Wikipedia:Reference desk/Science

Welcome to the science section
of the Wikipedia reference desk.

skip to bottom

Select a section:

• Computing
• Entertainment
• Humanities
• Language
• Mathematics
• Science
• Miscellaneous
• Archives

Want a faster answer?

Main page: Help searching Wikipedia

   

How can I get my question answered?

• Select the section of the desk that best fits the general topic of your question (see the navigation column to the right).
• Post your question to only one section, providing a short header that gives the topic of your question.
• Type '~~~~' (that is, four tilde characters) at the end – this signs and dates your contribution so we know who wrote what and when.
• Don't post personal contact information – it will be removed. Any answers will be provided here.
• Please be as specific as possible, and include all relevant context – the usefulness of answers may depend on the context.
• Note:
  • We don't answer (and may remove) questions that require medical diagnosis or legal advice.
  • We don't answer requests for opinions, predictions or debate.
  • We don't do your homework for you, though we'll help you past the stuck point.
  • We don't conduct original research or provide a free source of ideas, but we'll help you find information you need.

Ready? Ask a new question!

How do I answer a question?

Main page: Wikipedia:Reference desk/Guidelines

• The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.

See also:

• Teahouse
• Help desk
• Village pump
• Help manual

December 31

drinking rubbing alcohol

the effects of doing so are listed by this site as the same as regular booze only stronger. because of this i think it is safe to have 1 or 2 shots of rubbing alcohol safely. obviously more could be dangerous. —Preceding unsigned comment added by Thekiller35789 (talk • contribs) 03:48, 31 December 2009 (UTC)

Not if it's isopropyl alcohol, which is often sold as "rubbing alcohol" in the States. Even if it's ethyl alcohol, it's not going to do the lining of your throat any good at 98% abv. In general, it's not a good idea to drink anything that's not designed to be drunk, especially anything that says "EXTERNAL USE ONLY" in large capital letters on the bottle... Tevildo (talk) 04:14, 31 December 2009 (UTC)

If you drink a shot of rubbing alcohol, you will die or at least go blind. Edison (talk) 04:28, 31 December 2009 (UTC)

True for methyl alcohol, but isoprop isn't as bad. However, I would certainly recommend the OP to stick to cheap vodka; it tastes (marginally) better, and won't kill them as quickly. Tevildo (talk) 04:33, 31 December 2009 (UTC)

If you drink rubbing alcohol, which is isopropyl alcohol in the US, and possibly denatured alcohol in the UK, you will die or at least go blind or damage internal organs. See Rubbing alcohol and [1]. Cheap wine (3 buck Chuck) goes for under $4 per bottle. $2 in some states. Edison (talk) 04:28, 31 December 2009 (UTC)

It does not appear that pure isopropyl alcohol causes blindness. --Sean 15:09, 31 December 2009 (UTC)

Symptoms of isopropyl alcohol poisoning include flushing, headache, dizziness, CNS depression, nausea, vomiting, anesthesia, and coma. THESE ARE THE SAME SYPTOMS OF BOOZE . your not going blind and u can dilute it so it wont burn--Thekiller35789 (talk) 05:11, 31 December 2009 (UTC)

If you insist on asserting the untrue claim that it's safe to drink, consider why every wino and bum in the world doesn't drink it. They would if it were healthy, because it's dirt cheap. Comet Tuttle (talk) 06:19, 31 December 2009 (UTC)

Just to clarify. Drinking _isopropyl_ alcohol is very harmful to your health (not as bad as methyl alcohol, but still definitely "toxic"), and two shots (~50 cc) is probably enough to kill you. However, "rubbing alcohol" can be either _isopropyl_ or _ethyl_ alcohol. Drinking _ethyl_ alcohol that's been sold as rubbing alcohol (or mouthwash, or hand sanitizer) isn't going to kill you immediately, although it's still advisable to stick to alcohol that's intended to be drunk. Tevildo (talk) 10:20, 31 December 2009 (UTC)

Tevildo, while I certainly don't want to encourage anyone to drink isopropyl alcohol, I'm curious where you get your info. This page doesn't seem to back you up. It doesn't show a lethal dose for humans (only a "lowest published toxic dose" — not clear how bad symptoms need to be to qualify as "toxic" but I assume it's well short of death). However it shows LD50s for rats and mice (oral) and dogs (intravenous); these are all above 3.5 g per kg of body weight. For a 50-kilogram person that's 175 g of the stuff. --Trovatore (talk) 21:09, 2 January 2010 (UTC)

Especially since most non-food-use ethanol has been denatured - that is, mixed with toxic substances such as methanol or benzene, or with substances which make it disgusting to drink. The reason for this is that there is usually a heavy tax on alcoholic drinks, which solvent and rubbing alcohol manufacturers can avoid by rednering their product "unfit for human consumption". If you're looking at ethanol-based rubbing alcohol because it's cheap, you can bet your continued good health that it's going to be denatured, precisely to prevent people from drinking it. -- 128.104.50.17 (talk) 15:51, 31 December 2009 (UTC)

The main problems of isopropanol (as opposed to ethanol) are twofold. Firstly, rubbing alcohol isn't food grade. So this means it contains a wide range of impurities ... heavy metals, benzene (from chemical production), so and so forth. It's often denatured with bitterants, but the denaturants can in turn poison you much more acutely. Also, isopropanol is a secondary alcohol, which means it can't be easily metabolised into a carboxylic acid and remains in the blood as acetone. John Riemann Soong (talk) 06:58, 31 December 2009 (UTC)

See Surrogate alcohol. Drinking anything like this is potentially very dangerous. To do so would be extremely irresponsible and idiotic. There's no reason or need for anybody to drink these things. The dangers are well documented. 194.221.133.226 (talk) 12:26, 31 December 2009 (UTC)

I've often read news items where people at parties in 3rd world countries drink this kind of alcohol mixed in with sodas or pop and go blind as a result, and have other damage also. Do not drink it - it is poisonous! 78.151.128.34 (talk) 13:25, 31 December 2009 (UTC)

Don't feed the trolls, people. Matt Deres (talk) 15:52, 31 December 2009 (UTC)

Please do not provide medical advice. ~AH1^(TCU) 23:58, 31 December 2009 (UTC)

Reference desk

how can i see and answer people's questions on wikipedia? can i help others by answering them? —Preceding unsigned comment added by Priyankachopra01 (talk • contribs) 04:29, 31 December 2009 (UTC)

You're in the right place. :) If you'd like to answer some questions, please feel free - remember to sign your posts with four tildes (~~~~), and, if possible, include a link to the relevant article in your answer. Tevildo (talk) 04:33, 31 December 2009 (UTC)

And click the edit link next to the question to provide your answer! Graeme Bartlett (talk) 11:57, 31 December 2009 (UTC)

Remember not to do homework for somebody else, as indicated by the header, and try to link to external sources if you got the information outside of Wikipedia if you think the link will be helpful. There are also other reference desks where you can ask and answer questions, and another way to help is to get the information into articles on Wikipedia. Have fun! ~AH1^(TCU) 21:53, 31 December 2009 (UTC)

Sky

Does the sky begin at the interface with the ground? Even though we perceive extremely tall buildings as "sky scrapers" (spacing intentional), a being 1000 ft tall (making his or her height exceed 100 stories, let's say) would not think such a building was anywhere near they sky. So for an earwig or something of the like, wouldn't sky begin lower? DRosenbach ^{(Talk | Contribs)} 05:56, 31 December 2009 (UTC)

There is no such thing as "the sky". The sky is the name we give to the concept invented by ancient people who thought the stars were hung above the earth in giant rotating glass spheres, or who spent time pondering what the turtles stood on. The atmosphere is all of the gas gravitationally bound to the Earth, and it does indeed start right at ground level. The sky is not a concrete, scientifically definable concept, beyond "What I see when I look up". --Jayron32 06:03, 31 December 2009 (UTC)

Come, now. I think DRosenbach was talking about the visuals. You know — the blue stuff. The answer is yes. The sky "begins lower" for the earwig in the sense that the earwig sees less of the land around him, due to the curvature of the earth, than the 1000-foot fire giant sees around him, so the earwig actually sees fewer square inches of sky as he looks around than does the fire giant. Comet Tuttle (talk) 06:17, 31 December 2009 (UTC)

Obviously, the taller you stand the further you see, unless there is something in the way :) . The distance to the true horizon, as a function of height, is given in the article Horizon; it is roughly proportional to the square root of height. However, there is a caveat: further does not mean lower. We may or may not perceive the true horizon to be a certain distance away; but I do not think we ever perceive a clear sky to be of a particular height. And clouds are a different story altogether. --Dr Dima (talk) 08:47, 31 December 2009 (UTC)

OK I guess what I said is not particularly clear. Let me say it again more clearly. The distance to the true horizon is an actual measurable quantity (as opposed to a perceived illusory one), and it increases with the height of the observer. An observer 1000 ft tall (or high) can, under ideal conditions, see roughly 32 times further than an observer 1 ft high. We may or may not perceive the distance to the horizon as finite and well defined, even though it is well defined in reality. However, distance to the horizon is not equivalent to the "height of the sky" (which in reality is not defined at all, as there is no firmament above). And I do not think we ever perceive a clear sky to be of a particular height. --Dr Dima (talk) 09:10, 31 December 2009 (UTC)

You may also like this paper. Your mileage may vary :) --Dr Dima (talk) 09:23, 31 December 2009 (UTC)

Celestial sphere. ~AH1^(TCU) 21:48, 31 December 2009 (UTC)

The sky is a set of angles in two dimensions, those angles which do not end at an opaque object within the atmosphere, from a given location. See steradian. -Craig Pemberton 22:33, 31 December 2009 (UTC)

Calculating radioactive decay

Given the number of protons and neutrons in an atom, is there a formula (or a way of computing) the half-live, decay mode and energy? 95.115.191.19 (talk) 12:22, 31 December 2009 (UTC)

No, not as asked. There is no direct, simple, correlation between the number of nucleons and decay half-life. Predicting the half-life is a complex quantum mechanical problem which has by no means been fully solved. See nuclear structure and nuclear shell model. SpinningSpark 12:35, 31 December 2009 (UTC)

There isn't a theoretical formula, but you could probably produce a ballpark function by regression analysis. You'd be better off looking up the measured result though. Noodle snacks (talk) 13:38, 31 December 2009 (UTC)

Thank you for your answers. Now I am wondering why this is so. As I understand, the standard model of quantum physics is solid and well tested. So there should be a way of computing decay modes and half-life times. Are those subjects outside the reach of the standard model (due to relativistic effects?), is it "only" a matter of exploding computation complexity or are there principal computational issues (as in the three-bodies problem of classical mechanic)? 95.115.160.26 (talk) 15:39, 1 January 2010 (UTC)

Asbergers versus Williams syndrome

If Asbergers Syndrome is defined as an "extreme male brain" could Williams Syndrome be described as an "extreme female brain?" Trevor Loughlin80.0.104.152 (talk) 12:38, 31 December 2009 (UTC)

Having just read the first paragraph of Williams Syndrome, it doesn't sound particularly female to me. I would also question Aspergers being an extreme of male characteristics. Aspergers is characterised largely by a difficulty in empathising. Is there any evidence (beyond anecdotal evidence) that men are worse at empathising than women? I think it is more likely that men are just as good as women at working out how another personal feels emotionally but give those emotions a lower importance. I also wouldn't be surprised if that was entirely to do with the society they were brought up in rather than anything physiological. --Tango (talk) 13:28, 31 December 2009 (UTC)

Science does not have an answer to your question. Noodle snacks (talk) 13:34, 31 December 2009 (UTC)

(Edit Conflicts)Leaving aside the question of whether characterising Asbergers syndrome as "extreme male brain" is actually valid as either a literal description or a metaphor of coincidentally expressed behavior, I would say no, because (i) Asbergers syndrome is not significantly 'disabling' mentally and has no physical signs or symptoms that I know of (though Steve or others may correct me here); (ii) it appears to be part of a "continuous spectrum" of naturally occuring mental characteristics, and (iii) it has no root in any obvious genetic 'fault' (while its cause may be genetic, it's sufficiently obscure that we haven't discovered it yet).

There are a few physical manifestations - one that I'm familiar with is a tendency for Asperger's children to walk on the balls of their feet without their heels touching the ground. When I was diagnosed, my mother was amazed that this peculiarity of the way I walked as a kid had an actual explanation. But these symptoms are not very noticable - and not generally carried through into adulthood. SteveBaker (talk) 04:07, 1 January 2010 (UTC)

"Asperger and autistic individuals also exhibit motor control abnormalities such as impaired gait, balance, manual dexterity and grip" [2]. "Subjects with AS were found to perform more poorly than controls on tests of apraxia, one-leg balance with eyes closed, tandem gait, and repetitive finger-thumb apposition" [3]. --Mark PEA (talk) 15:33, 1 January 2010 (UTC)

I'm not aware of having poor one-leg balance - but I'm utterly useless at throwing and catching things - my kid says that I'm "ballistically challenged". SteveBaker (talk) 02:33, 2 January 2010 (UTC)

By contrast, Williams syndrome, in which the "female" characteristics it appears to exaggerate are (I would argue) likely more cultural than innate to the female sex, (i) is both significantly 'disabling' mentally and has marked physiological effects; (ii) is not part of a "behavioural spectrum", but a one-off condition; and (iii) is caused by a significant known genetic defect which the article details. 87.81.230.195 (talk) 13:45, 31 December 2009 (UTC)

Sorry to contradict the politically correct brigade who always want to insist there is no fundamental difference between male and female, but you are not supported by scholarly research. Asperger's and autism are well known to be strongly biased towards male sufferers and there are plenty of academic papers making the link between these conditions and extreme forms of male behaviour, see this for instance. I don't know the answer on Williams syndrome, but it is at least a reasonable question to ask. SpinningSpark 16:51, 31 December 2009 (UTC)

And it would appear that the claim that Williams syndrome is the "extreme female brain has at least been suggested (search document for "Williams") although the claim is disputed. What is not disputed is that there is strong difference between male and female brains, eg this paper along the lines of systemizing/empathising split. SpinningSpark 17:18, 31 December 2009 (UTC)

I didn't mean to be politically correct, I just hadn't seen empathy described (by scientists) as a female trait (and the paper you link to is a recent paper that says it hasn't been discussed much, so it's not surprising I haven't seem any discussion on it). --Tango (talk) 01:48, 1 January 2010 (UTC)

Asperger's does not seem extremely "male." It seems more nerdish. An "extremely male" attitude would be "Bah! I've no time for boring details. Out of my way. Let's just forge ahead from point A to point B, without getting tripped up by trivial details." A "typical male" does not stop to get directions in a journey. A typical Asperger's would stop and research all historical details about the location, and all of its notable inhabitants throughout history, then create a Wikipedia article, then talk about it on the Ref Desk, if it caught his fancy. Edison (talk) 03:22, 1 January 2010 (UTC)

You should take a look at Simon Baron-Cohen's Empathizing–systemizing theory and his book The Essential Difference before so quickly dismissing the idea of autism as 'extreme maleness'.[4] Fences&Windows 04:09, 1 January 2010 (UTC)

I want to make my own battery-powered heating pad.

A proper heated gilet (the kidneys are the most appropriate section to heat due to blood throughput and proximity to surface) is too expensive and also bulky and not possible to wear underneath normal clothing. I want to make a battery-powered pad that can be strapped around one's trunk via an elastic strap. My diagram attempts to show my plan. I can take a peice of felt, sew loops onto the felt and thread nichrome wire through the loops. I can then sew another peice of felt over the first, sandwiching the nichrome wire in between. The wire can then be connected to a battery pack, possibly with a switch. The questions I have now are,

a) how many watts of heat would I want to produce over an area of about half a square foot (450 cm2)? b) which nichrome wire should I buy? ebay has wire at 10, 20, 50 ohm/m and probably many outside and inbetween. I expect to be able to loop around 4 m of nichrome wire (15 rows of 25 cm stretches) c) what voltage should I use? I need most of the resistance to be in the wire.

I guess if I have a), I can figure out b) and c). Am I overlooking something that makes this idea stupid? Seems simple enough to me. I wonder though, since the nichrome wire is often used to make something very hot, if the resistance wont be a lot lower than that stated.. take this one for example; how much around 50 ohm/m will this vary, depending on temperature? ----Seans Potato Business 13:20, 31 December 2009 (UTC)

Well, felt is flammable... I would put something flame resistant (but not heat resistant) in-between the wire and the felt. I'm also not sure about your assertion that the kidneys are the most appropriate body part to heat. You have to be in real trouble before your core body temperature starts to drop, it is the extremities that get cold. One of the main reasons the extremities get cold is because the body cuts off most of their blood supply to preserve heat, but I'm not sure how it knows when it needs to. If it does so based on the skin temperature of the extremities themselves then heating your trunk won't actually have much benefit, other than possibly making your trunk uncomfortably hot. Personally, I prefer wearing well insulating clothes (layers that trap air in-between are usually best). --Tango (talk) 14:35, 31 December 2009 (UTC)

(ec) How much heat you need depends on how you are going to use it. Heated jackets are typically 50-100 watts. If you want to do some calculations, the first thing you need to know is the thermal resistance of the garment you are sewing this into. Next you need the temperature difference (body heat to ambient temperature) of the intended use (obviously a walk in the New Forest is a completely different requirement to a walk in Antarctica). You can now calculate how many watts you are going to be losing. Most of this will be made up by normal body heat, but the difficult part here is that body heat generation is related to activity. If you are intending to sit motionless in a hunting hide in a snowstorm you are liable to need more heat than if you are hiking. You really need a thermostat or other form of regulator in this because as activity changes, the temperature inside the jacket will change. The power you wish to generate along with the battery voltage will yield the resistance you need. You will need to make the battery at least 12 volts (24 would be better) otherwise the resistance is going to be too low compared with the battery internal resistance, unless you are aiming for a very low amount of heat. NiChrome resistance will only change by a few percent over the temperature range of interest so that is not an issue. The stupid thing that you have not considered is how are you going to protect the nichrome wires from the wet? Also, care that short-circuits can't happen is a good idea, a short piece of wire finding itself directly across the battery could get red-hot. Another thing to think about is that while the garment needs to a high thermal resistance, there also needs to be a lining of some low thermal resistance material to spread the heat from the wires evenly. All in all, I'm guessing that buying a heated jacket is going to be a lot easier and probably not much more expensive (possibly cheaper once failed prototypes are taken into account). SpinningSpark 14:40, 31 December 2009 (UTC)

One point that hasn't been mentioned - you're going to need a fairly substantial battery. A medium-sized 12V gel cell will have about 5 Ah capacity - so it'll run a 60 W heater (a typical electric blanket is about 150 W, but you won't need as much power for a heating pad) for about 1 hour. Will that be enough for your planned recreational activities? You might want to consider the chemical-based hand warmers you can get from camping shops as an alternative. Tevildo (talk) 15:16, 31 December 2009 (UTC)

Li-ion batteries may be better than industrial lead-acid gels for this application for weight and power density reasons. SpinningSpark 16:34, 31 December 2009 (UTC)

I would have thought that it's going to be really difficult to make this any better than a decent warm jacket. I've ridden my motorcycle for hours in sub-zero temperatures, ski-ed at minus 20°C and walked on the antarctic, and the only things that got cold were my extremities (my hands, feet and face) and that's mainly because it's impossible to get enough insulation on them. What's wrong with a few layers of inner clothing and then a decent coat? --Phil Holmes (talk) 17:49, 31 December 2009 (UTC)

You'd probably also want some kind of safety cutoff, probably in the form of a temperature sensor. If you forgot to turn it off and left it in a heap somewhere, it might catch fire and/or melt... TastyCakes (talk) 17:57, 31 December 2009 (UTC)

How did the church sign know the temperature?

