Wikipedia:Reference desk/Archives/Science/2008 September 23

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September 23

Mercury's core

Is Mercury's core hot or cold. If hot how hot is it. Over 5000 egrees C?--57Freeways 00:17, 23 September 2008 (UTC)

It's certainly not cold and not over 5000 centigrade (or over 9000). While I couldn't find an exact number, Mercury's core is primarily iron and recent data suggest that it's molten iron, which puts it somewhere between 1538 and 2862 centrigrade. -- MacAddct1984 ^{(talk • contribs)} 02:30, 23 September 2008 (UTC)

Around 1850 C. [1] Dragons flight (talk) 04:19, 23 September 2008 (UTC)

pet birds

which birds when kept as pets must be fed haraam foods in order to survive? I am thinking about buying a parakeet of some species but I do not wish to purchase a bird which requires this. —Preceding unsigned comment added by 90.240.33.166 (talk) 00:34, 23 September 2008 (UTC)

Haraam ("forbidden") foods being basically pork, alcohol and other kinds of meat that are not appropriately slaughtered? I think that almost every species of bird can be fed on a diet that would not violate the Islaamic dietary rules. Parrots eat seeds and nuts and stuff like that. SteveBaker (talk) 01:21, 23 September 2008 (UTC)

Vultures? -- MacAddct1984 ^{(talk • contribs)} 02:32, 23 September 2008 (UTC)

You could keep a vulture on (say) lambs killed and prepared in haraam-compatible ways. SteveBaker (talk) 09:46, 23 September 2008 (UTC)

Insectivorous species might be tricky. Or Halal article states that 'all insects except for the locust' are considered haraam. Might be interesting to find out if the Islamic definition of 'insect' matches the scientific one - if grubs or spiders would also be haraam, for example... --Kurt Shaped Box (talk) 15:45, 23 September 2008 (UTC)

The most common pet parakeet is the Australian budgie. They can survive entirely on store-bought bird-seed and the occasional cuttlefish bone. APL (talk) 02:51, 23 September 2008 (UTC)

Hmmm.... I see that the article contradicts me. However, my budgie has been surviving for 11 years on nothing but store bought "parakeet seed" so I assume store bought parakeet seeds contain a mix of seeds to ensure proper dietary balance. Regardless, it's still just all seeds. APL (talk) 02:56, 23 September 2008 (UTC)

Incidentally, Cuttlefish are mollusks. If that's not acceptable, you might want to check a pet store for artificial calcium supplements for birds.APL (talk) 03:35, 23 September 2008 (UTC)

Indeed, budgies/parakeets (While budgerigar, or just budgie for short, is the correct term, "parakeet" is practically synonymous with it even though it technically refers to a broader group of parrots) can survive on seeds, however fruits and store-bought pellet diets are considered much healthier. Incidentally, I don't know much about Islamic customs, but from the wikipedia article on Islamic dietary laws it seems that most of the restrictions are about meat products. Since most parrots are herbivores, I doubt you'll run into much problems getting your bird to conform to Islamic dietary restrictions. --Sapphire Flame (talk) 12:28, 23 September 2008 (UTC)

Store-bought budgie seed is often vitamin/mineral enriched. One brand of seed in the UK contains special 'coated seeds' (which my indoor bird usually avoids). There is debate in the bird-keeping community when it comes to pellets vs. seeds. Some consider the advice from (some) veterinarians to feed pellets to be paid endorsements on behalf of the pet food companies. Other vets recommend seed, as part of a balanced diet containing fruit and veg, with access to cuttlebone and a mineral block. Try giving your bird a slice of apple or raw carrot - those are big favourites amongst my budgies. You might have to let the bird see you eating the same in front of him several times before he'll go near it though. --Kurt Shaped Box (talk) 16:03, 23 September 2008 (UTC)

quantifying vitamin C's preservative properties

OK, I need some NUMBERS on Vitamin C's ability to prevent food decomposition, compared with other preservatives, but for some reason all the sources online (even Google scholar!) seem fine with reporting the idea that Vitamin C is somehow a preservative, without any numbers whatsoever. This is so frustrating! I see no comparison of Vitamin C's preservative ability with other preservatives, concentrations of Vitamin C injected into food plotted against rotting time, etc. (or something like that) ... where can I get this information? 199.111.200.70 (talk) 01:32, 23 September 2008 (UTC)

Maybe a refined search for ascorbic acid would be more helpful? Cross-referencing ascorbic acid and preservative seems to turn out some good results [2] -- MacAddct1984 ^{(talk • contribs)} 02:41, 23 September 2008 (UTC)

Why are some stars bright?

why are some stars bright —Preceding unsigned comment added by 117.193.164.137 (talk) 02:04, 23 September 2008 (UTC)

Either because they are bigger than others or because they are closer than others. See apparent magnitude for the maths. Plasticup ^T/C 03:21, 23 September 2008 (UTC)

It's due to a combination of luminosity (how much light the star emits) and distance from the Earth. The size of the star is indirectly related; large stars tend to emit more light. Axl ¤ [Talk] 09:28, 23 September 2008 (UTC)

