose not due to excess insulin, or
  3. a person has untreated or grossly undertreated insulin deficiency due to any form of diabetes mellitus, or
  4. a person has severe insulin resistance due to type 2 diabetes mellitus.

Does that answer your question or is that more than you wanted to know? The unhealthiness of most sugar drinks has several dimensions:

  1. the amount of sugar
  2. the amount of phosphoric acid (bad for bones and teeth)
  3. the amount by which healthier food intake is reduced.

Good luck with your project. alteripse 14:59, 12 March 2006 (UTC)

Unknown plant[edit]

Not a homework question, but what plant is best known for its healing of burns? Is it chamomile, becuase I couldn't find it on any of the sub-articles it recommends. Thanks! Kilo-Lima Vous pouvez parler 18:15, 12 March 2006 (UTC)

are you thinking of aloe? —Charles P._(Mirv) 19:18, 12 March 2006 (UTC)

Windows Media Player 10[edit]

Is it possible to export the information stored by Media Player (Play Count, Song Length, Rating etc) in the form of a spreadsheet/database? smurrayinchester(User), (Talk) 15:11, 12 March 2006 (UTC)

Hi, I have tried to get it on a spreadshett and a databse, but can't seem to go it; so I don't really think you can, sorry. Kilo-Lima|(talk) 17:10, 18 March 2006 (UTC)

March 13[edit]

noninteractive XML editor?[edit]

Anybody know of a good, noninteractive XML editor? I'm thinking of something analogous to sed. It could be based on XSLT, or something simpler. —Steve Summit (talk) 01:54, 13 March 2006 (UTC)

I use Kate. No annoying popups. No annoying auto-completes. Plus, you can open/edit/save on remote servers without doing any import/export garbage. --Kainaw (talk) 13:44, 13 March 2006 (UTC)
Thanks, but that looks pretty interactive to me! Anybody know of any noninteractive ones? —Steve Summit (talk) 16:16, 13 March 2006 (UTC)
I'm tempted to suggest rolling your own Perl program for whatever it is you want to do -- if you know sed then it's not much of a leap, and there's loads of XML parsing modules available. But then I love Perl and have a tendency to see everything as a nail that can be hit by its hammer. --Bth 16:31, 13 March 2006 (UTC)
Oh, believe me, I'm an incorrigible wheel reinventor, and I'm always sorely tempted to roll my own! But for once in my sorry, narcissistic life, I thought I'd see if there wasn't something prewritten which I might deign to use. And, in fact, there might be: I've since discovered that Xalan comes with a command-line tool which will do just what I want, as long as I'm content to express my transformations using XSLT. I've downloaded the Xalan and Xerces sources and built them; now all I have to do is get my head wrapped around XSLT, which at first glance seems several times more complicated than it ought to be, but that might just be me, or the unfortunate result of the fact that all the on-line turorials I've found so far are, alas, somewhat less than scintillating. —Steve Summit (talk) 05:06, 14 March 2006 (UTC)

Graphics of the PS3[edit]

Does anyone know if the PS3 will be able to achieve superior graphics than the XBOX 360? I have seen the technical specifications of both of the systems GPU's but I am not sure of the meaning of all those numbers. It seems that the PS3's GPU has higher spec numbers. The preceding unsigned comment was added by (talk • contribs) 02:35, 13 March 2006 (UTC)

I believe the XBOX 360 can pump out better graphics than the PS3. The 360's GPU is truly custom built. It was built from scratch by ATI while the PS3 uses a clone of the Nvidia GeForce 7800.
The preceding unsigned comment was added by (talk • contribs) 02:54, 13 March 2006 (UTC)
A few comments on this. If you're going to judge "superior graphics" as a direct relation to specs on benchmark testing (like 3D Mark), then don't expect a more concrete answer than "PS3 seems to be better than XBOX 360". Benchmarking works with hundreds of critera and there is often overlap between winners: XBOX 360 is likely the winner in some benchmark categories and PS3 is likely the winner in others. Tech specs are largely just part of the "numbers game" as well, because a lot of what is important is much more difficult to put into numbers that the public will understand. Sure 1 billion gigahertz is impressive, but it means absolutely nothing if there isn't efficient use of the cache system, or if the machine-code procedures are badly implemented.
The fact that the 360's GPU is custom built means very little. NVidia uses tried-and-tested, industry standard equipment, and they've been building quality products for decades. Unsigned's comments are rather a statement of his trust in the manufacturers employed by Microsoft, though POV is not un-welcome at the reference desk.
Besides, we all know that the games (and how they're built, who built them) matter a lot more than the system does (and I don't even play games anymore). This is especially evident when talking about the "ease of programming" that each system allows for it's programmers, something that PS2 had a huge leg-up on over Microsoft when XBOX was first released.  freshgavinΓΛĿЌ  05:04, 13 March 2006 (UTC)
Precisely. The PS3 is coming out a year after the Xbox 360, so presumably it'll have a year's worth of graphics advances. So I'd put my money on the PS3 having better graphics. But that's not certain, and it depends on the gamer's opinion and on the game itself. In addition, console graphics improve gradually as the console gets older (as programmers learn how to get the most out of the console), so the Xbox 360 may well catch up with the PS3 (especially if programmers find it easier to program for the Xbox 360 - I don't know if that's the case.) Sum0 20:09, 13 March 2006 (UTC)
Don't forget deadlines, budgeting, sponsorship. I'd be willing to bet that games created on the XBOX 360 at the same time as the release of the PS3 will be of much better quality all-round, but it really depends on what you're looking for.  freshgavinΓΛĿЌ  03:39, 14 March 2006 (UTC)


If you were to have a population of people that had one of two kinds of mouths, thin and oval, with 8 people having a thin mouth and 8 people having an oval mouth. Also, of these 16 people, 4 of the 8 oval mouths were black, with the other 12 mouths being white. Is this an example of epistasis, where the shape of the mouths is one gene, and the expression of color is the other? I've been working on this problem for at least a day, so your help would be greatly appreciated. Thank you. 02:37, 13 March 2006 (UTC)

Sounds suspiciously like homework, but... Two genes, let's call them A and B. Both can be in one of two forms (say j and k), with a 50% chance of a gene being one or the other. So you can get Aj, Ak, Bj, Bk. A controls mouth shape. Aj gives thin, Ak gives oval - irrespective of what form of gene B is. BUT both genes have to be in the k form for the colour to be black. Anything else will give white (i.e., Black is a recessive gene). An average population of 16 would give four each of AjBj, AjBk, AkBj and AkBk. The first eight would have thin mouths, the last eight would have oval mouths, but only the four with AkBk would have black mouths - the others would have white mouths. Whether that would count as epistasis, though, I'll leave to others who know more about genetics... Grutness...wha? 06:01, 13 March 2006 (UTC)
Yes, what you have described COULD be an example of epistasis. If you were able to find someone with a think black mouth, then you would disprove that the black-mouth-gene forced an oval mouth. In reality though epistasis would be much more complicated than this with genes encoding hundreds of different proteins all adding their two cents. That's why you don't see people walking round with only 'two types' of mouth!!
Anyway, to reiterate, epistasis is when one gene, via the actions of the protein it encodes, is able to influence the actions (or even stop all together) of another gene (or the protein it encodes). --Username132 (talk) 16:07, 20 March 2006 (UTC)

Lethal Dominant Genes[edit]

What could possibly allow a lethal dominant gene to exist, if it exerted its influence at birth? I'm curious because the article for Hairless Dogs states that the gene for hairlessnes is lethal, and can be either dominant or recessive. Ironically, in nature, only the type of dog that has the dominant lethal gene exists. JianLi 05:39, 13 March 2006 (UTC)

As I understand that article, the hairlessness is dominant, but the lethality is recessive. That is, dogs with two wild-type (normal) genes will be normal, with hair. With one affected gene, they will be hairless but alive. With two affected genes, they will not survive. Does this make sense? — Knowledge Seeker 06:02, 13 March 2006 (UTC)
Ah, I didn't catch that, but upon further inspection you are certainly right! So "homozygous lethal for the dominant gene" is just a confusing way of saying, "the hairlessness is dominant, but the lethality is recessive." So what is the mechanism that relates (double-allele) hairlessness with lethality? Can it merely be two genes linked so close together that they appear as one?JianLi 01:18, 14 March 2006 (UTC)

Check out thanatophoric dwarfism for an example of a human lethal single gene disease: [33]. Obviously all cases represent new mutations as no one survives to reproduce. alteripse 06:11, 13 March 2006 (UTC) PS, as it is a red link, we obviously need an article on it.


In the middle of the winter, Finland almost run out of electricity because of all the heating. What would happen if a country ran out of electricity and what does it mean? Would some lamps just not light any more, or would they be darker? Blueiris 06:47, 13 March 2006 (UTC)

Humans survived many thousands of years without electricity in bitter cold. Modern technology allows us humans to survive even better. No worries mate! WAS 4.250 06:59, 13 March 2006 (UTC)

To answer Blueiris, there would be power cuts or power rationing. Water heating might be turned off, or power might be turned off in general between certain hours of the day. To see what happens when power gets close to completely running ut in a Westernised urban area, have a look at 1998 Auckland power crisis. Auckland was lucky - it happened there in mid-summer. In winter in slightly-less-than-tropical Finland, though...? Grutness...wha? 07:05, 13 March 2006 (UTC)
Okay, thanks. :) Blueiris 07:26, 13 March 2006 (UTC)
If there was no power rationing and everyone was still connected to and drawing from the grid, then I would say that lightbulbs would go dimmer because there is simply less power. I would also guess that voltage would remain constant and that the amps coming into your lightbulb would drop, making it dimmer. Whether a lightbulb would even go on or not is a more difficult question. That would require looking at exactly how much power is going into it and how much power is required for the filament to begin emitting black-body radiation (i.e. how much power it takes to get the filament to a certain temperature). -Snpoj 07:39, 13 March 2006 (UTC)
Harrumph. If the voltage remains constant, the current (amps) through a particular load (resistance) must also remain constant. Ohm's Law, you know?
In fact, the delivery of electric power requires a careful balancing of load and generating capacity. If the load increases beyond what the generators can supply, the voltage starts to drop, creating a "brownout". With lower voltage, the current delivered is also reduced. Light bulbs shine less strongly, motors don't deliver as much power. But the voltage isn't allowed to drop more than a few percent, because if it did, appliances might start to malfunction. If the generators can't maintain even the slightly reduced voltage, they'll automatically "trip offline" and shut down. It's also possible that an excess of "reactive load" (basically motors as opposed to lights) will cause the frequency to drop rather than the voltage, and again the genertor trips offline. (The same thing also happens if the load is reduced suddenly due to some problem and the generator is delivering too much power.)
Power utilities will try to avoid this sort of thing if they possibly can; for one thing, an unplanned shutdown can take longer to recover from, and if compounded by other problems it can propagate to a much larger area than the area of the actual shortage, as in the Second Great Northeast Blackout (where the actual power shortage was confined to northern Ohio). To avoid it, as noted, they will ration power: for example, they may use "rotating blackouts" where different districts deliberately have their power turned off in turn for predictable periods of time.
--Anonymous, 10:01 UTC, March 13, 2006.
I guess I was assuming a transformer that took in whatever it needed to and spat out a constant voltage..but that transformer breaks Ohm's law eventually if you follow the reasoning through. If the load is more than the turbines can make then it's got to give.. -Snpoj
Didn't exactly that happen in Russia a few weeks ago? People died. Well, that was a general lack of energy, not specifically electricity. I suppose that in Finland the decision was made that heating was so important in winter that energy sources weren't used for electricity. That way at least people won't freze to death like they did in Russia. We may have lived without electricity until just one or two centuries ago, but we've become so reliant on it that we wouldn't know how to deal with lack of it. People don't generally have a bunch of oil lamps to light the house. But domestically that's mostly a nuisance (in winter a fridge isn't necessary).
The biggest problem, I suppose, wuld be with certain computerised systems not running anymore, but the most essential systems will probably have their own backup with a generator. For which they'd still need fuel, though, so that's rather begging the question and those generators would be much less efficient, thus aggravating the problem. DirkvdM 09:50, 13 March 2006 (UTC)
Unfortunately, though, you can't always separate "electricity" from "heating". I don't know what the common types of heating systems in Finland are, but many of the ones I'm familiar with here require electricity also. For example, my house has a gas-fired boiler, but without electricity to run the pump to force the hot water through the radiators, I wouldn't be able to heat the house. (And of course this is one more reason for having rolling blackouts, as opposed to, say, shutting the electricity off for good.) —Steve Summit (talk) 16:13, 13 March 2006 (UTC)
Thanks all... these were exactly the things I wanted to know. :) Blueiris 11:05, 13 March 2006 (UTC)
Yes, I would agree with most of what has been said here. We know some people living in Zimbabwe at the moment, and there is not enough power in the country for everyone, due to the general collapse of government and lack of fuel in general. They said that they used to have a "rota" where they would be told, "Tuesday, Thursday and Friday from 2pm-7pm you will have no power". And this system was rotated around, so different areas of the country were given different times and days. They said that there was nothing wrong with this and that you just learn to work round it ie. hot meal in the middle of the day, cold meal in evening instead of vice-versa. However, the country is now in such anarchy, that for at least the past several months, the power goes on and off entirely randomly, sometimes for a day or so. —Daniel May-Miller 20 March 2006 (GMT)

Last column of elements[edit]

What is the name for the elements in the last column, where did this name come from

See the "Etymology" section of Noble gas. Melchoir 08:57, 13 March 2006 (UTC)
Blue blooded fart? DirkvdM 09:52, 13 March 2006 (UTC)
Wha? Melchoir 10:31, 13 March 2006 (UTC)
Don't worry - just Dirk thinking like an alien again :) Grutness...wha? 13:11, 13 March 2006 (UTC)
Noble gas. You figure it out. DirkvdM 07:44, 14 March 2006 (UTC)
Ah. Five minutes earlier and one indent fewer, next time, perhaps. Melchoir 07:58, 14 March 2006 (UTC)

distributed compilers[edit]

i need information about the distributed compilers not compilers for distributed languages....any one who can guide me .... i will be thankful....

Is this the sort of thing you're looking for? --Bth 11:26, 13 March 2006 (UTC)

thankss...well...the right one....if u got any more articles tell me...and any information about the distributed compiler for C# language....what is their scope and where they will stand in the future(C# distributed compiler).....

Smoke inhalation[edit]

Yet another question from the Newcomer's help page:

There are some types of smoke , which cause injury to the system. Like cigarrette smoke, CO2 smoke etc. Similarly there must be some qualities of smoke which may be good. Ayurveda, an Ancient medical science from India has described burning of some herbs for creating the smoke. The benefits are mentioned having short-term and long-term effects. How can I find scientific information about such herbs.
Thank you,
Dr. Santosh

QuantumEleven | (talk) 12:18, 13 March 2006 (UTC)

"There must be some good quality of smokes which may be good." — That's not a logical conclusion. The best thing to breathe is pure smoke-free air. All kinds of smoke contain polycyclic aromatic hydrocarbons like benzopyrene and other nasties. —Keenan Pepper 13:18, 13 March 2006 (UTC)
Don't be a buzz killer man. Just tell him that smoking pot is good for him and everyone will be so much happier. --Kainaw (talk) 13:41, 13 March 2006 (UTC)

You ask "How can I find scientific information about such herbs." meaning herbs with "some qualities of smoke which may be good". Read the articles I link here and some of what they link to and then googgle relevent terms. You want to know about pharmacologic agents, especially medicinal plants like Medical cannabis that can be turned into smoke so the route of administration is inhalation. While the sum of the effects on a healthy person may be bad, the sum on an unhealthy person may be good - which is why medical treatments for unhealthy people are generally not good for healthy people - or more exactly, most medical treatments are good for specific conditions not as general health aids. WAS 4.250 20:17, 13 March 2006 (UTC)

Note that essences of some plants are inhaled regularly in westrn medicine, too - notably eucalyptus. Grutness...wha? 22:39, 13 March 2006 (UTC)
Yes, because those vapors are not smoke. Smoke is the result of combustion and contains soot and tar, which are carcinogenic. Some vapors are also harmful, like chlorine bleach vapors, but others are not, like water vapor. StuRat 04:29, 14 March 2006 (UTC)
And CO2 isn't smoke either. And whether something is good or bad has a lot to do with quantity and concentration. Many 'poisons' are healthy provided the dosage is right. Other than that, WAS said it. DirkvdM 07:51, 14 March 2006 (UTC)


Hey. In the past, I have performed electrolysis experiments by passing electricity through salt water (NaCl). Now, theoretically, the water is supposed to be split into hydrogen and oxygen, but I know this doesn't really happen. The results appear to be hydrogen and chlorine. Oxygen gas does not form because it is more readily attracted to the Na ion and forms NaOH in solution, while hydrogen bubbles out, and the chlorine remains a liquid in the cold water. This is as far as I understand the mechanism.