Tuesday a sign in front of a church had details about the church in what I assume was a rotating series of messages. The time and temperature were also displayed, which reminds me of my savings and loan which still has the time and temperature sign with incandescent light bulbs forming the numbers in the time and the temperature. The church sign was a newer technology, but maybe the science is the same. How do these signs know the temperature and convert it to a group of bulbs?Vchimpanzee · talk · contributions · 17:32, 31 December 2009 (UTC)

Interestingly, Wikipedia needs an article on electric signs in general. I can't find one other than Neon sign, which is about the neon tube variety only; there's one on Westinghouse Sign, which was one particular sign; but surely the topic is interesting and notable enough for an article. The evolution from neon bulb controllers to the current crazy gigantic video screens in Las Vegas would be a good read. Comet Tuttle (talk) 18:05, 31 December 2009 (UTC)

(edit conflict)Well it's probably a type of matrix display like an LED display. Each of the lights can be turned off and on by a microcontroller or computer. The controller has routines programmed into it that know what lights to turn on to display particular letters and numbers. Originally someone must have gone and made computer functions saying "for an A, turn on this, this this and this", and so on, but this is all removed from the usual operation of the thing, where the user will just send it a string of letters or numbers and it'll display them. You can read some nuts and bolts on an LCD display connected to an arduino in this tutorial. And here is a guy that turned a gameboy display into a LED matrix which probably uses a similar idea. As far as getting the temperature, that would be a simple matter with a thermistor or simply getting retrieving it every so often from the internet. TastyCakes (talk) 18:09, 31 December 2009 (UTC)

We also have Variable-message sign, but that's a specific application despite its generic name. DMacks (talk) 18:25, 31 December 2009 (UTC)

HD44780 Character LCD is probably worth a look for a defacto industry standard for character displays. The computer functions that convert characters to letters are probably not really subroutines in some program. It is more likely that they are implemented with a programmable logic device. The data is usually sent in a serial manner. Noodle snacks (talk) 01:29, 1 January 2010 (UTC)

I was really wondering where the temperature comes from. The savings and loans had these signs before the Internet, though there are surely other sources. My question was really whether the sign could update without human intervention. It would be on after the savings and loan closed.Vchimpanzee · talk · contributions · 18:24, 31 December 2009 (UTC)

Building a temperature sensor into a large sign is a fairly trivial piece of electronics nowadays. You can buy such signs off-the-shelf (example). SpinningSpark 18:59, 31 December 2009 (UTC)

Thermistor may be the old type - resistance changes as temperature changes. (Beware - the article seems to be 95% aimed at electronics nerds.) Comet Tuttle (talk) 19:41, 31 December 2009 (UTC)

95% of all the science articles on WP are aimed at nerds of one type or another. Telling a layman to read the article on "such'n'such" just serves to confuse and bury the person in technical jargon. This is one area where Wikipedia needs a Layman's Wikipedia. It's not so simple as to belong on the Simple English WP but not so complex that the average person can't even get through the introduction without having to look up at least five other terms or principles. Dismas|^(talk) 22:13, 31 December 2009 (UTC)

Calling people nerds is offensive and in my experience is an insult used by the educationally sub-normal against anyone who has an understanding or an interest in a subject which goes beyond their own pathetically limited understanding. It seems in the US a desire to learn is to be despised. SpinningSpark 23:31, 31 December 2009 (UTC)

Dismas I don't think you mean to be offensive but this is not the place to launch a discussion about Wikipedia's complexity level. It seems that you partition readers as either laypersons or specialists and that is a patronising attitude. The formal purpose of the Ref Desk is indeed to tell an OP where to read more. If the subject is abstruse then it does the OP no good to pretend that some underlying concepts don't need to be understood first. Pointing someone in the right direction is more important that careless name-calling like nerd (Wikipedia has an article on that word) or taking a pot shot at education in the US. Neither of the "95%" figures quoted by Comet Tuttle or Dismas have any more than rhetorical significance. Cuddlyable3 (talk) 00:02, 1 January 2010 (UTC)

A) I would call myself a nerd. B) You both missed my point. C) thank you for having some good faith and assuming (correctly) that I didn't mean to offend. And D) I find it hypocritical that S. Spark would first say how offensive the word "nerd" is and then make a harsh generalization about people in the US. But you're right... this isn't the place. Dismas|^(talk) 00:26, 1 January 2010 (UTC)

(EC)I can't speak with certainty for Dismas, but I self-identify as a geek and haven't heard 'nerd' or 'geek' used perjoratively somewhere like this: surely everyone on this desk is a geek (or nerd)? As a geek, or nerd, I find it far more offensive that someone would use 'educationally sub-normal' as an insult: not cool.

Most of Wikipedia's articles on mathematics and science topics are inaccessible for anyone who actually wants to learn from them, and this is a recognised problem that many editors have been working on for a long time. The problem is that most editors who know a lot about the topics (particularly more casual editors) get caught up in being precise and complete, at the expense of being accessible or even readable to most readers. I'm a geek, and if I were writing an article on certain topics that I am particularly geeky about I would have to constantly check it with editors who are less familiar with the topics to keep it readable. Mentioning this here increases the chances of interested editors taking a look at those articles and improving them, even if that requires making parts of them less accurate or complete. 86.176.48.114 (talk) 00:38, 1 January 2010 (UTC)

Can we go back to discussing how the church sign measures temperature? I'm interested in knowing the answer myself. --99.237.234.104 (talk) 03:31, 1 January 2010 (UTC)

It may be a Church of God with Signs Following. Cuddlyable3 (talk) 19:00, 1 January 2010 (UTC)

There are plenty of ways for electronics to measure temperature. There are electrical components called "thermistors" who's electrical resistance varies with temperature. The computer inside the sign could measure the resistance of the thermistor and thereby infer the temperature. Displaying that on the sign is then a simple matter. Another way to do it would be to measure the deflection of a 'bi-metallic strip' - two strips of metal with different rates of thermal expansion that are glued together - when the strip get warmer, one metal expands by more than the other causing the strip to bend. The computer could use all sorts of ways to measure the amount of bend. There are LOTS of ways this could be done. Which specific method is being used by a particular kind of signboard is hard to say - that would probably require calling the manufacturer. SteveBaker (talk) 03:57, 1 January 2010 (UTC)

Flower identification

Hello. I'd be very appreciative if someone could give me a species name, or at least a genus, for the following images: 1, 2, 3. Thanks for the help. —Anonymous Dissident^Talk 21:55, 31 December 2009 (UTC)

Dahlia sp.? -Craig Pemberton 22:14, 31 December 2009 (UTC)

Also, the third could be Impatiens sp. but don't take my guess at face value. Plants can be tricky. -Craig Pemberton 22:27, 31 December 2009 (UTC)

1 and 2. Zinnia. 3. Petunia.--Eriastrum (talk) 23:33, 31 December 2009 (UTC)

Thanks a lot, both of you. —Anonymous Dissident^Talk 03:34, 1 January 2010 (UTC)

January 1

Full Moon on New Years

This New Year's Eve is a full moon. I can't find a calculator that will calculate for me when the next time that will occur. Can anyone help me out (or know where I should look)? Shadowjams (talk) 00:33, 1 January 2010 (UTC)

In the USA, 2018 according to this calculator, but in my location it will not be totally full till the following day. SpinningSpark

Thanks for the link. Don't know why I thought it would be so much further out. 2028 looks like the next closest to today. Thanks. Shadowjams (talk) 00:55, 1 January 2010 (UTC)

Resolved

Oops, sorry, you said New Year's Eve, that was for New Year's Day. The next one would appear to be Dec 31 2028 at UTC time zone. SpinningSpark 00:57, 1 January 2010 (UTC)

The next full moon after that, by the way, is on January 29, 2010 and it will be a close perigee to Earth. Mars will be close to opposition and peaking in brightness at magnitude -1.3, with the Beehive Cluster in between the two. I think WolframAlpha is a good calculator for calculating astronomical events such as this. ~AH1^(TCU) 01:39, 1 January 2010 (UTC)

What is a "close perigee"? Does the distance at perigee vary? If so, why? --Tango (talk) 01:43, 1 January 2010 (UTC)

Yes it does vary, here's a table. The moon is effected by other solar system bodies besides the earth, primarily the sun. The effect is greatest when apogee or perigee coincide with a new or a full moon. And even greater when that coincides with the Earth at perihelion. SpinningSpark 02:36, 1 January 2010 (UTC)

Is this a solution for gravity?

Big Bang has the Expansion of the Universe occurring through space, but that doesn't work. The expansion of the Universe is through Time.

The mistaken assumption here is that an object (planet) stays the same size while magically pulling stuff toward it (gravity). This assumption makes the Big Bang "universal dispersal" idea seem perhaps even obvious. If things stay the same size while mysteriously pulling things to them while they all race away from each other in the night, then you'll get your big bang. Included in that scenario though are two huge mysteries:

• A. Why do things mysteriously pull things toward them? (gravity) and,
• B. Why is the universe expanding with all the galaxies racing away from each other?

So there we've got two huge mysteries and a Big Bang that ultimately does not work, at least according to mathematics.

On the other hand though, if we abandon our fixation on maintaining objects at the same size during the forward progression of time, and reversed our thinking on where the force of gravity is originating, instead of planets pulling things toward them, planets can be seen as pushing outward against things. Getting bigger in time doesn't mean getting bigger in space, it just means moving forward in time. So the expansion of our planet isn't an expansion through space, but through time. Pushing outward makes a whole lot more sense than magically pulling something to you. There's no magical mystery at all to gravity when it's viewed as pushing something (spaceship, car, etc.). Gravity is really just the forward progression of time.

So then, there are two answers to question B. Why is the Universe expanding? Time, and Gravity.--Neptunerover (talk) 01:43, 1 January 2010 (UTC)

I strongly recommend that you take a step back from your own 'home-grown' theories and study the works of the experts. The mathematics of the big bang work out just fine and there is a large (and growing) pile of observational evidence to back it up. No, planets don't "push" (I drop a rock - it falls to the ground - it doesn't fly off into space! We don't need to revise any of our current thinking - sure, there are still some puzzles - but this isn't one of them!

You are making the astoundingly common error of assuming that the expansion of space is a movement of objects through space. It is not. It is space ITSELF stretching. The reason we know this is because every object in the universe appears to be receding from us. If it were merely objects moving - then it would be a totally gargantuan coincidence if we happened to be at the precise center of that expansion. But if space itself is stretching, then from every point in space, this same phenomenon would be observed. Since space is stretching, all of your issues with gravity having to push objects around are of no concern. Besides, if the universe is infinite, gravity pulls identically in every direction because the mass of the universe is (on the average) uniformly spaced around us...if gravity pushed instead of pulling, there would be no net change in direction.

I'm sorry - but your grand thesis here is rooted in a total misunderstanding of how the expansion of the universe is working. Please study some more before posting this kind of diatribe against the work of a very large number of very smart people. SteveBaker (talk) 01:57, 1 January 2010 (UTC)

How can the universe be infinite? Bus stop (talk) 04:07, 1 January 2010 (UTC)

"How" is hard to answer - and we're not sure whether it's actually infinite or not. Read Universe#Size, age, contents, structure, and laws for example. SteveBaker (talk) 02:29, 2 January 2010 (UTC)

Thanks. That's pretty interesting reading. I would as much object to an assertion that the universe were finite as to an assertion that it was infinite. I just can't accept either notion. Bus stop (talk) 02:24, 3 January 2010 (UTC)

I've studied many experts through their works, which I often find overly complex.--Neptunerover (talk) 03:34, 1 January 2010 (UTC)

That's unfortunate - because until you understand the current theories - you are pretty much doomed because anything you come up with is essentially certain to be inferior to the rather complete and elegant theories that we currently have. How are you going to explain the cosmic microwave background? Can you explain the precession of the orbit of mercury? Does your theory explain black holes and why they 'evaporate'? If not - you have a lot to understand about the current theories which explain those things rather nicely. If you're going to be a cosmologist - your first job is to study and understand the current 'state of the art'. SteveBaker (talk) 03:43, 1 January 2010 (UTC)

So I guess you haven't read my book. What is it you want explained? --Neptunerover (talk) 03:50, 1 January 2010 (UTC)

The Cosmic Background Radiation is easy enough: It only has two dimensions to contend with. It doesn't know 'space.' --Neptunerover (talk) 04:04, 1 January 2010 (UTC)

Please feel free to try and disprove it mathematically. BTW, have lots of fun.-- Neptunerover (talk) 02:44, 1 January 2010 (UTC)

You may not understand the expansion of the universe, but that doesn't mean it doesn't work. It is a perfectly consistent theory, just one that is a little difficult to get your head around. --Tango (talk) 02:22, 1 January 2010 (UTC)

Thank you Tango, I forgot to mention earlier. It seams you may have answered my question of the section title while I was caught up trying to defend my right to ask a question here. --Neptunerover (talk) 14:33, 1 January 2010 (UTC)

Neptune, you fundamentally misunderstand the Hubble flow (the dominant component of the universe's expansion). It is not an active process at all. There are no special force making the universe expand, magical or otherwise. Envision an explosion. Initially the explosive fragments and the associated cloud is small, but it is imparted with an initial velocity that causes it to grow larger with time. The Hubble flow is exactly like that explosion. The universe is expanding because its constituents were given an initial velocity by the big bang, and mere inertia causes it to grow in size. Everything started together but some parts received a greater initial velocity. Those parts with greater initial velocity persist in moving faster and consequently are now farther away. The net effect is that the further away we look, the faster things are moving relative to us. General relativity adds a variety of details and refinements, but the basic principle is the same. The core of the universe's expansion is merely the inertia it has carried as a consequence of the initial velocities imparted by the big bang, nothing more and nothing less. Dragons flight (talk) 03:33, 1 January 2010 (UTC)

Okay, so Olbers' Paradox would be because of time. We see darkness in the night sky because we're not riding high enough on the time wave. If we were to go the speed of light through time, then we would be a Buddha, and there would be no darkness. In any case, how can this big bang you describe have done all that. I think they still aren't too clear on that. But maybe if we give them a bunch more money they can confuse us some more.--Neptunerover (talk) 03:46, 1 January 2010 (UTC)

With Gravity and Time being equal, there would have to be Time Waves then. Have the experts ever postulated those or studied them? Perhaps they have tried to detect them? (which are legitimate question for this page, I believe, even though I have my own "home grown" reasons for asking them) --Neptunerover (talk) 02:57, 1 January 2010 (UTC)

Gravity and time aren't equal - they aren't even remotely similar! Saying that they are doesn't even mean anything! A clock is ticking - measuring time...I drop a ball onto the table, it falls due to gravity - if I measure the force exerted on the ball, it's proportional to the mass of the planet you're standing on. What the heck could you possibly mean by saying that time and gravity are "equal"? It's just meaningless babble. So everything you say after that may safely be ignored.

You deeply misunderstand the scientific method. It doesn't work by some random individual stringing science-sounding words together and then demanding that people disprove whatever conclusions are guessed at! Doing that puts you firmly in the 'nut job' pile along with the loonies who come up with ideas like the Time cube.

Science is actually the process of coming up with a clearly stated hypothesis (which you have partially done) - then coming up with the proof that it is true (which would entail you carefully examining ALL of the evidence - doing some math - and using your hypothesis to explain ALL of the currently known related phenomena). Once your hypothesis has all of that theoretical and practical backing - it's time to present it to the world. If it contradicts even one of the currently know facts that the current theory explains - it's busted. When you have every little detail nailed down, you may try to get your work peer-reviewed and then published. Then - and only then - are you going to be taken seriously. Science doesn't advance by people just coming up with crazy thoughts and demanding that other people "prove" them. Even people like Einstein who come up with ideas so stunning that revolutionize the way the universe is imagined - are building on concrete observations and seeking explanations for things that are not already well explained. Einsteins theory did three major things that made it widely accepted:

1. It did not inhibit our understanding of already-understood phenomena (eg Newtons laws at experimentally measurable velocities).
2. It encompassed some known phenomena for which did not fit with the theory of the time (eg the constancy of the speed of light).
3. It made some testable predictions that would not have been true with existing theory (eg the bending of light from a distant star by the gravity of the sun).

Your ramblings do none of those things - if you persist in this manner, serious scientists are going to ignore your ideas and place you firmly into the same mental category as the Time cube folks.