Also, if you're seeing a really bright star that's much brighter than every other star in the sky, chances are it's actually Venus. --Sapphire Flame (talk) 13:25, 25 September 2008 (UTC)

Planets interior

Is Mars core hot for certain. They said it's sulfur not iron. If hot is Mars as hot as our core. What about Pluto. Is it's core hot or cold. Scientist found out it is made of ice silicates of it's center.--57Freeways 02:54, 23 September 2008 (UTC)

All planetary interiors will be hotter than their exteriors because cooling occurs primarily at the exterior. Dragons flight (talk) 04:21, 23 September 2008 (UTC)

Is that so? What about planets that have reached thermal equilibrium? There are some exoplanets that are quite old - PSR B1620-26 b is supposedly 12.6 billion years old. On what timescales do planets cool down? --Stephan Schulz (talk) 07:47, 23 September 2008 (UTC)

For the Earth, the interior temperature drops something like 100 K per Gyr from a core temperature of ~6000 K. Gas giants have a much bigger mass to cool, and a much higher initial temperature, but they also have the benefit from more efficient convention. Even so, Jupiter currently has an estimated core temperature of ~25,000-35,000 K at an age of 4.5 Gyr. In all likelihood your very old planet still has a very warm core. Dragons flight (talk) 08:19, 23 September 2008 (UTC)

Ok. So in hypothetical case of a planet in thermal equilibrium... ;-) --Stephan Schulz (talk) 08:38, 23 September 2008 (UTC)

In your hypothetical case, the core temperature is equal to the surface temperature by definition (thermal equilibrium). Axl ¤ [Talk] 09:35, 23 September 2008 (UTC)

Not necessarily - thermal equilibrium just means that core and surface temperatures are not changing over time. They do not have to be equal if there is a source of heat energy such as those mentioned by Coneslayer below. Gandalf61 (talk) 13:18, 23 September 2008 (UTC)

Also, it's an oversimplification to imagine a planet as an inert body that's cooling off from some initial temperature. Jupiter is still converting gravitational potential energy to heat (by shrinking), and the earth's interior is heated through radioactive decay. Bodies can also be tidally heated if they orbit close to a massive body. -- Coneslayer (talk) 11:35, 23 September 2008 (UTC)

This depends on the size of the planets. For Pluto, geenral answer is nobody knows, but one guess is warm enough for water to evaporate but unlikely to be over 500 C or 1000 C. For Mars it is made of iron oxide, so it's core must be hotter than Mercury's core but unlikely to be hotter than ours. The good range of Mars core is 2000-4500 Celsius. Venus' core orange-yellow glow must be same temp. as our core perhaps little cooler. All gas giants core si definitely hotter than surface of sun. It's mantle must be so white as a dense vapor fluid the rockets burn. Even Neptune's core is close to 20,000 C.--57Freeways 23:23, 23 September 2008 (UTC)

chromatography

If I made a substance that was supposed to be asprin how could I use chromatography to tell if it is really asprin? —Preceding unsigned comment added by 209.97.86.194 (talk) 03:03, 23 September 2008 (UTC)

You can try looking at Chromatography - in particular note that there are many different kinds of chromatography so the specific method will vary. The very rough answer is that you perform your chromatography of unknown-but-suspected-to-be-aspirin substance and compare the results to those of a known-to-be-aspirin substance that undergoes the same test. This may involve getting some aspiring and doing the test yourself, or referring to some kind of standard set of results. Confusing Manifestation(Say hi!) 05:18, 23 September 2008 (UTC)

How literate in English would a person have to be in order to practice neosurgery in the USA?

I came here from a political forum on which a user (who is basically a troll) claims that she is a neurosurgeon but is barely literate in English. Here is an example post by her:

"For you are the putrid c-nt who no one like and you threads are the stupid and the boring like you."

What I want to know is if it is even possible to have this level of literacy in the English language and be a neurosurgeon in the USA. If one can barely even construct a basic sentence, how could one possibly understand all the complicated terms used in that profession? This claim seems ridiculous to me. Another thing which arouses my suspicion is that this user has on multiple occasions invited other members of the forum to come and watch her perform surgeries. Would guests even be allowed to watch doctors perform surgeries in the USA? In addition to these almost certainly bogus claims, this user has claimed to be a supermodel of Indian origin and has posted pictures of an attractive woman which she claimed to be her own, but a quick google search revealed them to be pictures of Aishwarya Rai.