Now its time for my question. What is the true end result of electrolysis? I have read in the sodium hypochlorite article that NaOH and Cl2 react to form NaClO, NaCl, and H20. I also read that NaClO, which is bleach, partially breaks down into Na and ClO ions, which can become NaOH and HClO (hypochlorus acid). Also, the Cl2 can react with the water to form HClO and HCl. So...what is really in the water? It seems that it could eight different chemicals at once. Thanks. --Chris 16:27, 13 March 2006 (UTC)

Unless you have really overdone it with the salt solution (lots of salt as opposed to just enough to make a conductive electrolyte) you will get oxygen at the anode and a small amount of chlorine. Hydrogen will collect at the cathode plus a small amount of sodium (immediately reacting with water to liberate more hydrogen). NaOH and HClO will not coexist very long in solution as one is acid and the other is base, HCl will not last long either in the presence of a strong base. NaClO is relatively stable, although it slowly liberates Chlorine. So, yes, you will have 8 different chemicals together, but the acid and base will only be there for a brief time. If you keep the electrolysis running, you will continue to generate these chemicals, until the water is totally decomposed into hydrogen and oxygen and no more liquid is left. Since the Sodium is a solid and does not leave the solution, whereas the chlorine is a gas and some will escape, you will probably end up with a salt deposit contaminated with NaOH.

Well, I have done this with filtered water and a lot of NaCl. I have also done it with mere tap water. With both, I never seemed to get oxygen. I know that chlorine more readily escapes from the solution that oxygen, but there are some salts that do not take part in the reaction, and are only there to conduct the electricity. I do not know which salts these are though. But I assume that what you are saying is that there isn't going to be too many secondary reactions. Just hydrogen, chlorine, NaOH, and remaining salt will remain. Thanks for your help. --Chris 21:58, 13 March 2006 (UTC)
I tried to do this once and Wiki boogered it up. Try again. Tap water should have sufficient ions to make the water conductive, but minimize unwelcome contaminants in the Oxygen. If you are using metal electrodes, the oxygen and chlorine, etc. might be reacting with it. Try this, use distilled water with a small amount of NaOH dissolved (wear gloves) this will guarantee no Oxygen contaminants. Then get use graphite electrodes. Get some of those replacement leads for mechanical pencils, or pressure cook a few carpenters pencils and carfully peel the wood off. Use DC current. You might get some unwelcome CO2 at the anode, but leaving it idle with the current off will allow the CO2 to react with the NaOH and remove it.
Interesting. Well, I'm at college now and I can't really do this until I get home. I am a chemistry major, but I'm only a freshman. I will definately try using graphite though. It sounds promising. Thanks a bunch. --Chris 05:02, 15 March 2006 (UTC)
Chemistry major? That means you should have access to a lab... Why wait until you get home?

Chimpanzee IQ[edit]

What is the approximate IQ of a chimpanzee? Is it true that the smartest apes are smarter than the least intelligent humans? The Mad Echidna 16:53, 13 March 2006 (UTC)

  • Given my experience with a lot of the vandals here, I'd say, yeah, easily. --jpgordon∇∆∇∆ 17:35, 13 March 2006 (UTC)
As opposed to people who make smart ass remarks, you mean? (No, this remark is not meant to be self-referencing.) DirkvdM 08:07, 14 March 2006 (UTC)
The smartest ant is smarter than the least intelligent human. Therefore, the smartest apes are smarter than the least intelligent humans. Note - the least intelligent human is a human with no mental capacity. This may be caused by birth defect or brain damage. Some humans have no brain activity at all and are kept alive purely by machines. So, they are the least intelligent humans. Anything with a heartbeat is more intelligent. --Kainaw (talk) 19:56, 13 March 2006 (UTC)
I think it's a testament to all wikipedian's maturity, that no one has mentioned george bush yet
That doesn't mean we weren't thinking it.  :-) Dismas|(talk) 22:46, 13 March 2006 (UTC)
The chimp is very being a chimp, just as a human is good at being human. IQ is a general measure of human abilities, and by applying it to a chimp, you might suggest that a chimp with a very high IQ isn't actually a very good chimp. It's off putting a square plug into a square hole and solving equations instead of eating bananas. Just something to think about :)--inksT 01:45, 14 March 2006 (UTC)
Somehow or other, someone deleted my response, so I'll type it again :/ . The question as posed is really a null question. The average chimpanzee IQ is 100 - because it will be tested using chimpanzee-based IQ tests. Since all species have different types of intelligence, it's really difficult to find any way of truly comparing intelligence, even with species as close as chimpanzees and humans. As to the smartest apes being smarter than the least intelligent humans, yes, that is true - buyt then again, humans are apes so it's bound to be true. If (as is likely) you mean non-human apes, then the chances are that yes, they are also more intelligent. then again, the least intelligent humans are - as Kainaw pointed out - so mentally incapacitated that the question is again meaningless. A better question would probably be what level of intelligence to chimpanzees reach compared to humans. Again, this is pretty difficult to judge, but it would probably equate fairly closely with a child of about 5-7, IIRC. Grutness...wha? 05:35, 14 March 2006 (UTC)
That sounds about right. Obviously an IQ test is a bad example, but if you're talking about a problem solving, non-language-based test, I'd take a chimpanzee against the average human child any day. EWS23 | (Leave me a message!) 06:15, 14 March 2006 (UTC)
There is no one IQ test. There are different test for different levels of intelligence. So I don't see a problem with designing a test for chimps because they're not too far from humans. Apparently, some gorilla called Koko has "an IQ of between 70 and 95 on a human scale". An ant IQ test would be something different, though. DirkvdM 08:07, 14 March 2006 (UTC)
  • There's no such thing as the approximate IQ of a chimp. Their IQ varies just as it does with people. - 10:02, 14 March 2006 (UTC)
  • Hi! Not as relevant a comment as the others (I have only just found the Reference Desk and I think it is a brilliant idea). I'm sorry I haven't got a reference, but I heard that some studies suggest that chimps might be quicker at basic mental arithmetic (adding and subtracting small numbers) than humans. —Joe Llywelyn Griffith Blakesley talk contrib 10:56, 14 March 2006 (UTC)
Can't resist this... If you think Dogs can't count, try putting three dog treats in your pocket and only giving the dog two.
I did not know that the IQ test could be performed without language, can chimps communicate now?

AIDS transmission[edit]

How is the HIV transmitted by sharing infected needles ? Does the virus lie dormant in a dry needle ? How is it then that HIV is not spread by mosquito bites ? Jay 17:26, 13 March 2006 (UTC)

It is spread just the way you think it is, large numbers of HIV moving from one human's blood to another human's blood, lying "dormant" between human cell infection. Mosquitos don't suck blood from one person and then inject that blood into someone else. They digest the blood (and the viruses in it) as its food and don't catch HIV themselves. They aren't sloppy eaters so HIV doesn't tag along on their mouth parts. WAS 4.250 19:41, 13 March 2006 (UTC)

But the mosquito saliva mixes with the blood and sometimes the virus infects the next person the mosquito feeds on as it's body fluids will mix with the victims. This is how malaria is spread, AIDS is a fragile virus and does not last long outside the body, so it it is hard to infect someone that way.
I always thought that the HIV virus died within a few minutes of leaving the body and being exposed to the outside world. Sum0 20:00, 13 March 2006 (UTC)
It dies shortly after leaving the blood. When a needle is used, blood is left inside the vial/needle. That infected blood is passed to the next user. So, the virus never has to leave the blood to get from one person to another with needle sharing. --Kainaw (talk) 20:08, 13 March 2006 (UTC)
The only problem is AIDS is temperature dependent also, so if the needle is left idle for too long before reuse, the virus can't remain viable.
Yes. But be aware there is nothing magical about blood in terms of HIV surviving. It needs moisture and warmth (ie dryness and cold and heat "kill" or denature it). It can survive in a warm moist vagina quite long enough. WAS 4.250 20:22, 13 March 2006 (UTC)
You could have just said "warm moist environment" and saved all of us the distraction.  freshgavinΓΛĿЌ  03:32, 14 March 2006 (UTC)
Right. Because we all know AIDS transmission is all about random "warm moist environments" and not vaginas or rectums.... NOT. WAS 4.250 04:56, 14 March 2006 (UTC)
Some kinds of distraction I don't mind at all. DirkvdM 08:09, 14 March 2006 (UTC)
Doesn't the blood/fluid in a needle dry up, maybe in 24 hours ? Does the dry needle kill the virus (that was my original question)? So wouldn't there be a time limit for when a used needle becomes sterile for AIDS ? By the way the idea of blood remaining in the needle was totally new to me. Jay 08:03, 14 March 2006 (UTC)
I can't imagine that the fluid in a syringe can dry up through the tiny needle hole. It would probably stay moist for years. But the temperature drop in most rooms would kill HIV in a short time. However, needle sharing is a common model, especially where free supplies of needles or needle exchanges are banned/scarce; people may be effectively waiting in line for the next use. Notinasnaid 09:23, 14 March 2006 (UTC)
If the needle is kept in the junkies' pockets or underwear, it could be kept nice and warm, and least until they die and cool off a bit. StuRat 00:35, 15 March 2006 (UTC)
I found this [34] --Username132 19:50, 14 March 2006 (UTC)
HIV can survive much longer if kept in blood than outside. The needle holds the HIV virus inside of blood and protects it from air. In Victoria,BC we have services that give out small containers of bleach water that can be used to clean needles. This kills HIV, but does not kill all types of hepatitis. A good rule of thumb, is DO NOT use a needle that someone else used. HighInBC 21:59, 18 March 2006 (UTC)

Mission to Mars[edit]

I am currently 21 years old and would love to see a human being walk on Mars in my lifetime. Does anyone know a realistic date in which NASA would send humans to Mars.

Well, NASA's Vision for Space Exploration doesn't set a date for Mars, but says 2020 for the Moon, while ESA's Aurora Programme says 2030 for Mars. These are both highly speculative, of course. See also Exploration of Mars. Melchoir 21:33, 13 March 2006 (UTC)
It's a programming, budgetary, and risk issue more than a technological one. If one were prepared to cancel the shuttle immediately and/or give NASA (or some other group) lots of money immediately, and were prepared to accept a greater risk of the astronauts not coming back (maybe 10-20% rather than the 2% the Shuttle astronauts face), the job could almost certainly be done within the decade. As a further example of a technology that could get us to Mars quickly (in both senses of the word) but which is likely to remain undeveloped for various reasons, have a look at Project Orion.
FWIW, I too hope to see somebody walk on Mars in my lifetime, and I'm 29. I remain reasonably confident that it will happen. --Robert Merkel 00:34, 14 March 2006 (UTC)
Because most white-collared first-worlders don't believe there's a valid reason for a human to actually have to GO to mars (as opposed to a robot) I think the only way it could possibly become a reality is if the world were to suddenly erupt in a massive war. In an instant all of the men of the world would be looking for a way to puff their chest and a place to pee on and call their own. The moon, being "done", wouldn't be good enough, and so huge amounts of money ("to be used for something of value that until now was not realized") would be pumped into the Mars program.  freshgavinΓΛĿЌ  03:30, 14 March 2006 (UTC)
If you're talking about the American space program, there doesn't really need to be a reason other than rallying the common man around a common goal. In that case, I'd think it an almost certainty that a man will step foot on Mars by the end of our lifetime (myself being a 21-year-old male). I'd be very surprised if a man hasn't been to Mars 2 or 3 times in the next 40 years. EWS23 | (Leave me a message!) 06:08, 14 March 2006 (UTC)
The same man? Give others a chance too! And why a man? (Let me be 'politically correct' for once.) Anyway, Freshgavin is right. The only reason to send people into space is because it looks cool on tv. It reduces science to mass entertainment, which is a major pain for scientists. For the price of sending one (wo)man to Mars, they could probably send dozens of robots, which would be hugely more informative. Luckily they can say "yeah but we need to send robots first, to explore, so we know what we're going to land on" and get some useful info out of the budget. Sending people to the Moon was a huge waste of money, but with sending them to Mars it will be much worse because of the distance, for starters. With a robot it's basicaly just the same thing, except you 'shoot a bit further'. A robot doesn't care about being in space for years (well, not entirely true, but you get the point). DirkvdM 08:17, 14 March 2006 (UTC)
I disagree with "sending people to the Moon was a huge waste of money". At the time, robotics wasn't yet up to the challenge, so people were still needed. The cost of sending people to the Moon was actually far less than sending robots with the same capabilities, using 1960's technology. StuRat 00:30, 15 March 2006 (UTC)
I didn't mean walking robots or anything fancy like that, but the kinds of robots that were actually sent at the time. The one that took photographs of the back side of the Moon made the greatest achievement of the exploration of the Moon up until now. Later, humans were sent so they could have a look for themselves, but that was a totally useless effort. DirkvdM 14:15, 20 March 2006 (UTC)
Well, I don't think they had the technology at the time for moon rovers which could go out and take samples to return to Earth, so humans were needed for that task. StuRat 20:39, 20 March 2006 (UTC)
One could come up with a list of scientific questions which could be answered by going to Mars, things which could be learned, etc. But the question is whether these outbalance the risk and the cost. Without even bringing up whether the proposal is a political stunt. Which in this case it clearly was. --Fastfission 16:34, 14 March 2006 (UTC)
Thanks for dissecting my lazy English, Dirk. :o) I completely agree with you that the benefits of sending a (wo)man to Mars probably wouldn't justify the cost, and that doing so would be much more of a political/entertainment venture than a scientific one. However, perhaps the more appropriate question might be, "If we eliminated the possibility of sending a (wo)man to Mars, would the people/government still be willing to fund robotic missions there at all?" I imagine a large percentage of the (non-scientific) public considers sending robots to other planets a relatively minor achievement, and only a stepping stone for us traveling there in person. EWS23 | (Leave me a message!) 18:07, 14 March 2006 (UTC)
Look, it's probably true that if you're looking purely at cost-effectiveness for short-term and medium-term scientific goals, then robots beat humans. That's not the point. If you believe in long-term human expansion into space, then you've got to start somewhere. It's not about politics or entertainment, although that might be the way to sell it to dreamless bureaucrats. It's manifest destiny. --Trovatore 18:26, 14 March 2006 (UTC)
Furthermore, you guys are probably overestimating the capabilities of robots, particularly when they are multiple light-minutes away from human decision makers back on Earth. The efforts of the Mars Exploration rovers, wonderful though they have been, take days to accomplish what a human can do in minutes. And human explorers are approximately one squillion times more flexible. --Robert Merkel 06:21, 15 March 2006 (UTC)

March 14[edit]


I have heard about a substance called pykecrete, where wood pulp is slurried with ice and frozen to create a very strong substance. Does anyone know what the proportions should be? Even a rough estimate to begin experimenting would be nice.

Check out Pykrete, which recommends "approximately 14 percent sawdust or some other form of wood pulp (such as paper) and 86 percent ice by weight". Melchoir 00:20, 14 March 2006 (UTC)
Thank you. The spelling eluded me as well apparently!
Well, it's good you asked! Pykecrete is now a proud redirect. Melchoir 00:33, 14 March 2006 (UTC)
Er... it will be when a certain cache updates. Melchoir 00:35, 14 March 2006 (UTC)

Cutting Mirrors[edit]

For my parabolic dish solar hot dog cooker I need to cut mirrors. I've figure out a way to get the measurments, but what equipment do you guys recommend to actually do the physical cutting of the mirrors?