SteveBaker (talk) 03:38, 1 January 2010 (UTC)

Time cube? I wish you hadn't given me that link. The last thing I want to do is try to twist my mind into a little box. That was horrible, whatever it was. If you even tried to comprehend that, then I should pay no attention to you. That was like a right hook. --Neptunerover (talk) 04:23, 1 January 2010 (UTC)

But the thing is - your writings seem to a scientist just like the Time-Cube junk seems to you. That's why scientists aren't going to pay the slightest attention to your ideas. The problem with both your writings and the time-cube stuff is that neither are following the scientific method. What you are doing isn't science - and no amount of science-sounding words stuck in there will make it so. SteveBaker (talk) 02:22, 2 January 2010 (UTC)

I already know it's true. Why should I bother with the math? I don't do math. We have specialized humans for that work. I am a mere theorist with a vantage from outside the box attempting to help. I don't believe I'm trying to force my opinions on anyone. Why should I madly bang my head against a scientific community who are firmly invested in the status quo? --Neptunerover (talk) 04:00, 1 January 2010 (UTC)

If you're are satisfied with your belief system and don't try to impose it on anyone then that is fine, but if you want anyone to take your theory seriously so that it can be verified and added upon and mathematically developed, then the burden of proof rests upon you to convince people that this is worth doing. In other words, your theory will (most likely) die with you unless you can show that it is scientifically superior to current theories. To do this you will have to do the math, because that is how science (especially physics) is understood.

The theorists are the ones who do the math. If you aren't doing math and you aren't doing experiments (and at least some statistics) then you aren't a scientist - period. I can't think of any scientist every in history who didn't do math. You might (maybe) lay claim to being a philosopher - but those guys are a waste of quarks. SteveBaker (talk) 02:22, 2 January 2010 (UTC)

The reason that the scientific community is so firmly invested in the status quo is because the current theories explain everything better than anything else we know of. This is evidenced by the fact that we have computers, lasers, the internet, gone to the moon, etc... If the current theories were significantly wrong, then how were we able to figure this stuff out? This is not to say that our theories are perfect, we know of several flaws, but any new theory will have to explain all of the phenomena explained by the old theories, and explain something that wasn't explained before. This means every equation and formula from the current theories that explains some observed phenomena correctly will have to fall out of the new theory in some form (of course, the old formula might turn out to be just an approximation to the real formula). It will be simply incredible if you manage to stumble on something that does this without doing any of the math yourself. Jkasd 05:58, 1 January 2010 (UTC)

Neptunerover, you appear to be using the reference desk to advocate for your own theory of the evolution of the universe. The reference desk is not intended for advocacy. Rather, we seek to provide factual answers rooted in accepted scholarship. I'd suggest you review the big box at the top of this page and the reference desk guidelines. If your goal is to discuss new theories of your own invention, I'd suggest that you would be better off going to other websites and web forums, but that the Wikipedia reference desk is not really an appropriate place for new research or theories. Dragons flight (talk) 04:46, 1 January 2010 (UTC)

Wow, you're not biased at all. Especially since I'm only asking science questions, as far as I know. You certainly don't need to read my questions if you personally find them disagreeable. I've heard this is a free place. --Neptunerover (talk) 05:13, 1 January 2010 (UTC)

On the contrary, I don't believe you have asked a science question. You posted some cosmological claims without any evidence, and later demanded that we disprove them. As Dragons flight stated, that is not the purpose of the reference desk. It is the purpose of Usenet. Comet Tuttle (talk) 06:20, 1 January 2010 (UTC)

http://xkcd.com/675/ -Craig Pemberton 07:25, 1 January 2010 (UTC)

I posted a question pertaining to one of the huge mysteries of science, and so I am afraid Comet Tuttle that I do not understand where you are coming from with your irrelevant 'not a science question' remark. As well, I certainly make no demands of anyone who doesn't first make some demand of me. If you personally do not think my proposal is a valuable one, then answer my question with a no. If you're looking to argue about something, I suggest taking it outside. It's all in your attitude. I am just a mirror. --Neptunerover (talk) 10:37, 1 January 2010 (UTC)

But it's not a mystery. We have perfectly good theory for all of that stuff. Just go and read about it! SteveBaker (talk) 02:22, 2 January 2010 (UTC)

Please can you re-state your original question, perhaps more succinctly ? I have read this thread, but I am afraid I cannot see what your question is. Gandalf61 (talk) 11:13, 1 January 2010 (UTC)

Besides, you can't ask the Rain man to put down on paper a mathematical model explaining the details of how he was able to determine the number of toothpicks there are, and especially not without even counting the toothpicks for yourself. Although I suppose one could try. And if you don't like counting toothpicks, then be happy that you are free to not count toothpicks, but don't go pointing fingers at the Rain man just because you don't like counting toothpicks. He wouldn't either if he had to count them that way. He just had a question (secretly hidden in the section title). Go ahead and ignore him; I promise he won't mind. --Neptunerover (talk) 11:20, 1 January 2010 (UTC)

As long as this whole idea is recognized as originating within the free space of Wikipedia, then I really have no other concern. Wikipedia can never be left out no matter who works it out in a mathematical proof, which would not be a meritless task for whoever did that, I believe. Me, I don't do math. --Neptunerover (talk) 11:54, 1 January 2010 (UTC)

Hmmm. So I think your question is "Can the phenomena normally attributed to gravity be explained by assuming there is no attractive force between matter, but instead every astronomical body is expanding in volume at an accelerating rate that depends on what we conventionally call its surface gravity ?" Answer - no. Reasons - many. Here are three:

1. We can detect movements in the Earth's crust of the order of a few mm per year. We would certainly notice if the distance between London and Sydney were increasing at any significant rate at all, let alone an accelerating rate.
2. If the Earth is expanding then in the past it must have been smaller. To avoid quickly reaching the point where the Earth was nonexistent, you must assume that the rate of expansion in the past was much slower than it is today. But that leads to a much lower effective surface gravity in the past, which would mean no atmosphere, no oceans and no life on Earth.
3. Gravity acts at a distance, and this property is required to explain the dynamics of the orbits of the Moon, the planets, and even the stars in a galaxy. The planetary expansion model only replicates the effect of gravity at a body's surface; you would need some entirely new and different mechanism to explain orbital dynamics and tidal forces. Gandalf61 (talk) 13:07, 1 January 2010 (UTC)

Thank you Gandalf61. I see where my solution is hung up. Time. Thanks. Peace out.--Neptunerover (talk) 14:53, 1 January 2010 (UTC)

Off-topic discussion moved to talk page. --NorwegianBlue ^talk 21:37, 2 January 2010 (UTC)

El Nino Southern Oscillation

Hi. My previous question on this subject did not receive an answer. If anybody has an answer, please provide it here. Also, as an aside, is it common for oscillations such as ENSO, PNA and AO to result in storms that have a rapid and significant effect on global ocean currents and circulation? Thanks. ~AH1^(TCU) 01:47, 1 January 2010 (UTC)

I did try and find an answer last time you asked but could not turn up anything definitive. This book would appear to have a map showing what you want but Google books seem to have failed to scan it properly, you may have to go and get it from a library. Note that they are using the more modern term "Peru current" instead of "Humboldt current". If you use Humboldt current el nino or Peru current el nino as a search term in Google books you will get a lot more with descriptions of this phenomenon. They all seem to agree the upwelling is pushed west, but where exactly it ends up there is no clear statement. SpinningSpark 12:30, 1 January 2010 (UTC)

Ah, I can now see the map on Amazon "look inside". Unfortunately there is little point posting the link, you can only use "look inside" if you have an account with Amazon with a recent purchase on it. The map shows the whole Peru current levered westward by the El Niño current and ending slightly further West and South in the direction of Tahiti (but not getting anywhere near Tahiti before it meets the South Equatorial Current). Hope that helps. SpinningSpark 12:41, 1 January 2010 (UTC)

Hi. Thanks for that answer, but is there any idea where the cold upwelling ends up after meeting the S. Equatorial Current; does it pushed underneath? Where does the colder water appear to end up in the current condition of El Nino? Also, this will probably be more difficult to answer, but do El Nino and the other oscillations have a mutual effect if huge storms are produced in the anomalous weather patterns and sea surface temperatures, then the storms themselves in turn have an effect on SSTs and ocean currents? Thanks. ~AH1^(TCU) 19:51, 1 January 2010 (UTC)

The never dying fruitcake

We often make our Christmas Cake and Christmas Pudding in late December/early January for consumption the following Christmas and save some for the following Easter. What gives these and other types of fruitcakes their longevity (Wedding cakes have been to known to still be edible decades after the event)? Is it perhaps the concoction of the mixture itself, the added alcoholic content, the icing on the cake or a bit of all? Nanonic (talk) 02:11, 1 January 2010 (UTC)

Fruitcakes last longer than sponges anyway because of the high sugar content, and low water and fat. On top of that, Christmas cake is often properly doused in alcohol, which, as you say, has an effect. Instructions on keeping a cake for a long time usually tell you to feed it at regular intervals, topping up the evaporated alcohol. Proper storage will also help. I'm not convinced that the icing increases their longevity, since the cake lasts so long un-iced. But certainly if you iced it with fondant or buttercream, rather than marzipan and royal icing, the icing itself would degrade much sooner, and possibly take the cake with it. 86.176.48.114 (talk) 02:22, 1 January 2010 (UTC)

The high sugar content (from both added sugar and the sugar in the fruit, I suppose) relative to the amount of water results in a low water activity, which makes it very difficult for bacteria to grow. (Or something along those lines.) --Tango (talk) 02:29, 1 January 2010 (UTC)

Some website or magazine article once said that the longer a plum pudding is kept, the better it is. I believe there is one in the back of a shelf in the kitchen which has been lurking there for several decades, so it should be very good indeed, unless someone threw it out in a fit of cleaning up. Sugar, like salt, alcohol, freezing or desiccation , can be a preservative, moving a food outside the comfort zone of bacteria. Now to rummage through the kitchen shelves. Edison (talk) 03:17, 1 January 2010 (UTC)

Don't forget the Rum Sauce! If the pudding has any problem that'll fix it! --220.101.28.25 (talk) 08:57, 1 January 2010 (UTC)

We will not provide medical advice. ~AH1^(TCU) 19:38, 1 January 2010 (UTC)

Lunar exploration and Moon rock

Hello, I want to know

1. how to purchase moon rock. Here is a site offering moon rocks and other extraterrestrial rocks for sale. Is it genuine? Do I require any license or something like that to possess a rock of extraterrestrial origin?
2. what will be the cost of an Apollo 11-type lunar exploration where one man will descend on the surface of the moon, collect rocks and return to earth? --Qoklp (talk) 05:23, 1 January 2010 (UTC)

Our article Moon rock says the Apollo moon rocks are "currently considered priceless" but the Lunar meteorite article says that rocks ejected from the Moon which landed on Earth are sometimes available . It claims that one out of every thousand newly discovered meteorites is a lunar meteorite (but that statement has no citation). To your second question, this report from the GAO says the Constellation program moon mission will cost US$97 billion through the year 2020, but the report says in the same breath that the cost is quite uncertain what with the changing mission objectives. I'm not actually certain whether the $97 billion number includes the manned mission. Comet Tuttle (talk) 06:09, 1 January 2010 (UTC)

1. (ec*2) If it is genuine, they are almost certainly lunar meteorites.
2. According to our article Apollo program, the cost of the Apollo spacecraft and Saturn rocket was about $83 billion for one trip. The cost of doing something similar to collect rocks would be comparable. Jkasd 06:15, 1 January 2010 (UTC)

Yes, the site is selling broken up pieces of meteorite, not rocks brought back by Apollo, despite the suggestive pictures in the advertising. I would also point out that although they claim the rocks to be guaranteed genuine lunar rocks, the guarantee comes from "fellow members of the International Meteorite Collectors Association". That is, it is not an independent guarantee. The huge cost of retrieving rocks from the surface of the moon is shown by this: if gold bars were stacked up on the surface of the moon all ready for transport back to earth, it would still not be an economic proposition to go and get them with an Apollo type mission. Even bringing back a thousand tons of gold would not cover the costs, and Apollo was only capable of bringing back a few pounds of material. All the moon rock brought back in this way is being used for scientific purposes. The only Apollo moon material that has found its way on to the open market, as far as I know, is in a painting by Buzz Aldrin who mixed into the paint some moon dust found in his personal belongings. SpinningSpark 13:10, 1 January 2010 (UTC)

Correction, the painter is ex-astronaut Alan Bean of Apollo 12, not Buzz Aldrin. SpinningSpark 17:56, 1 January 2010 (UTC)

Bringing back 100 tons of moon rocks would also severely distort the market and likely cause the price to shrink considerably. Googlemeister (talk) 16:29, 4 January 2010 (UTC)

yield for reduction of amides with LiAlH4

It seems to me that the critical step (during the tetrahedral intermediate stage) that the tetrahedral intermediate could go both ways. A C=O bond is thermodynamically more stable than a C=N bond, but I know there are kinetic effects at play. I'm thinking -- if the amino group gets expelled, it remains a good nucleophile and it's hard to pick up a proton in an LiAlH4 environment, so it reattacks the carbonyl, which is activated because the oxygen is bound to aluminum. Whereas if the oxygen gets expelled -- the amino group can lose a proton and the imine can become relatively resistant to the Al-OH nucleophile? If I were to carry out such a reaction (assume simple amides, e.g. an N-acylated amino acid but say the amino leaving group is large enough not to evaporate), what sort of yields should I expect? John Riemann Soong (talk) 10:53, 1 January 2010 (UTC)

P.S. aluminum hydroxide is actually acidic, right? I can't tell on our Wikipedia page whether the pka is for the conjugate base (as R2Al-O-) or the conjugate Lewis acid (R2Al+) HOH. I suspect the former.

Diesel automobiles without diesel particulate filters

I want a list of the currently produced diesel automobiles which aren't available with a diesel particulate filter. --84.62.205.233 (talk) 11:33, 1 January 2010 (UTC)

This source states "According to one auto parts catalog, from 1960 to 2002, over 25 Manufacturers have made at least 236 different passenger vehicle models with diesel engines." and provides a list of manufacturers and models. One way to compile your list would be to survey all these models; an easier way might be to investigate which vehicles are marketed in the U.K. and approved under the London low emission zone diesel pollution regulations. Cuddlyable3 (talk) 01:05, 5 January 2010 (UTC)

Gluten free bacon

I bought my usual bacon yesterday which comes from a local company and noticed that it had a selling point on it that said "Gluten free". After looking at the ingredients of that and the big name (Oscar Mayer) brand, I couldn't figure out where the gluten comes from or went. Is this just an empty statement like a bottle of water claiming "Sugar Free!" or some such thing? 68.142.57.167 (talk) 15:02, 1 January 2010 (UTC)

Yes, I think it's an empty statement. I can't see why there would ever be gluten in bacon... Sausages, sure - they sometimes contain bread crumbs - but not bacon. --Tango (talk) 16:07, 1 January 2010 (UTC)

It's not really an empty statement, there are loads of things that are obvious when you think about it but that label makers put on to highlight their product. "Lactose free" for any kosher parve item is an example. DRosenbach ^{(Talk | Contribs)} 16:15, 1 January 2010 (UTC)

It's not necessarily an empty statement; see for example this discussion thread. Among other possible routes for gluten is via 'seasonings' added to the meat. Apparently some manufacturers may incorporate soy sauce (which often contains wheat, and hence gluten) in their flavouring mix. Some companies (e.g. Kraft, of which Oscar Mayer is one of their labels) have a corporate policy to always indicate wheat- and gluten-containing ingredients on their packaging: [5]. Some other companies may have different policies; it's important to do your homework on this one. TenOfAllTrades(talk) 17:33, 1 January 2010 (UTC)

Bacon may contain maltodextrin, a sugar commercially obtained in the EU from wheat or maize. This may be added to sweet-cure bacons such as 'maple-cured' bacon to impart a palatable sweet flavour without actually having solely to use maple syrup, which is rather expensive and may not be familiar to European tastes. I am unclear as to whether or not this could provoke an allergic reaction in those sensitive to wheat and gluten additives, although products containing maltodextrin are commonly labelled as having containing wheat products in the EU. You might wish to try plain, unflavoured bacon products, which are not labelled as having containing gluten. —Preceding unsigned comment added by 86.180.35.161 (talk) 23:00, 3 January 2010 (UTC)

Maltodextrin is a highly processed polysaccharide, and regardless of what it's made of, contains no gluten, which is a protein. It's therefore generally considered safe for those with celiac disease (though some individuals with celiac avoid it anyway). I don't know anything about wheat allergies, and had a hard time making sense of the information I found, so I don't know the story there. It'd seem to be safe to me, but I'm no expert. Other "malted" or "malt flavoring" ingredients are usually made of barley, and can contain gluten. "Natural flavorings" also may or not be trouble. So yes, plenty of sources of hidden gluten, and if a product contains none of them, there is a market segment (people with celiac who must avoid all gluten, people with wheat allergies who ditto, and people with neither who avoid gluten for other reasons) who may be more likely to purchase said product if the hard work of label reading is done for them. Marketing device? Sure, but useful for some folks, and sometimes less obvious (what goes into a hot dog?) than others (there's no wheat in a banana...der). The "gluten free" label on the front of a package is not the same as the "CONTAINS: WHEAT" at the end of the ingredients list, which is required by law for all foods sold in the United States (though a food can contain no wheat and still be chock full of barley). Some jerk on the Internet (talk) 17:31, 4 January 2010 (UTC)

A long time ago, in a galaxy far, far away...

