Wikipedia:Reference desk/Science

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March 7

annoying keystroke shortcut in Outlook

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

Are you sure the message is only sent, and nothing else is done? According to http://office.microsoft.com/en-us/assistance/HP030842231033.aspx, the keyboard shortcut for sending emails is Alt+S. One way to fix the problem is to leave out the "To:" field until you're ready to send. --Bowlhover 05:17, 7 March 2006 (UTC)

I don't use Microsoft products, but isn't Ctrl-W the MS shortcut for "Close everything right away without giving me any sort of warning of any kind." I get a lot of people who apparently hit it while in Word, Excel, IE, and Outlook and complain that the window just closes. For me, it is Nano's "where is" shortcut. --Kainaw ^(talk) 13:29, 7 March 2006 (UTC)

For mine it's "ask if you want to save, then close". It could be irritating if hit accidentally but it shouldn't be disastrous except for users who don't believe in reading the boxes they click on. I realize that's a large segment of the population, but I can't find much sympathy. — Lomn Talk 14:32, 7 March 2006 (UTC)

Ctrl+Enter in Outlook means "instantly send this message that I haven't finished typing". Bowlhover's suggestion (leaving the To: field empty until the last minute) is the only defence I know of. --Heron 20:49, 7 March 2006 (UTC)

I know of another defence, at least on Thunderbird: tell it to encrypt emails by default, and it will complain when trying to send if you don't have the public key for the person you are sending to. At the last moment, turn off encryption for that particular message. I don't know if it works on Outlook, since I never used it, but I do know it has encryption support. --cesarb 21:17, 7 March 2006 (UTC)

Nazi human experimentation

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

This question is addressed at Talk:Nazi human experimentation. Short answer, no. Melchoir 06:19, 7 March 2006 (UTC)

The U.S. made a secret deal with Shiro Ishii, Unit 731, and Unit Ei 1644 leaders that germ warfare data based on human experimentation would be offered in exchange for immunity from war-crimes prosecution in 1948. The US also made secret deals with Nazis. How many have not been since unclassified is unknown. WAS 4.250 16:02, 7 March 2006 (UTC)

Untrue, I recall reading in Hans Rudel's book, Stuka Pilot, there was a discovery about how pilots could survive in freezing water. This was discovered using human experimentation. —The preceding unsigned comment was added by 12.41.204.3 (talk • contribs) 15:00, 7 March 2006.

Ah. That deserves checking on, if anyone has access to the book. I'll copy this discussion to the talk page. Melchoir 02:14, 8 March 2006 (UTC)

Does our hypothermia article mention it ? StuRat 02:17, 10 March 2006 (UTC)

I heard this mentioned several times as the one single piece of useful knowledge that came out of the experiments. Celcius 03:23, 10 March 2006 (UTC)

Development of Artificial Chemical Expert system

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

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

I think you meant scientific journal. Black Carrot 23:37, 7 March 2006 (UTC)

Lorenzo's oil

I was searching the internet to purchase Lorenzo's oil and your website came up, although I couldn't find anywhere to purchase it. Any suggestions? Thanks (Email removed to avoid @spam) 65.78.72.157 06:01, 7 March 2006 (UTC)

I'll say it again, it's not my website, and there is NO cabal. I found this on the first link that google gave me:

In the U.S., Lorenzo’s Oil is currently only available to patients taking part in a clinical trial under the direction of Dr. Hugo Moser of the Kennedy Krieger Institute. He can be reached at (800) 873-3377. We are working with Dr. Moser and the FDA to obtain approval of Lorenzo's Oil as a drug, so that it can be widely available. The oil is jointly manufactured by Croda International of Britain and SHS International (Scientific Hospital Supply). SHS is also the worldwide distributor of the oil; for a list of international offices, please refer to their website. SHS North America can be reached at (800) 365-7354.