To be clear, you are talking about using a series of small flat mirrors to approximate a paraboloid, not actually constructing a curved mirror, right ? You can cut mirrors with a glass cutter: [35] Typically you score the glass in a straight line, then break it off with one half supported by a table and the other half hanging over the edge. You should wear goggles and thick leather gloves when doing this. StuRat 02:01, 14 March 2006 (UTC)
KISS! Just smash the mirror and make it a mozaic. You just want to roughly focus the light in a certain area, not build a newton telescope, right? And when you're done could you write the parabolic dish solar hot dog cooker article. We're sorely in need of that. DirkvdM 08:39, 14 March 2006 (UTC)
I did consider that approach, but think carefully cut pieces of glass will likely get a better grade than random shards of glass. StuRat 00:18, 15 March 2006 (UTC)
I think a glass cutter is a better idea. And it is less dangerous. Find one at a hardware store, you probably don't want to wait for ebay. Good luck! -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 11:07, 14 March 2006 (UTC)

Another option is to buy mirrored tile: [36]. The largest square tiles are the best price per area, but the circular tile would be safer (no sharp corners) and might look better. StuRat 15:21, 15 March 2006 (UTC)

I am also curious about how you are going to build a parabolic fixture to which you plan to attach the mirrors. I was thinking that strips of papier mache hung from a hoop might very well form a close approximation of a parabolic shape, from which you could use grout (or even gum) to adjust each tile's position to aim at the hot dog. (I suggest covering the existing mirrored tiles so you can see if the current tile is properly aimed.) You could use a hula hoop supported by a wooden frame. The weight of the apparatus would likely require many support points for the hula hoop, however, so a stronger hoop would be better, but I can't think of a good place to get a cheap, large, strong hoop right now. StuRat 15:41, 15 March 2006 (UTC)

I thought of another way, how about using a circular garbage can for the hoop and support structure ? One caution, it may be too flexible, allowing the structure to shift when moved. StuRat 16:45, 15 March 2006 (UTC)
The hanging thing won't work. The shape formed by a rope (or chain, string, etc.) suspended at its ends is a catenary, not a parabola. It's a curve, of course, so it'll look rather like a parabola, but it won't focus light the same way.
Besides, if you're looking to cook a long skinny thing like a hot dog, you'd really want to make a cooker that looks like an extruded parabola rather than a rotated one. The extruded parabola will focus light along a line, thus cooking the entire weiner. The rotated parabola focuses all the light at one point, leaving you with a snack that's burned at one point and raw everywhere else.
From a construction standpoint, the extruded parabola design is nice in that you don't need a million little bits of glass. You can use long, narrow strips of mirror laid edge to edge along a parabola. And you can construct a cooker that cooks four or five hot dogs evenly all at the same time by just making the cooker longer.
I think you are picturing this a bit more precisely than this kid is going to be able to create it. Getting an approximation where some of the light from each mirror hits the hot dog somewhere is about the best he can hope for. The grout or gum will allow him to compensate for error from the shape not being a true parabola. If it's heated unevenly, this will be OK so long as it is heated slowly enough for the heat to distribute itself evenly. But your idea of making it elongated might work. I've seen elongated "tubs" for bathing children/dogs that might work for a structure from which they could suspend papier mache. StuRat 03:10, 19 March 2006 (UTC)
I think it might be better to just use tinfoil rather than actual glass mirrors, because it's easier to shape. It isn't so flat as glass mirrors but I don't think you need that anyway. – b_jonas 00:34, 20 March 2006 (UTC)
I disagree. Aluminum foil, which I assume is what you meant, will reflect light all over the place, not just at the hot dog. Also, some way to contain the heat, say a glass box around the hot dog, would be a good idea. One last thing WEAR DARK SUNGLASSES when you use this, or you could suffer retinal damage ! StuRat 20:45, 20 March 2006 (UTC)

Walking On The Moon[edit]

I am sixteen. I am going to join the Marines. I would like to walk on the moon. Based on NASA's projections, what is the probablility that my dream to walk on the Moon will become a reality? Here7ic 01:39, 14 March 2006 (UTC)

As I mentioned above, NASA's Vision for Space Exploration proposes manned Moon missions by 2020. Assuming that actually happens, I guess it depends on how old astronauts are supposed to be. Melchoir 01:47, 14 March 2006 (UTC)
Very interesting. Perhaps that info is in the Wikipedia on Astronauts. I must check this out. Here7ic 01:59, 14 March 2006 (UTC)
Well, good luck on your research! For such a visible occupation, Wikipedia has surprisingly little information about the astronaut career path, especially in the United States. Hopefully you can educate us all! Melchoir 02:49, 14 March 2006 (UTC)
Actually, on second thought, I should stop thinking about Wikipedia for a second and encourage you to ask your Marine recruiter the same question. Melchoir 02:55, 14 March 2006 (UTC)
Um, I wouldn't take the recruiter's answer at face value. He has a quota to fill. He probably won't literally promise you the Moon, but he might try to make it sound like joining the Marines is your best shot at it, even if it isn't. (Has there ever been an astronaut from the Marines? I think, at least in the early days, a lot of them came from the Air Force.) --Trovatore 03:05, 14 March 2006 (UTC)
Good point. I don't have any idea about the breakdown by services, but I guess it couldn't hurt, Here7ic, to talk to your Air Force recruiter as well! As long as you maintain a healthy level of skepticism, more information can't hurt, right? Melchoir 03:09, 14 March 2006 (UTC)
If you're sixteen, and there are plans to land on the moon by 2020, that would make you 30 at the very earliest, and the way things work in the real world it's much more likely that you'd be 40 or 50, if everything goes approximately according to NASA's plan.
That's no reason to give up your dream though, working in a field related to space exploration would certainly be a fascinating job for you, and even if you don't get to walk on the moon yourself, you could very well have a hand in helping somebody else get there.  freshgavinGLL.KJ  03:08, 14 March 2006 (UTC)
Historically speaking, 40 is about right; Neil Armstrong and Buzz Aldrin were 39 when they hit the Moon. But that was a long time ago, and the target age may have shifted radically since then. Anyone know if it has? Melchoir 03:16, 14 March 2006 (UTC)
Not radically, seems to be around the early 30s now, and there have been many more over-age astronauts than under-age. You're right though, 40 could be just right, though I'd say 50 is pushing it.  freshgavinGLL.KJ  04:19, 14 March 2006 (UTC)

On a related note, do most astronauts have a good physics background? In my opinion, it'd be a shame if the few people humanity sends into space don't even appreciate how they got there. Then again, I doubt most race car drivers have engineering backgrounds. JianLi 03:54, 14 March 2006 (UTC)

I'd have to guess that yes, they do. Melchoir 03:57, 14 March 2006 (UTC)
Every astronaut I've heard of has an engineering degree. Can anyone name an exception? Fredrik Johansson 03:59, 14 March 2006 (UTC)
I looked at List_of_astronauts_by_name. So far, the majority of articles on the list give an engineering/science degree JianLi 04:03, 14 March 2006 (UTC)
I can find a few exceptions, such as Ellen S. Baker, who has degrees in geology and medicine, but not engineering JianLi 04:06, 14 March 2006 (UTC)
Has anyone ever heard of an engineering student who was anything more than a glorified business major? so what's it matter if they're engineers or burger flippers, they'll know about as much physics either way-- 04:09, 14 March 2006 (UTC)
In the immortal words of Michael Jackson, that's just ignorant. Melchoir 04:15, 14 March 2006 (UTC)
You're an engineering student aren't you? oh well, know your audience and all that jazz-- 04:41, 14 March 2006 (UTC)
Far from it! Melchoir 05:49, 14 March 2006 (UTC)

Why do you want to join the marines? Why do you want to walk on the moon? People who want to do one rarely want to do the other. I suggest you get some real world experience and don't make lasting commitments until you are 21. WAS 4.250 05:02, 14 March 2006 (UTC)

Marines: I want to join because I feel like it's the only way I'll get the training, and the action, I feel I need. Moon: I want to go to the moon because I feel that it's just the first step. The first step to a world that isn't confined to our current residency, Earth. Chances are poor that I will be alive for the terraforming, or colonization of farther planets, and even poorer that I will even see the first contact with an intelligent extraterrestrial species. It's my insurance, if you will, that I will have done something so profound that it will impact the lives of every human being on this Earth. In short, I'm in it for the thrill. Here7ic 05:31, 14 March 2006 (UTC)
You are 16 years old and want thrills and profoundness in your life. "Know thyself" is ancient wisdom, and Clint Eastwood's charcter said "A man's gotta know his limitations." Understanding your motivations is important. I recommend you seek thrills and profoundness NOW while also seeking to stay alive and out of jail so you can continue seeking thrills and profoundness as many decades as possible. What do you think you can do today to find thrills and profoundness (that don't land you in jail or the hospital)? When I was your age many decades ago I sought those in finding the love of a beautiful woman (married at 18) and trying to understand the nature of the universe (religion led me to philosophy led me to logic led me to physics led me to the computer sciences). It has been an exciting profound journey. WAS 4.250 17:43, 14 March 2006 (UTC)
I think it's fantastic to have a goal like that. It will take hard work, and as noted in other responses, perhaps another branch of the armed forces might provide a better path, but I wish you all luck. Now move zig! For great justice! --LarryMac 15:20, 14 March 2006 (UTC)
You may be interested in the How to become an astronaut FAQ. A military background is a good thing to have on the resume, but you will need a PhD in a relevant scientific field; if you want the fast track to getting this that means getting in as an officer (and earning your university degree), not an enlisted grunt.
This time around, I expect that the Moon-Mars program will be more science focussed, so if you want to go, become one of the world's foremost expert on something Moon or Mars-related; not having any health problems whatsoever wouldn't be a bad idea either (and is, unfortunately, largely out of your control).
That said, becoming an astronaut is somewhere up there with winning the lottery in the scale of probabilities. But you could have a fascinating career in science or engineering even if you don't become an astronaut. --Robert Merkel 06:04, 14 March 2006 (UTC)

Astronauts don't really navigate the spaceships. Well, for a Moon expedition anyway. That's all controlled from Earth. The astronauts are just on board for publicity reasons. And while there are people on board they might as well be scientists so they can be of some use. Another thing is that they need to solve things when they go wrong and for that you need intelligence and preferably a good broad scientific education. If you're stupid enough to want to join the army (and the marines at that) then you probably don't have what it takes to become an astronaut (oops, sorry, my political correctness in the 'mission to mars' question (two up) probably made me want to compensate here). Oh, and the physical fitness thing is important too. You don't need to be exceptionally fit, just plain healthy. Of the first Dutch astronaut, Wubbo Ockels it was said the only thing wrong with him was a crooked tooth. DirkvdM 08:57, 14 March 2006 (UTC)

The "spaceships" are not controlled from Earth--they're mostly controlled by the onboard computer. Radio waves take approximately 2 seconds to travel from the Moon to Earth and back, which is way too long. For example, the Apollo moon landers had exhaust nozzles that could be gimballed to compensate for the astronauts' moving around. If the nozzles took 2 seconds to respond to the astronauts' movements, the lander will crash.
I would suspect (speculate) that, like Robert Merkel and DirkvdM said, being a scientist is going to be more important than being in the army if you want to walk on the Moon. I also strongly recommend against joining the Marines. Ultimately, the goal of all military-related stuff is to kill/capture people or steal information. Why do you want to be trained to do those things? Why do you feel that you need the training and action? If you want to exercise, join a fitness club, run around the streets for an hour every day, play basketball, or something like that! Just don't do something as stupid as joining the army. --Bowlhover 15:53, 14 March 2006 (UTC)

The guys who go into space the most frequently are the commanders and the pilots, like Kent Rominger and Curtis Brown who seem to almost exclusively have military backgrounds. Specifically, they tend to have been pilots in the armed forces, and good enough at it to become instructors and/or test pilots. I also see a lot of people around me, here at the Massachusetts Institute of Technology, getting their graduate degrees in engineering and the sciences paid for by the US military. So if you're willing to take the risk that you're going to be sent to war, and possibly killed, an officer position in the military is a pretty good route to NASA. It's only going to work if you're bright, and coordinated, and good at math, and not gay or at least willing to be in the closet indefinitely if you are.

So from that point of view, though, the Marines are out. The Marines, as part of the Army, are not permitted to operate fixed-wing aircraft, and I doubt that helicopter pilots are the sort of pilots we are talking about. --Trovatore 22:28, 14 March 2006 (UTC)
No, in the U.S., the Marines are part of the Navy and the certainly use both fixed wing and rotary wing craft. Rmhermen 22:53, 14 March 2006 (UTC)
John Glenn was a Marine as was Story Musgrave, the only man to fly on every space shuttle. And Charles F. Bolden, Jr., Robert Cabana, Gerald Carr, James F. Buchli, etc. Rmhermen 23:00, 14 March 2006 (UTC)
As of Jan 2005, there were seven active astronuts from the Marines, another seven from the Army, but 31 from the Navy, 24 from the Air Force and 1 from the Coast Guard. Rmhermen 23:08, 14 March 2006 (UTC)
Thanks to Rmherman for the info. However the Marines are not part of the Navy. It does look like I was wrong about them being part of the Army, and it also appears that they do operate fixed-wing aircraft. --Trovatore 23:23, 14 March 2006 (UTC)
Yeah, the United States Marine Corps article says it's its own branch, separate from both the Army and the Navy, and that they fly both fixed- and rotary-wing aircraft. Still, I'd go with the Navy.
"The Department of the Navy consists of two uniformed Services: the United States Navy and the United States Marine Corps." from the Navy website. The Marines report to the Undersecretary of the Navy, their officer's are trained at the Naval Academy, their crimes tried at the JAG-Navy, etc. Rmhermen 21:11, 15 March 2006 (UTC)
Not at all. Rmhermen's talking about the Navy department, a political (executive branch) structure, not a military one. The Marines are a separate service from the Navy, even if they're under the same cabinet secretary. Heck, they even use Army ranks and grades, not Navy ones. That's probably a big part of why I thought they were part of the Army; the other reason is that they mostly fight on land rather than water. I get the sense that Marines and Navy men generally don't think much of each other, or at least affect not to. --Trovatore 01:53, 16 March 2006 (UTC)
Read The Right Stuff by Tom Wolfe. Skip the movie, it's unrealistic.(SOrry, I was thinking of the movie of Apollo13; THAT's unrealistic.) Learn as much science as you possibly can. --GangofOne 23:37, 14 March 2006 (UTC)

Military recruiters are salesmen, and right now their main goal is to enlist as many people as they can to go to war in the Persian Gulf, not to go to the Moon. There's currently no war on the Moon that I've heard of, and, as everyone knows, the business of the U.S. Marine Corps is war. If your idea of a thrill is being constantly in danger of being shot, blown up, or otherwise killed and maybe having to kill another human being, then the Marine Corps may be for you. Being an enlisted soldier, which is what you'll be if you sign those papers at your recruiter's office, is not going to get you any closer to the Moon. As far as I know, astronauts are frequently military fighter pilots with advanced degrees in engineering. Try the ROTC programs of the Navy or the Air Force instead, and get a degree in aeronautical or electrical engineering. Then apply for pilot training. See how it goes after that. Even if you qualify as a fighter pilot, your chances of going to the Moon are slim to none. Brian G. Crawford 00:22, 15 March 2006 (UTC)

For some reason, a lot of boys in my class are interested in military stuff. I think it's because they like destroying other people's property spectacularly (without getting into trouble) and killing other people. But Here7ic: why do you really want to join the Marines? What kind of training and action do you think you need? Do you really want to kill other people or destroy property? Do you really want to see other people dying in pain? If not, why join the Marines? --Bowlhover 04:18, 15 March 2006 (UTC)
But Bowlhover, why don't you tell us what you really think of the military ? In a perfect world, we would not need a military, true, but do you really think this is a perfect world ? Total unilateral disarmament is a really bad idea. StuRat 16:29, 15 March 2006 (UTC)

I would like to assure you all that I've got my bases covered. I've already worked out how I will be entering the Marines. Next summer (while I'm 17) I will go to Basic Training, then complete my grade school career. I am currently 9th out of the 134 students in my class. After I graduate, I will spend four years in college, paid for by the United States Marine Corps, then for and additional four years I will begin and Officer Training Course (depending on how I do), and will hopefully make this dream a reality.

Bowlhover, do you really think that a .50 calibur hollow-point through the cerebral cortex will hurt?

More so, I want to join the Marines because I do want frontline action. You may think it wrong to kill, but sometimes it's just your final option. That aside, my reasons are my reasons. Some are hard to explain, others just an urge. I hear the back of my mind telling me that I have to, I need to do this. As StuRat pointed out, this isn't a perfect world. If we didn't have a military, and followed world politics with a passive attitude, some dictator with a cruel and murderous regime would long have taken us over. It's just like being Jewish, and standing with your guard down in a room full of Neo-Nazis who know your Jewish. You're going to get yourself killed. 17:02, 15 March 2006 (UTC)

"But Bowlhover, why don't you tell us what you really think of the military? In a perfect world, we would not need a military, true, but do you really think this is a perfect world? Total unilateral disarmament is a really bad idea."

I'm a pacifist, but that doesn't matter right now. I feel that people should not join the U.S. military just because they get a sudden urge to do so, because injuring/killing others is probably not going to be as fun and exciting as they think it's going to be.

I respect your pacifist beliefs, Bowlhover, but you shouldn't try to apply them to the actions of others, only to your own actions. StuRat 00:39, 16 March 2006 (UTC)

"I am currently 9th out of the 134 students in my class."

Congratulations! If you don't join the military (and maybe get killed), you can use that intelligence to your advantage in the workforce.

"Bowlhover, do you really think that a .50 calibur hollow-point through the cerebal cortex will hurt."

No, but do you really think that the same calibur through an arm won't hurt?

"More so, I want to join the Marines because I do want frontline action."

Then don't get disappointed. Only a small fraction of those who enlist will get to fight in the front line.

"You may think it wrong to kill, but sometimes it's just your final option."

But in this specific case, it isn't your final option. If a stranger is trying to strangle you, you will lose your life if you don't kill that person. However, if you don't join the Marines, you will not lose anything.

"That aside, my reasons are my reasons. Some are hard to explain, others just an urge. I hear the back of my head telling me that I have to, I need to do this."