There is also another user on the forum who is basically a troll who claims to know this user personally and defends her bogus claims, which makes me suspect sockpuppetry. I just want to know if her claims about being a surgeon are even the least bit credible, given her level of literacy.--68.93.135.252 (talk) 05:15, 23 September 2008 (UTC)

Why do you even ask when you know the answer? Do you want proof, to stand her up? Why are you feeding the troll? Why hasn't she been banned? Avnas Ishtaroth _{drop me a line} 05:25, 23 September 2008 (UTC)

It's basically an unmoderated political forum. Pretty much the only thing that will get you banned is posting child porn.--68.93.135.252 (talk) 05:29, 23 September 2008 (UTC)

Taking the question at face value – I've done medical transcription, and had occasion to listen to medical residents from India, China and Vietnam among other places; some of them could be very hard to understand, but I can't imagine any of them saying "the [adjective]". —Tamfang (talk) 07:41, 23 September 2008 (UTC)

I don't think this snippet of text constitutes proof at all. Some fairly smart people just don't bother to type too carefully or check grammar/spelling in forum-type posts. I agree though that the claims of being a supermodel and posting of fake photos is not a particularly positive sign. However, it's all circumstantial evidence - the way neurosurgeons behave in their off hours could easily be unrelated to how they behave in their work. Sock puppets are often easy to nail because they all make the same grammatical/spelling errors. Look for a word that this person always misspells and see if you can subtly get one of the socks to use it several times in a post. If you see the same misspelling - then you have some evidence. If you can find several different words like that - then you have quite strong evidence that they are in fact the same person. But in an unmoderated free-for-all, you have very little recourse. I recommend simply ignoring this person's posts - reply to everyone else directly but simply never mention or refer to this one person's posts. SteveBaker (talk) 09:41, 23 September 2008 (UTC)

Honestly, who cares? On the internet you are whatever you want to claim to be. And not a single person has to believe you. --98.217.8.46 (talk) 13:22, 23 September 2008 (UTC)

Indeed. -- Coneslayer (talk) 13:26, 23 September 2008 (UTC)

Indeedly-doodly. AlmostReadytoFly (talk) 14:55, 23 September 2008 (UTC)

Many doctors in the U.S. got their medical training in non-English speaking countries and barely speak English. They might write and speak more fluently and with greater literacy in their native language. I believe that they have to pass the "Test of English as a Foreign Language" to practice medicine here, but many have failed it multiple times, and maybe one day they got lucky and scored higher than their actual language proficiency would dictate, or maybe they cheated (getting the answers in advance via corrupt proctors,or from a n administration earlier in a different time zone, hiring a substitute, electronic communications). A magazine article a few years ago complained about this lack of English proficiency, in which an Asian doctor in a US hospital asked the patient "Who fam doc?" repeatedly until a bilingual nurse told them he wanted to know the name of their family doctor. So in my view, yes, there could be a practicing surgeon in the U.S who might write the sample posting. Poor grammar, poor spelling, limited English and a lack of attention to correct typos as well as a generally bad attitude could yield the sample document. Edison (talk) 15:31, 23 September 2008 (UTC)

Out of curiousity, do you have a link to this person's posts? —Preceding unsigned comment added by Schwarzes Nacht (talk • contribs) 01:30, 25 September 2008 (UTC)

Most medical doctors wishing to practise in Great Britain, and coming from outside the European Union, are required to demonstrate proof of their English aptitude (in all four skills -- reading, writing,listening, speaking). This is normally done by taking the Academic module of the IELTS exam. Not sure whether the US has a specific equivalent. BrainyBabe (talk) 11:53, 27 September 2008 (UTC)

In the US, it would be the TOEFL. Arakunem^Talk 11:59, 27 September 2008 (UTC)

Hydrogen ballooning

Does anyone still use hydrogen for manned balloons, and if so, what do they use for balloon fabric and where can I get some? --67.185.172.158 (talk) 05:53, 23 September 2008 (UTC)

According to our article on balloons, hydrogen is "not widely used for aircraft since the Hindenburg disaster because of high flammability (except for some sport balloons as well as nearly all unmanned scientific and weather balloons)." As for the fabric, no clue. -- Captain Disdain (talk) 09:25, 23 September 2008 (UTC)

I had to research something like this once for a school project, and eventually found a reference (i don't remember where) to ruberized silk. Didn't know then and don't know now what that actually is though 124.243.155.3 (talk) 11:21, 23 September 2008 (UTC)

For the Roziere it might be dacron or/with ripstop nylon. Mion (talk) 12:20, 23 September 2008 (UTC)

the Martian sky

If you stand on the equator on Mars at midnight at the northward equinox, what constellation is directly overhead? In other words, where does the Sun-Mars vector point at L_s=0? —Tamfang (talk) 07:43, 23 September 2008 (UTC)

According to this Martian calendar, it is probably Sagittarius (constellation). You've probably already found Timekeeping on Mars, that article has a lot of information. Nimur (talk) 22:26, 23 September 2008 (UTC)

Looking for specific puzzles

I found via wikipedia maybe a year ago a page containing possibly several hundred logic puzzle images that had first been designed (from memory) around the turn of the previous century. The wikipedia page itself was brief, what I'm really after is the page it linked to.

The external page had links to at least 130 pairs of images on the site. They were colour-coded on this page, to indicate who created each puzzle, with the names and references at the bottom of the index page. The puzzles themselves were two images, and you had to determin what the unique difference between them was. Each subsequent pair of images had a different answer. Does this sound familiar to anyone? Thanks in advance. —Preceding unsigned comment added by 219.89.54.45 (talk) 10:38, 23 September 2008 (UTC)

accelerating charged particles and radiations

Why do accelerating charged particles emit radiations? —Preceding unsigned comment added by 210.212.187.69 (talk) 14:13, 23 September 2008 (UTC)

I think that particles only emit radiation when they collide with other matter (assuming the particles were non-radioactive to begin with), because their kinetic energy is turned into radiation due to the conservation of energy. This is true for anything with mass moving at extremely high relative velocities. ScienceApe (talk) 19:59, 26 September 2008 (UTC)

You would want to look at bremsstrahlung and the question archives, as we touched on a similar question a few weeks ago. :-) EverGreg (talk) 21:40, 27 September 2008 (UTC)

Help from more experienced molecular biologists: statistical software packages?