It just hit me -- what in the word does this opening line of all the Star Wars films even mean? Certainly the story depicted didn't happen a long time ago, or else we'd have records of it? The technology is far greater than we will ever see in reality. Wouldn't it have been better to have said, "Sometime in the future, in a galaxy far, far away..."? Granted its not as poetic, but I'm sure Lucas could have thought up something nicer. DRosenbach ^{(Talk | Contribs)} 16:13, 1 January 2010 (UTC)

If it happened in a "Galaxy far far away" then the information travelling at the speed of light may not have made it to us. I suspect he put it in the past instead of the future to give it a more historic rather than speculative feel. Most people ignore that sentence completely. RJFJR (talk) 16:22, 1 January 2010 (UTC)

This is the reason that all articles at Wookieepedia are written in the past tense. Staecker (talk) 16:25, 1 January 2010 (UTC)

So you're saying that our planet was in the outer rim to such an extent that we were not involved in the Republic? Seems implausible. And the fact that most people ignore that sentence doesn't make it any less canon and therefor damning in terms of the overarching ramifications it has on the story line. DRosenbach ^{(Talk | Contribs)} 16:34, 1 January 2010 (UTC)

Note that he says "In a galaxy far far away". A close galaxy is Andromeda Galaxy, and it is two million light-years away. So if he said a galaxy that is not close ("far, far away") that could mean hundreds of millions, or even billions of light years away. We could have been warm slime in some ancient ocean when the "events" took place, and we still wouldn't be able to detect any remnants of their civilization. J.delanoy^gabs_adds 16:41, 1 January 2010 (UTC)

There are a lot of sci-fi "futuristic" stories that are set in our past. (Battlestar Galactica also comes to mind.) The general idea is often that we are meant to be descendants from those people, but we've lost out on our history. As to how it actually works out, canonically, I don't think that is meant to be spelled out explicitly (and would be pretty boring). As for not having records of it, there are a million plausible ways for that to be the case (e.g., earth humans were "seeded" and did not come here knowingly or voluntarily). (As for whether the tech is plausible or not... that's pretty much not the point of Star Wars.) --Mr.98 (talk) 16:45, 1 January 2010 (UTC)

Hmmm...OK, that's a good response. J.delanoy's post was particularly helpful :) DRosenbach ^{(Talk | Contribs)} 17:05, 1 January 2010 (UTC)

And in any case, the poetic nature of it is mostly the point. Star Wars is a classic Hero's Journey in a scifi setting: it's supposed to be like an old legend that happened once upon a time. The opening line tells you how to process the story you're being told. 86.177.121.171 (talk) 17:04, 1 January 2010 (UTC)

The "outer rim" signifies that we are in the same galaxy. According to the sentence, we are not. Since they don't really leave their own galaxy in Star Wars, this should provide some continuity. Awickert (talk) 17:05, 1 January 2010 (UTC)

for the claim most people ignore the sentence. I don't consider myself a major Star Wars fan but I was well aware that the Star Wars universe was supposed to be in the past. The Weird Al Yankovic song probably helped as did the fact one of my brothers went thru a phase of watching Star Wars a lot but it's not like it's that confusing, there's no earth after all. I never really thought of the ramifications in depth, although I did sometimes think may be we were supposed to be the descendents or maybe just a different people that for some strange reason look the same... I don't really see any reason to presume most people who paid any attention weren't similarly aware of this. Obviously some people (perhaps even 'most people') wouldn't have been aware as they don't know much about the story universe and background because they didn't care and ignored most of it including the long time ago thing. And I'm sure some people did find it confusing and so ignored it, but I don't see any reason to presume it's 'most people'. In any case of all the implausible things in Star Wars that requires major suspension of disbelieve (Ewoks anyone? Death Star design? And we haven't even gotten to 1-3) it seems to me that "long time ago, galaxy far, far away is a very minor thing". Nil Einne (talk) 18:24, 2 January 2010 (UTC)

Instead of speculating, why not look in Wookiepedia who may actually have the answer. In their time travel article they say:

• Time travel was also a plot device used in Alien Exodus, a canceled and thus non-canonical novel. In Alien Exodus, the humans of the Star Wars galaxy are revealed to be the descendants of a group of refugees from Earth whose ship accidentally traveled through a wormhole. This wormhole took them not just to another galaxy, but to another time, billions of years in the past: in other words, they found themselves "a long time ago, in a galaxy far, far away."

Strangely, they appear to have had an article A long time ago, in a galaxy far, far away at one time but it is now deleted. Maybe RJFJR is right, most people, including Wookiepedia, ignore it.

SpinningSpark 18:16, 1 January 2010 (UTC)

They do, however, still have the article Galaxy Far, Far Away. --NorwegianBlue ^talk 21:32, 1 January 2010 (UTC)

I believe the Lego Star Wars figures are closer to the real Star Wars and that human like figures were only used in the films to cut down costs. In one of the Star Wars games there is a bonus level where they act out being in a galaxy far far away on a planet that looks like Earth. ;-) Dmcq (talk) 00:32, 3 January 2010 (UTC)

Measuring vitamin C

How would you measure how much Vitamin C is in a sample? There was an article that mentioned some high school students tested commercial fruit juice and when the results didn't match the packaging the company got in trouble; so it shouldn't be too hard (but it could be 'send sample to lab and wait six weeks.') If it's really easy then I'm curious how much vitamin C there is in my cup of nettle tea. RJFJR (talk) 16:25, 1 January 2010 (UTC)

It looks like one test is a fairly straightforward titration against DCPIP: [6]. Another variation noted in our article (ascorbic acid#Determination) uses titration against iodine in the presence of starch. Both of those assays are based on straightforward colour changes, so you don't need any specialized equipment. (Getting DCPIP may be more difficult.) I will note that extended heating and exposure to air will both oxidize ascorbic acid, which may mean that your apparent yield of vitamin C depends quite a bit on your tea brewing process. TenOfAllTrades(talk) 17:19, 1 January 2010 (UTC)

Here's a guide to using iodine:[7] Fences&Windows 17:21, 1 January 2010 (UTC)

Hmm, I thought there would be a problem of selectivity, e.g. the issue of false positives (if there are other antioxidants involved), but I guess the fact that a test fails even with nonselective tests damns the companies more. John Riemann Soong (talk) 21:16, 1 January 2010 (UTC)

Testing for vitamin C content isn't that uncommon in school I believe since it can be a fairly simple test particularly with DCPIP . I did it in my A-level biology for example and think it's also done sometimes in Malaysian form 4 or form 5 (Sijil Pelajaran Malaysia level). Incidentally, in the Ribena#Vitamin C content case you're thinking of, iodine was evidentally used [8]. Note I expect it is highly unlikely the results from the 2 schoolgirls or any similar amateur results would have any standing in court, particularly if the company produces professional results which show something else. However they may be enough (as they were in this case) to convince regulatory authorities or consumer affairs organisations to look in to it and conduct their own tests or pay for a professional test which will. Ideally the company themselves will look in to it and take action themselves when they find out you were right (which didn't happen). Nil Einne (talk) 18:44, 3 January 2010 (UTC)

Slim elderly people

Most or perhaps all very elderly people I can recall seeing seem to be slim. Is there any evidence that this is due to either a) only slim people surviving to a ripe old age, or b) even formerly overweight people losing weight as part of the process of becoming very old? 92.24.69.222 (talk) 21:19, 1 January 2010 (UTC)

You may be interested in this SpinningSpark 22:21, 1 January 2010 (UTC)

Selection bias. All the very elderly people you see in public are the most healthy and athletic (more likely not to be overweight). Looking in homes and hospitals you see the rest. You get the same selection bias with smokers who acquire emphasema and drop out of public view. Polypipe Wrangler (talk) 22:43, 1 January 2010 (UTC)

Agreed. It's selection bias. You may come from a fairly slim family to begin with, so your older relatives are therefore slim. If you want wp:or, a grandmother on my side and another on my wife's side were both overweight and both lived into their 80s. If you want more notable examples, Marlon Brando lived to 80 and was overweight. Jack Nicholson is 72 (don't know if that counts as "elderly" for you) and is overweight. Dismas|^(talk) 23:43, 1 January 2010 (UTC)

Plus, you can add in the factor of increasingly overweight populations in developed countries, which affects the younger groups more than the older groups. On top of that, it is pretty common for people to lose weight if they develop dementia, as they forget to eat properly. 86.177.121.171 (talk) 03:57, 2 January 2010 (UTC)

"Very elderly" people to me would be people in their late eighties, nineties, and beyond. 78.146.22.20 (talk) 12:45, 2 January 2010 (UTC)

• The term used in the literature is "oldest old". Being underweight probably reduces life expectancy among people over 70, but being obese may not, though the literature is mixed on the question (obesity will certainly reduce quality of life and increase medical costs). One recent study found that "low BMI (<22 kg/m2) increased the risk of fracture by 38% (hazard ratio = 1.38, 95% CI 1.11, 1.73) and all-cause mortality by 52% (hazard ratio = 1.52, 95% CI 1.30, 1.79)."[9] Another found that "obesity has little effect on life expectancy in adults aged 70 years and older. However, the obese are more likely to become disabled. This means that obese older adults live both more years and a higher proportion of their remaining lives disabled."[10] This is supported by a review that concluded that "Obese seventy-year-olds will live about as long as those of normal weight but will spend more than $39,000 more on health care."[11] Another study found that "Modifiable healthy behaviors during early elderly years, including smoking abstinence, weight management, blood pressure control, and regular exercise, are associated not only with enhanced life span in men but also with good health and function during older age".[12] Also see this review that argues that obesity does shorten life expectancy (although the effects of weight on longevity might not be the same at each stage of life). Fences&Windows 17:41, 2 January 2010 (UTC)
• Oh, and see this: "The average body mass index among survivors decreased by age."[13] Those above claiming selection bias (with no reference to the literature, come on guys) might be wrong. Fences&Windows 17:46, 2 January 2010 (UTC)

Some of my elderly relatives experience pain in chewing and/or difficulty swallowing, which dramatically diminishes their desire to eat. In some cases depression and/or dementia also seems to diminish their appetite. -- Coneslayer (talk) 12:43, 4 January 2010 (UTC)

Triple point

If you put a substance at its triple point, which phase would it look like if you had a large enough amount to see it? It can't look like a solid, liquid, and gas all at the same time, can it? --75.13.226.103 (talk) 23:11, 1 January 2010 (UTC)

Sure it can. It looks like a mixture of solid and liquid at the bottom of your vessel, and the gas phase at the top. That's exactly what it is. I guess that you are probably confusing triple point with a critical point. At the triple point, three different phases (solid, liquid, and gas; or, generally, any three distinct phases) coexist, but differ in their structure and properties. At a critical point, two distinct phases (usually liquid and gas, or two solid phases) become indistinct. --Dr Dima (talk) 23:21, 1 January 2010 (UTC)

So some of the material is in each of the three phases, rather than the whole substance being indistinct? --75.39.194.94 (talk) 14:22, 2 January 2010 (UTC)

Exactly. --Tango (talk) 14:47, 2 January 2010 (UTC)

I find it hard to believe that no energy is needed to change phase. That implies that the actual phase of a substance at its triple point depends on the direction from which it was brought to the triple point. Cuddlyable3 (talk) 23:29, 2 January 2010 (UTC)

Why would that be hard to believe? Many real life situations are not symmetrical with respect to time. 86.177.121.171 (talk) 01:04, 3 January 2010 (UTC)

A substance at its triple point is in dynamic equilibrium - bits are constantly changing phase in all directions with the total number of particles in each phase staying approximately constant and the energy changes all cancel out (temperature refers to the average energy, the energies of individual particles are constantly changing). An arbitrarily small (but non-zero) change in temperature or pressure can break that equilibrium and make the whole substance change to one phase. I'm not really sure what you mean by "no energy is needed to change phase" - a substance at its triple point won't be in one phase, it will be a mixture of all three, so you can't change the phase. The proportion of each phase will depend on the route taken to reach the triple point. --Tango (talk) 01:43, 3 January 2010 (UTC)

What Cuddlyable3 is saying is that by adding or removing energy to/from the system the amount of substance in each phase will change accordingly and he is right. Not only that. The total volume of the system can also change by (de)compressing it without changing its pressure and the total amount of substance in each phase will change accordingly. Dauto (talk) 01:56, 3 January 2010 (UTC)

Carcinoma in Situ

I have been searching for some information about Carcinoma in Situ, via Google search-Carcinoma in Situ-Treatment-and I haven’t got any information on how long will the Carcinoma take to become a true cancer? One of my family members has it, initially existed, and I’m wondering if it is too late? Perhaps it progressed into a true cancer and we still don’t know it! How much time do we have before its too late? —Preceding unsigned comment added by 77.42.173.160 (talk) 23:39, 1 January 2010 (UTC)

Wikipedia has an article on carcinoma in situ which may provide some background information. However, Wikipedia's editors cannot offer you advice or speculation about the diagnosis or prognosis of any particular person. By far your best source of information is your family member's physician or oncologist, and I would strongly encourage you to go there with your questions. TenOfAllTrades(talk) 00:02, 2 January 2010 (UTC)

Manifestation of carcinoma-in-situ and its progression to metastatic disease differs between the various types of malignancies -- as such, much like life itself, this is not a simple question and thus cannot be solves with a simple answer. If you would put a more specific diagnosis, you'd likely get a more specific response -- but then again, a more specific diagnosis would only exacerbate your question's violation of the "no requests for medical advice" on the reference desk. Thus, I'd agree with Ten above and suggest you speak with your oncologist, unless you're unhappy with him or her. In that case, speak to another oncologist (or at least a pathologist). DRosenbach ^{(Talk | Contribs)} 13:54, 5 January 2010 (UTC)

January 2

formation of amides by reacting amides with esters

Because anhydrides and acyl chlorides are awful to use ... I'm having trouble finding a water-soluble ester where the leaving group has a lower boiling point than the ester. But maybe if I use acetone as a solvent (will it dissolve deprotonated amino acids or amino acids with charge of -1?), it will change the boiling point dynamics? Thanks. John Riemann Soong (talk) 01:34, 2 January 2010 (UTC)

Wouldn't you form an amide by reacting an amine with an ester?

Ben (talk) 01:44, 2 January 2010 (UTC)

Quite true. I'm actually trying to be cheap-ass and using a cheaper protecting group, since Cbz, etc. are quite expensive. I'm conducting various coupling experiments with amino acids. (The main reason why I want to protect the amino group is that I'm carrying out an aldol reaction, and a free amine in that position, in addition to being a competing nucleophile will end up forming a troublesome enamine during enolisation.) Although urethane formation wouldn't be bad either, if I could react an amine with an carbamate ester (though I don't see that happing conveniently). John Riemann Soong (talk) 01:50, 2 January 2010 (UTC)

Water may not be a not a wise choice if you are doing acyl-exchange reactions. You should be able to figure out why. Why not use the ester as solvent? Even if the alcohol LG does not distill out (I assume that's why you are asking about "LG" bp, but as usual you are not clear and precise in your explanations), the huge concentration of that ester would push the equilibrium forwards? But anyway, the bp trends should be obvious to you: longer chain on the acyl side of an ester raises ester bp without affecting bp of alcohol part (the LG being displaced), shorter chain on the alcohol part lowers bp of the ster and alcohol LG, longer chain decreases water solubility. So you can now do your own research by looking up the bp of a bunch of possibilities and decide what is the best compromise among these competing issues. DMacks (talk) 17:13, 2 January 2010 (UTC)

Calculate time and direction of Moonrise

How can I calculate the time and (compass) direction of Moonrise from a specified place on the Earth? Bubba73 ^{(Who's attacking me now?)}, 01:58, 2 January 2010 (UTC)

This might be a good resource (found by searching with Google for the phrase moonrise times). Tonywalton ^Talk 02:01, 2 January 2010 (UTC)

Thanks, but that says to put your information into their software. I want to list Moonrises that occur at night in a range of compass directions. I don't think there is a practical way to do it with their software, which is why I want to calculate it. Bubba73 ^{(Who's attacking me now?)}, 02:08, 2 January 2010 (UTC)

Do you speak Perl? If so, CPAN has modules specifically designed for this sort of thing; you could even reverse engineer their algorithms and write your own software from them if you wanted. Tonywalton ^Talk 02:17, 2 January 2010 (UTC)

Do you mean you want to do the calculation backwards from the way you first described it? You have a place and compass direction and you want to find a time and date when moonrise will be in the direction from that place? --Tango (talk) 19:12, 2 January 2010 (UTC)

For a particular place, I want to find out what dates and times that the Moon rises from a range of compass directions (basically south of east). I ordered a book that should give me enough information to write a program to do it. Bubba73 ^{(Who's attacking me now?)}, 20:49, 2 January 2010 (UTC)

Yoursky has a night sky map shown when you insert your latitude/longitude and specify a time in the past, future or right now. You might have to experiment with the time, however, until the altitude of the moon is close to the horizon. The numbers used for azimuth are discussed on the website. ~AH1^(TCU) 03:00, 2 January 2010 (UTC)

I have Starry Night (planetarium software) but it would be impractical to do what I need to do that way. Bubba73 ^{(Who's attacking me now?)}, 04:10, 2 January 2010 (UTC)

What about Celestia? Although I haven't tried any moonrise calculations myself. ~AH1^(TCU) 18:35, 2 January 2010 (UTC)

Thanks, but I don't see anything like what I need in it. Bubba73 ^{(Who's attacking me now?)}, 01:42, 3 January 2010 (UTC)

The procedure to find the time of moonrise or moonset is outlined on page 487 of Seidelmann's Explanatory Supplement to the Astronomical Almanac (1992). You may be able to find this at a library. Also, Jean Meeus has written a number of books on astronomical calculations for amateurs which you might find at your library.

The process of finding the time will also lead to finding the Greenwich Hour Angle and declination of the moon at the time of interest. These can be put into formulas available in the Astronomical Almanac to find the altitude and azimuth. The final step would be to correct the true azimuth to a magnetic azimuth. --Jc3s5h (talk) 19:57, 2 January 2010 (UTC)

The book I ordered is by Jean Meeus. Our library would not have the book you mentioned. Thanks for the reply, I think I'm on the right track. Bubba73 ^{(Who's attacking me now?)}, 20:44, 2 January 2010 (UTC)

Whoops, I saw that author but I actually ordered Astronomy with your Personal Computer by Peter Duffett-Smith. Bubba73 ^{(Who's attacking me now?)}, 20:52, 2 January 2010 (UTC)

Insomnia

Hi. First of all, I'm not asking for medical advice, just the name of a possible scientific term. Please do not give medical advice. In the article, it discusses several patterns of insomnia, and some of them encompass trouble falling asleep, maintaining sleep, etc. However, what is it called if the person is unable to sleep for the entire night? I've heard a non-scientific term as "pulling an all-nighter", but this usually refers to doing it on purpose. I'm not looking for delayed sleep phase disorder. Thanks. ~AH1^(TCU) 02:56, 2 January 2010 (UTC)

As far as I know there is no special word for that -- I would probably just call it "total insomnia". Looie496 (talk) 16:52, 2 January 2010 (UTC)

Really bad insomnia? Some related info: someone may believe they've had no sleep even when they have; insomniacs often underestimate their total sleep time:[14], and insomnia in which someone wakes up at 2 or 3am and then can't sleep the rest of the night is often associated with depression:[15]. Fences&Windows 17:17, 2 January 2010 (UTC)

OK, but could the person's brain activity, if it is very high during the night, cause the person to be unable to enter into phases such as deep sleep and REM sleep, thus causing total or near-total (ie. less then 2 hours) insomnia? ~AH1^(TCU) 18:19, 2 January 2010 (UTC)

Restless leg syndrome and PTSD have a loss of REM sleep.[16][17][18] Fences&Windows 21:33, 2 January 2010 (UTC)

One of the common symptoms of major depressive disorder is that people find it very difficult to fall asleep and then once asleep go very quickly into REM, thus leading to a very severe deficit of non-REM sleep, which is the restorative kind. Looie496 (talk) 17:45, 3 January 2010 (UTC)

How do birds shelter themselves in winter?