In the U.S., Lorenzo's Oil can be obtained through prescription only by Kennedy Krieger authorized physicians. A 500ml bottle costs $56.00. Some insurance companies will provide coverage for the oil, but others do not because it is still considered an experimental drug by the FDA. Parties residing outside the U.S. should contact Scientific Hospital Supply directly at + 1 (301) 795-2300, to obtain pricing and shipping information.

 freshgavinΓΛĿЌ  06:33, 7 March 2006 (UTC)

Silly question, but we are sure that 65.78.72.157 isn't just looking for a DVD of the movie, right? Grutness...wha? 12:59, 7 March 2006 (UTC)

Actually, I would think that more likely. I'm not advocating any single seller, but typing "Lorenzo's Oil" into Amazon.com and eBay seem to get enough results for the 1993 VHS release and the 2004 DVD release. EWS23 | (Leave me a message!) 18:04, 7 March 2006 (UTC)

How silly of me. But still I doubt that. This is the science page and there are quite a few people asking where to buy difficult to find industrial and medical substances here.  freshgavinΓΛĿЌ  02:09, 8 March 2006 (UTC)

External fertilization

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

In vitro fertilisation?  freshgavinΓΛĿЌ  06:35, 7 March 2006 (UTC)

Its not possible, sperm has to get to the egg, probably only possible through the vagina. -- Mac Davis] ☢ ญƛ. 04:28, 8 March 2006 (UTC)

I take it you haven't heard of in vitro fertilisation either then.  freshgavinΓΛĿЌ  04:34, 8 March 2006 (UTC)

Ask Louise Brown - she may have an opinion on the matter. Grutness...wha? 06:51, 8 March 2006 (UTC)

Portable document readers

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

Sony Reader is one. It uses e-paper, a few megabytes of storage, and can handle special books and PDFs. -- Ec5618 13:34, 7 March 2006 (UTC)

Thanks, Ec - yes, I had seen the Sony reader, it just surprises me that someone has only come up with an item like this recently, or have there been other examples in the past (but which failed commercially, for whatever reason?) — QuantumEleven | (talk) 14:19, 7 March 2006 (UTC)

Weight / battery life / ease of use / reasonable cost have been a difficult combo to achieve. I don't think it's so much been a case of past failure as past lack of a feasible design. — Lomn Talk 14:35, 7 March 2006 (UTC)

• I have one called Paper. Features: Inexpensive. Requires no batteries. Lightweight. Durable. Disposable. Environmentally-friendly. Handles all text formats. Easier to read than LCD displays. (does require an external light source). Supports annotation and underlining. Etc. I'm serious here.. there aren't many benefits that justify spending $300 on a e-book reader (or even much less) when you can get a used paperback for $0.50. Looking at Amazon, it appears a new paperback is cheaper than the e-book. And that's if it's available as an e-book. I don't have to worry about dropping a paperback either. It's the classical case of a solution in search of a problem. --BluePlatypus 15:36, 7 March 2006 (UTC)

It depends a lot on what you what to read, and where. I do scientific research for a living. I'd love to have a lightweight, portable device that I could store, read, and annotate papers in. Something light, easy on batteries, maybe solid state storage, durable, touch screen for annotation...it would be sweet. I can imagine that someone travelling to a non-English-speaking country might want someplace to keep his novels—putting a month of reading in a backpack would be far too heavy. University students would be thrilled not to have to cart textbooks around.

Though the solution doesn't solve any of your problems, it's a bit hasty to suggest that it's useless. Presumably since the questioner is asking, he has a purpose in mind. TenOfAllTrades(talk) 16:19, 7 March 2006 (UTC)

The question was "Why aren't there any e-book readers?" or "Why aren't e-book readers more common?", and my answer was that they're simply not useful for most people and purposes. Especially compared to the hype they were getting 10 years ago. I didn't say they were useless. --BluePlatypus 16:58, 7 March 2006 (UTC)

When I have to wait for something, and I'm totally bored, I read classic novels on my Blackberry. It's good enough for reading and it's convenient. Proper e-books will never sell if the publishers want to price it the same as paper books. This is the same thing with the record collusions. --Zeizmic 18:13, 7 March 2006 (UTC)

How to categorize inventions?