If you can't even explain to yourself why you want to join the Marines, it's likely just a sudden urge that you will regret following. You should make this decision based on the advantages and disadvantages of enlisting vs. not enlisting, not based on an unexplainable urge. --Bowlhover 20:07, 15 March 2006 (UTC)

It sounds to me like he does have a plan, and Basic is probably pretty good at disspelling any sudden urges. Melchoir 20:30, 15 March 2006 (UTC)
"9th out of the 134 students" 134 students? small town, life boring, seems like there aren't a lot of options? had recruiters in your school since you were in 6th or 7th grade? I've known a number of people like you, just don't, you'll regret it later on, and it will be too late to back out. Also, the last war the US fought that actually involded fronts, was probably korea. One more also, only a small fraction of soldiers wind up dead, true, but a much larger fraction wind up wounded, disfigured, and paralyzed, in fact I'd bet most wind up wounded in some way or another, which probably kills the health requirements for the space shuttle right there-- 22:00, 15 March 2006 (UTC)
134 students in my class. I think there's something around 400-500 students in my high school, but that's not an issue I want to get into. I can safely say that the recruiters that come to my school (only since last year, they don't bother with the middle school) haven't effected my decisions or opinions in anything. The only time I even talked to one, besides saying "Hi", anyways, was when I got a copy of America's Army. You say I'm probably going to regret it forever because it's a "sudden urge", but it's not. Something that sticks with you for five years isn't what I'd call a "sudden urge". Here7ic 01:43, 16 March 2006 (UTC)
I'm not going to try hard to convince you not to join the military. Just be aware that there is a significant risk of you dying or being wounded. However, I recommend you join the Air Force rather than the Marines. It will give you a greater likelihood of being chosen as an astronaut. Superm401 - Talk 03:15, 16 March 2006 (UTC)

"You say I'm probably going to regreat it forever because it's a "sudden urge", but it's not. Something that sticks with you for five years isn't what I'd call a "sudden urge"."
OK, then it's just an urge. But as I said before, if you can't explain to yourself why you want to join the military, don't join the military. Try to think of what would happen if you get what you want--that is, if you get sent to war. I hope you've seen real photographs of injured people dying during a war, because if you're ignorant of such things, you'll get a real shock when you witness it. Also, I'm almost certain that if and when you get injured, you'll regret your decision to join the military. --Bowlhover 06:02, 16 March 2006 (UTC)
You don't understand the concept of instinct, do you? Here7ic 16:37, 16 March 2006 (UTC)
I do understand it, which is why I know you're misusing the term. According to the article you linked to: "Instinct is the inherent disposition of a living organism toward a particular behavior." Having an urge to join the military is not an instinct, since you didn't know there's something called the Marines when you were born (that was learned). See the article for things that are instincts. --Bowlhover 04:02, 17 March 2006 (UTC)
You didn't answer me yet. Will you consider joining the Air Force instead of the Marines? It will give you a better shot at becoming an astronaut, you're still helping your country, and it's less likely that you'll be injured or killed. Superm401 - Talk 04:24, 17 March 2006 (UTC)
Fine then. A slight mistranslation, but nothing crippling. Perhaps "sub-conscious motivation" would be better, a 'prime directive' that must be attained even at high costs. It's what some would call a 'gut feeling'. I know I have to do it, and I know it has to be the Marines, Superm. If I weren't to, I'd be betraying the most human part of my mind, my sub-conscious. And in this world, I don't think it's worth it to betray my sub-conscious. I'm sure as a Marine I'll have at least a slight chance of making it into NASA's Space Flight program, and maybe that's all I need. I guess only time will tell. Here7ic 17:06, 17 March 2006 (UTC)

This is ridiculous--"betraying the most human part of my mind, my sub-conscious". I won't try hard to convince you to not join the military, but you should really think about your own actions, instead of relying on a "sub-conscious motivation" to make decisions for you (and then blaming it if the decision was a bad one). Get a conscious motivation! If you can't, you should probably resist the sub-conscious motivation. (If you get a gut feeling that you have to rob a bank, you should probably resist it.) --Bowlhover 05:08, 19 March 2006 (UTC)
No, dear Bowlhover, what's ridiculous is to think that I haven't consciously thought this over. I have, and I do every day. I know there are risks to joining the military, but it's something I have to do. It's a sense of fate that every thing human about me tells me is right. If you won't buy that, and want a reason I can provide with a more logical reference, well then the military is currently the most secure branch of employment available. You say I have a good chance of dying if I join because they'll send me over(an accuasation I've pointed out to be improbable) to Iraq. Well, you have a better chance at being struck by a car tomorrow, or being murdered on your way home from work. Do you think that just because I enter a politically debated war that I will die or that I won't have any better chace of staying alive? Do you honestly think that by staying out of the war you've insured your life? Many things are reliable. Life isn't. Here7ic 05:29, 19 March 2006 (UTC)


how pervasive computing is can be used in goal oriented programming paradigm?

plz if u can help me then tell me any thing u know about it............

Have you looked at pervasive computing? -- Flag of the United States.svg Mac Davis] ☢ ญƛ. 11:09, 14 March 2006 (UTC)

Air pressure[edit]

What is the differnce between Static pressure and Atmospheric pressure?? -- 11:29, 14 March 2006 (UTC)

If you take a look at static pressure you'll see that atmospheric pressure is an example of it. --Bth 11:42, 14 March 2006 (UTC)
By contrast, you would get dynamic pressure if wind was blowing on an object. StuRat 00:09, 15 March 2006 (UTC)
And by using a Pitot tube, we use the concepts of both dynamic pressure and static pressure to find the speed of airflow. EWS23 | (Leave me a message!) 00:53, 20 March 2006 (UTC)

Special Relativity & Orbit of the earth[edit]

Dear users can anyone explain to me why things gain mass when they were accelerated at the speed of light? Why does it contracts in length?

Can anyone tell me why the Earth spins on its own?


1) We have a splendid article entitled special relativity for beginners, but feel free to come back here if you need anything explained in more depth.
2) Conservation of angular momentum. The stuff from which the Earth formed was spinning. In turn, that was because the nebula from which it condensed was spinning. And that's because it got a random off-centre kick at some point. --Bth 12:56, 14 March 2006 (UTC)

Atomic Shells[edit]

Can anyone tell me why things need 8 electrons in the outer shell to be stable? why not 5 or 10? thanks!

It's difficult to know how complicated an answer you want. The glib answer is: because of quantum mechanics. The full-on version is at electron configuration. I'll try and give an answer intermediate between those two.
Electrons are found in fuzzy regions called orbitals, which act as subshells of the shells. Each orbital can only have 2 electrons (because electrons are fermions and they obey the Pauli Exclusion Principle -- each orbital can have one spin up and one spin down electron). Each time you increase n, the number of the shell, you get another 2n-1 subshells that are available to be filled by electrons.
So for n=1 there's only one orbital (the s-orbital), which can have 2 electrons -- that's why Helium is a noble gas with only 2. For n=2 there's the s-orbital and three new p-orbitals, each of which can have 2 electrons, so six in total. Therefore you have eight electrons in the outer shell.
That works for n=2. But why isn't it 18 for n=3, 32 for n=4, etc.? That's because of the order in which the subshells get filled. The s-orbital for the next shell up is at a lower energy than the new subshells (named d,f,g in each case) so the next electron after filling up the n-1 shell's p subshells go in there, but the p subshells for shell n are at a higher energy. So the filling order goes: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p (and gets even more complicated after that; even that's ignoring some subtleties). This is why we get the transition metals -- they're what happens when you fill up the d orbital with 10 electrons in between filling the 4s and 4p. But when you get along to the end you've still only got 8 electrons in the outer shell.
--Bth 12:48, 14 March 2006 (UTC)
  • You have three quantum numbers involved in identifying an electron in an orbital. (Why this is, is a longer story) It has Spin (s, ±1/2), Orbital angular momentum (l, an integer) and the Magnetic quantum number (m, which can take a value from -l to +l). Only one electron can have one combination of quantum numbers (because of the Pauli priniciple mentioned above)
  • So, for l = 0, m must be 0, and all you have is spin up and down, so you can fit two electrons in there. (an 's' orbital) For l = 1, m can be (-1,0,+1) and with spin that means six electrons. (a 'p' orbital). The octet rule (stable with 8 electrons) comes from counting only the outmost p and s orbitals, so 2+6=8. There are other orbitals (d and f, corresponding to l = 2 and l = 3), but they get filled before the outmost p and s ones, so that's why the rule works. --BluePlatypus 14:40, 14 March 2006 (UTC)

Chemistry--Is it Acid or Chemical?[edit]

I am an Artist, living in india. While travelling I saw an old man copying pictres and letters of news paper to a blank white paper.I wonder how he can trace pictures without using a machine.He only uses a liquid (I don't know Acid or Chemical) he pastes that liquid on that paper and presses that blank paper on the picture he want to it happening sir? can u clear my doubt? which liquid he is using?Thanks (Sathiyamoorthi)

Most newspapers use powdery ink that comes off and turns your hands black. In the U.S., there has been a lot of study on making cheap ink that doesn't rub off. But, most newspapers around the world still rub off. Just add a little water (damp sponge perhaps) and press a sheet of paper on it and the much of the ink will move easily from the newspaper to the paper. Also note, an acid is a chemical. Perhaps you meant "acid or base". --Kainaw (talk) 15:54, 14 March 2006 (UTC)
Yes, most US newspapers don't use ink that rubs off easily any more. They were losing customers who didn't like ending up with ink covered clothes and hands after reading the paper, so made the change. StuRat 00:02, 15 March 2006 (UTC)
There is one other possibility. Was the old man, by any chance, selling this chemical? Notinasnaid 16:37, 14 March 2006 (UTC)
If he was - wouldn't it be easier to just get a tub of Silly Putty and sell that instead? --Kainaw (talk) 16:41, 14 March 2006 (UTC)
Continuing the thought, which perhaps wasn't very clear: if someone is demonstrating a wonderful substance with miraculous properties, it often turns out to be snake oil. It's easy to imagine a set up based on invisible ink which purports to demonstrate a "photocopier in a can". Notinasnaid 09:05, 15 March 2006 (UTC)

Regarding higher quality ink that doesn't run when it gets wet: I believe there was a process for creating copies using a chemical akin to paint thinner, which then transferred some of the ink from the original to the copy. This method was used to copy the US Declaration of Independence, for example. However, the process has some negatives, such as degrading the original and making a limited number of blurry copies, as well as the toxic fumes. So, once photocopiers came out, this process mostly died. You can now buy a standalone 8.5" x 11" flatbed copier for under US$100, so there isn't much economic incentive to using the chemical process anymore, either. (The cost of the toxic chemicals will be more than the copier after a few hundred copies.) StuRat 15:01, 15 March 2006 (UTC)

thanks for your answer


I tried to play the 2004 two-disc edition of The Meaning of Life with xine, with the latest libdvdcss (1.2.9) installed, but descrambling failed. Here was someone with the same problem one year ago (but he never got a reply). What is the meaning of this? Have they come up with a new scrambling algorithm now? It really puts you off not pirating movies when you find you are unable to play the ones you didn't pirate. dab () 15:36, 14 March 2006 (UTC)

I don't think CSS is implemented as widely as commonly thought to be. Other scrambling algorithms have started to be used as well, especially recently. Are you sure it's been scrambled using CSS? -- Daverocks (talk) 05:47, 15 March 2006 (UTC)

browser history drop-down[edit]

In both Mozilla Firefox and Internet Explorer, when I use the browser's history dropdown box in an attempt to find a shortcut to a web page I recently visted (having previously entered the URL into the browser), I usually don't find the URL I want to use. But the browser offers up a lot of addresses I visited a few days or weeks ago. What gives? Is the list in the dropdown box supposed to be in LIFO order, as I assume? If not, is there a way to sort the list? (I think not.) How is a person supposed to make practical use of this "feature" in the browsers? What am I missing? Thanks, --Halcatalyst 19:31, 14 March 2006 (UTC)

I usually do my best to provide references when I answer ref desk questions, but I'm going to wing it on this one. The drop-down list on the address/location bar contains only those URLs that you have specifically typed in, and then hit enter (or clicked GO, or whatever). Early versions of Netscape Navigator limited the drop-down list to the last X entries (where X varied from one release to the next). I believe that the lifespan of entries on that list is now governed by your "days to keep" History setting. I think you are correct on the LIFO nature of the list, at least for Firefox. I think IE might use a MRU scheme instead.
When you start typing a URL in the bar, the auto-complete feature found in many current browsers searches your complete browsing history, which will contain all pages that you have visited, perhaps by linking rather than explicit URL entry (subject to the same "days to keep" setting).
As far as using the feature . . . at work I have a limited number of entries in my drop-down list, and is one of the ones that always stays there, as well as my direct employer's webmail (I'm a contractor; Outlook connects to the client companies servers). I just use those entries to get to the few sites that I can visit while at work. I hardly ever use bookmarks/favorites. --LarryMac 21:09, 14 March 2006 (UTC)
I have a tip for when you want to type in an address in the address bar and not have it appear in the drop-down box. This tip only works in Internet Explorer though. After typing the URL, grab the white space to the left (the area that normally shows an IE document-type image) and drag it into the page. The page *should* start loading. I find myself doing this quite a bit. It's one of the reasons I still use IE. --Optichan 21:51, 14 March 2006 (UTC)

I think I was wrong when I said the address drop down didn't contain URLs I had typed in. It probably does. I was confusing that with the browser's ability to call up suggested URLs when I start typing in the address box. Well, at least that's clearer to me now. Thanks to both for your help! --Halcatalyst 22:59, 14 March 2006 (UTC)

I've noticed that when my browser (AOL) locks up, I kill and restart it, but the drop down never seems to have the URL of my last page. I suspect that it doesn't update the stored list until it is closed down properly, which is pathetic, guaranteeing it won't work to recover my web page whenever AOL locks up. StuRat 23:57, 14 March 2006 (UTC)

Metal Racks in Microwaves[edit]

I've always heard that putting any metal in a microwave and turning it on results in arcing, which can ruin the microwave. But a lot of the over-the-range models these days are coming with metal racks in them. What's the deal with that?

From my very first microwave to the one I have now, the whole casing - inside and out - is metal. It is an urban legend that "any metal" in a microwave will "kill the coils/blow it up/cause rips in the fabric of space and time..." In fact, my first microwave said, in the instruction manual, that the best way to reheat chicken legs is to wrap tin foil around the bone end while reheating. --Kainaw (talk) 20:29, 14 March 2006 (UTC)
The metal casing including the mesh in the glass window is there to reflect/absorb microwaves so they don't heat things outside the micrwave (like people). The casing defines the interior microwave space and is not in it. Metal and water absorb the microwaves and heat up. Micowave racks, to the best of my knowledge, are not made of metal, although some look metallic ("metallic finish" says one adv.). WAS 4.250 21:05, 14 March 2006 (UTC)
I've wondered about 'microwave-safe foil dishes', so I looked it up. You can put metal in a microwave, so long as it is rounded, and doesn't touch other metal. You can put in those foil packets, but not on metal trays. [37] Standard foil has too many crinkles and sharp edges, so it will spark. --Zeizmic 22:31, 14 March 2006 (UTC)
OK, the story as I know it is, you have to have enough microwave absorbant material in the microwave uncovered in metal to absorb the energy or there is too much feedback on the magnetrons and they arc. In the early days, even a thin gold rim on a plate was anough to cause trouble, but maybe the ovens are more durable now.

I had a rare case of arcing with no metal in the mic. I was melting cheese on saltines with jalapeno peppers on them, and got arcing between two ends of a semicircular pepper slice that scorched the cracker. I can't explain it, but my best guess is it was some weird electrochemical reaction with energy supplied by the microwaves. The acid in the pepper and the salt on the cracker probably played a part. StuRat 23:47, 14 March 2006 (UTC)

Our microwave manual says that to warm a cup of water evenly you should put a metal spoon in the cup. It also says that the spoon shouldn't touch the metal casing. And I've read somewhere that metallic things were a problem in pre-90's microwaves, but not any more. – Blue ҉ Iris 05:39, 15 March 2006 (UTC)
That's a different thing though, it doesn't have to be a metal spoon. The reason you want to do that is that, in rare cases and if the cup is smooth, the water can be heated so fast that it doesn't nucleate and start boiling. The water then becomes superheated, which is dangerous, becuase when you take the cup out and disturb it can start boiling instantly and blow hot water into your face. Adding a spoon to the water creates nucleation sites for the bubbles, and reduces the likelyhood of the water becoming superheated. --BluePlatypus 14:23, 15 March 2006 (UTC)

How have microwave ovens changed to prevent metal arcing ?[edit]

Per the above convo, I would be interested in knowing how microwave ovens have changed to make them handle metal better now. StuRat 14:50, 15 March 2006 (UTC)


A non-surgical consultant physician has MRSA in the throat following abdominal surgery. Is he/she permitted to return to work and what risks to patients and the employing hospital's liability would be posed if such return was allowed? This is a UK question.

I checked the our CDC Infection Outbreak list (contains American data only) to see if there have been outbreaks of MRSA. There has been in correctional facilities, athletic locations with common showers, in the gay-male communities, and in childcare centers. These are areas where outbreaks of just about everything occur normally. So, that makes me assume that the chance of an outbreak at a normal working facility is the same as any other common bacteria or virus. According to the CDC, they are monitoring MRSA infections in hospitals, but not in office workspaces. So, since this is a physician, they may be at increased risk of getting MRSA because of the hospital setting - that is assuming that hospitals in the UK are similarly full of infections like the ones in the US. But, I have to say, I got sick all the time when I worked for Sony. Since I've been working in a hospital, I haven't even caught a cold. --Kainaw (talk) 20:04, 14 March 2006 (UTC)
Here in the UK we have a big flap on (largely inspired by the Daily Mail and its ilk) about patients being infected by their doctors(' ties). (In fairness, we do have above average infection rates in our hospitals so it's not completely tabloid hysteria). I suspect the question is more whether the guy would be allowed back to work until he's fully recovered, given that he might be (perceived as) putting his patients at enhanced risk. Unfortunately I can't find anything helpful via Google. --Bth 20:19, 14 March 2006 (UTC)

I think I need to suitly emphazi MRSA. StuRat 23:37, 14 March 2006 (UTC)

sound in pdf or similar?[edit]

I want to create a pdf that has an embedded sound file. Actually, I think I want pdf, maybe something else - I want a mostly text file that I can send to collegues and be confident that they will not have to install something to read it. It is mostly text, but I want them to be able to click on a sound icon and get a sound file played. How do I do this? I am using OS X, but want to distribute mostly for win 2k / xp.