I've been tasked with finding a statistical software package to help us with some of the more routine statistical analysis in our molecular biology lab (mostly ROC curve and multivariate analysis), and I was looking for recommendations from the community. Most of the information I'm finding is from company web sites that (naturally) insist their package will change your life, or from other investigators who really only have experience with a single package, if any at all. Is there anybody out there who some experience in this subject who can recommend anything that stands out and is worth the expense? Many thanks! – ClockworkSoul 15:23, 23 September 2008 (UTC)

Note: I just found the list of statistical packages, but some practical advice would be invaluable! – ClockworkSoul 15:26, 23 September 2008 (UTC)

I don't know about their abilities with the specific methods that you mention, but here's what I do know about a few different packages. SAS has the reputation for being high powered and versatile, but with a steep learning curve and ridiculous amounts of documentation to wade through. I don't know if they make a version of SAS with a GUI yet, but for a long time it was all command line driven. The more user friendly-packages I've used include SPSS, Stata and Minitab. I found it easy to write scripts for complex and repetitive data manipulation and analysis in Stata, but I never attempted scripting with the other packages for comparison. I don't have much else intelligent to say regarding a comparison of these three except that Minitab seems to have a big user-community, which is always helpful. Since they probably all now perform most of the same methods, you might find that they differ more in terms of the prettiness of the charts they can produce. ike9898 (talk) 17:25, 23 September 2008 (UTC)

In the bioinformatics community, which is close to your line of work, R (programming language) is an important tool. The Bioconductor package is built on R. The learning curve for R is somewhat steep, but it pays off. There may be a bioinformatics user-group somewhere nearby that you could get in touch with, and they might organize courses. R is an excellent tool for multivariate analysis, and also excels at making pretty graphics. I have no experience in using R for ROC curves, but a google search suggests that packages are available for the task. --NorwegianBlue ^talk 20:56, 23 September 2008 (UTC)

SAS does have a GUI now, called SAS Enterprise Guide. It's basically a front-end that calls an installation of SAS either locally or on a server. It's probably a bit easier than using SAS directly (which itself has a kind of GUI/text editor interface to the command line interpreter), but to do anything really powerful statistically you still need to be able to wade into the code a bit. Confusing Manifestation(Say hi!) 22:55, 23 September 2008 (UTC)

project

Yes, I work for a company that builds the fuel pump for some cars. We've had a lot of problems with scrap- (meaning problems with the armatures.) I mean a lot of bad armatures. I need someone to help me with some suggestions is to how some of this could be prevented. I hope too, that this is a question that is suitable. Thanks, tqr —Preceding unsigned comment added by Quantinatqr (talk • contribs) 15:40, 23 September 2008 (UTC)

Electrical armatures like all components will eventually break down. I don't know of any sure ways to prevent this, and I guess that's why armature-winders are employed to locate broken coils and to repair or replace them with new ones, or completely rewind all the coils from scratch. Perhaps a more dense iron core and better quality coils would help, although I'm sure the company you work for will have researched these possibilities already. JessicaThunderbolt 16:18, 23 September 2008 (UTC)

Let that be a lesson to you: NEVER work with armateures. Instead, use professionals, then you wont have any troubles. —Preceding unsigned comment added by 79.76.251.108 (talk) 22:57, 23 September 2008 (UTC)

Your starting point should be to identify the problem a little more specifically. Why are they breaking? Can you fix that problem. Plasticup ^T/C 04:42, 24 September 2008 (UTC)

One reason for a lot of older fuel pumps failing is the introduction of ethanol into our fuel supplies. Ethanol conducts electricity where gasoline does not - some older fuel pumps had exposed metal parts that were at 12 volts - which now have a low-resistance path to ground resulting in overheating and reduced pump pressures. Ethanol also chews it's way through rubber seals - modern fuel pumps should have synthetic plastic seals everywhere. But I would imagine that both of these issues are very well known facts for the designers of fuel pumps and it's hard to imagine a well-designed modern pump having this problem. The problems I've seen have been with fuel pumps on old cars - more than 15 years old.

Another possibility is that fuel pumps that are immersed inside the gas tank to keep them cool are at risk of overheating when people run their cars very low on fuel. I suppose that it could be that the increased cost of gasoline over the past year or two is somehow causing more people to leave it to the very last minute before filling up their tanks - thereby causing the fuel pump to overheat more - and for longer periods than it used to.

Failing that - you have to find an armature manufactured in the era before they all started failing and compare it VERY carefully with the more recent ones - literally put it under the microscope. Maybe they changed the formulation of insulation on the windings? Maybe they use a different gauge of wire or a different number of turns? Maybe the copper in the wire comes from a different place - maybe it's not so pure perhaps? Perhaps a different adhesive is being used somewhere and it's mildly corrosive? Something must have changed - and if it's not the environment the things are running in - then it must be the design or the construction.