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

• http://www.uspto.gov/go/classification/selectnumwithtitle.htm
• 002 Apparel
• 003 - UNUSED -
• 004 Baths, closets, sinks, and spittoons
• 005 Beds
• 006 - UNUSED -
• 007 Compound tools
• 008 Bleaching and dyeing; fluid treatment and chemical modification of textiles and fibers

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

Banned Gases

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

It was CFC. --cesarb 17:54, 7 March 2006 (UTC)

You're probably thinking of Freon, which is in the article on haloalkanes. —Keenan Pepper 18:00, 7 March 2006 (UTC)

That'd suck if they banned carbon dioxide.  freshgavinΓΛĿЌ  02:12, 8 March 2006 (UTC)

While carbon dioxide does not damage the ozone layer, it is a greenhouse gas, and, as such, excess levels of $CO_{2}$ may contribute to global warming. Thus, there have been attempts, such as the Kyoto Protocol, at limiting $CO_{2}$ releases. Ironically, ozone itself is also a greenhouse gas. StuRat 01:00, 10 March 2006 (UTC)

Health question

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

If benadryl clears up the problem, then it is probably an allergy. --Kainaw ^(talk) 18:43, 7 March 2006 (UTC)

Or a self-limited problem. alteripse 01:04, 8 March 2006 (UTC)

This sounds like a question that should be answered with: You should probably go to a family doctor and have your son checked out, especially if he is very young.  freshgavinΓΛĿЌ  02:15, 8 March 2006 (UTC)

Well, do that then, if you are so inclined. I, however, prefer not to bother people with the blatantly obvious. (This, of course, should itself have been a blatantly obvious remark, but given the amount of people who blurt out these disclaimers, apparently it is not.) DirkvdM 13:24, 9 March 2006 (UTC)

I don't know, I didn't think that giving a child benadryl was an obvious solution. I've actually never seen benadryl before, and I don't know (yet) how powerful or safe it is, though I'll surely check it up now. I also said that because it seemed like a pretty serious rash (spreading over the face, stomach, arms, and legs) and I thought it might be an indication of something else.  freshgavinΓΛĿЌ  07:32, 10 March 2006 (UTC)

A rash could be a zillion things - of course it's a case for a doctor! If he had a headache, fine, aspirin, but a rash over the kids entire body isn't something to just diagnose yourself or over an internet "forum"!! Do people in America have to pay to see a GP? --Username132 17:12, 12 March 2006 (UTC)

drug screen

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

I'm at a loss on the first, but I'd go with cocaine, PCP, opiates like heroin, and amphetamines. — Lomn Talk 18:29, 7 March 2006 (UTC)

Upon searching "THC drug" here at WP, it's tetrahydrocannabinol, the active chemical in marijuana. — Lomn Talk 18:32, 7 March 2006 (UTC)

I believe one tests positive on such tests for THC for years after the last usage, which makes the tests rather useless, I suppose. Depending on what one wants to know of course, but who would want to know you once had a joint as a kid? DirkvdM 13:27, 9 March 2006 (UTC)

THC (marijuana), COCaine, PCP, OPIates (heroin), AMPhetamines (ecstacy).

Impacted wisdom tooth

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

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

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

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

Interesting! Thanks for the reply. --BluePlatypus 19:47, 8 March 2006 (UTC)

Survey Question (Curiosity)

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

Records, a mouse, a New Folder icon (just kidding).  freshgavinΓΛĿЌ  02:19, 8 March 2006 (UTC)

I\'ve only bought ferrofluid, neodynium magnets, and planning to buy 205x4 foot sheet of mylar. — Preceding unsigned comment added by Mac Davis (talk • contribs)

A New England Patriots shirt, camo trousers, and a pair of Doc Martens. Not all at once, obviously. Sum0 16:44, 8 March 2006 (UTC)

Books, and some Frankoma pottery. User:Zoe|^(talk) 16:45, 8 March 2006 (UTC)

Nothing. Does that count? DirkvdM 13:30, 9 March 2006 (UTC)

Not really. I\'m trying to learn the market. You may have heard of the misspelling thing on eBay? Well, I\'m trying to see if I can make any money off that, but it requires knowing what will sell in the first place. Black Carrot 20:31, 9 March 2006 (UTC)

I have a total hatred for "spoof" sites (that use misspellings of common web URLs) which will prevent me from ever buying anything from them. From eBay I've bought a board game (King Oil) and a book ("North By Northwest" - The Alfred Hitchcock movie). StuRat 00:53, 10 March 2006 (UTC)

World's largest desert...