I doubt you can embed sound in PDF, but I'm not sure. Melchoir 23:38, 14 March 2006 (UTC)
Actually, I guess you can. The question is, do you have access to software that will do it? Melchoir 23:40, 14 March 2006 (UTC)
Adobe Professional, which you need to make an PDF file and integrate sound into it, costs 449 USD. There is a 30-day trial version, but it's only for Windows. --Bowlhover 01:03, 15 March 2006 (UTC)

Is there another way to do it? HTML?

Yeah, it's trivial to do it with HTML. ☢ Ҡiff 00:58, 15 March 2006 (UTC)
If you want to use HTML, you'll have to have a sound file first, and than link to it using <a href="soundfile.extension">link name</a>. I'm pretty sure this is not what you want, since the user will have to download the sound file first, and then use another application (like Windows Media Player or Realplayer) to play it. It's the same as sending the sound file directly except that you'll waste time creating an HTML file. Bowlhover 01:04, 15 March 2006 (UTC)
You can use the embed tag to embed a sound file into the webpage and start it playing without having the reader do any action (other than waiting for it to download). --Kainaw (talk) 01:24, 15 March 2006 (UTC)
Don't forget the similar bgsound tag, used like: <bgsound src="">. Mind you, neither embed nor bgsound will work in Firefox, as it blocks background sounds. -- Daverocks (talk) 05:54, 15 March 2006 (UTC)
It's not very good practice though; forcing users to listen to your music without them having done anything to request it is rather rude -- if nothing else, think of the skiving office workers being caught out when their PC starts blaring the Red Flag (or whatever it is you want to embed). And frankly, the majority of sites that use such things tend to be bad in one way or another. Another reason to love Firefox. --Bth 08:58, 15 March 2006 (UTC)

Large intestine[edit]

Quick Biology question:

How long is food digested in the large intestine?

Thank you.

Well, it spends a few hours in there, but it isn't really digested there, that happens in the stomach and small intestine. The large intestine mostly just removes water. StuRat 23:33, 14 March 2006 (UTC)
If you type "large intestine" into the search box, you'll come up with Colon (anatomy), the first section of which is "Role in digestion". Melchoir 23:37, 14 March 2006 (UTC)

I need to find specific hours when water, etc... are removed in the large intestine. If anyone could please help out before tomorrow, I would appreciate it.

March 15[edit]

short-term memory[edit]

Could you tell me in what ways would life be different without short-term memory?

What did you say?

In a way, short term memory allows you to create a continuous timeline in your mind and memory. Without it, you'd be living in discrete, unconnected intervals of, say, 5, 10 minutes. This is a terrible thing. ☢ Ҡiff 00:35, 15 March 2006 (UTC)

The article Anterograde amnesia has, um...
Slumgum 01:03, 15 March 2006 (UTC)

It may be worth looking at the Korsakoff's syndrome article too. This is a rare disease of chronic alcoholics. Brian G. Crawford 01:16, 15 March 2006 (UTC)

Also note that it is the common current assumption that long-term memory is created by transferring select bits of information from short-term memory. So, without short-term memory, you have nothing to transfer into long-term memory. But, this is a theory about the brain. It will probably all be bunk in another 10 years. --Kainaw (talk) 01:26, 15 March 2006 (UTC)
However, if the problem with short term memory is just an inability to consciously access it, memories might still make it into long term memory. StuRat 03:06, 15 March 2006 (UTC)

This is a philosophical or definitional problem in that "life", "different", "short-term", and "memory" are so ill defined in common useage that the question bogs down at the level of the definition of the terms involved. Just for an example, take a bacteria (life), and its recognition of a gradient (different and memory): what does "short-term" mean in this instance? WAS 4.250 01:34, 15 March 2006 (UTC)

Um, bacteria don't "recognize" anything, they have roughly the cognitive ability of your average taste bud, absolutely none, their receptors simply turn in the direction of a chemical stimuli, then tumble until they've started to move in the other direction-- 21:43, 15 March 2006 (UTC)
Wrong. Totally wrong. Read this. WAS 4.250 22:11, 15 March 2006 (UTC)
Recognizing simple chemical signals doesn't make them intelligent, no more so than my taste bud, or a pH meter would be considered "intelligent"-- 23:02, 15 March 2006 (UTC)
Recognizing simple chemical signals doesn't make humans intelligent either. Both humans and bacteria do MORE than that. WAS 4.250 01:03, 16 March 2006 (UTC)
Um, what? Higher order mammals have these funny organs that usually handle that whole conscious thought, thing, bacteria have, um, practically nothing, just a primary genome, and in some cases a plasmid, so barring any nonsensical/theological explanations, or some sort of junk-science about bacterial souls, I have no idea what you're talking about-- 05:40, 16 March 2006 (UTC)
Doctor: "Had any trouble with your memory lately ?"
Patient: "Not that I can recall, no."
StuRat 03:08, 15 March 2006 (UTC)

An interesting screenshot from's news listings (this oughta be some sort of fair use, I'd think): File:NetscapeNewsOops.jpg. --Trovatore 22:21, 15 March 2006 (UTC)

LOL, is the article about how hungry the author is, and what they would like to munch on, and how big their hands are, and how words lose their meaning when you repeat them a lot ? StuRat 01:50, 16 March 2006 (UTC)

Microsoft Word[edit]

I recently came across a 2003 article on the security risks of Microsoft Word [38].

  1. Is this truly something to worry about
  2. how and with what programs would one be able to access the encoded information, and
  3. has Microsoft done anything to solve this since then?

JianLi 01:43, 15 March 2006 (UTC)

There is a document cleaner in MS Word now. Some people do not trust it and convert the Word documents to evil PDF documents before sending them out to people. I don't use MS Word and I will quit my job before even saving a death-spewing PDF to my hard drive. So, I can't say what menu item does the document cleaning or how to convert a word doc to a satan-spawn PDF. --Kainaw (talk) 01:48, 15 March 2006 (UTC)
Why're .pdf files evil? Slumgum 02:14, 15 March 2006 (UTC)
I'll let someone else answer that, but I'll opine that they're also seethingly annoying. If you use them for distributing documents which you print out on paper and then read, they're fine. But when used for distributing documents which are to be intended to be read on screen (e.g. on web pages) they're just *wrong*. The screen is not a piece of paper, and the lengths which PDF goes to in an attempt to reproduce exactly what you'd see on a piece of paper are often unnecessary if not downright detrimental for screen reading. The fonts are often too small, and even if your PDF reader lets you zoom in (some do; web browsers with PDF plugins may not) you've then got the problem of scrolling around. The scrolling you do within a "page" is often distractingly different from whatever you have to do to "turn the page". And don't even get me started on the up-and-down zigzag scrolling you have to do if the document carefully uses a newspaper-like multicolumn format. —Steve Summit (talk) 05:25, 15 March 2006 (UTC)
Kainaw: If you don't use Microsoft Word or PDF, what do you use? —Keenan Pepper 03:14, 15 March 2006 (UTC)
To distribute electronic documents? Me, I usually use plain text. It's guaranteed that the recipient can read it, and I'm more interested in impressing my reader with my content than my typography. —Steve Summit (talk) 05:25, 15 March 2006 (UTC)
First, pdf files are evil because, as mentioned above, they are not meant to viewed on a computer. They are meant to be printed. I print, at most, 2 things a month. I'm not going to suddenly start printing PDF documents so I can read them. While it is humanly possible to read a pdf on the screen, it is more annoying than getting a jalapeno enema while trying to take the GRE. I have been well known to go down 12 floors, leave my office, walk six blocks, go up 8 floors, and yell at someone for sending me a PDF attachment in an email with the note: "Read This".
[Wow. You got it even worse than I do. Condolences, 'n' that. :-) —Steve Summit (talk) 04:27, 16 March 2006 (UTC)]
I know that I will never be able to solve world hunger, end all wars, or stop the constant onslaught of movie remakes of old television shows. However, I hope that I will someday be able to put an end to the plague of PDF documents that pollute computers around the world.
As for what I do use... Text. When I send an email, I just type plain text. If I am taking notes, I use plain text. When it is absolutely necessary to have text formatting and pictures, I use HTML. If it is not absolutely necessary to have text formatting and pictures, I stick with text. When I do receive a Word document, I use Open Office to read it. Unlike PDF documents, you can open a word document and view it online without scrolling up-right-left-down-shift-jumped a page(damn!)-up-up-right-left-(wait for a page to load)-down-right-left-down-jumped a page again(double damn!)... --Kainaw (talk) 13:24, 15 March 2006 (UTC)
Maybe it's the software you're using to view the PDFs. Evince is a pleasure to use. —Keenan Pepper 15:34, 15 March 2006 (UTC)

Haha, btw, this all arose because I got one of these in the signature line of an email:

Please do not send me attachments encoded in a secret proprietary
format such as MS Word or Power Point;  I am unable to read them.
Please use instead a publicly available format such as PDF
(Portable Document Format) or plain text (ASCII).  For more information,
see [39]


  • Most versions of Word now have an option in their settings so that they will 1. warn you if a document contains hidden data (like tracked changes) and 2. allows you to strip the document of any personal data upon saving. It is in the preferences somewhere. That signature is somewhat humorous -- if I'm sending someone a document which they need to edit, neither PDF or ASCII will be very useful. A less proprietary format which allows semi-complex formatting and editing would probably be RTF, if one is not interested in the open source Word alternatives (i.e. AbiWord or --Fastfission 04:01, 15 March 2006 (UTC)

My answers:

  1. Yes, the danger of "leaking" unintended information via Word documents is quite real. All bashing aside, Word .doc format is a less-then-appropriate format for distributing documents, especially confidential ones. The .doc file is much more than just a representation of what the final form of the document "looks like" -- the file typically also contains all sorts of information about how the document got created and the revisions it went through. Back in the day, when you released the final version of a paper document for distribution, you released the final version; you obviously wouldn't release the manila folder containing your rough drafts, or the filing cabinet containing your confidential research.
  2. When someone sends me a Microsoft Word document that I need to read, these days I usually use the Unix "strings" utility. This shows me all of the text, none of the formatting, and incidentally sometimes also (a) metadata such as the names of the authors or the document filename on the author's hard drive, and (b) some of the deleted ("redlined") text. I have also used a utility called wvware.
  3. Microsoft may have worked on it, but if you're paranoid in this regard, it's wise not to trust them. If you have secrets which you can't reveal, and if you accidentally do via a Word document which you or Microsoft mistakenly thought was "clean", then even if you can get Microsoft to apologize, it's too late to save your secrets.

There was recently a memo put out by none other than the U.S. National Security Agency (NSA) which, despite spending 10 or so pages describing "How to Safely Publish Sanitized Reports Converted From Word", also admitted that "Using original source formats, such as MS Word, for [sanitized documents] can entail exceptional risks". —Steve Summit (talk) 05:25, 15 March 2006 (UTC)

I agree with the earlier statement that you should send documents as either plain text or HTML, which everyone can read with no security risks. Not everyone can read the proprietary formats like WORD, and then there is the extraneous info such formats contain, which make the file unnecessarily long as well as providing security holes. I also agree that people spend way too much time on the formatting of their documents and too little on the actual content. (I wanted to add some dancing babies at this point, but couldn't figure out how.) StuRat 14:41, 15 March 2006 (UTC)
To avoid leaving hints about a MSWord document history, just copy'n paste into a new one. To avoid using Word, I tried OpenOffice, which is not too bad, you have to get used to it, maybe there should be extensions for OO, just like for Firefox.
To avoid pdfs, just avoid customers : the rule in plenty of offices is to give your customers pdf to eat, because they can't change the text. Here, in 2006, we're still waiting for reliable open source tools, non proprietary formats, and so on. --DLL 20:41, 15 March 2006 (UTC

What was invented this decade?[edit]

What was invented in 2000, 2001, 2002, 2003, 2004, 2005, and 2006? (I already know Digital Satellite Radio, Artificial Heart, and Podcasting were invented this decade.) -Anonymous

Sub-question: If the last decade was called the nineties, what is the name for this decade? --JianLi

The name is problematic, perhaps the "naughts" ? The 2010-2019 decade will be tricky, too. You could call it the "teens", but that excludes 2010-2012. I believe artificial hearts go back decades, although none ever worked very well. Perhaps you mean the first self-contained artificial heart ? StuRat 04:36, 15 March 2006 (UTC)
Probably JianLi got the list of three from Timeline_of_invention#2000s. Jay 16:50, 15 March 2006 (UTC)
Actually, the original question wasn't mine. I just wrote the subquestion. -JianLi
This decade often gets called "the naughties" (and I know what they mean ...) JackofOz 04:48, 15 March 2006 (UTC)

Recent decline in inventions[edit]

I've plotted the inventions per decade since 1800, from Timeline_of_invention (doubling the number for the 2000's, since that decade is only half over), and got the following:

1800's *********
1810's **********
1820's *******
1830's *************************
1840's ************
1850's **********
1860's *****************
1870's *******************************
1880's ********************************
1890's ***************************
1900's ****************************************
1910's **********************************
1920's ****************************
1930's *******************
1940's *************
1950's ****************
1960's ************
1970's ***********************
1980's **************
1990's *************
2000's ******

It looks to me like the rate of inventions peaked in the late 1800's and early 1900's. This is counter to books like Future Shock, which predicted an ever increasing rate of inventions. So, my question is, what's going on here and what are the implications for the future ? I personally think that science and engineering have become unfashionable, at least in the US, and that might have something to do with it. Will the number continue to decrease until we reject science entirely and enter a new dark age ? StuRat 17:28, 15 March 2006 (UTC)

Geez, that was a lot of work! In my alter-life I am caught in a giant techno-bureaucracy. With these things, there are hardly any 'inventions' but lots of mundane improvements. So the patent rate (of silliness) goes up. There's not a lot of scope these days to invent something significant in a garage. --Zeizmic 18:48, 15 March 2006 (UTC)
Is that chart a count of inventions or patents? It seems like software patents are flooding the USPTO. I'd expect them to outnumber real inventions. --Kainaw (talk) 18:51, 15 March 2006 (UTC)
It's a count of stuff in the wikipedia article, so it's by no means unbiased. You'd be insane to draw any real conclusions from that. If anything, it's a measure of the timespan required for an invention to be considered significant. Also, you could interpret it how the "inventor-invention" idea is more rooted in the late 19th century when you did have a lot of individual innovators, whereas research and innovation today tends to be done in larger groups and more incremental steps. Rest assured that by any reliable metric such as number of patents, number of researchers, number of scientific papers published, amount of money spent on R&D, etc, the pace of innovation is higher today than ever before. --BluePlatypus 19:43, 15 March 2006 (UTC)
This is my point. It seems like more money is being spent, and more patents obtained, for truly insignificant things, like yet another pharmaceutical ever so slightly different from all the others in it's class, which is not significantly better than it's predecessors in any way. At the same time, the number of real, meaningful inventions is falling dramatically. StuRat 01:59, 16 March 2006 (UTC)
Exactly. To be precise, Selection bias. Melchoir 19:44, 15 March 2006 (UTC)
The fact is that there are less births and deaths in the years 500-1000 than in 1850-1900 in the Selected anniversaries (WP's main page).
It takes time to really recognize the value of anything - people, inventions, events. The most recent ones may still be ignored. Plenty of immense inventions died twenty or thirty years later ; floppy disks, telex, LPs ... may be forgotten soon. We might well have the same plotted graphic in 2050. --DLL 20:29, 15 March 2006 (UTC)
I thought of that, but it seems to me that inventions 50 years old are old enough to be recognized as valuable or not by now, yet we still see a decline even then. It seems like a reasonable bell-shaped curve, too. I would think any bias by Wikipedia editors to be a recency bias, so would expect even more inventions to be listed recently. StuRat 01:43, 16 March 2006 (UTC)
Also, I think what you may be missing is that while not that as much "new stuff" is being invented, the stuff we already have is being radically improved. Jet airliners may be over 50 years old, but these days you can fly across the Atlantic for a very small fraction of the cost you could then. --Robert Merkel 04:09, 16 March 2006 (UTC)
Yes, but that isn't new, either. Our use of wheels, fire, and agriculture have been radically improved over the ages, too. So, are we destined to stop inventing new things and only work on tweaking existing ideas ? StuRat 20:00, 16 March 2006 (UTC)
I think he's trying to imply that the distance between "improvement" and "new thing" is pretty subjective. --Fastfission 21:37, 18 March 2006 (UTC)
As for patenting trends, they are hard to generalize about without crunching a lot of data and taking into account changes in industry, patenting law, and society. In the US, for example, from about 1870-1970 you have a pretty steady increase in patenting with the exception of World War II. From about 1970 to the present you have some major changes following modifications to the patent system. In the last twenty years there have been some major changes to the way patents are filed and prosecuted, which have led some people to argue that the patent system itself is now functioning counterproductively (see Innovation and its Discontents for one such book). But anyway, I think generally speaking, if one removes from consideration the number of frivolous patents out there (which are probably not too many, in the end), the more inventions one has, the more improvement upon those inventions one gets, some of which end up being quite radical. It is very easy to lose sight of exactly how radical some of these changes have been: just about every aspect of an iPod would have been technologically impossible only a decade ago, and now we are happy to take it completely for granted. In any case, there's no simple answer to even assessing the trends, much less explaining them. I don't think your "bell curve" model is at all correct, though. --Fastfission 21:37, 18 March 2006 (UTC)
Well, the bell curve happened to correspond with my personal observation that truly new inventions seem rare these days (although I would have put the peak a bit later, perhaps at WW2). To just take one field, let's look at disease. When is the last time a disease was actually eliminated ? The last that comes to mind to me is the polio vaccine in the 1950's. Let's look at the last new way to produce energy that actually works on a large scale. Wouldn't that be nuclear fission reactors, also invented in the 1950's ? Let's look at major innovations in transportation. That would be jet airplanes, from the 1950's again. Am I imagining all of this ? (I suppose you could count maglev trains, but they are expensive and rare and really just a tweak on traditional trains and were patented as far back as 1969, in any case.) StuRat 04:36, 19 March 2006 (UTC)

I think you ought to consider bias in the article as the likely explanation. Just looking briefly around my house I can see many significant inventions (significant to me, anyway) not in the list: the condensing boiler, the electronic piano, thermostatically controlled central heating, handheld game consoles, wireless LAN, laptop computers, inkjet printers, pin tumbler locks, print on demand books, silicone sealant, chip and PIN cards, handheld electronic dictionaries, ... I could go on. Gdr 00:35, 20 March 2006 (UTC)

Well, if we look at that list, we have:
  • electronic piano: first sold in the 1950's. Pianos, of course, go back centuries.
  • thermostatically controlled central heating: central heating via hot water goes back at least to Roman baths, with the thermostat going back maybe a century.
  • laptop computers: just a small, powerful, portable version of computers from the 1940's.
  • print on demand books: This isn't really a new invention, just more practical now with faster download speeds.
  • chip and PIN: a variation on credit cards, which go back to the 1950's.