SteveBaker (talk) 01:53, 25 September 2008 (UTC)

object at infinity

if mirror is concave and object is at infinity ,is there any measurement of infinity,i-e what it should be ,greater then 3f,4f ,5f or others —Preceding unsigned comment added by Khubab (talk • contribs) 15:53, 23 September 2008 (UTC)

It appears to me that this is asking about the angle of reflection in the concave mirror. The closer an object is to the mirror, the sharper the angle. The further away an object gets, the angle of reflection approaches a straight line. At infinity, since it is impossible to be at infinity, the angle would be a straight line, which is impossible to achieve. -- kainaw™ 17:15, 23 September 2008 (UTC)

I think the OP is probably asking how far away an object should be in order to be treated as being "at infinity" for practical purposes. This distance can be expressed as a multiple of the focal length (hence 3f, etc.). I think the rule-of-thumb that I learned was that 200f is "infinity" for most purposes, but I am not a reliable source. -- Coneslayer (talk) 17:36, 23 September 2008 (UTC)

evidence of increase in iron content in well water

What could cause this increase in iron content from a scale of a 1 to a 7 in one year? —Preceding unsigned comment added by 69.250.196.171 (talk) 17:09, 23 September 2008 (UTC)

The water could become more acid, or anoxic conditions could be reducing insoluble ferric compounds to mobile ferrous ions. Iron is a natural component of ground water, and it may vary in concentration when it comes from different aquifers - exposed to different rocks. Graeme Bartlett (talk) 21:18, 23 September 2008 (UTC)

Actually making money from a patent

I'm looking for information about how often a patent holder actually makes some money from his patent, either by licensing it, using it himself, or some other means. More precisely, I'm interested in the percentage of patents that never benefit their holder in any concrete way. ike9898 (talk) 17:11, 23 September 2008 (UTC)

You don't make money from the patent itself, you make money from whatever it is you've patented. The patent just stops anyone else using it and stealing your market. To make money from an invention you need to make whatever it is you've invented and sell it (or license someone else to do so). --Tango (talk) 17:33, 23 September 2008 (UTC)

I think ike9898 understands that... he's asking how often that actually happens, versus a patent sitting around collecting dust (neither being licensed nor put into production by the inventor). -- Coneslayer (talk) 17:38, 23 September 2008 (UTC)

But do you wish to include blocking patents (well darn, we have no article on them) which intentionally collect dust. Someguy1221 (talk) 18:14, 23 September 2008 (UTC)

It's an interesting question. I'd guess offhand that the vast majority of patents never make a cent directly or indirectly. But it would be really interesting to follow up on, at least with a study of, say, 1000 patents chosen at random. There are many different ways that a patent can be "of value"—most of which not including that they mean you can sell the product at the market (e.g. defensive patenting is of very high value even though it has no direct revenue, it just protects against hypothetical revenue depletions). --140.247.253.44 (talk) 19:35, 23 September 2008 (UTC)

The average cost of obtaining a patent is ~$30,000, so I'd imagine nearly everyone goes in with the expectation that it will either make them money or prevent them from losing money (whether directly or indirectly). What fraction of patents actually realize those revenues? I have no idea. It would be interesting data to have though. Dragons flight (talk) 19:58, 23 September 2008 (UTC)

Many technology corporations/companies will pay the inventor for submitting a patent, and provide additional financial incentives to the inventor at each additional stage of the patent procedure (filing, granting, etc). In this regard, the inventor can earn fixed quantities of money directly from the corporation; the corporate office is then responsible for the additional challenge of monetizing the actual invention. To capitalize on this, you should first seek employment in the research wing of a company with some such inventor compensation plan. Nimur (talk) 22:14, 23 September 2008 (UTC)

Well, keep in mind that most "inventors" are really corporations anyway. The age of the small-time inventor (in the US anyway) died a long time ago. As to whether capitalizing on an invention in a corporation—it really, really depends on the corporation's patent plans. --98.217.8.46 (talk) 22:33, 23 September 2008 (UTC)

Where are you getting that figure from? That sounds awfully high. I'm assuming you're talking about lawyer's fees in particular, as the patent office fees are not very steep. Are you referring to individual inventors or corporate inventors? --98.217.8.46 (talk) 22:33, 23 September 2008 (UTC)

Our article on patent, for example, says that in 2005 the average cost of filing and maintainence during first 10 years in Europe was ~32,000 Euros. Most of the cost is patent attorney costs. $10-15 thousand to prepare the filing, and roughly that much again to repsond to challenges and finish the process during the next few years would not be uncommon. Of course the complexity of the invention matters, and I'm sure one can get patents on the cheap, but you won't necessarily save in the long run by doing so. Dragons flight (talk) 22:56, 23 September 2008 (UTC)