The temperature is hovering near 0° F here and the birds are nowhere to be seen. This led me to wonder: How do they shelter themselves in winter? --Halcatalyst (talk) 05:12, 2 January 2010 (UTC)

They most likely flew south. ~ Amory (u • t • c) 05:32, 2 January 2010 (UTC)

Supposedly a truck carrying monk parakeets crashed in New England, and all the birds escaped. Now they survive by living in the big power transformers (heat energy lost by voltage change keeps them warm through the winter) and are something of a political issue.-Craig Pemberton 07:23, 2 January 2010 (UTC)

(ec) Some birds migrate, but many hang around. If you put food out they will soon appear. The smaller ones shelter in creepers like ivy, and in evergreen trees and hedgerows. Larger birds like crows will roost in woodland. Pigeons like to roost or and around buildings.--Shantavira|^{feed me} 07:28, 2 January 2010 (UTC)

One of the properties of a bird's plumage is its insulation. Ask any penguin who has sat through howling blizzards for a couple of days, not to mention the chicks. Most birds that do not migrate tend to find a sheltered spot, hole or crevice and plump up their feathers. They may do this singly, but some species have discovered the advantage of communal roosting in low temperatures to conserve heat. Have you ever wondered why that cheeky little robin looks fatter when there is snow on the ground - s/he's just keeping warm. Caesar's Daddy (talk) 16:38, 2 January 2010 (UTC)

Bernd Heinrich wrote an entire book on this subject that I highly recommend: The Winter World: The Ingenuity of Animal Survival published in 2003. I highly recommend any book written by Heinrich; he is an excellent scientist and and excellent writer.--Eriastrum (talk) 18:27, 2 January 2010 (UTC)

• Thank you. I put this book on my wish list at PaperBackSwap.com. --Halcatalyst (talk) 22:46, 2 January 2010 (UTC)

(edit conflict)Migratory birds such as Canada geese are supposed to fly south for the winter, but more recently this did not appear to be the case. There are just my own observations, but in mid-November in S. Ontario, I saw a small flock of around 20 geese flying north, then a few days later I saw geese resting in a pond. At this point, there were still dandelions and earthworms. By 28 November, I saw a double flock flying south in formation with approximately 130 members. However, the next day, I think I remember seeing around 100 geese staying put about 15 km to our south. The next day, I saw a mosquito in my house and a friend reported seeing a caterpiller. On 3 December, I saw two geese flying north, after a storm had brought us colder air. I may have seen another flock flying south after that, but on 11 December I saw a flock of roughly three dozen geese flying north-northeast. Another big storm had just passed, and temperatures were close to -10C and very windy. After that, there were still seagulls around the area, and birds chirping in shrubs (as I have seen a few winters prior). ~AH1^(TCU) 18:33, 2 January 2010 (UTC)

Yeah, I just had to walk around a flock of Canada geese (wading in several inches of snow!) in Denver a few days ago, and while driving in the Great Plains a few days before that, I noticed a flock of geese heading north. Nyttend (talk) 13:51, 4 January 2010 (UTC)

Reverse orgasm/sinking feeling?

What is happening in your brain when crushing realization hits you and you just feel these terrible punishing feelings wash over you like a reverse orgasm? Is there a term for it? It is not butterflies in the stomach, fight or flight, nor panic attack although it is probably related it is negative and resigning. Any ideas? -Craig Pemberton 07:37, 2 January 2010 (UTC)

Do you mean Acute stress reaction ? --Dr Dima (talk) 08:39, 2 January 2010 (UTC)

Sounds to me like what you describe is just fear, if you feel it in your belly, mostly. It can feel like many things, but I think it just means one's brain is stuck on a feeling of fear. It's very common. --Neptunerover (talk) 09:18, 2 January 2010 (UTC)

Melancholia, depression, downer, anti-climax? Mitch Ames (talk) 13:06, 2 January 2010 (UTC)

Guilt? Cognitive dissonance? --Mark PEA (talk) 14:12, 2 January 2010 (UTC)

Acute stress reaction is probably the best description of what happens in the brain -- at a psychological level, the word I would probably choose is despair. Looie496 (talk) 16:49, 2 January 2010 (UTC)

See the article Major depressive disorder. Cuddlyable3 (talk) 23:17, 2 January 2010 (UTC)

Despair. 78.146.54.230 (talk) 15:05, 3 January 2010 (UTC)

Transmissible cancer

Noticing the main page in the news section, there is a post regarding transmissible cancer, in particular that scientists have discovered how devil facial tumour disease transmits. Apparently it is caused by the transfer of Schwann cells. My question is why does this make a difference? If a liver cell or blood cell was transferred between two Tasmanian devils, it would be removed by the animal's immune system. So what makes Schwann cells so special in the fact that they are not removed by the immune system as foreign cells? Do they lack antigens on their surface? Do they somehow affect the recipients ability to recognise cancerous cells? Regards, --—Cyclonenim | Chat  11:02, 2 January 2010 (UTC)

It's been known for a while that DFTD was a transmitted cancer and that the cells are identical, cytogenetically abnormal, small neuroendocrine-like cancer cells. The significance of the current report is that they used high-tech molecular biology to catalog the gene expression profile and it most closely matches Schwann cells. So, the origin of the tumor cells in the index case was probably a Schwann cell, that then progressively became cancerous and somehow developed the ability to transmit between individuals. I don't think there's anything particularly special about Schwann cells in terms of their ability to escape the immune system. The devil facial tumour disease article says that "the infectious facial cancer may be able to spread because of increasingly low genetic diversity in devil immune genes (MHC class I and II).[13] The same genes are also found in the tumours, so the devil's immune system does not recognise the tumour cells as foreign.[14][15]". The larger significance of the new research is that there may be a way to target treatments to the cell of origin, but this is speculative. --- Medical geneticist (talk) 14:11, 2 January 2010 (UTC)

Aurora/solar wind as an Earth power source?

Is there any way the interaction between the Earths magnetic field and charged solar particles at the poles could be exploited and turned into free electrical power? Trevor Loughlin80.0.106.142 (talk) 13:54, 2 January 2010 (UTC)

I'm not quite sure if this Geomagnetic storm is what you are asking. I seem to remember some time ago I read an article about why this can not be used as energy source but, I can't find the article now and I didn't understand the reasoning anyway. 93.132.179.189 (talk) 14:31, 2 January 2010 (UTC)

If you have a wire in a place with a changing magnetic field (and the Earth's magnetic field will change when it is interacting with solar wind) then a current will be induced in that wire. That is generating electricity from the interaction, however I doubt it would generate enough to be worthwhile. A solar panel would probably be a more efficient (in terms of cost) way of getting electricity from the Sun. --Tango (talk) 14:34, 2 January 2010 (UTC)

I remember asking a question on the Reference Desk proposing a multitude of ideas for electricity generation, including lightning, aurorae, animals, etc. and the answer was no. There was a NASA article on it. However, I cannot find the question in the archives, but in the case of lightning I remember something about it being difficult to convert from direct current to alternating current. ~AH1^(TCU) 18:14, 2 January 2010 (UTC)

Indeed - there is a big difference between something being possible and it being practical. I'm sure you could get electricity from lightning if you wanted to, but it would be far more work than it is worth. --Tango (talk) 19:08, 2 January 2010 (UTC)

What the OP talks about is possible except for the word 'free'. It wouldn't be free. In fact it would be quite expensive.Dauto (talk) 19:59, 2 January 2010 (UTC)

Yes, but solar energy and wind energy also cost money to build infrastructure, but aquiring the energy is a free process. ~AH1^(TCU) 20:15, 2 January 2010 (UTC)

No, wind power and solar power are not free either. Solar power is still more expensive then fossil fuels and wind power has only become price competitive in the last couple of decades. Dauto (talk) 01:42, 3 January 2010 (UTC)

If the only cost you consider is the immediate monetary cost, then yes, that is correct. If you consider a broader meaning of cost then you get a vastly different result. --Tango (talk) 01:45, 3 January 2010 (UTC)

Meaning please. Dauto (talk) 02:28, 3 January 2010 (UTC)

In the grand sense, human economics cease to matter, and only geophysical and astrophysical costs are relevant. Therefore, to extract the maximum possible usable energy from our environs, we need to run right up to the edge of the Second Law of Thermodynamics, by tapping off energy from the hottest possible source and dumping it into the coldest possible source, with as close to zero frictional loss as possible, taking into account the engineering details. It seems that the hottest energy reservoir we know of is the enormous quantity of binding energy stored in subatomic particles - we presently harness that with nuclear fission. The "costs" incurred, if we are going to walk down the lane of ignoring 2010-economic and into the realm of "speculative future costs", become impossible to define - so I posit that we just want to maximize the total time integral of the temperature differential of our energy source over geologic timescales, so that we can eject the maximum quantity of momentum out of our solar system; after the sun collapses, nothing else will matter. At present, it seems that we do this best with fossil fuel (and thus-derived chemical products); I have great hopes for nuclear energy in the future. Solar energy is great, but we can't really extract a lot of energy from it with current technology, in the form of photoelectric or "weird" electromagnetic energy such as those trapped in the aurora-related electromagnetic processes. I know some guys who claim to have used Earth's ionosphere and magnetosphere to extract energy, but it takes literally tons of fossil fuel (to power the radio transmitters) to get even a couple of watts of amplified energy extracted from the Earth's magnetic field. Nimur (talk) 15:27, 3 January 2010 (UTC)

I didn't really mean the entropy cost - that's far too long term to be significant in current decision making. I meant things like the limited availability of fossil fuels, the costs associated with global warming, etc.. --Tango (talk) 16:11, 3 January 2010 (UTC)

Replacing a diode

Hello, I need some help identifying an electronic component so that I can replace it. I am pretty sure it is a diode as the PCB it is from has a diode symbol >| on and there is a D for the component number. It needs replacing as one of the 'legs' has broken off. I have taken a photo but sorry it's not better quality, it's so small that I can't get a good focus on it.

Image: http://img509.imageshack.us/img509/1923/imgp1436o.jpg

The component is 2 or 3 mm long (excluding the legs)and is in a clear casing with a smaller red casing inside that. There is a yellow ring on the outer case and a silver ring on the inner case. I don't know anything about diodes, apart from that they ensure current can only flow in one direction. Is the component at the following link suitable? It looks very similar but I'm not sure the size is the same. http://www.maplin.co.uk/Module.aspx?ModuleNo=46386

Thanks,

Gary —Preceding unsigned comment added by 78.33.180.73 (talk) 13:56, 2 January 2010 (UTC)

click to enlarge

Well, to definitely identify the diode, we'll need more information. Do you have any idea what the circuit does? What sort of device (radio, washing machine, car electronics?) did it come out of? Do you have a photo of the whole board, and/or the area the diode came from? On the other hand, it does look very much like a 1N4148 (which is the Maplin component you identified), and that's far and away the most common type of signal diode. The 1N4148 will probably work, but a more accurate identification will help. Tevildo (talk) 14:13, 2 January 2010 (UTC)

I agrees with Tevildo. Doesn't look like a power diode at all does it? Do they still make 1N914 signal diodes? equiv. to 1N4148 anyway I recall. This picture from Diode may help but is unfortunately not labelled with the diode types. Fourth from the bottom looks the closest. --220.101.28.25 (talk) 15:16, 2 January 2010 (UTC)

It is definitely a 1N4148. These components were often marked with their part number in colour code. The bands in the picture are yellow and grey, coding for 48. I bet my Christmas dinner that the colours on the piece we can't see are yellow and brown, coding for 41. The part is still obtainable but if you are having trouble I have used BAT49 small-signal Schottky diode in a similar role as a fast switching diode in recent designs and I am sure it will be just fine here. (TERMINOLOGY WARNING - any "recent design" that I had a hand in is going to be at least twenty five years old). PS, the page you linked to at Maplin is a 1N4148 as shown by the part number in the search bax at the bottom. SpinningSpark 16:09, 2 January 2010 (UTC)

I agree it looks like half a 4148 but replacement depends on what its doing in the circuit: If it is biasing (or compensating) a silicon BE junct, then it better be a silicon diode. Or if in any way the circuit depends upon the ~0.6v forward drop, it better be silicon. These diodes (1N914/1N4148) are still available/current.--79.67.75.108 (talk) 03:39, 3 January 2010 (UTC)

On a side topic, for taking close-up images, many digital cameras have a "macro mode" that extends the focusing range (see this random article). On my camera, the button and display indicator uses a flower icon. -- Tom N (tcncv) talk/contrib 17:46, 2 January 2010 (UTC)

Thanks for all your replies, I suspect the diode is a 1N4148 so I will order a few from Maplins unless anyone has any further advice. To answer your questions, it came off a control panel PCB from an electronic organ, I have a photo of the area of the board here: http://img64.imageshack.us/img64/6563/imgp1439.jpg - the buttons adjacent to the diode have stopped working and when I inspected it, I realised that one of the leads had broken off the diode (D303). There are several identical diodes on this board near to the broken one but they appear to be OK. It is almost certainly not a power diode as there is a transformer inside the organ that steps down the voltage, all the boards are the LV side of the transformer, although for some reason, they have wires earthing them to the metal chassis. Thanks again for any further advice! —Preceding unsigned comment added by 78.33.180.73 (talk) 10:33, 3 January 2010 (UTC)

Looking at your picture, that's a very common piece of design, the diodes are part of the keyboard scan decoding and almost any signal diode is going to work as a replacement, but as I said above, use a fast one to be on the safe side. The stuff about the forward volt drop above is a red herring. First of all you are not easily going to find anything other than silicon nowadays, and secondly the forward volt drop of germanium diodes, even if you can still find one, is 0.2-0.3 volts, ie lower than silicon, so will still be read as a logic 0. Anything else, like selenium rectifier, for instance, does not come in small signal packages. SpinningSpark 12:57, 3 January 2010 (UTC)

Music/sound

If you blow into a short tube, it makes a high-pitched sound, but if you blow into a longer tube, it makes a low-pitched sound. What physical property causes this? --75.39.194.94 (talk) 14:26, 2 January 2010 (UTC)

This sounds like it might be a homework question, so I was going to give you a link to an article that contains the answer rather than just give you the answer, but I can't find such an article... Therefore, I will give you the answer: Resonance. If this is homework, please do go and read that article before writing down the answer - I don't want to get in trouble with your teacher! --Tango (talk) 14:41, 2 January 2010 (UTC)

Also see harmonic. Dauto (talk) 15:42, 2 January 2010 (UTC)

While harmonics are interesting further reading on the topic, they don't affect this question. The pitch of the note is determined by the fundamental frequency, the harmonics affect the timbre. --Tango (talk) 16:01, 2 January 2010 (UTC)

A cavity can be made to vibrate in higher modes, as any woodwind musician will tell you, simply by blowing harder. This is shown quite clearly in the article Dauto linked with the string example. This is not just harmonics of a fundamental, it is a change of mode resulting in a different pitch (at a harmonic of the first mode). SpinningSpark 16:18, 2 January 2010 (UTC)

True, but I don't think varying the embouchure is really within the scope of the OP's question. I used to play the trumpet (albeit not for long) so I am familiar with the idea, but I think it best not to confuse people with far more information than they ask for. --Tango (talk) 16:31, 2 January 2010 (UTC)

I was not really talking about embouchure, I was referring, and I suspect Dauto was also, to the normal modes of vibration of a system. SpinningSpark 17:17, 2 January 2010 (UTC)

They are the same thing, are they not? You select different modes by varying the embouchure. --Tango (talk) 17:48, 2 January 2010 (UTC)

Schizophrenia and the human ear

There seem to be many hypotheses for what causes schizophrenia. Could it be caused by some type of small critter burrowing in through an ear into the brain? I ask because 1) It would make auditory hallucinations a plausible symptom. 2) The only way most of us can get detritus out of our ears is with our fingers, but for our nose and mouth we have sneezing, spitting, or swallowing and digesting--yet we get plenty of illnesses through those channels. It seems there should be "more" than just "ear infections" to make us sick by way of the ear than we are aware of. Thanks, Richard L. Peterson,just realized I'm not logged in. 69.181.160.248 (talk) 15:55, 2 January 2010 (UTC)Rich (talk) 16:01, 2 January 2010 (UTC)

The auditory hallucinations associated with Schizophrenia are often described as "hearing voices". Something burrowing in your ear may make you hear things, but I can't see how it would make you hear voices - it would most likely just be noise. --Tango (talk) 16:07, 2 January 2010 (UTC)

If a "critter" burrowed into the brain, it would cause a massive brain infection that could easily kill the victim, but it wouldn't cause hearing voices. Looie496 (talk) 16:44, 2 January 2010 (UTC)

• I don't think there is good reason to be sure of your statement.-Richard Peterson69.181.160.248 (talk) 17:13, 2 January 2010 (UTC)

There may be a link to middle-ear infections, see Peter Mason et al. 2008: Middle-ear disease and schizophrenia: case–control study. British Journal of Psychiatry, 193: 192-196 (though note a reply to this study) and Mason and Winton, 1995: Ear disease and schizophrenia: a case-control study. Acta Psychiatrica Scandinavica, 91(4):217-221.

A review of the association of physical illnesses and schizophrenia has this to say: "Mason and Winton (103) found that the middle ear disease was significantly more common in people with schizophrenia than in other people with psychiatric illness. There is also a large body of early literature on vestibular response abnormalities as an explanation for schizophrenia [for review see Levy et al. (104)] and on the association between deafness and schizophrenia [for review see Cooper (105)]. The hypothesis was that predisposed individuals with hearing impairment may misperceive auditory stimuli and may therefore develop inappropriate associations. This assumption found support in a study of a large cohort of 50 000 male Swedish conscripts. In a link of medical examinations of these conscripts with a Swedish National Register of psychosis care, the proportion of schizophrenia among those with severe hearing loss was significantly higher by a factor of 1.8."[19] More detail in this book by the authors of the review.