So, nothing much new in that list, is there ? Only a few tweaks to old stuff.

StuRat 21:06, 20 March 2006 (UTC)

Every invention is based on previous inventions, but that doesn't mean that these inventions aren't significant. For example, you might think that a piano is just an improved clavichord. But with a piano you can fill a concert hall and compete with an orchestra: without the piano, no Beethoven piano concertos. And as for your idea that these inventions are just a "few tweaks", I think that's breathtaking arrogance. Gdr 00:00, 21 March 2006 (UTC)
I see no justification for you to resort to personal insults here. There are inventions that weren't tweaks of previous inventions. For example, a car was definitely not a minor tweak of a horse and carriage, and an airplane was definitely not a minor teak on a hot air balloon, and nuclear weapons aren't just a tweak on conventional explosives. However, mostly the inventions I've seen recently don't fall into the category of "major new invention". StuRat 01:23, 21 March 2006 (UTC)
Change is not necessarily the same as invention, however; it can be evolutionary. The cars of today are very different from those 100 years ago, but you can't really blame that on an invention, though tens of thousands of little inventions have gone into it. Similarly the computers of today are very different to those of 30 years ago, but the basic concepts haven't changed much.

There is a school of thought that the pace of change is now so rapid we are heading for a crisis point where everything after that point is incomprehensible before. Increasingly, innovation is happening in software, rather than physical inventions, and the argument goes that once computers are smart enough to start innovating the world will never be the same again. For a discussion of this idea, which I have probably misrepresented, see Technological singularity. Notinasnaid 21:58, 20 March 2006 (UTC)

Yes, that's similar to the Future Shock book I opened this question with. I don't see it happening, though. Which required more of an adjustment, switching from horse and wagon to a car or switching from a car without a navigation system to one with it ? StuRat 01:23, 21 March 2006 (UTC)

How do I get Quake 3 to run in Linux?[edit]

(no question body)

You could try Wine, which works pretty well for most Windows applications, but it doesn't perform too well with DirectX 3D games. On that note, you might be interested in Cedega, a fork of Wine which concentrates specifically on running Windows-designed games on Linux, and the DirectX API. Unfortunately, unlike Wine, it isn't free. In general, it's been a difficult journey to get anything Windows-based running on Linux, but DirectX, being proprietary and used extensively by Quake 3, is difficult to implement. I think I heard somewhere that an earlier legal battle will soon force Microsoft to release some of its rights on DirectX, making it easier for programmers to implement it on other platforms. Good luck. -- Daverocks (talk) 06:41, 15 March 2006 (UTC)
Quake 3 uses OpenGL, and the source code was released some time ago. I'm almost positive there was a port done to Linux, but you wouldn't know it from the Q3A article... Tzarius 07:47, 15 March 2006 (UTC)
Actually, an official Quake 3 port was released by id Software when the game was first released. If you don't have that, as far as I'm aware, you can use the Linux Quake 3 demo executable or the latest point release update executable with the .pk3 files from the full Windows or Mac version. There's a short HOWTO here, and Google will give you plenty more guides if you search. Ahh...I remember the old days of the Quake 3 Test release, which was first released for Mac, then for Linux, and eventually for Windows, and after the release of the Linux version, all Quake 3 forums were filled with people asking for help with their Linux installations...good times. --Aramգուտանգ 09:44, 15 March 2006 (UTC)
Wow. Never knew about any of this. I just assumed Quake 3 used DirectX, silly me. Oh well, <cliché> you learn something new every day. </cliché> -- Daverocks (talk) 09:02, 16 March 2006 (UTC)


good uses and bad uses

Have you looked at our article on Uranium? You might find the Applications section particularly useful. -- Daverocks (talk) 06:43, 15 March 2006 (UTC)
Well, you need uranium to build the Manhattan Project wonder, and nuclear weapons (obviously those are bad uses). It speeds construction of some spaceship parts, too, I think (which would be a good use). And if you have more than one mine you can trade it to others, but that probably counts as bad because of what they'd do with it. .... Oh, wait, I've been playing too much Civilization IV, haven't I? --Bth 09:07, 15 March 2006 (UTC)
There are some benefits to nuclear weapons. They ended WW2 (the Japan part), preventing perhaps millions of additional deaths, and prevented an otherwise inevitable war between the Warsaw Pact nations and NATO. Thus far, they have saved far more lives than they took, although their potential to take lives probably does put them back in the evil category. Uranium also is useful in producing nuclear power, which does far less environmental damage than most of the alternatives. Depleted uranium can also be used in armor or shells, and deciding weather these are good or bad uses depends on if you support the armies that use them, like the US military. StuRat 14:25, 15 March 2006 (UTC)
Uranium can also be used to dye glass and pottery nice colors of green and orange. This was all it was really known to do before the discovery of radioactivity, so it was considered pretty innocuous for a long time. In the end, it is powerful stuff -- power can be used in many ways, both good and bad. --Fastfission 23:34, 15 March 2006 (UTC)
It can even be used for "fast fission". :-) StuRat 19:56, 16 March 2006 (UTC)

C# distributed compilers[edit]

well...i asked this question before but no response from anyone.... i m putting it again...coz i need information about it immediately.... my question is.... what is the scope and future of C# distributed compiler? i will be thankful....

I'm confused as to what you want, and in what context -- are you looking for an actual compiler, or just information about a potential one? Google doesn't seem to be turning up any actually-existing distributed C# compilers, just noodling on mailing lists and IRC logs about how they'd work and who might do it (eg [40] [41]). Hunting around the various external links from our C Sharp article doesn't produce anything when you search for the phrase "distributed compiler". You could try asking on the article's talk page where you might get more knowledgeable people (not everyone reads the Ref Desk), or better yet sign on at somewhere like CSharpFriends, and ask in their forums. --Bth 09:34, 15 March 2006 (UTC)

improving my inyelligence[edit]

please tell me how do i improve my intelligence??? thanks for replying.

Well, for one thing it's not spelled inyelligence-- 21:39, 15 March 2006 (UTC)
You could train your brain (ooh, it rhymes!) by doing e.g. IQ tests or the like. Or by cracking ciphers (my favorite way). But to be honest I don't think IQ tests are a real measure of intelligence. – Blue ҉ Iris 09:37, 15 March 2006 (UTC)
Honestly? Just question everything and be always ready to learn and discover new things. Ask, study, learn, observe and try to understand everything, at all times, as long as you live. Seek knowledge just the same way you breath air, and always try to challenge what you know whenever you're given the chance. This is a concept I've invented a few years ago (but that's surely not a new thing) which I called "scientific spirit" (from Latin scientia = knowledge, spiritus = breath, also in the sense of attitude.) I dare to say that lack of scientific spirit is the fundamental flaw on the people of the world nowdays. ☢ Ҡiff 09:56, 15 March 2006 (UTC)
Yeah, he's right. keep and open mind, and always be learning, that is the way. Be skeptical of things to, don't just accept everything, ask why. As for your "IQ," you won't be able to get a better one without practicing different IQ tests. -- Flag of the United States.svg Mac Davis] ⌇☢ ญƛ. 11:26, 15 March 2006 (UTC)
MAke sure you get enough of each type of vitamins, eat plenty of oily fish, and get enough sleep every night. Logic puzzles and suchlike will also help you home your mental agility. Proto||type 12:30, 15 March 2006 (UTC)
And get your daily supply of Wikipedia, that can help you recover from the brain damage caused by watching regular TV (excluding PBS, the Discovery Channel, Biography, and perhaps some good Sci Fi shows). StuRat 14:10, 15 March 2006 (UTC)
The Guardian (UK) just had an article about this; apparently there was a BBC TV show also. --LarryMac 16:53, 15 March 2006 (UTC)
I heard that if you're put in a different culture, get sick, or are placed under similar stressful conditions, your IQ diminishes significantly. How true is it and why? Are IQ tests really that reliable as an indicator of intelligence? Igor the Lion(Roar!) 14:45, 15 March 2006 (UTC)
IQ is a measure of your ability to perform a certain set of mental tasks. That's much narrower than what most would call "intelligence" in general. What it indicates is entirely dependent on what kind of test you use. A magazine-variety "IQ test" along the lines of "what figure comes next?" isn't going to tell you much compared to the tests used by psychiatrists. But I think it's safe to say no simple test can assess the whole spectrum of what people call "intelligence". As for stress, it seems to me that it's quite normal that your ability to perform just about any mental task will be diminished if you're distracted. --BluePlatypus 14:55, 15 March 2006 (UTC)
Then are they really that accurate as people think they are? Or do they merely calculate a person's intelligence at the given time and not his brain's "potential" for intelligence (or how intelligent he would be in an ideal, totally stress-free environment)? And is intelligence only relative to the culture one is in? Like I don't know anything about, say, farming, so if I were transported to a farming nation (which for convenience wouldn't value things like English literature or skill in calculus) would my "intelligence" drop significantly? Is intelligence equal to common sense? (A bit vague, but I hope the points get across) Igor the Lion(Roar!) 15:09, 15 March 2006 (UTC)
No, they're not terribly accurate. Marilyn vos Savant, who has the highest IQ recorded hasn't done anything terribly remarkable, unless you consider writing a magazine column the pinnacle of human achivement. Intelligence isn't really relative to culture, IMO. People usually distinguish between knowledge and intelligence. But learning ability is usually considered to be an important part of intelligence, so general-knowledge questions can be used to measure intelligence. But you've got to choose the questions carefully. If you've never been exposed to information about farming, the fact that you don't know anything about it means nothing. If you live in a farming community where everyone is always talking about farming, the fact that you don't know anything about it means a lot. Common sense is an almost even vaguer term. But in the sense of "reasoning ability" (as in analyzing things, drawing conclusions, making generalizations), then yes it is. And there's a big difference between having the ability to reason in the abstract and doing it in practice; there are plenty of highly intelligent people who mostly use emotional reasoning, and plenty of average folks who are capable of being cold-headed. How you use intelligence is a personality and maturity issue. --BluePlatypus 17:10, 15 March 2006 (UTC)
Hey! Where would the world be now if Marilyn vos Savant hadn't correctly solved the Monty Hall problem!? --Kainaw (talk) 20:00, 15 March 2006 (UTC)
  1. are they really as accurate as people think they are? No they are not.
  2. do they merely calculate a person's intelligence Not even that.
  3. not his brain's "potential" for intelligence (or how intelligent he would be in an ideal, totally stress-free environment)? That's right.
  4. is intelligence only relative to the culture one is in? What is measured in some intelligence tests is, what is measured in other intelligence tests is not.
  5. Is intelligence equal to common sense? No. WAS 4.250 16:09, 15 March 2006 (UTC)

As I understand it, "intelligence" is an absolute, being the theoretical maximum "brain capacity" a person has. However, measuring intelligence is basically impossible, as any test is inherently biased towards the language and culture in which it is administered, and the person taking the test isn't likely to be at their full potential. So, while actual intelligence would not drop by changing cultures, the measure of it would. Thus, if you moved to China and were asked to interpret Confucius, you would likely test worse than if asked to interpret Shakespeare. StuRat 16:02, 15 March 2006 (UTC)

Scientifically speaking, "intelligence" is an absolute, being the theoretical maximum "brain capacity" a person has is nonsense. WAS 4.250 16:13, 15 March 2006 (UTC)
I hope you're not confusing what I said with "brain pan capacity", or the total cubic inches/cubic cm which the brain occupies. I am referring to the maximum number of neuron connections in a brain, which is independent of it's size. StuRat 16:18, 15 March 2006 (UTC)
"the maximum number of neuron connections in a brain" is a nonscientific reference (ie scientific nonsense). What is that for a single cell animal? for an animal with 100 neurons? or 101 neurons? More for 101? Humans lose neurons throughout life after infancy. Stop making things up off the top of your head, please. WAS 4.250 21:26, 15 March 2006 (UTC)
I didn't say the number of nuerons, but the number of neuron connections, which is not necessarily directly related. Stop misquoting me, please. StuRat 03:16, 16 March 2006 (UTC)

Too many people are giving replies about the exact meaning of intelligence, which wasn't the question. You can play chess (and studey the game properly) which should help. Also, always review your knowledge, especially any fundamental material you have covered. This preserves a strong sense of the basics, which helps mental adaptability. The other thing would be to take up an instrument, especially the cello or violin (these require a strong sense of pitch) since this will help your mathematical ability. The Mad Echidna 17:32, 15 March 2006 (UTC)

We are discussing the meaning of intelligence so that we can better answer the question "How do I improve my intelligence?" In any case, I don't think a person is that intelligent if he only has all these bits of information in his brain. Where I come from, there are many "gifted" children who memorize the flags of the world or the distances from here to whatever star they fancy. There are also those who play 10 different instruments. That alone, IMO, does not constitute intelligence. What does is the ability to process information, comprehend it, and adapt to a given situation. Also, a person with expertise in one field may be more intelligent than one who dabbles in several different fields. Re comprehension, Richard Feynman once commented on the educ system in Brazil; the students memorized everything by rote, but when asked about a simple application, were unable to answer and were in fact astonished when the underlying concept was revealed. Not very intelligent, though great calculators. Igor the Lion(Roar!) 17:50, 15 March 2006 (UTC)
I totally agree. Some people think I'm "gifted" simply because I know more about math, science, and computers than most of my classmates. However, that's knowledge, not intelligence. Even a stupid person would know a lot about math and science if they've been using a computer to read about it for 5 years. (By the way, my IQ is probably below average, somewhere around 96). --Bowlhover 05:38, 16 March 2006 (UTC)
Whoa there! Feynman commented on the educational system of Brazil? I must read that one! He's totally right, though. People here don't learn anything, they just memorize it. It's depressing and it goes against everything I believe on. I never felt I've studied a single day in school on my entire life! I'm pretty much an autodidact in everything I know. ☢ Ҡiff 13:21, 16 March 2006 (UTC)
It's in Surely You're Joking, Mr. Feynman. Great book, lots of fun, too. GangofOne 21:33, 22 March 2006 (UTC)
Sufficient iron intake is extremely important. [42] --Zeizmic 14:28, 16 March 2006 (UTC)
READ HighInBC 22:03, 18 March 2006 (UTC)

Listen to NPR. Drink a lot of coffee and be passionate about stuff. Don't get hung up on little things like misssspellllling words. Think about the Big stuff. Eat beans. BDSIII 04:15, 20 March 2006 (UTC)

HIV-1 Genome Insertion[edit]

Is there any particular place HIV-1 inserts its genome or does it occur at random? Do any provirus have specific loci at which the insert their genomes? --Username132 (talk) 12:55, 15 March 2006 (UTC)

"The integration of HIV-1 cDNA shows a significant preference for genes actively transcribed by pol II."[43] Addition data can be found at [44], [45], [46], [47]. WAS 4.250 14:23, 15 March 2006 (UTC)

Gene + Promoters/Enhancers = ?[edit]

Is there a term that can be used to refer to a gene and its respective promoter and enhancer sequences? --Username132 (talk) 16:35, 15 March 2006 (UTC)