Contingent fee trial lawyers. You file a patent for something you think will be invented anyway, and then you wait for microsoft or yahoo to infringe, then you fire the trap. The best example of this is Research in Motion. Additionally, many companies offer "advanced settlements" so that not only do you have zero-risk by accepting a contingency fee deal, you can sign a contract with a laywer at the same time you receive an advanced settlement (which you don't have to repay unless you win). This is risk-free profit, and its like those people who register domain names, oneday hoping the company will buy it from you for $1M. However, I follow this, and the patent system is going through major overhaul and is trying to blend in many experts including engineers and private sector MBA's and thus squeezing out the huge percentage of lawyers and bureaucrats involved in the process. Sentriclecub (talk) 03:28, 24 September 2008 (UTC)

Cause of death

Not a medical question in the sense that if affects anyone that I know, is purely hypothetical. There is a cause of death which presents with hugely bloated stomach and fecal vomiting (post mortem, i.e. fecal drainage from the mouth) I'd imagine it is some kind of intestinal/gastro bleed or leak? SGGH ^speak! 18:21, 23 September 2008 (UTC)

I hope this isn't a request for medical advice. If so, you're a little late :-) Chances are it could be a result of a number of things. Gastrointestinal perforation is the first to spring to mind. Also, perhaps, though less likely, being upper GI, is Boerhaave syndrome. Fribbler (talk) 21:54, 23 September 2008 (UTC)

Various types of bowel obstruction can cause faecal vomiting, if severe enough. Many of these won't cause death in and of themselves, but aspiration of the vomit could do so. In one imaginary scenario (since we are discussing such, I believe?), the individual might lose consciousness through the pain and dehydration caused by the obstruction, and when retroperistalsis causes the backlogged bowel/stomach matter to be vomited, some leaks through the mouth, and some finds its way into trachea and lungs, causing, effectively, death by drowning. That do you? Gwinva (talk) 22:24, 23 September 2008 (UTC)

It's hypothetical in that I do not know anyone who has died of this, but I am aware that this manner of death does occur and was wondering what caused it. The perforation was my guess. Unfortunately searching fecal vomit does not turn up too much. Thanks guys SGGH ^speak! 22:54, 23 September 2008 (UTC)

True "fecal vomiting" (i.e. vomiting feces) is rare and is usually due to gastrocolic fistula (an abnormal connection between stomach and colon). Feculent vomiting (foul-smelling dark brown vomitus) is a little more common (though still uncommon) and is due to large bowel obstruction. This should be distinguished from brown vomitus that is not foul-smelling. Another commonly used (and abused) term is "coffee-ground vomiting". This is supposed to describe thick black vomitus due to upper gastrointestinal bleeding. Unfortunately the term is misused by junior doctors, nurses and other health professionals; it is incorrectly used to describe brown vomiting. The symptoms of "hugely bloated stomach [abdomen] with vomiting" sounds most likely to be due to perforation. If a post mortem report genuinely states "fecal drainage from the mouth", I would hope that the pathologist also looked closely for evidence of fistula. Boerhaave syndrome can follow vomiting, but is rarely associated with hugely bloated abdomen. Axl ¤ [Talk] 19:49, 24 September 2008 (UTC)

Mysterious Hamster Illness

Before I begin, I will say that this is not a request for medical advice, as the hamster in question is dead. The question is about what killed her.

I had a hamster (Pearl Dwarf Hamster) and I first noticed she was a little odd when she would give off screams at random, usually when 'sleeping' under all the wood chippings we used for bedding. One night, my wife turned to me and said she was not moving, so I picked her up and found she was dead. He eyes were tightly shut and were caked with blood. Does anyone have any idea what could have caused this? I doubt it was an injury, because we had another hamster in a cage underneath and she had no problems. Please note, they could not have been fighting, as they had no possible contact with each other.

My theory was that it was a brain haemorrhage, but would this cause the eyes to bleed?--ChokinBako (talk) 19:18, 23 September 2008 (UTC)

Allergies can cause this, or porphyrin staining if it is albino, or a viral infection. Allergies might have been from the bedding, possibly some sort of dust, or something like that. You have my sympathies, it isn't nice to loose a pet! SGGH ^speak! 19:31, 23 September 2008 (UTC)

Out of curiosity, what sort of wood chips were you using for the bedding? I used to work at a pet shop and might be able to give you some answers. Allergies are a big possibility. Also, some hamsters you get from less reputable pet shops will have neurological issues from interbreeding. Believe me, I've seen it all. Red Gown (talk) 21:32, 23 September 2008 (UTC)

On the more traditional side, any kind of tumor on/in/near the eyes could have done it. Plasticup ^T/C 01:27, 24 September 2008 (UTC)

How old was your hamster? The Perl White ones only live 18 months to 2 years - perhaps it was just old age? SteveBaker (talk) 01:34, 25 September 2008 (UTC)

Ubiquitination: specific E1 needed for particular E2?

I know that a relationship exists in terms of which E3s associate with which E2s but how many E1 ubiquitin activating enzymes are there? Can any E2 gain the ubiquitin protein from any E1? ----Seans Potato Business 19:57, 23 September 2008 (UTC)

What will happen exactly if all the arctic ice melts?