In contrast, a recent overview of auditory hallucinations and schizophrenia concluded that "auditory hallucinations are internally generated speech perceptions that are localized in the left temporal lobe".[20] Fences&Windows 16:50, 2 January 2010 (UTC)

I'm not entirely sure why you think the ear would be a more common means of transmission of diseases. The ear canal is much more of a closed system than the mouth or nose—it doesn't feed into the blood stream or the lungs or any of the other major organs in a straightforward way. It also doesn't get involved in food, mouth-to-mouth communication, sex, etc. It is also not the most straightforward path inside, protected both by hairs, a tight passage, and the fact that humans find things in their ears rather intolerable. There is also ear wax as a means of trapping and secreting things.

Re: the schizophrenia studies... there are a LOT of studies that show schizophrenia correlates with a LOT of things. I'm not an expert but I've seen enough of these things to think that either "schizophrenia" is such a large umbrella that it is looking at a lot of different things, OR that it is a general condition of the brain that is brought by all manner of things. On the general question of, "could it be caused by critters," it has also been shown to correlate strongly with Toxoplasmosis. --Mr.98 (talk) 20:05, 2 January 2010 (UTC)

I didn't say that I think more infections come by way of the ear than the mouth, just that there might be some "critters" that go in that we we don't know about. If humans find things in their ears intolerable, we probably have that response for a good reason. Also, trying to get a thing out of our ears with our fingers may push it further inside. Also, why wouldn't a licelike "critter" enjoy the hairs in our ear passages? But thanks for your and everyone's helpful and thoughtful replies. Best wishes, Rich (talk) 22:46, 2 January 2010 (UTC)

The reason we don't like things in our ears is because our ears are important and the insides are breakable. I don't think it's about avoiding disease. I think we'd be pretty aware if lice tried to get into our ears. Keep in mind that getting into your brain through your ear is a non-trivial matter... you'd know if something was boring its way through! --Mr.98 (talk) 23:12, 2 January 2010 (UTC)

Follow up wildebeest question

I recall seeing on a wildlife programme wildebeest that had become infected with a parasite that that did just what the OP described, burrowed through the ear (and I think eventually into the brain). This caused the poor wildebeest that had been afflicted to insanely rotate like a dog's "tail-chasing" game. The direction of rotation, apparently, being determined by which ear is affected. Does anyone know the name of the species causing this? SpinningSpark 17:57, 2 January 2010 (UTC)

According to this site, it's caused by a botfly. Matt Deres (talk) 19:10, 2 January 2010 (UTC)

Shampoo "build up"

For many years, I've heard an advice that you should switch your shampoo regularly, because sticking with one supposedly will cause the ingredients of that particular shampoo to build up in your hair. I'm somewhat skeptical as switching shampoo will work only if different shampoos have no common ingredients. Is there any truth to the supposed shampoo build-up problem? --173.49.16.188 (talk) 17:41, 2 January 2010 (UTC)

Well I don't know having 2 equivalents of ingredient A is any worse than 1 equivalent of ingredient A and 1 equivalent of ingredient B. If you're truly worried about ingredients remaining from your shampoo (which except for moisturisers, is a weird thing to be worried about since shampoos are designed to be water-soluble) it's better to find a shampoo with the least harmful ingredients and stick with it. John Riemann Soong (talk) 18:18, 2 January 2010 (UTC)

Snopes says no—look down on the page a bit to the parts about vinegar. Old shampoos, a long time ago, maybe. But modern shampoos, no. I suspect it is psychological. You use the same shampoo for years—you get used to how it deals with your hair. Maybe you get bored with your hair. You switch—and wow, there is something different with your hair! It feels a little different, smells different, etc. But this isn't because the old shampoo "stopped working" or "built up"... it's because you just got used to it. Switch if you want to, but don't think that there's some necessary reason to do it. This kind of vague old-wives-tale chemistry is, in my experience, usually a sign of the rumor being total B.S. (like the pads that supposed remove "toxins" from your feet, without specifying what "toxins" are being removed—as if there was just a chemical called "toxins" in the world for you to avoid). --Mr.98 (talk) 20:13, 2 January 2010 (UTC)

This may have originated during the 1980s, when 2-in-1 shampoos were developed and spiral perms were the fashion. These shampoos were supposed to coat the hair with something which rendered the perming chemicals relatively ineffective, and so other shampoos were developed to remove this build-up from the hair before perming took place. This page gives some ideas of what happens: [21] There's also this Wikianswers page which confirms my point about perms: [22] --TammyMoet (talk) 12:50, 3 January 2010 (UTC)

I don't buy the old wives' tales. You can find a million people helpfully saying "put vinegar in your hair" on the internet, but nobody can cite a reliable source or study saying it actually works. It sets off my B.S. meter in a major way. --Mr.98 (talk) 17:30, 3 January 2010 (UTC)

OK, but that's why I quoted a "professional" virtual haircare site. It's quite possible that companies who make the shampoos that remove the built-up product fromhair have done research on it, but won't publish it because it's commercially sensitive. Does the lack of published research evidence mean the experience of consumers is all BS? And also research in such fields tends to be medical because that's where the funding is (such as preventing or curing hair loss). Because I was a consumer who experienced the problem with perms, I am aware of the situation the OP refers to and I am aware of the products developed to remove build-up. It's taught on hairdressing courses too. Accredited courses in the UK generally don't go in for teaching "old wives tales". I suppose I could be wrong there though! --TammyMoet (talk) 19:41, 3 January 2010 (UTC)

Non-Ejaculatory Semen Removal from Testicles

Since the semeniferous tubules are constantly producing sperm, how is excess semen removed from the testicle if a male does not ejaculate (including nocturnal emission)?

The only statements that I've been able to find say that it is "re-absorbed" by the body. But by what process; are there specialized cells that facilitate this? --※Cōdell 18:16, 2 January 2010 (UTC)

I don't know about sperm in particular, but in general dead cells are absorbed by phagocytes (from Greek for, roughly, "cell that eats"), a type of white blood cell. It is likely that old sperm apoptose (kill themselves in a controlled fashion) and are then absorbed by phagocytes. --Tango (talk) 18:59, 2 January 2010 (UTC)

I can't remember which source I saw this in, but I believe Tango is pretty much in the right ballpark. Sperm apoptose after a given period of time and are removed by phagocytosis; or if not reabsorbed, the remainder are excreted through urination. In short, they don't build up in volume beyond a certain point, and excess sperm are removed by the aforementioned process. As far as I know, this doesn't involve any particularly specialised cell other than the sperm itself and phagocytes. Regards, --—Cyclonenim | Chat  19:49, 2 January 2010 (UTC)

How is dead sperm removed by phagocytosis if semen doesn't contain white blood cells?--※Cōdell 20:14, 2 January 2010 (UTC)

Not sure, but macrophages are found in the semen of some infertile men:[23] Fences&Windows 21:02, 2 January 2010 (UTC)

"Unejaculated sperm are usually phagocytized by macrophages of the reticuloendothelial system or by the cells lining epididymal ducts. In some instances, they may also be passed down the epididymal duct and combined with nitrogenous wastes",[24] i.e. some are passed in urine. Fences&Windows 20:46, 2 January 2010 (UTC)

More on phagocytosis of sperm, its role and mechanism are disputed: [25][26][27] Fences&Windows 21:02, 2 January 2010 (UTC)

Thanks so far. There are indeed opposing viewpoints in Fences&Window's links:

There is no convincing evidence for significant absorption of spermatozoa, defective or otherwise, by spermiophagy or dissolution in the epididymis of normal animals.[28]

Ubiquitin is secreted by the epididymal epithelium and binds to the surface of defective sperm. Most of the ubiquitinated sperm are subsequently phagocytosed by the epididymal epithelial cells.[29]

--※Cōdell 22:42, 2 January 2010 (UTC)

Vasectomy#Side_effects might help. Note that sperm and semen are not the same thing. Mitch Ames (talk) 07:41, 3 January 2010 (UTC)

Tortoise species

What is the species of tortoise mentioned in this article? Is it Desert Tortoise or something else? The Hero of This Nation (talk) 20:12, 2 January 2010 (UTC)

The article refers to them as such, so I suppose so (though they do mention it in a very generic sounding way, so I agree it's unclear). It would seem to be the Mojave subspecies, which our article mentions as being threatened. Matt Deres (talk) 21:15, 2 January 2010 (UTC)

January 3

Cirrus clouds and snow

How can a really thin ciruus cloud produce so much snow?Accdude92 (talk to me!) (sign) 00:45, 3 January 2010 (UTC)

You might get more responses if you let people know what you are talking about. Dauto (talk) 02:21, 3 January 2010 (UTC)

The question seems simple enough and clear enough. If you cannot respond to it, no posting is necessary or desirable. How does a large amount of precipitation fall when no large and dense cloud cover is visible? Edison (talk) 02:33, 3 January 2010 (UTC)

I beg your pardon but I don't think it was clear at all. He seemed to be talking about an specific event without telling us what the event was or giving us some description of what happened. Dauto (talk) 18:15, 3 January 2010 (UTC)

Our article, and numerous other sources on the internet, agree that cirrus clouds do not produce significant precipitation. However, they can be a precursor of other weather patterns. — Lomn 02:55, 3 January 2010 (UTC)

Well, I could easily see through the cloud to the blue sky, yet is was snowing lightly.Accdude92 (talk to me!) (sign) 03:05, 3 January 2010 (UTC)

Your first post said "so much snow" which, to me, would suggest a large amount. Now you're saying it was "snowing lightly". So, which is it? Dismas|^(talk) 03:09, 3 January 2010 (UTC)

Maybe the OP means a lot of snow considering it was a clear sky. It may have been snow blown in from a nearby cloud of a snowsquall, or perhaps even diamond dust if the humidity was high. Probably wasn't the thin cirrus clouds, even as there were sun pillars at my location (S. Ontario) today. ~AH1^(TCU) 03:49, 3 January 2010 (UTC)

Exactly.Accdude92 (talk to me!) (sign) 04:19, 3 January 2010 (UTC)

Common cold in animals

Other than humans, can other animals (like domestic cats) get the common cold--from the rhinovirus? rʨanaɢ ^talk/_contribs 01:53, 3 January 2010 (UTC)

Chimpanzees, apparently. Scientists have been able to infect mice with it as well, but it takes some work, it won't happen automatically. The linked-to article discusses some of the reasons why other species can't be infected by it—they lack certain receptors for it. I suppose chimps are close enough to humans for it to work. --Mr.98 (talk) 02:21, 3 January 2010 (UTC)

Thanks! rʨanaɢ ^talk/_contribs 02:35, 3 January 2010 (UTC)

The rhinoviruses are normally species-specific, and some animals, especially cats, have their own versions of the common cold. Dbfirs 08:08, 3 January 2010 (UTC)

Thrust Curve

What is a thrust curve and how can I get one for my motorbike? 86.26.12.165 (talk) 11:41, 3 January 2010 (UTC)

I've never heard of a "thurst curve" applied to a ground vehicle. Usually, there are power and torque curves, which are plots that show the engine's power and torque output vs. RPM. Presumably, these can be converted in to an effective thrust, but that terminology is more usually used for aircraft. These curves give you an intuitive feeling for the efficiency and acceleration capacity of your engine, and give you an idea of the optimal speed and RPM you should aim for when driving your bike. You can get such curves from enthusiast websites or from the dealer. Here is an introductory article from Total Motorcycle, including charts for Honda Nighthawk bikes and comparable engines, HP and Torque vs. RPM. Nimur (talk) 16:20, 3 January 2010 (UTC)

(a) it is the thrust v. time graph of a solid-fuel rocket engine, see Solid-fuel rocket#Grain geometry. (b) don't do it unless you are looking to get a Darwin Award for stupidity. SpinningSpark 16:20, 3 January 2010 (UTC)

I'm surprised Wikipedia has no article on torque curve, power curve, or dyno chart. Power curve directs to power band, but I've never heard that terminology applied to anything (except maybe power chords). We also have engine tuning. Nimur (talk) 16:51, 3 January 2010 (UTC)

A thrust curve, also known as a tractive force graph, is the linear force at the tyre/road interface and is the force you feel when you are actually riding your bike. Due to most bike's gearing, this tractive force is highest in 1st and decreases with each higher gear, hence you get faster acceleration in lower gears. Some dynos can display this directly on a grpah, or it can be calculated by knowing engine torque and the bike's gear ratios. The maths is a little long to go into here (and i can't write it very well on here), but its fascinating. Alaphent (talk) 16:52, 3 January 2010 (UTC)

Distance time graph

As the article on distance points out, distance cannot be negative and is not characterized by direction. However, there are several distance time graphs "out there" that do include a sense of direction. For instance, on this site a graph is shown in which the red downward sloping line represents the return journey. But isn't this incorrect? Distance is ignorant of direction, and thus, the return journey should increase the "distance in m" instead of decrease it. In my opinion, this should be called a "displacement time graph". Am I wrong? Lova Falk (talk) 12:12, 3 January 2010 (UTC)

I would imagine that 'distance' in this case means 'distance from origin' even if that's not explicitly stated, which would decrease on the return journey, rather than 'total distance covered'. Distance cannot be negative but a change in distance can be. Mikenorton (talk) 12:33, 3 January 2010 (UTC)

That is just my point! "Distance from origin" is displacement. Lova Falk (talk) 12:37, 3 January 2010 (UTC)

Well, not exactly, as we're only talking about the scalar part of the displacement vector. You could be walking in a circle centred on the origin, your displacement would be constantly changing while your distance remained the same. Mikenorton (talk) 14:54, 3 January 2010 (UTC)

Clearly, the terminology is used loosely in practice. Abuse of notation is always a problem in scientific/technical presentations - unfortunately, even the best scientists occasionally use the wrong word. Lova Falk seems to understand the intended meaning of the graph, so the actual text-label is irrelevant. Nimur (talk) 16:57, 3 January 2010 (UTC)

I think 'didtance IS the correct term for that specific graph linked by the OP. That's the term I would use. Dauto (talk) 18:12, 3 January 2010 (UTC)

Plant species mentioned in "Guns, Germs and Steel"

I'm just reading "Guns, Germs and Steel" and cannot correlate some trivial names of plants to species:

• Which species of Chenopodium is meant by "Goosefoot"?
• Which species of Dioscorea is meant by "African Yams"?
• Which plant does the author has in mind when referring to it only as Groundnut?

--Pjacobi (talk) 13:26, 3 January 2010 (UTC)

There are a number of possibilites for the species of Chenopodium and Dioscorea, and I don't know which ones Diamond is referring to (quite possibly to more than one species, or possibly not to specific species at all). However, the "groundnut" is the peanut Arachis hypogaea.--Eriastrum (talk) 17:06, 3 January 2010 (UTC)

The goosefoot cultivated in what is now the eastern U.S. was Chenopodium berlandieri.--Cam (talk) 05:16, 4 January 2010 (UTC)

Diamond is referring to ancient African cultivation of groundnuts, but peanuts are of American origin. He may mean Bambara groundnuts (Voandzeia subterranea).--Cam (talk) 05:33, 4 January 2010 (UTC)

Many thanks for your answers. Also I now have seen Eastern Agricultural Complex, an article which I should have found earlier by more careful reading. Some quick Google Scholar seem to support the first impression, that the EAC article and the articles about the related plant species, need improvement and update from somebody with access to relevant scientific journals. --Pjacobi (talk) 06:51, 4 January 2010 (UTC)

percentage illumination of moon's surface by sun light

Could you please indicate what percentage of the total moon's surface is illuminated by the sun at a given time196.209.216.206 (talk) 13:39, 3 January 2010 (UTC)

Why should it not be 50% if the Moon is a sphere ? Even correcting for a non-spherical Moon, it must be very close to 50%. Gandalf61 (talk) 13:51, 3 January 2010 (UTC)

A lunar eclipse would change that, albeit briefly. Vimescarrot (talk) 14:20, 3 January 2010 (UTC)

percentage illumination of moon's surface by sun light

The distance between sun and moon is very large and the rays would probably be virtually parallel when arriving at the moon. Given the fact that the sun is much larger, is it possible that this percentage of illumination might be slightly larger than 50%? —Preceding unsigned comment added by 196.209.216.206 (talk) 14:20, 3 January 2010 (UTC)

If the moon were a perfect sphere, then yes, slightly more that 50% would be illuminated. I think 50% of the ground would be able to see at least half the disc of the sun, but there would be more that can see just a little bit sun sticking up above the horizon. However, the moon isn't a perfect sphere - there are lots of mountains and craters. Mountains near the terminator (the boundary between light and dark) can be illuminated when flat ground wouldn't be and the insides of craters can be dark when flat ground would be illuminated. I don't know which of those factors is bigger or by how much, so I don't know if that would reduce it by enough to take the total illuminated area to less than 50%. --Tango (talk) 15:56, 3 January 2010 (UTC)

Maybe also some refraction through the moon's (albeit thin) atmosphere to push it up a couple of percent as on Earth? - Jarry1250 ^{[Humorous? Discuss.]} 18:44, 3 January 2010 (UTC)

Tango I think you are forgetting that the light is not collimated, and that the size of the sun is significant. —Preceding unsigned comment added by 92.22.51.77 (talk) 19:33, 3 January 2010 (UTC)

Does Earthshine when the moon is more than half full (from Earth) and light filtering through the Earth's atmosphere during a lunar eclipse increase this figure to more than 50%? ~AH1^(TCU) 20:24, 3 January 2010 (UTC)

Earthshine will illuminate the dark side of the moon, but not very much - the Earth is far far dimmer than the Sun. Lunar eclipses will reduce the amount of illumination, although light refracting round the Earth will reduce the extent of that - they are rare enough that they won't have a large impact on the average illumination. --Tango (talk) 20:34, 3 January 2010 (UTC)

I don't think I'm forgetting either of those things. What makes you think so? --Tango (talk) 20:34, 3 January 2010 (UTC)

The OP is asking a simple question in geometry, don't they teach this stuff any more? The increase in area illuminated for a perfect sphere for small subtended angles is the ratio of the moon-sun distance to the diameter of the sun. This is approximately 1.4x10⁶/1.5x10⁸, or just under 1%. SpinningSpark 21:51, 3 January 2010 (UTC)

Consider a spherical cow in vacuum. . . Cuddlyable3 (talk) 22:34, 3 January 2010 (UTC)

That is a bullshit response to a reasonable answer to the OPs question. Of couse it is an approximation, but a valid one. I knew it was an approximation, the OP knows it is an approximation, and there was no need for you to tell us you know it is an approximation as well with a sarcastic response. If you have a more accurate model, I'm sure we would all be delighted to hear about it. SpinningSpark 23:22, 3 January 2010 (UTC)

Why is the Large Hadron Collider underground?