Burning papa johns sticker[edit]

Okay, here's a wierd question. I wanted to heat up some breadsticks that I got from papa john's so I placed them in my oven at 200 degrees (F) inside the cardboard box. Remembering Fahernheit 451 I thought that the box would be okay. After a while I started to smell burning paper so I hurridly got the box out. The box was fine but the sticker on the front had turned black. The sticker was originally white with black printing. The glue on the back is still sticky and not discolored. When I touch the front it doesn't feel any different and no carbon residue comes off on my hand. The sticker has just shaded completely to black and emitted a burning smell. I will obviously take the sticker off before trying it again but does anyone have any ideas about what occured? I'm just curious.Trngl999 16:38, 15 March 2006 (UTC)

Some inks are designed for use in thermal printers; they turn black when exposed to heat. Was it a stick-on receipt or address label? TenOfAllTrades(talk) 16:41, 15 March 2006 (UTC)
I don't think it's the ink, but special paper designed for the thermal printers still used in many cash registers. They really need to upgrade such printers, those receipts are crap, the ink also rubs off if you use a highlighter on it, fades with time, etc. This low level of quality is not acceptable to me. StuRat 16:50, 15 March 2006 (UTC)
I for one, want my highlighted boxes of breadsticks to last well into the next decade. --Username132 (talk) 16:55, 15 March 2006 (UTC)
I've been on an expense acount, which requires that I submit receipts to get paid, and those blackened receipts with faded lettering didn't cut it. StuRat 17:34, 15 March 2006 (UTC)
I agree, StuRat, receipts have ridiculously low quality these days. Sometimes I think they'd last longer if they wrote me one by hand using pencil, much less a higher quality ink. At one of the grocery stores I go to, the combination of poor quality paper and ink causes the receipt to turn yellow and the ink to fade within 2-3 days of purchase (and yes, this does matter, because like StuRat, I sometimes need these receipts to get reimbursed for certain items). EWS23 | (Leave me a message!) 18:05, 15 March 2006 (UTC)
Thermal printers have the advantage that the paper is the only consumable used, rather than the paper plus the ink cartridge/ribbon/toner of other technologies. I've actually had the receipt stuck to a pizza box turn black just from the heat of the pizza, no oven necessary. --Bob Mellish 17:30, 15 March 2006 (UTC)
Sounds kind of like pyrolysis to me. And I don't think those stickers are paper..some type of plastic I thought. -Snpoj 03:47, 16 March 2006 (UTC)

Open Access "E-Prints" Respositories[edit]

If an institution maintains its own Eprints repository, and someone searches for the article using ISI Wed of Knowledge or PubMed, will the database know that it's out there, available, for free? --Username132 (talk) 18:08, 15 March 2006 (UTC)

  • I doubt that ISI Web of Knowledge or PubMed use spiders, so no, they probably don't know about something unless someone adds it manually. Only databases with spiders (like Google) update automatically. --Fastfission 23:36, 15 March 2006 (UTC)


if there is a total of one liter of nitrogen gas dissolved in the body tissues at sea level how much would be dissolved in a diver breathing air at 99 feet below sea after the tissues have been equilibrated with the higher nitrogen pressure?

That's an excellent homework question! The solution is closely related to the pressure under 99 feet of water, why not start there? — Lomn Talk 18:59, 15 March 2006 (UTC)


thanks i got the answer --4 liters..

I was about to say: They're probably expecting her to reason that if "the pressure" rises by a factor of 4, the dissolved volume also rises by a factor of 4. It's a naive question to begin with, since the body actively regulates its blood content, and there's no reason to think that the gas mixture in one's oxygen tank is the same as the mixture in the atmosphere. At the 13-year old level, though, the question probably isn't asking her to think that hard. Melchoir 20:08, 15 March 2006 (UTC)
For most diving at 99 ft I think the gas inside your tanks is going to be compressed air. afaik, only very advanced divers actually use "oxygen tanks" and when they do they're going far beyond 99 ft. So I think it's a very good assumption that the gas mixture in your tanks is the same as the atmosphere. -Snpoj
I don't think any SCUBA divers use pure oxygen, but some use trimix, to prevent nitrogen narcosis. StuRat 03:06, 16 March 2006 (UTC)
It doesn't necessarily take very advanced diving to start using gas mixtures other than air. All recreational dive agencies now teach the use of nitrox, which is gas mixtures between 21-40% oxygen (with the remainder nitrogen), typically 32% or 36% oxygen (which are actually also NOAA standard gases called "Nitrox I" and "Nitrox II" respectively). It also doesn't take exceptional depth to start using oxygen on decompression -- I used it yesterday to decompression from a 70 minute dive at ~100 ft (where I was using a 30% Oxygen / 30% Helium / 40% Nitrogen Trimix mixture), switched to 100% O2 at 20 feet for 15 minutes. However, in the context of the problem I'm pretty certain they were assuming air... Although if the diver was using a 32% O2 nitrox mix at 100 ft (fairly common in some places where nitrox is available) then the answer would have been 3.44L instead of 4L. -

Courier typeface[edit]

I would like to reference the article on the courier typeface and would much appreciate the name of the author to this article.



Like most articles on Wikipedia, that article was written by several people. I think you'll find the citation info you need here. Melchoir 21:34, 15 March 2006 (UTC)
See also Wikipedia:Citing Wikipedia for guidelines and hints for how best to cite Wikipedia articles. TenOfAllTrades(talk) 23:18, 15 March 2006 (UTC)

March 16[edit]

Why is iodine coloured?[edit]

hello , please could you tell me why iodine is coloured? I cnt seem to find any information on it. Does it have something to do with the electron configuration? Please msg me if you can. thanx

I'm no fan of spectroscopy, so I'll just point out [48] and [49] and let someone else explain. Melchoir 23:40, 15 March 2006 (UTC)
All the halogens are colored because their bonds are weak compared to those of other diatomic molecules (such as oxygen and nitrogen), which makes them absorb visible light rather than ultraviolet. Iodine's bond is the weakest of them all, so it vibrates slowly and absorbs low-frequency red and yellow light, leaving a mixture of light that looks purple. —Keenan Pepper 01:15, 16 March 2006 (UTC)
Here's another good link: [50]Keenan Pepper 01:23, 16 March 2006 (UTC)

Learning Computer Programming[edit]

I'm currently a high school senior who has never taken any computer programming courses. When I go to college next year (as a mathematics/physics major), I'm assuming that I'll be at a considerable disadvantage because of it, so I want to learn programming before college starts next year.

I'm considering going to a community college or doing distance learning, but, if those are not possible, what are some effective self-teaching materials/methods that perhaps you personally have found useful? And is it important to learn a specific language, provided that I'll be going to college next year?JianLi 00:08, 16 March 2006 (UTC)

PS, I tried teaching myself Pascal a few years ago. I think that I got up to arrays, but became discouraged shortly thereafter.

First of all, your college should teach you from the basics, and that's a good thing. Many people show up to college with some bad programming habits, and it's harder to teach them than the beginners. If you want to learn on your own, go through a formal system like a recent book or a well-recommended online tutorial. You should also figure out what language you want to learn. Many schools these days are starting with Java though some with less trendy faculty still like C, and some more trendy schools like other things entirely, like Smalltalk or Python. See if you can find the academic calendars of the schools you're interested in, and see what language their "Introduction to computer programming" classes use.
I wouldn't worry about knowing a specific language -- that's what they are there to teach you. If you want to get ahead though, learn the concepts of Object-oriented programming, which is usually all they care about teaching you at first (the language is often just a means to learn the concepts). -Quasipalm 00:36, 16 March 2006 (UTC)
I would have to disagree with that, if you haven't programmed much he'll only be confused by it. I tried explaining polymorphism to a guy that had only programmed a while, and his head literally exploded (I really mean literally, I was cleaning gunk out of my eyes). I suggesst getting the very basics down first, so you know them well. Stuff like:
These are the basic things that you should know through and through. Since you say that you are good at maths, some very basic algorithms shouldn't be to difficult to learn. I think that if you are smart and have aptitude for maths, you will probably learn faster this way than going through meaningless excercises. For instance, you could try one of the most basic problems first: Given an array, program a subroutine that sorts it into ascending order. Don't worry at first if it's fast or anything, just try to make something that works (if you wanna cheat, wikipedia has all sorts of different sorting algorithms in it). You could also look up simple algorithms and try to understand them. If you understand the Tower of Hanoi recursive algorithm, you've come a long way =)
As for languages, I'd recommend QBasic. Basic gets a lot of hate from people, but it's a magnificent language to learn programming in. It's simple, intuative, and still a pretty decent language. Hope this helps at all. Oskar 01:01, 16 March 2006 (UTC)
I agree, learn BASIC first. But then again, I'm a FORTRAN programmer, which is similar to BASIC, so I may be biased. StuRat 03:00, 16 March 2006 (UTC)
If you're going into science, do not take a course from a computer science department, and don't learn any of the fancy masturbatory languages. Linked lists and sorting algorithms are great, but they're not your job. In physics research, you'll want to know C; failing that, maybe Fortran. In your classes, you probably won't need to program at all, but it's still a good skill. Once you've learned the basics outlined by Oskar, make friends with Numerical Recipes in C. Melchoir 03:36, 16 March 2006 (UTC)
eh, I wouldn't worry about being at a disadvantage. The physics/math classes you'll be taking freshman year almost definitely will not require you to do any programming. Just take a basic computer science course first semester (one that's meant for science/math people) and they'll teach you everything you need to know. I've found that many researchers/professors heavily use VisualBasic with Excel because of it's simplicity, availability and versatility. -Snpoj 03:41, 16 March 2006 (UTC)
Visual Basic? Seriously? Huh. In my world it's all Matlab and C. And the occasional forward-looking prof likes Java, and the oldschool ones like Fortran.

colors of planets[edit]

where did the colors of planets came from/originated?

The planets have colors for the same reason most other objects have colors: they are made of colored materials. For example, Mars is red because of all the iron(III) oxide on its surface. —Keenan Pepper 00:51, 16 March 2006 (UTC)
Planets, gods, metals, colors, days ... were associated long time ago, half symbolically, half for other reasons such as plain appearance. --DLL 17:28, 17 March 2006 (UTC)

Odor of some black people[edit]

This is not a racist comment. It is a simple observation.

Some (not many) black people have a peculiar smell. The smell is only noticeable within (say) a meter, or less, of them. I don't think I have ever met any white people who smell like this.

What is the source of this smell?—Preceding unsigned comment added by (talkcontribs)

Perhaps you are noticing the lingering odour of food that is unusual to you. People often tend to eat foods traditional to their roots, and people from different backgrounds may notice different odours because they seem foreign to them. For example, I've been told that Japanese people can notice the faint smell of potatoes on westerners.
Slumgum 02:07, 16 March 2006 (UTC)

I'm partial to lots of garlic and onions! Perhaps there is some odour there.. --Zeizmic 02:28, 16 March 2006 (UTC)

Or it's entirely possible that they have a gene for a kind of sweat gland that white people don't have. —Keenan Pepper 02:36, 16 March 2006 (UTC)
I don't know how to describe the smell, except that it is (to me, at least) unpleasant. One black stripper who was dancing for me seemed to have this smell rather strongly. And it was NOT her perfume! I don't think it was food. I really think I was smelling HER. What is it, some strange kind of pheromone or something?

I believe one culprit is "hair relaxer", which makes curly hair straight. It's a rather nasty chemical and smells like bug spray. Whites who have curly hair don't typically try to make it straight using such products, so don't give off that odor. StuRat 02:53, 16 March 2006 (UTC)

StuRat's right. It's probably the hair care products and other grooming products that are marketed to and consumed by black people exclusively, and many of them say right on the box or bottle that they contain cocoa butter. Cocoa butter lotion, which is heavily marketed towards black people, has a distinctive smell on skin. Maybe you could get some and put it on yourself, and see how you smell. Brian G. Crawford 13:58, 16 March 2006 (UTC)

Additionally, different people sometimes just smell different, and there are properties of this (smell of perperation, for example) which could easily be correlated amongst populations in a way colloquially identified as "race". But just remember this: it's not that they smell strange -- to them, you probably smell pretty strange too, but you're just used to your own smell and as such regard it as the baseline. --Fastfission 16:42, 16 March 2006 (UTC)

If the people have dreadlocks perhaps you are smelling patchouly. This essentail oil is believed by many to drive insects out of hair. This is not something specific to black people. HighInBC 22:10, 18 March 2006 (UTC)
You don't see many non-blacks wearing dreads, not even Judge Dredd. :-) StuRat 14:09, 21 March 2006 (UTC)

tracking a path of a helium-filled balloon[edit]

What information do scientists gather bt tracking the path of a helium-filled balloon?

If you are talking about a weather balloon, you can track the balloon itself for wind data, and it also carries instruments to measure atmospheric pressure, temperature, and humidity. In short, they help scientists predict the weather. Oskar 02:18, 16 March 2006 (UTC)
Could a balloon constructed by say, Russia not blow over to the UK? --Username132 (talk) 08:40, 16 March 2006 (UTC)
Yes, of course. --HappyCamper 13:45, 16 March 2006 (UTC)
Do we end up with concentrations of balloons in particular areas? How many balloons are there? And how much damage is caused by balloons bursting and dropping their equipment? --Username132 (talk) 18:02, 16 March 2006 (UTC)

Venus Rotation[edit]

Given the speed at which planet Venus rotates, is it probable that it's core has slowed considerably? This would explain the planet's negligible magnetosphere, correct? What would be some logical ways of returning the planet's rotation to a prograde standard (if ever it was a prograde orbit)? Here7ic 01:57, 16 March 2006 (UTC)

I'm not sure what you mean by it's "core has slowed considerably". I believe terrestrial planets, like Venus, have their core, crust, and atmosphere all rotate at the same rate. As for us significantly changing the rotation rate of a planet, forget that. That would require far more energy than all of humanity has ever used. StuRat 02:48, 16 March 2006 (UTC)
I guess I could've meant the planetary rotation, or the outer core (if Venus is that similar to Earth). As for accelerating the rotation, if this should become a question of the future, I suppose Dark Matter would have a place in the topic. Would you agree? Here7ic 03:57, 16 March 2006 (UTC)
No, unless you include science fiction writers. Why would anyone use dark matter to change Venus's rotation, and how would it be used? --Bowlhover 06:09, 16 March 2006 (UTC)
Are you suggesting that humans can not and never will attain the ability to harness any forms of energy which results from experimentation with Dark Matter? Namely Hot dark matter? Truth be told we haven't even beached onto any real knowledge of it's potential. We didn't know the potential of a Hydrogen atom until we split it. It is, in all probability, plausable that some day, albeit in our distant future, we, as humans, will harness great quantities of usable energy from such experimentation. However, as a logical person, I must volunteer that any real discovery of the potential of dark matter will most likely come at a point in time far beyond our colonization on Venus. The future is rather like an ocean; the further you look into it, the darker and stanger things get. Here7ic 17:34, 16 March 2006 (UTC)
No, I'm not suggesting that "humans can not and never will attain the ability to harness any forms of energy which results from experimentation with Dark Matter". I just don't see how dark matter can be used to change Venus's rotation. --Bowlhover 22:22, 17 March 2006 (UTC)
Venus is totally unsuitable for human colonization. It rains sulfuric acid (battery acid), for one thing. We are lucky to get a lander to last a few minutes before it is destroyed. Mars, the Moon, and space colonies would all come before we would even consider colonizing Venus. If you want a way to change it's rotation, how about a linear accelerator around the equator and extending into space which could launch iron mined from the planet at the speed of light into space ? A huge fusion reactor could power it. It would still take years, perhaps millennia, to significantly change the Venutian day. StuRat 19:45, 16 March 2006 (UTC)
I would like to correct a statement in your last post. Venus is currently totally unsuitable for human colonization. It is entirly possible for human intervention to alter or reconstruct the Venutian atmosphere. Perhaps in this era we are still only in our technological infancy, but to terraform a planet is still a good-looking prospect for our future development. As you may have gathered from my recent flare in activity, I have a passion for thinking about the future, a characteristic for which I hope you will hold me to no less a standard. Here7ic 20:29, 16 March 2006 (UTC)
The point is that it is far less suitable to terraforming than Mars, the Moon, or even space. Less protection would be needed for a colony in space than one on Venus, as a vacuum is less corrosive than sulfuric acid rain. StuRat 04:57, 19 March 2006 (UTC)

bittorrent beta releases[edit]

Where can I find a beta release of MS Office 12 BETA 1 refresh (not through microsoft, of course) for free (no reg, preferably bittorrent)? --hello, i'm a member | talk to me! 02:01, 16 March 2006 (UTC)

I'm not sure I should be publicly aiding this unlawful pursuit, but let's just say that The Pirate Bay can be very useful. Oskar 02:09, 16 March 2006 (UTC)
Arr!! The Pirate Bay is my favorite, because it is most user friendly. You can also get Scientific American and Penthouse searching for Ebooks under browse. :) A bigger site, not that you would use it, because its evil is [[51]]. -- Flag of the United States.svg Mac Davis] ⌇☢ ญƛ. 07:31, 16 March 2006 (UTC)
Here's some I found [52], [53], [54], [55], [56]. If you need any help with them see my talk page. -- Flag of the United States.svg Mac Davis] ⌇☢ ญƛ. 07:39, 16 March 2006 (UTC)

flu pandemic[edit]