My 5 year old son is asking me and I want to explain to him exactly what will happen and how this will affect him. Please explain to me as if you were to tell a five year old child. --Anilmanohar (talk) 20:31, 23 September 2008 (UTC)

Not really a 'simple answer' kind of question. There are dozens of different things which would happen. Polar bears and various seal populations which live on the ice part of the year would lose their habitat and decrease in numbers. Dark sea water would absorb more heat from sunlight than ice would - thereby resulting in increased ocean temperatures. Air above the oceans would also be correspondingly warmer, resulting in weather changes for surrounding land masses and further melting of the 'permafrost'. Sea ice also provides a buttressing effect preventing land ice from falling into the ocean - without it glaciers on Greenland and other arctic land masses would decrease more quickly, resulting in increased sea level rise. Methane and carbon deposits trapped beneath the ice would be released - increasing the concentration of greenhouse gases in the atmosphere and further accelerating global warming. Ships could sail through more often. Oil and natural gas which are currently unreachable through the ice might be extracted. Et cetera. Those are most of the 'big ticket' items, but it would contribute to countless already ongoing changes the world over (species migration northwards and to higher altitudes, glacial retreat, sea level rise, average temperature increases, et cetera). A common misperception is that melting Arctic ocean ice would directly raise sea levels. However, since that ice is floating it is already displacing an amount of water equal to the volume it would melt into. --CBD 21:03, 23 September 2008 (UTC)

One little experiment you might like to do with your son, if he's interested in a bit of fun home science, will show how melting the Arctic ice cap won't directly raise the sea levels, but melting the Antarctic ice, or the ice on Greenland, Canada, far north Europe, etc will. Take a glass of water and drop an ice cube or two into it. Note that some of the floating ice sticks out above the water (like an iceberg). Mark the water level with a piece of tape, and then wait for the ice to melt. The water level will be the same afterward, even though the ice that was sticking out the top has turned into water.

Then try the experiment again, but this time, hold the ice cube completely out of the water (you could perhaps balance it on a spoon above the glass so as it melts the water runs into the glass). This time the water level will have risen. The floating ice cube imitates the Arctic ice cap, which simply floats above the ocean. The suspended ice cube imitates the ice on Greenland, Antarctica, etc, that is, ice sitting on top of continents, held out of the water. Of course, we can't selectively choose which ice melts if the globe warms up, but this will be an interesting and easy way to see that it isn't the melting Arctic ice cap that will result in raised sea levels, it's all the other ice. Maelin (Talk | Contribs) 01:07, 24 September 2008 (UTC)

Actually, when ice that's floating on the sea melts, it does contribute a little bit to sea level rise, although not nearly as much as it would if the ice had been resting on a land mass. The reason is because (unfrozen) fresh water, which the ice is a frozen version of, is less dense than the salt water of the sea. See [3]. Red Act (talk) 05:13, 24 September 2008 (UTC)

Yeah - exactly. The ARCTIC ice melting doesn't DIRECTLY do much to the sea level at all because it's all floating ice. However, if the ANTARCTIC ice melts (well - if MORE of it melts - lots of it is already gone) - then the sea level will rise by over 60 meters(!). It the snow and ice on Greenland melted, that would raise the ocean levels by a further 7 meters. Additionally, because water expands as it's heated, there would be further increases in sea level even after all the ice had melted. When you add up all of that - including glaciers, mountain-top ice, etc - you get a total sea level increase of perhaps 100 meters. That most extreme situation would leave almost all of the world's major cities under water. Some of the effect are tough to predict because the weight of all of that water presses down on the continents - as the weight of the antarctic ice was released, the antarctic continent would rise up - which would displace yet more sea water...the pressure of that extra water flowing inland onto the other continents would press them down - causing yet more flooding. Even more depressing is that the ice is bright white and reflects most of the sunlight that hits it off into space. When the ice melts, it's replaced by darker land or much darker ocean which absorbs more sunlight and accellerates global warming to an even greater extent. If the ocean temperatures rise enough then deep ocean deposits of frozen methane would melt - releasing enormous amounts of the stuff into the atmosphere. Methane is a much worse greenhouse gas than Carbon Dioxide - so we'd be even more screwed up. As the earth heats up - more water evaporates from the oceans. If this condenses out as cloud, then it reflects sunlight away and that would help to slow the heating due to sunlight...but sadly, water vapour is ANOTHER nasty greenhouse gas...so there is no saving us at that point.

The worst of this is that it's like rolling a heavy ball up over a low hill. All the while you're rolling it up the hill, you can stop pushing and it'll gradually roll back down again. But if you push it just a little bit too far - the ground starts to level off - and even a gentle push will keep it going. But once you cross the brow of the hill - the ball starts rolling down the opposite side - and no matter that you stopped pushing, it's going to keep on going until it eventually rolls to a halt far away on the other side. We really don't know for sure where the top of the hill is - but the accelerating rate of arctic and antarctic ice melting suggests that the slope is at least levelling off and we can't be far from that tipping point beyond which we're screwed. There is some evidence that this is exactly what happened to Venus - and if that's where the level ground on the other side of the hill is - we're in deep trouble.