The Large Hadron Collider was built in the tunnel formerly occupied by the Large Electron–Positron Collider. Is there any particular reason why either of them had to be built underground? I imagine it must be much more expensive than building it above ground, even allowing for the cost of short bridges to carry roads over it. Or railway-like cuttings to keep it level. 78.146.54.230 (talk) 15:10, 3 January 2010 (UTC)

Particle accelerator says "Very large circular accelerators are invariably built in underground tunnels a few metres wide to minimize the disruption and cost of building such a structure on the surface, and to provide shielding against intense secondary radiations that may occur. These are extremely penetrating at high energies", but does not provide a reference for either claimed reason. Finlay McWalter • Talk 15:15, 3 January 2010 (UTC)

According to Lyn Evans, the project manager of the Collider: "Cheaper... It would cost a fortune to acquire the land in France and Switzerland to build the racetrack on the surface." See [30].--Fuhghettaboutit (talk) 15:19, 3 January 2010 (UTC)

Building it underground helps block some of the background radiation from cosmic rays and that way improve the signal to noise ratio. Dauto (talk) 16:09, 3 January 2010 (UTC)

Is there a reliable source that supports this claim? Super-Kamiokande is 1000 meters down, Sudbury Neutrino Observatory is 2000 meters down. But LHC is only 50m down. -- Finlay McWalter • Talk 17:14, 3 January 2010 (UTC)

Safety reasons come to mind. The total kinetic energy of the two proton beams is 362 megajoules. That's enough energy to accelerate a Nimitz-class aircraft carrier from rest to more than five knots — or to push a three-ton SUV to nearly twice the speed of sound: [31]. A full-power beam can bore a hole forty meters into a block of solid copper. Safely dumping those beams at the end of experimental run requires controlled beam defocusing and scanning across a custom-designed ten-ton cylinder of graphite, embedded within a thousand tons of concrete and steel shielding. The beam dump hits a peak temperature of 750°C (about 1400°F) and takes a few hours to cool down. [32] If a group of bending magnets fail simultaneously, I'd rather have that uncontrolled beam go through the wall of the facility into nice, solid, Swiss (or French) rock. TenOfAllTrades(talk) 17:03, 3 January 2010 (UTC)

I guess that's what the article means when it says "to provide shielding against intense secondary radiations that may occur. These are extremely penetrating at high energies" - that the surrounding rock acts as a beam quench in such emergencies. That would explain why linear accelerators, whose failure modes can't send the beam of in any direction, aren't underground. We need to get a clear ref for this for the particle accelerator article. -- Finlay McWalter • Talk 17:19, 3 January 2010 (UTC)

Does that "secondary radiations" include Synchrotron radiation as the beam is bent? That's another serious concern around the periphery of the ring that is a non-issue in linear configurations. DMacks (talk) 19:19, 3 January 2010 (UTC)

But if the beam is somehow deflected upward and it can penetrate 40 metres of copper while the tunnel is 50 metres underground, wouldn't there be a slight risk of the beam going above ground? ~AH1^(TCU) 20:19, 3 January 2010 (UTC)

Do you have a mechanism in mind that might unintentionally deflect the beam upward? It seems to me that anything that accidentally got in the way of the particle beams would just have holes cut through it. --173.49.16.188 (talk) 22:36, 3 January 2010 (UTC)

The holes would be microscopic - the beam is very narrow. What if I walked above the beam with a really big magnet? I wonder how big of a magnet I'd need to really mess up the beam. The idea is that left/right the beam is controlled by magnets that might fail. But up/down it needs no control, since it just travels in a straight line. So all it needs is focusing magnets, but not steering magnets. Ariel. (talk) 23:02, 3 January 2010 (UTC)

The LHC got shut down when a bird dropped a baguette into a cooling unit. Imagine the trouble a bird could cause if the whole machine was on the surface; never mind the havoc a squirrel could create! 75.41.110.200 (talk) 23:51, 3 January 2010 (UTC)

Here's a link for the bird-baguette story for the curious. -- Scray (talk) 01:08, 4 January 2010 (UTC)

Amateur 3D video, also sound editing question.

I have a mid to high-end HD video camera with a hard drive and AVCHD recording format http://www.sony.co.uk/product/hdd-avchd-hard-disk-drive/hdr-xr520ve and wonder if I got a second HD camera (perhaps a cheaper one) or an identical model, would this would be cheaper to film in 3D and somehow use software (assuming there is any) to convert it to an "official" 3D movie format later (assuming there is an "official" 3D video standard yet) or would a dedicated 3D HD camera ever come down in price enough for ordinary consumers? Which option would be the cheapest? Also, when filming Rozi Plain's new song "Wiggling",I spontaneously said "Oh Yeeeaah" in an adenoidal and pervy way. This ruined my recording at the start of the song. If I said the same thing and recorded it repeatedly to create an average signal, is their any software I could buy that could subtract my awful voice and restore the original notes at the beginning? —Preceding unsigned comment added by 80.2.199.128 (talk) 15:33, 3 January 2010 (UTC)

Per your first question, you can create a 3D movie in that way; the hardest part is the projection technology. If you're willing to force viewers to wear 3d goggles, you just need two video channels to make this happen; a lot of high-end graphics cards (such as those designed for dual monitors) now have hardware acceleration for such two-channel video; NVIDIA 3D Vision is one such example. If you want to project with polarization/Real3D glasses, you need "professional" special purpose equipment. As for your audio trouble, your proposed method may work in theory, but in practice you stand a better chance manually editing the audio track, applying a series of filters. Alternatively, consider re-recording the song and overdubbing the first few seconds - this will be much easier than subtractive audio processing (which is more art than science). Nimur (talk) 15:44, 3 January 2010 (UTC)

So humans have feet, dogs have paws, horses have hooves...

...and what do ducks have? Are they flippers? Are they feet? It sounds like a bit of a silly question, but I haven't been able to find a clear answer. Thanks! --saxsux (talk) 15:37, 3 January 2010 (UTC)

Ducks have webbed feet. Nimur (talk) 15:44, 3 January 2010 (UTC)

Mercury-vapor lamp usage

I understand that streetlights many times use mercury-vapor lamps. What type of areas or towns or cities favor these type of lights, verses say sodium-vapor lamps or other gas-discharge lamps that use an arcing mechanism?--Doug Coldwell ^talk 15:47, 3 January 2010 (UTC)

Just a gues but somewhere I read that mercury vapor lamps produce a very large amunt of ultraviolet and are therefore valuable in making germicide lamps. 71.100.1.76 (talk) 16:28, 3 January 2010 (UTC)

I also posted an answer on the humanities reference desk. For the other question, please read the article on street light interference. ~AH1^(TCU) 19:58, 3 January 2010 (UTC)

I think it's a matter of color versus cost. Sodium lamps produce more orange-colored light - which is not popular in areas where people are working, eating or shopping - but adequate for driving cars. Mercury lamps produce whiter light - but they use more energy and cost more to make - and when they have to be replaced, the mercury they contain is not good for the environment. SteveBaker (talk) 21:00, 3 January 2010 (UTC)

What type would you guess are these in Street light interference?--Doug Coldwell ^talk 00:39, 4 January 2010 (UTC)

I would believe that the whole business of Street light interference is just so much bullshit. Hence it doesn't matter a damn what kinds of light they are. Between people who are so desperate to feel more important than everyone else (who'll make up any story to make that happen) and observer bias (if a street light just happens to turn on or off as you walk past...) it's all just complete nonsense. We don't need to explain anything. I'm sure that if you (or someone you know) can reliably do this then James Randi will give you a million dollars when you demonstrate it under reliable scientific conditions. SteveBaker (talk) 01:32, 4 January 2010 (UTC)

Results of oppositely charged or poled bodies in outer space

Normally when considering the dynamics of force in outer space one thinks of gravity only. But what about the magnetic/electric force which is likewise limited in intensity by distance like the force of gravity but which intensity can be increased or decreased irrespective of distance. My question is what if the force responsible for propelling the universe to expand is opposite electric charges and/or opposite poles? Has an experiment ever been done using either or both electric charge or magnetism to see what would happen to identical objects with opposite charges or poles over a long period of time while orbiting some body in space... and to see if their distance apart can be controlled by varying the intensity of the field? 71.100.1.76 (talk) 16:25, 3 January 2010 (UTC)

Metric expansion of space is not due to electromagnetic interaction. However, electromagnetic effects are non-negligible in certain situations of orbital mechanics. Dynamics of Dust near the Sun describes electromagnetic interaction and radiative forcing for very tiny grains of dust. The consequence of this is an effectively "reduced gravitational force" - there's a name for this type of electrostatic drag (which eludes me now, I will look it up later). There is also Poynting–Robertson effect drag, due to electromagnetic radiation pressure, not net electric charge. Around planets such as Earth (because we have a geomagnetic field), there are electromagnetically trapped particles (ions and electrons), which we commonly call the van Allen belt. Those magnetic field alignment and field-trapping effects are only relevant for single-atom-sized objects; electrostatic effects can have consequences for objects as large as dust grains. As objects become larger than micrometeorite size, the effect of electromagnetic and radiative forcing becomes more negligible, and purely gravitational effects dominate the orbital mechanics. Experiments to quantify the total effective net charge of astrophysical objects like planets have yielded ambiguous results. We discussed the experimental and theoretical implications of electric charge on Earth, on May 9, 2009, "Net charge of earth". Nimur (talk) 16:31, 3 January 2010 (UTC)

Battery life

I have a bag full of AA batteries and a volt meter. I would like to discard the bad ones. Is there a minimum voltage level below which I should toss out a battery? What about using the low-voltage ones in a device that requires a low current, such as a portable clock? Hemoroid Agastordoff (talk) 17:07, 3 January 2010 (UTC)

The trouble with non-rechargeable batteries is that they retain the same voltage until just before they die. So you can't tell whether they are nearly dead. Worse still, a battery that went 'dead' while you were using it will recover a little after a matter of a minute or two and give a few seconds more life before dying again - so measuring the voltage with a meter might not tell you anything. Once the voltage has dropped significantly - you should toss it out. Using them in low-current devices like clocks might work for a short time - but it's hardly worth the effort. That said, non-rechargeable AA batteries are supposed to produce 1.5 volts - anything much lower than that means that the battery is probably dead. SteveBaker (talk) 19:46, 3 January 2010 (UTC)

I rarely disagree with Steve, but in this case I do. (Most) rechargeable batteries keep their voltage until shortly before they die - hence they are recommended for high-current devices like cameras. Non-rechargeables, on the other hand, do show a slow drop in voltage as they are depleted (as anyone will be able to attest who has ever uses a flashlight that went dimmer and dimmer and dimmer but kept going). --Stephan Schulz (talk) 21:40, 3 January 2010 (UTC)

A high impedance load such as a voltmeter would continue to show about 1.5v even with a somewhat worn out AA cell so, what would be a reasonable load resistor value in parallel with a voltmeter to better access its true condition? hydnjo (talk) 22:26, 3 January 2010 (UTC)

The no-load voltage from a cell (originally the word "battery" was reserved for multiple cells) doesn't show much difference between a new and a 50% depleted cell. I would discard as "bad" any non-rechargeable cell that gives 0.9V or less. Saving such cells, such as keeping them to run an undemanding clock, is risking leakage that can damage internal contacts, especially from cheap carbon/zinc cells. Cuddlyable3 (talk) 22:30, 3 January 2010 (UTC)

My recommended procedure for cheap cells is "remove from package; discard immediately". That way you don't find yourself wondering why the remote control for your new video player that came with no-name batteries is sitting in a lake of white goo on the coffee table. </off-topic rant> Franamax (talk) 23:36, 3 January 2010 (UTC)

Whilst I agree to some extent with Franamax above, I don't follow this advice. I hate to throw out cells that might have some remaining charge, so I waste time comparing voltages under both no-load and a heavy load (just an ohm or two) to see how much use they have left. I even have a multimeter that includes this function. I then throw out only the worst, and keep some "used" cells for non-critical use later (battery clocks are a good example where a significantly-reduced voltage often makes little difference to operation). It is probably not worth the effort, but I can't stop myself from doing this! Rechargeable batteries can also be compared by this method. Dbfirs 23:52, 3 January 2010 (UTC)

I hear ya, I hate throwing stuff away too (especially batteries, which should always be kept out of the waste stream). I just hate throwing away the entire device more than I hate taking a poorly-constructed battery to a hardware store for disposal. And why would you keep battery clocks anyway? I saw a TV show about that, it's so cruel keeping the clocks in a tiny cage. :) Franamax (talk) 00:42, 4 January 2010 (UTC)

They have more time to lay eggs that way. Unfortunately, they don't hatch into either new cells or new clocks, but I suppose one could use them to go back to a fully-charged time?  :) Dbfirs 10:06, 4 January 2010 (UTC)

You might consider capturing the decision parameters of a battery tester (needle in red= bad/needle in green=good). For a 1.5 volt cell, such a tester would load the battery with a resistor which put some well chosen drain on it, and noted whether the voltage dropped below a criterion. The criterion might be 10% below nominal or 1.35 volts, and the load might be 300 ma, implying a load resistance of 5 ohms. If your device will function at a lower voltage, or if it has a different load current, the cutoff voltage and the load resistor might be chosen differently, per Ohm's Law. The "no-load" voltage as measured by a high quality voltmeter, is largely uninformative, except that any cell with a very low no-load voltage is shot. I have little faith in AA batteries with 1.3 volts or less with no load. An appreciable but small load will collapse the voltage of a battery in poor condition, but a good battery will sustain near-no-load voltage. Never test a battery with an ammeter, only with a load resistor and a voltmeter. The actual device to be operated, or its electrical equivalent, can be a good test circuit. Edison (talk) 01:22, 4 January 2010 (UTC)

I agree that the output voltage from a depleted cell at zero current can be surprisingly close to the nominal voltage. Therefore using a voltmeter to measure the voltage at zero current is not a suitable method to determine the state of the cell. The output voltage must be measured while the cell is supplying an output current. If the cell is is a good state the voltage drop will be small, but if the cell has little life left the voltage drop will be substantial. I have an inexpensive instrument called a battery tester that contains a galvanometer and internal loads. If you don't have such an instrument, any resistor of suitable resistance to serve as a load will do the job. As Edison suggested above, the actual device to be operated by the cell will make a good load while you measure the output voltage. Dolphin51 (talk) 02:56, 4 January 2010 (UTC)

A few years ago AA cells had a built-in tester which when activated (pressed) indicated the cells condition (depletion?). This feature has been since eliminated (cost vs benefit?) but at the time it showed some indication of remaining energy. I'm not the OP here but am asking: what would be the appropriate load (ohms) to read a voltage which would give some approximation of the remaining energy of an AA cell. hydnjo (talk) 03:17, 4 January 2010 (UTC)

My reading of the above suggests the answer to your question is: the load for which you propose to use the cell. That test strip was pretty cool, but ultimately just tested the cells ability to operate the test strip. Franamax (talk) 04:45, 4 January 2010 (UTC)

Avoiding the British winter

Where would be the nearest place to go to avoid the British winter and the oppressive long dark winter evenings? Going all the way to Australia or New Zealand would be one solution, but its a long uncomfortable plane trip. Are there any nearer solutions? Thanks 78.147.11.181 (talk) 21:20, 3 January 2010 (UTC)

Spain or the south of France? In Madrid, for example, the shortest day was about 9 hrs 20 mins this Winter (sunrise to sunset - sunset being 1751hrs). That compares with 7hrs 50mins for London (sunset 1553hrs local time). Some of the difference in sunset times is due to timezones - Madrid is pretty much due south of London but is an hour ahead (mainly to be the same same as France, I think). --Tango (talk) 21:33, 3 January 2010 (UTC)

On any particular date during the northern hemisphere winter, the farther south you go, the more daylight you get each day (until you hit 24-hour daylight somewhere in the Antarctic). So this is a matter how much more sunlight you would need to see in order to consider that you have "avoided the long dark evenings". If you go south and slightly west from England until you run out of Europe, you reach the Costa del Sol in Spain. At Malaga for today's date you have about 1 hour 45 minutes more sunlight than in London (even more if you live farther north in England). As Tango says, the time zone in Spain shifts the sunlight to later in the day, so Malaga today had sunrise at 8:30 am and sunset at 6:12 pm. Will that do? If not, you need to go further south. --Anonymous, 21:37 UTC, January 3, 2010.

The Canary Islands are a popular destination. Egypt is traditional. If you really want to hit it, go to Réunion, Mauritius or anywhere in Southern Africa. As opposed to South America or Australia, these are (a bit to much) closer, and they have much less difference in time zone, and hence less jet lag. --Stephan Schulz (talk) 21:59, 3 January 2010 (UTC)

IDoes anyone know if there is an article about the very large piece of rock in the Canary Isles that is prediced to slide into the sea and cause a large tsunami? I cannot find any. 78.147.11.181 (talk) 23:19, 3 January 2010 (UTC)

Mega-tsunami#Canary_Islands Franamax (talk) 23:38, 3 January 2010 (UTC)

La Palma has some on that subject. 75.41.110.200 (talk) 23:45, 3 January 2010 (UTC)

If you want 24 hours of daylight you need to go at least as far south as latitude 66.6° South where the penguins live. Alternatively move to Northern Norway and enjoy Scandinavian instead of British winter. There is less pollution. Cuddlyable3 (talk) 22:10, 3 January 2010 (UTC)

You could go to Chicago and gain more than a hour of daylight over London. Of course, Chicago was expecting -18 Fahrenheit windchill this morning so you have to consider more than simply hours of daylight. 75.41.110.200 (talk) 23:45, 3 January 2010 (UTC)

The nearest place to go to avoid the British winter would be the nearest place that is not Britain. Then you would be dealing with the Irish or French winter or maybe Isle of Man. The nearest place to go to escape oppressive long dark winter evenings is somewhere (a pub on trivia night, your friend's place, a concert, Wikipedia) where you are enjoying yourself and are simply not thinking about whether a long evening is oppressive or not. Changes in day length may (or may not) be associated with serious psychological effects and these can sometimes be countered with light therapy (or not). But many people do get the "winter blues", IMO there's not much point in wishing the Sun would appear more often, 'cause it never listens. Franamax (talk) 00:28, 4 January 2010 (UTC)

Auxetics utilization in model?