Is it possible that the flu pandemic that eveyone's worried about may never happen? KeeganB

Sure, look on the bright side. A gamma ray burster might wipe us all out first. --Trovatore 06:29, 16 March 2006 (UTC)
Yes, its very possible it may never happen. -- Flag of the United States.svg Mac Davis] ⌇☢ ญƛ. 07:32, 16 March 2006 (UTC)
Sooner or later, there will be another flu pandemic just by the law of large numbers. It might be soon, arising from H5N1, or it might be in 50 years time arising from some completely other source. But barring biosphere-destroying cosmic accidents there's going to be one sooner or later. --Bth 08:19, 16 March 2006 (UTC)
The world freaks out about "pandemics" too much for one to do considerable damage, in my humble opinion. Even someone as young as I has lived through periods when people lived in fear of Mad Cow Disease, West Nile virus, Anthrax, and SARS (and now bird flu). Also think of the ever-present "threat" of a meteor impact, nuclear war, and supposed "global warming". Do you not think that our world leaders, as well as nature itself, are doing whatever they can to prevent the destruction of mankind? Basically, don't worry about it. :P —OneofThem 18:40, 16 March 2006 (UTC)
Actually, world leaders are quite pathetic at protecting their citizens from infrequent, but predictable disaster, such as the tsunami in the Indian ocean, hurricane Katrina, and the 1918 Spanish flu pandemic that killed millions. You might think we are better prepared today, but we are not. Politicians tend to only look at the chance a disaster will happen while they are in office. If that chance is small, they don't worry about it. Some factors, like airplane travel, and intentional spreading of disease by terrorists, could cause even more than the 50-100 million deaths due to the 1918 outbreak. StuRat 19:30, 16 March 2006 (UTC)
Two of those are unpredictable natural disasters, you know. :P —OneofThem 19:42, 16 March 2006 (UTC)
Natural disasters aren't all that unpredictable, in the long run. Hurricanes hit the US every year. At the very least, a hurricane would hit New Orleans every 300 years, on average, which was powerful enough to breach the levees. However, global warming probably made this a much more likely occurrence. Large tsunamis also happen with regularity, although infrequently enough for politicians to ignore them, apparently. StuRat 05:09, 19 March 2006 (UTC)

Yes it is possible because within the next hour a huge astroid will smashed into the earth and kill all living things except for cockroaches. Ohanian 11:49, 16 March 2006 (UTC)

There's also the possibility of a huge solar pulse. I read somewhere about a hypothesis that one big enough to fry all the electronics on one side of the globe would occur every 300 years on average. --Halcatalyst 03:08, 17 March 2006 (UTC)

RE:Copying content of paper[edit]

Me, A student want to know that how we can trace a paper content to another one by pressing a blank paper by putting top of the source paper. For example: If I want a image of a magazine or currency to another blank paper, What chemical should I use in between source paper and blank paper before pressing these two?--Afsalh 08:24, 16 March 2006 (UTC)

Sometimes it's not possible or necessary to have access to all mod cons. As to the original question, it really depends on your source image. Just saying it's "on paper" is not sufficient - is it painted, drawn with pencil or ink, part of a magazine, an inkjet print, a laser print, a photocopy ...? Actually, in the last two cases, you can do an image transfer using acetone or xylene. Googling for "image transfer acetone" got me several pages, including this one. No heat is required for this method, so there might still be something else. More clarification on the question would be helpful. --LarryMac 14:23, 16 March 2006 (UTC)thanks
Did you post the very similar question earlier? If so, you never answered my question: was the old man selling this liquid? NO sir he is not selling this liquid but he sell a candle like meterial(light red colour)Notinasnaid 15:07, 16 March 2006 (UTC)thanks
Last year of my high school abortion i did an experiment on the subject and came up with the following-

1) find the image you wish to reproduce 2) print it out using a laser printer (not needed if using magazine) 3) In a tray of sort place the image facing up 3) get some GooGone and pour a sufficient amount in the tray 4) place the blank page a top of the image 5) using a metal spoon begin rubbing over the blank page with enough force to transfer the image When all is said and done when you lift your blank page and it will have the mirror image imprinted on the previously blank page. Remeber that the the image will only transfer where you rubbed the spoon on the paper.

pervasive computing[edit]

what is the basic idea behind goal oriented programming paradigm and how it is linked with pervasive computing? plz help me to answer this question,ill be grateful to u
see Ubiquitous computingSuraj vas 09:53, 16 March 2006 (UTC)
Also see programming paradigm Suraj vas 09:56, 16 March 2006 (UTC)

mentos and coke[edit]

why when we put the mentos inside the coke ,explosion happen? why this can be happen?

One of the main ingredients of Mentos is gum arabic, which is extremely good at lowering the surface tension of water. When you drop a Mentos inside carbonated water (water with CO2), this reaction releases this gas from water in large amounts, causing it to release bubbles. Since the process is fast and the released gas occupies more volume, the pressure inside the bottle raises quickly, pushing the liquid upwards. ☢ Ҡiff 13:10, 16 March 2006 (UTC)
So, it isn't an explosion - just a gush of water (like when you drop your root beer bottle and then open it). I was hoping for an explosion big enough to make the TSA start confiscating mentos and cokes from people as they board the airplane. --Kainaw (talk) 13:54, 16 March 2006 (UTC)
No, of course not, otherwise they'd be arresting flight stewards and stewardesses for "possession of dangerous items". Applies for everybody else who has mentos and a coke. Now, the big question is exactly how do we make a softdrink that really explodes when you drop a mentos in it? ;)
The easiest way would be to just carry a bottle of nitroglycerine; if you throw the mentos into the bottle with sufficient force, a fun explosive is bound to happen. On the other hand, it might not be the most refreshing softdrink imaginable... -- Ferkelparade π 14:43, 16 March 2006 (UTC)
Though it is used to drastically lower blood pressure. My mother carries a bottle around for her anginas. We haven't been arrested. Yet.
Well, if the Mentos were on fire, then whiskey, which is drinkable (but not a soft drink) would probably at the very least go POP! smurrayinchester(User), (Talk) 17:33, 16 March 2006 (UTC)
Or O'Pop, if it's Irish whiskey. JackofOz 19:28, 16 March 2006 (UTC)
--groan-- for JackofOz.  :-P Now I want to go out and buy some Mentos and Coke just to try this... Dismas|(talk) 22:35, 16 March 2006 (UTC)
If you eat Mentos and drink Coke simultaneously, will your mouth explode? :)
I doubt it, but you'd probably get an interesting facial expression. As for the original question, it sounds like someone saw the first half of an episode of Clever and missed the ending. The result was a pretty nice fountain of soft drink. Confusing Manifestation 23:20, 16 March 2006 (UTC)
If you put a carbonated beverage in a paint shaking machine you can get a nice 20 ft fountain out of it. StuRat 02:04, 17 March 2006 (UTC)

Website listing and reviewing main competitors in Internet fields?[edit]

I am looking for a website which lists and gives information/reviews on the main competitors in various computer/internet fields.

For example, if the field is webmail, the website would list AOL Mail, Gmail, Yahoo! Mail and Hotmail. It would then give information regarding the features and storage, and give reviews, or allow users to post reviews.

If the field is operating systems, the website would list Windows, Mac OS and Linux (and tell me the main Linux distributions), and then procceed to provide information regarding the features and interface. Again, it will review each OS and allow users to give feedback.

If the field is web browsers, the website would list Internet Explorer, Mozilla Firefox, Opera, Netscape, Mozilla, Safari and some others I might miss. As I said, it will compare the security and features of each browser and offer reviews, and allow users to review them.

Such a website would be help Internet users make the right choices regarding the provider of a product. If someone wanted webmail, by reading the reviews, he would probably pick Gmail. If he was dissatisfied with Internet Explorer, he would go to the website to look for alternatives and probably pick Firefox. (These are guesses on my part.)

Such a website would also help web developers in designing compatitible products and services. For example, owners of social networking sites which allow you to import your webmail address book and send invites to friends would, after reading the webmail reviews on the site, offer options for importing contacts from AOL Mail, Gmail, Yahoo! Mail and Hotmail (Surprisingly, Friendster only allows imports from Yahoo! and Hotmail). Web designers must know the top browsers to optimize their websites for (besides Internet Explorer).

Does such a website exist? If so, may I have the URL of the website, and a link to a Wikipedia article about it, if such an article exists? --J.L.W.S. The Special One 15:08, 16 March 2006 (UTC)

Why not try Wikipedia itself?
These articles are really helpful! :D —OneofThem 18:56, 16 March 2006 (UTC)

Website listing number of accountss on various other websites?[edit]

Is there a website tracking the number of accounts on various websites? For example, if I go to the website and enter in their search bar, they will tell me that NeoPets has 115 million accounts? If not, how many accounts do RuneScape and have? —This unsigned comment was added by Hildanknight (talkcontribs) 16:08, March 16, 2006 (UTC).

Not that I know of. I'm not sure how it would be possible to get this kind of information unless you own the website and keep records for yourself. -- Daverocks (talk) 06:22, 17 March 2006 (UTC)
Also, it can be difficult to define "accounts" in a meaningful way - for instance, do you count multiple accounts belonging to the same person as one or several? What about deleted accounts? Inactive accounts? The 115 million number for NeoPets in particular smells like exaggeration to me. — QuantumEleven | (talk) 10:22, 17 March 2006 (UTC)
The Neopets article lists (or used to list) a reference that claims to know how many inactive/frozen/etc. accounts there are, but I have no clue how that website got the information. It might be okay for something that's not very important, but I wouldn't trust it if I would you. The count on Neopets is just the raw count, I think - how many have been created, including multis and inactive. (115 million is not suprising considering that Neopets is now on a very international scale, though a significant number of those are probably multis or automated.) --AySz88^-^ 02:31, 18 March 2006 (UTC)

slow scan TVs and Copthorne McDonald[edit]


Does anyone have any idea how I can find an old article (from the 50s) for my 83 year old blind dad, by Copthorne McDonald regarding slow scan TVs that appeared in Stuart Brand's Whole Earth Catalog?

Thanks for any insight.


Carol Adams

If he's really blind, you will need to read it to him or find it on audio, but I doubt if an article from the 50's would be in Books for the blind. StuRat 16:55, 16 March 2006 (UTC)
Hi Carol; I don't quite understand your request - the Whole Earth Catalog was only published regularly from 1968 through 1972. If you click through to our article on the WEC, there is more info on subsequent editions after that. I found a history page that mentions articles written by McDonald in 1958 and 1961 in something called QST, but I haven't yet discovered what QST is (or was). I suppose it is possible that the WEC reprinted one or more of those articles; I'll see what else I can find. --LarryMac 20:57, 16 March 2006 (UTC)
QST is the publication of American Radio Relay League. ARRL . Search there for SSTV, etc. (The Whole Earth Catalog had issues in 1980 and 1995? "Whole Millenium Catalog", FYI.) GangofOne 23:02, 16 March 2006 (UTC)

flash bulbs[edit]

What process did the manufacturers use when they inserted the shredded thin metal filament inside the bulbs so it expanded and evenly filled the space?

I think it does that automatically when you try to insert a stiff wire into a small volume. StuRat 19:22, 16 March 2006 (UTC)

enlarged breast in a pit bull dog[edit]

I own a pit bull she has had her first heat and shortly afterwards began getting large breast, like having milk in them but there is none. She has not been breed. Please help thank you vicki

A couple possibilities come to mind:
1) She got away from you and got knocked up. It only takes a minute.
2) She has a medical problem, like an enlarged ovary pumping out too many female hormones.
In either case, I suggest seeing a vet. StuRat 01:59, 17 March 2006 (UTC)
...and bring your dog to the vet, too, while you're at it. StuRat 21:44, 20 March 2006 (UTC)


Does magnesium have a shortened name like a nick name of some sort. I've looked every where and can't figure out if there's one or not.

Mag? Magne? I dont think so! --Chachu207 ::: Talk to me 18:05, 16 March 2006 (UTC)
Actually, I have heard "mag" used, as in mag wheels. StuRat 18:54, 16 March 2006 (UTC)
In the hospital, it's quite common to hear magnesium citrate as "mag citrate", magnesium oxide as "mag oxide", and so on. — Knowledge Seeker 19:15, 16 March 2006 (UTC)
"Mg" would work, I should think. Here7ic 20:13, 16 March 2006 (UTC)
Except for the obvious confusion with milligrams. StuRat 21:14, 16 March 2006 (UTC)
Oh, come on. First, milligrams are "mg" while magnesium is "Mg". (Megagrams are "Mg", but nobody calls them that; we all say tonnes or metric tons.) Second, in what context could they be confused anyway? --Anon, 00:08 UTC, March 17, 2006.
Using capitalization to distinguish between completely different things only makes sense to C programmers (who also start counting at 0, not 1). In a list of vitamins and minerals you might very well see both. StuRat 01:55, 17 March 2006 (UTC)
Meh, it happens all the time in science. We only have twenty-six letters to work with in the alphabet, we're lazy (efficient!) enough to want abbreviations for commonly-used terms, and we tend to impose a further requirement that the abbreviations should bear some relationship to the term that the represent.
One of the many hats I wear from time to time is 'chemist', and in that capacity I would have no qualms about writing (or understanding) something like 'add 10 mg Mg to the reaction...'. When I'm wearing my 'biologist' hat, I'm not worried about confusing km with KM. If I'm pretending to be a physicist, I have to know that I can't just cancel out the ds in dy/dx.
We have to accept that case and context are important in scientific shorthand. The price of brevity is a reduced redundancy and a need for greater care in writing. TenOfAllTrades(talk) 04:58, 17 March 2006 (UTC)
The problem would be that a slight error could make it unreadable,
Um, did you read what TenOfAllTrades wrote? He conceded that point. One of the prices of brevity is the possibility of error, unless you're careful. —Steve Summit (talk) 15:19, 18 March 2006 (UTC)
LIST OF REACTANTS = 10 mg Na, 5 mg, 15 mg Cl
This could mean 5 milligrams of an unlisted reactant or 5 units (presumably milligrams) of magnesium. Having more difference between abbrevs would make it clearer what portion is missing from the instructions. StuRat 15:54, 17 March 2006 (UTC)
Yes, but notice that capitalization is the key. It would solve your problem very easily if capitalization was involved. I would automatically interperit this as 5 milligrams of an unnamed substance; this is further supported by the fact that you've capitalized Potassium and Chlorine in the list, and didn't capitalize milligrams. Here7ic 17:15, 17 March 2006 (UTC)

It's Mg on the Periodic table. -LambaJan 04:28, 17 March 2006 (UTC)

Yes it is, but I'm not sure if that should be used as a standard for non-scientists or we will end up using Au = gold, Ag = silver, Hg = mercury, W = tungsten, Fe =iron, K = potassium, Na = sodium, etc. (did I get those all right ?) Also note that "Mg" is only a written abbreviation. You would presumably still say the whole word. "Mag", on the other hand, is both a written and oral abbreviation, like gym or lab. StuRat 15:34, 17 March 2006 (UTC)

youngest fossils[edit]

We all know that fossils can be very old. But how young can they be? Is the age of any fossils measured in mere thousands of years? Generally what in the making of fossils requires time? Thanks, --Halcatalyst 18:39, 16 March 2006 (UTC)

Are you talking about the type of fossil where bone is replaced by rock ? Other types, like an insect caught in amber, can form in just a few days. StuRat 18:52, 16 March 2006 (UTC)
Yes, the type where minerals are infused into bone. --Halcatalyst 19:27, 16 March 2006 (UTC)
I recall reading where bones in the vicinity of a mineral springs were mineralized in a few hundred years.
The Fossil article reminds me that other body parts than bone can be fossilized. It also says, "Because fossils are by their nature old, the word has also entered the modern vernacular as a derogatory term for an elderly person." That would be me, ha. The article refers to fossiliferous rock and has a link to Paleontology. However, neither article suggests an age when fossils might be "new." --Halcatalyst 21:16, 16 March 2006 (UTC)
I searched all over for this. There are various 'grades' of fossilization. Things are about to be fossilized go through a pre-mineralization stage, which may be only hundreds of years. Full fossilization may take 10,000 years or more. BTW, you can't search far before running into tons of 'biblical literalists' who insist that dinosaur fossils are the standard 4000 years old. --Zeizmic 21:42, 16 March 2006 (UTC)
LOL, that would explain why the Bible is so full of stories about shepherds protecting their sheep from T-Rex attacks. StuRat 01:51, 17 March 2006 (UTC)
I think it really depends on the chemical environment. Presumably the decomposition of the organic material would occur much faster than the mineralization, so it's basically just a question of how fast can you form the rock. So the mineral-springs idea above seems quite plausible. --BluePlatypus 01:17, 17 March 2006 (UTC)

Thanks, all. I'm querying "thousands of years" in a 5th grade science book I'm editing and was going to suggest "millions of years." Guess I'll just suggest they be vague about it. Very old fossils are what we're talking about. Obviously it's not a huge issue at that level, but we do want to be accurate. --Halcatalyst 02:22, 17 March 2