SteveBaker (talk) 01:11, 25 September 2008 (UTC)

Other human issues so far unmentioned: the lives of the Inuit people and Eskimos (and Sami for that matter), from Greenland to Canada to Russia, will be changed beyond recognition; at first this will be predominantly bad, but soon more positive may appear, especially in places such as Nunavut, where the Inuit have more control over their lives. Migration will increase; northerners will move south to the cities, as the economies become more intertwined; southerners will move north, as possibilities expand. Issues of the North will be more prominent, culturally and politically, in their related polities to the South. (There might even be a former governor of Alaska as President of the United States, for example. At a trivial level, Nanook of the North will be reissued, and hockey will get hotter.) Animal and plant species will change hugely, from the migration patterns of caribou and the great rorquals, to an ocean-wide bloom of phytoplankton, which entrepreneurs will attempt to harvest as a human food source. Mineral and oil exploration will become easier and cheaper, relative to now, although not necessarily relative to other places. The Northwest Passage will become a year-long reality and Canada will attempt to back up its claim to the Arctic Ocean as territorial waters, with a predictable response from the United States. Tourism to the North Pole will pick up, as it has to Antartica, Mount Everest, and space. Santa Claus will travel by flying whale rather than reindeer. At that point, my crystal ball grows cloudy. BrainyBabe (talk) 12:35, 27 September 2008 (UTC)

Saturn's disc color

Is Saturn truly blue-silver in disc color almost like Uranus or Neptune. When I went to 6th grade science camp on one night we had astronomy lesson the scientist told me Saturn's sphere color is blue-silver instead of yellow or tannish color.--57Freeways 22:34, 23 September 2008 (UTC)

Saturn looks a kind of yellowish-gold in a telescope. Most of the photos in our article show it as a yellowish orange. It does tend to look more blue when you are seeing the disk of the planet through the rings. SteveBaker (talk) 00:40, 25 September 2008 (UTC)

Tooth extraction

Not seeking med advice -- just curious. If a tooth is broken off at or below the gum line, how does the dentist remove it? (as she cant get hold of anything) I just had it done but wasnt watching at the time.--GreenSpigot (talk) 22:51, 23 September 2008 (UTC)

I had my wisdom teeth out last month and I think that the root of one of the teeth broke off inside the gum. For the next four weeks little pieces of tooth would (each over the course of several days) force their way to the surface, through it, and out. Presumably my body was forcing it out through the process of granulation. It's not exactly a surgical technique, but it was pretty cool to see my body ridding itself of these shards. Plasticup ^T/C 01:24, 24 September 2008 (UTC)

The same thing happened to me when I had one of my molars removed - but with fragments of jawbone. The infection beneath the tooth had started to consume the bone and my dentist had to have a good hack away once the tooth was out, see? --Kurt Shaped Box (talk) 01:32, 24 September 2008 (UTC)

I really, really wish I hadn't read this. DuncanHill (talk) 01:35, 24 September 2008 (UTC)

I read about your condition on WebMD and at first I was worried that it could be pieces of jawbone. Inside my mouth these fragments felt huge, but when the first one fell out it was no larger than 1 mm³ and I figured it couldn't be anything too serious. Plasticup ^T/C 04:37, 24 September 2008 (UTC)

Also from personal experience, both of my upper canines snapped off at the gum line (curse you refrigerated Chunky Kit Kats) and were removed by cutting away the gum, drilling out the middle of the remaining stump and what seemed to me to be an inordinate amount of sheer pulling force. For my wisdom teeth; the dentist drilled out the centres, placed his pliers/tools/mouth-butchery devices inside and twisted forcefully until the tooth shattered. Yay NHS... Nanonic (talk) 12:03, 24 September 2008 (UTC)

Also, see Dental extraction#Types of extraction with some lovely pics. Nanonic (talk) 12:08, 24 September 2008 (UTC)

Thanks all. But I was looking for more detail on the process of extraction. Ive heard that things called Dental elevators are used to lever up the tooth. Unfortunately, no article!--GreenSpigot (talk) 03:17, 25 September 2008 (UTC)

find the resonance frequency of a tube

In order to do a high school science experiment, I need to find out the resonance frequencies of a certain tube that I'll be using. The trouble is I don't know the exact specifications of the pipe I'm going to get, but I assume there's a formula out there somewhere. I already looked at the Acoustic resonance article, and that had a formula, but it didn't take into account diameter (as well as other variables I might not know about), which I assume is a large part of the equation, as well as possibly material the tube is made out of and the things inside the tube (different types of gasses), although these aren't quantifiable variables.

I can imagine that a seasoned science teacher/student can imagine what experiment a high school senior would want to do with this information, but I think I'll keep that to myself for now. Thanks in advance for the help. —Preceding unsigned comment added by Hypershadow647 (talk • contribs) 22:57, 23 September 2008 (UTC)

OK Why do you think the dia is not mentioned? —Preceding unsigned comment added by 79.76.251.108 (talk) 23:00, 23 September 2008 (UTC)

Instead of taking a look at acoustic resonance, try reading the article. It does, in fact, show the formula for air tubes which include correction for the diameter of the tube. -- kainaw™ 23:09, 23 September 2008 (UTC)