Hey, you guys have helped me out a lot, hopefully the smart people at the refdesk can help me out on something else this time... I am making a model of a stretcher, weaving elastic cord in a 12" by 5" grid in squares about 1/4 inches in size. I wanted to incorporate this into it but seeing as my string is too small in diameter for using thread to work I am unable to practically do so. Is there any practical way to apply this to the entire model? Thanks, ♠The Ace of Spades^♣♥_♦ 00:43, 4 January 2010 (UTC)

January 4

jap heating

why dont japs insulate their homes and have central heatring —Preceding unsigned comment added by Thekiller35789 (talk • contribs) 01:04, 4 January 2010 (UTC)

As in Jewish people or Japanese people? And is your don't meant to be distributed, so that japs neither insulate their home nor have central heating, or undistributed, in that japs fail to insulate their homes yet have central heating? DRosenbach ^{(Talk | Contribs)} 02:10, 4 January 2010 (UTC)

i mean japan and both they dont insulate their homes or have central heatring — Preceding unsigned comment added by Thekiller35789 (talk • contribs)

Do you have evidence, like written down somewhere, that says that Japanese people do not heat their homes or insulate them? Where does this information come to you from? --Jayron32 03:33, 4 January 2010 (UTC)

Having visited Dai Nippon during winter I noticed no lack of heating. If there is it may be that the Japanese are a rather stoical race and put up with such things, they are trying to save energy, or it might just be a cultural hold over from days when their 'traditional style' houses were almost entirely wood and rather combustible. Therefore having a large fire was not practical. Fire was taken very seriously (I gather) in old Japan. Not 100% sure but I think arson was a capital offence Also the more common occurence of earthquakes there caused serious problems if a house collapsed on a open fire. --220.101.28.25 (talk) 03:55, 4 January 2010 (UTC)

See here Japanese_houses#Heating for a discussion of heating arrangements --220.101.28.25 (talk) 04:03, 4 January 2010 (UTC)

none of that explains why they dont insulate their homes —Preceding unsigned comment added by Thekiller35789 (talk • contribs) 05:41, 4 January 2010 (UTC)

And you didn't answer Jayron's request for a source that states they don't. Vimescarrot (talk) 09:11, 4 January 2010 (UTC)

I agree some evidence is needed. In any case the lack of central heating and poorly insulated homes is hardly unique to Japan if both really occur there. NZ homes are well accepted to be generally poorly insulated [33] [34] [35] and usually lack central heating. It's sometimes said people from very places with extreme winters have trouble adapting because of how cold our houses are in winter, e.g. [36]. There are some attempts to change both nowadays. [37] A variety of regulatory, traditional and cultural factors contribute and I expect it's difficult to say why except that that's the way things are done. The severity of the winter is likely one. It's clearly going to be far more difficult to have poorly insulated homes in Siberia or perhaps of greater relevance Canada, most of the northern US and most of the UK; then it is in most of NZ. Nil Einne (talk) 10:27, 4 January 2010 (UTC)

Two reasons: 1) Earthquakes. A system of complicated gas pipes in every home and the infrastructure to set one up, apart from the difficulty, would be a massive problem in the event of one of their plethora of quakes. An air con unit on the wall, well screwed-on, is not going to cause explosions or death. Agreed, insulation is non-existant in most places, especially on those single-pane double doors that so many of their apartments have. 2) Energy. Japan imports pretty much all of its energy. Gas would involved some sort of US-Japan pipeline. Oil is more feasible, and electricity to power heating and cooling aircon units is just far more practical. Bear in mind also that Japanese people tend to destroy and re-build houses once every 20-30 years, so the costs of putting all those systems of heating and insulation would also be considerable.

Lucas 83 13:59, 4 January 2010 (UTC) —Preceding unsigned comment added by Lukerees83 (talk • contribs)

Verification Needed - unlikely cite check.

I have doubts that anyone here would be able to verify this source, but I thought that I'd try anyway. If this post is not appropriate for this location, please notify me and I will remove it.

The citation information is:

• Staff (Aug 1, 1990). "FICS Awards Gold Medal To Dr. Press". Dynamic Chiropractic 8 (16): 1.

The relevant information that needs verification is that Dr. Press is the founder and first president of the FICS.

Thanks, DigitalC (talk) 01:07, 4 January 2010 (UTC)

I can't access that document myself but the FICS website states that he was the first president on it's website and past versions of the site state that it was founded at a meeting he convened. A precis of an article in Dynamic Chiropractic (with the full article lurking behind a forever cursed paywall) states he is "founder and past-president of the Federation Internationale de Chiropratique Sportive (FICS)". I don't know if that's what you're looking for? Nanonic (talk) 01:27, 4 January 2010 (UTC)

Hrmm and evermore strange, I've just found that Dynamic Chiropractic have some articles archived on their website and yet neither your article or the one above that is paywalled feature. Nanonic (talk) 01:37, 4 January 2010 (UTC)

Actually, that paywalled one is available here (if you scroll down). Unfortunately, this is not enough for some editors, so having a second source would be beneficial. I think a hard copy would be the only way to verify the info. DigitalC (talk) 02:01, 4 January 2010 (UTC)

Sounds like something that may be difficult to find but you should ask at Wikipedia:WikiProject Resource Exchange/Resource Request first. And perhaps read Wikipedia:WikiProject Resource Exchange too Nil Einne (talk) 10:13, 4 January 2010 (UTC)

cramped legs

Why do my legs get cramped when in a car, but not anytime else, even when im sitting?Accdude92 (talk to me!) (sign) 02:11, 4 January 2010 (UTC)

Perhaps you meant why do my legs get cramps and a possible response would be because they are cramped when you sit in a stuffed car -- when you sit on a couch, though, there is generally a lot of room for your legs to move, and even if they don't move, the mere fact that you have room to move them around may contribute to a lack of the sort of claustrophobic-like feeling that may accompany cramped situations. DRosenbach ^{(Talk | Contribs)} 02:37, 4 January 2010 (UTC)

You also tend to be stuck in one position for a lot longer in a car than when sitting elsewhere, especially if you are the driver - you can't really fidget, and your one leg is nearly constantly flexing to some degree or another. ~ Amory (u • t • c) 04:51, 4 January 2010 (UTC)

Animal intelligence

Could it be that animals know things (and I don't mean in terms of instinct) about the world, such as gravity, peer pressure, earth's orbit, the birth-life-death cycle, etc. but we just don't speak the same language? This is, of course, assuming said organism has a long enough lifespan to appreciate life in a way similar to the way we do, with past experience impressing upon future action. DRosenbach ^{(Talk | Contribs)} 02:35, 4 January 2010 (UTC)

The relevant articles are Animal cognition and Emotion in animals. They are quite detailed. Regarding your specific question about gravity - it is not well posed. A plant seed lacks a nervous system altogether, but it "knows" the local direction of the gravity field. However, no animals and only some humans are aware of Newton's law of gravity, let alone what a graviton is. --Dr Dima (talk) 02:57, 4 January 2010 (UTC)

The same applies to the notion of the Earth orbit. Both plants and animals have circadian and annual rhythms, as a direct result of Earth orbital motion; however, no animals and only some humans are aware of Kepler's laws, or even of the fact that the Sun, Moon, and the stars are not actually attached to the celestial spheres. --Dr Dima (talk) 03:20, 4 January 2010 (UTC)

Considering how hard it was for humans to figure out that stuff, even with our massive cognitive abilities, I don't see why we should assume animals know that kind of stuff. Animals know what they need to know to survive. Some of that is instinct, some of that is learned. To know about gravity in an abstract sense isn't necessary to survive unless you have a very peculiar society that rewards such abstract knowledge (which humans have only really had for a few hundred years out of our long existence as a species). Note that when we have taught animals how to better communicate, they say things like, "Banana me eat banana" and so forth. That isn't definitive, of course, but it doesn't really point towards the idea that animals have all sorts of advanced abstract intelligence just bubbling beneath the surface, which is fairly implausible anyway for the other reasons mentioned. This is not to say that animals are dumb—but their intelligences are quite different than humans'. --Mr.98 (talk) 04:00, 4 January 2010 (UTC)

This may be of interest Tool use by animals or Animal_cognition#Tool_and_weapon_use --220.101.28.25 (talk) 05:03, 4 January 2010 (UTC)Bold text

Expansion in a matter of time

How could 16,000 gallons of water expand to 932 °F steam in a matter of seconds?24.90.204.234 (talk) 02:38, 4 January 2010 (UTC)

Drop it in the sun? Place it under a thermonuclear bomb? The rate of temperature increase is related to the difference in temperature between two areas. Very broadly speaking, if two areas are under a different temperature, the warmer will heat up the cooler (and visa versa) and the rate of change is related to how different the temperature is. So, if you want to heat something up about 1000 degrees very fast, place it in contact with something at say 10,000 degrees... --Jayron32 03:31, 4 January 2010 (UTC)

Actually, it was in a boiler aboard the SS Norway that 16,000 gallons of water expanded to 932 °F steam in a matter of seconds.24.90.204.234 (talk) 03:54, 4 January 2010 (UTC)

Alright then. It expanded to 932 deg F steam in a malfunctioning boiler. You've answered your own question. At atmospheric conditions, steam is about 1000x less dense (that is, 1 mL of water will generate 1 L of steam). So, 16,000 gallons of water, when converted to steam, at equilibrium with the atmosphere, would "want" to occupy 16,000,000 gallons of space. In a confined space, by Boyle's Law, that means it is at a pressure of 1000 atmospheres instead. I doubt the boiler could withstand those kinds of pressures. 1000 atmospheres equals about 15000 pounds per square inch, give or take. So, imagine the weight of say, a half-loaded Mack Truck balanced on 1 square inch of space. Then put that weight on EVERY square inch of the boiler. No wonder it went KABOOM rather spectacularly... --Jayron32 03:56, 4 January 2010 (UTC)

See this previous discussion from the Science desk acrhives. Gandalf61 (talk) 10:26, 4 January 2010 (UTC)

Cause of death

Flogging seems to imply (but doesn't explicitly state) that loss of blood is the culprit. Is it? Clarityfiend (talk) 03:46, 4 January 2010 (UTC)

Shock is likely a greater influence than just loss of blood. Shock can occur when blood pressure or blood flow is restricted to many vital organs, if ones back is flayed sufficiently it can cause interruptions in blood flow which may result in serious shock, even if "loss of blood" is not as much as say, slashing a major artery. --Jayron32 04:00, 4 January 2010 (UTC)

"protecting plastics" for cargo

Does anyone apply the protecting group philosophy to whole objects instead of functional groups? I was thinking of like putting a polymer on a certain object, adding some plasticiser... the polymer would be fairly resistant at pH 7 and against heat and moisture, and but when you add an acid/base catalyst (or maybe hydrogen or a reducing agent) the polymer bonds collapse to give you your original product? John Riemann Soong (talk) 04:32, 4 January 2010 (UTC)

Sounds like a messy way to do stuff. The protecting plastic would still exist, albeit in a different form. Disposing of packing peanuts and cardboard seems like an less messy prospect than standing in a puddle of goop that formerly encased your product... --Jayron32 04:38, 4 January 2010 (UTC)

I was thinking of actually protecting something during manufacturing (e.g. a sensitive part) while it underwent various transformations. John Riemann Soong (talk) 05:19, 4 January 2010 (UTC)

Etching, as a process, usually involves "protecting" the un-etched areas of the substrate with some sort of acid-resistant substance, such as a wax, which is later removed. See also Photochemical machining and Industrial etching and Etching (microfabrication) all of which have some methods which operate on the same basic principle; you first protect the areas you want untouched, then you chemically react away the unprotected parts, then you remove the protecting material. Is that the sort of processes you are asking about? There are also multi-pass printing techiniques where plates are treated with special chemicals which allow the ink/dye/toner to stick to certain areas of the plate and not to others, the treated areas are "protected" so they don't attract ink; such plates can then be cleaned and reused. --Jayron32 05:31, 4 January 2010 (UTC)

Yeah, that was sort of what I was thinking about (though not necessarily so nanoscale but that works too) -- I was thinking even two sets of polymers in the style of orthogonal protection. Does the world have any use for a polymer that is fairly tough and resistant ... except with one critical (and useful) weakness. Also, how would I encourage this polymer to fall apart "cleanly" (i.e. it is easily washed off) as opposed to clumps of disgusting stuff you have to chip away? John Riemann Soong (talk) 05:41, 4 January 2010 (UTC)

what do you call this alkene? is it a good dienophile?

Is there a reasonable dehydrogenation reaction that would create a conjugation-stabilised product 2?

Trying to figure what you would call product 2. My IUPAC naming conventions are failing me right now, and never mind what the common name is called. I'm trying to use it for a Diels-Alder reaction. Is there a reasonable reaction (e.g. not reaction conditions like 500C) that would remove H2 from 1?**

Is it a good dienophile? I'm worried the phenyl group is too electron-donating ... how would it affect the transition state? What type of substitution pattern would it encourage if I say, used pyrrole as the dienophile? Also I'm worried about side products like ... the unsaturated C=O bond, polymerisation -- both via DA modes and enolisation....

**I initially thought of synthesising it via phenylacetaldehyde and potassium cyanide, hydrolysing the nitrile and eliminating water ... but some preliminary literature tells me phenylacetaldehyde polymerises very quickly -- Sigma-Aldrich only sells it at 90% purity! :o And oh, cis-trans isomerism is an issue. Any other ideas? John Riemann Soong (talk) 06:14, 4 January 2010 (UTC)

As far as naming, I'd call it 3-phenylacrylic acid. Then I looked it up, and its also called Cinnamic acid, which is readily availible commercially. I see no reason to make #2 when you can buy it probably as cheaply as #1. --Jayron32 06:30, 4 January 2010 (UTC)

Also see Phenylpropanoid for more on this general class of compounds... --Jayron32 06:33, 4 January 2010 (UTC)

It would appear that the entire class of molecules are all produced naturally from Phenylalanine. Also, I see several sources that call #1 in your synthesis "Hydrocinnamic acid" which would indicate that it is more common to work your reaction mechanism backwards; that is to hydrogenate cinnamic acid to make #1 rather that to dehydrogenate #1 to get #2... --Jayron32 06:37, 4 January 2010 (UTC)

Thanks so much! An issue is that I suspect I might need the cis isomer not the trans isomer ... the entire theme of my research is actually various derivatives of amino acids, so a phenylalanine reaction would be perfect.... the most immediate knee-jerk thing that comes to mind is some sort of stereospecific deamination of phenylalanine (or maybe stereoselective deprotonation of the benzylic proton), but I feel that would be really uncontrolled and unreliable. John Riemann Soong (talk) 07:12, 4 January 2010 (UTC)

Well, what are you doing with the Cinnamic acid? What's the next step? Is THAT product stereospecific? --Jayron32 07:14, 4 January 2010 (UTC)

I'm trying to Diels-Alder react cis-cinnamic acid with pyrrole to form troparil (and similar derivatives). (okay the product is missing a carbon, but I'm still curious -- I suspect the methylene carbon affects the conformation of the 7-membered ring and I wonder what would happen if it was removed. notably dopamine has the amino group 2 carbons away from the phenyl group but in troparil it's 3 carbons away.) Diels-Alder is pretty stereospecific, so yeah. Don't worry my interest in troparil is mostly academic. I work in a drug addictions lab in the medical school (as a lowly work-study undergrad), and I'm thinking it would impress my supervisor if I came up with a theoretically cheaper way to synthesise compounds that cost thousands of dollars per experiment to test each time -- just for the material alone!

(Also I figure practicing wouldn't hurt me since I might have no orgo courses until grad school. I'm also trying to find someone who's willing to supervise my experiment if my reaction conditions aren't too harsh...) John Riemann Soong (talk) 07:29, 4 January 2010 (UTC)

Frozen organisms

What's the largest organism that can survive frozen in a block of ice? (My question is open-ended on what minimum survival time is meaningful. Let's make it 2 separate questions: what's the largest organism that can survive frozen in a block of ice for a day; and what's the largest that can survive for a month?) Comet Tuttle (talk) 06:28, 4 January 2010 (UTC)

A number of species of frogs are known to be able to overwinter completely frozen; they alter their blood chemistry right before going into hibernation in such a way that prevents formation of large ice crystals (which would have caused irreversible tissue damage if allowed to form). It is also likely that some species of freshwater fish in the permafrost belt can do the same, as some ponds there do freeze solid (Couldn't find a reference though). Among the warm-blooded, I remember a documentary with Sir David Attenborough showing a hibernating bat with an icicle hanging from it (no kidding!); the bat itself was cold (almost invisible in a thermal scan) but not frozen. If it freezes solid it dies AFAIK. --Dr Dima (talk) 08:45, 4 January 2010 (UTC)

OK, I found the refs I was looking for. Cold-climate fish and insects prevent the formation of large ice crystals by having Antifreeze proteins in their tissues. There is a whole bunch of references in the Antifreeze protein article. --Dr Dima (talk) 09:09, 4 January 2010 (UTC)

Not directly relevant to your question, but I think it is worth noting that viable microorganisms have been extracted from ice at least several hundred thousand years old (and some claimed extractions for millions of years). In addition, at least some bacteria remain metabolically active when imprisoned in ice provided that some form of food source is available such as an adjacent dust grain or concentration of organic impurities. Dragons flight (talk) 09:12, 4 January 2010 (UTC)

pull of gravity or magnetism or any force

Is it safe to say that no matter how close two objects, particles or any matter comes to each other the atractive or the repulsion forces will never be infinite? 71.100.1.76 (talk) 08:42, 4 January 2010 (UTC)

Yes, that's fair. Infinite force will not actually occur. Formulas that appear to lead to infinities will generally be approximations of reality that aren't actually valid in the vicinity of the expected infinity. Dragons flight (talk) 09:19, 4 January 2010 (UTC)