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

Antarctica appears to be bigger than the Sahara. [1] The Sahara is only the biggest (at least in its category) if you separate it like so: [2]. And another source with a nice map: [3]. EWS23 | (Leave me a message!) 00:34, 8 March 2006 (UTC)

Answer - it depends. If you define a desert as having less than a certain amount of precipitation per year, antarctica (which actually gets very little rain or snow) qualifies as a desert and thus is the largest desert in the world. If you define desert in terms of present ambient water, Antarctica (which contains a lot of permanently frozen water) does not qualify and thus the sahara is the largest. Raul654 03:15, 8 March 2006 (UTC)

Yes, it depends on what answer you want. For the largest dry desert, it is Antarctica, for the largest hot desert, it is the Sahara.

You appear to be rather proud you have an answer on that, that you advertise it so boldly. :) DirkvdM 13:32, 9 March 2006 (UTC)

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

Hm. That honour (?) often goes to Pitcairn Island. As to deserts, it's a little known fact that the Sahara contains so much sand that - if it was spread out - it could cover all of North Africa. Grutness...wha? 06:57, 8 March 2006 (UTC)

• Yes, Antarctica is definitely a bigger desert. The problem is that a lot of people don't define desert correctly. Hopefully, desert states correctly a desert is an extreme environment (not just a hot and/or dry one), but adjusting Sahara to say "hot desert" and Antarctica to say something else would fix this inaccuracy. - Mgm|^(talk) 09:39, 8 March 2006 (UTC)

Scientific Misconduct

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

See Scientific misconduct. -- Toytoy 08:17, 8 March 2006 (UTC)

In the US, the method mentioned for penalizing lawyers by disbarrment is mostly theoretical. An attorney can violate law (eg, in knowingly misrepresenting the identity and criminal status of a witness in a criminal trial) and suffer no penalty whatsoever. Not from employer (local district attorny's office), not from the courts, not from any agency charged to police crime -- perjury and subornation of justice would seem to be crimes to which attention ought to be paid by police, ... Even when the conduct is admitted under oath in another coart and in an affidavit given under penalty of perjury. The police are not interested, the FBI is not, and the courts ruled that no further filings would be accepted in matters relateing to the trial and alleged perjury during it.

The local Bar Association took nearly a year to even appoint an investigating attorney, he took several years to 'gather' evidence, and in the end the Bar Association Disciplinary Committee decided there was nothing to discipline. Actually happened in the 80s in King County Washington, believe it or not. Justice is not a word I'd apply with a straight face to such a system. An attempt at it perhaps. The theory's good, though. ww 12:15, 8 March 2006 (UTC)

Yes, there usually is one or even two ways of policing research fraud. First is that most (reputable) universities will appoint, if an accusation of fraud occurs, a review board to scrutinize in detail the research in question. If it's found to be fraudulent the researcher can face suspension or termination from their position. And there will be notices of this in the journals who published the papers. Secondly, the people issuing grants almost always have independent reviewers and auditors of the research conducted for their grant money (They don't just give the money away without checking that you're doing what you said!). For serious research fraud, it almost certainly means your career as a scientist is over, because you'll have little hope of getting a new job, or getting grants.

As for what kinds of scientists get involved in it.. I think it depends on the fraud. Ideally, a scientist is supposed to have an open mind, and be prepared to drop any idea as soon as there's convincing evidence for the opposite. In practice, this can be harder to do. How do you not get emotional about something you've worked hard on for years? Also, there's an entire spectrum of dishonest behaviour, and it's not always clear when you're in the wrong. Some of the main things reviewers encounter are whether you've investigated alternative explanations enough, and whether your conclusions are supported by the actual results. It's pretty much accepted that people will often draw conclusions as large as can possibly be supported. Then you've got leaving out things which may cast doubt on your results. It could be something insignificant, but it could also be something which you're fooled yourself into believing is insignificant. At the far end, you've got folks who systematically fabricate results without even doing the experiments. I guess they're motivated by careers. I wouldn't really know, though. --BluePlatypus 19:19, 8 March 2006 (UTC)

March 8

Composite Spacecraft

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

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

Would about kevlar?

The Sea as the Largest Desert

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

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

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

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

According to Chambers

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

And I agree.
Slumgum 02:45, 8 March 2006 (UTC)

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

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

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

Is natural selection inherently "intelligent?"

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

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

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

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

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

I think you first gotta define what intelligence is. What do you consider to be intelligence here? One could argue it's about conciousness. You think the biosphere is self-aware? ☢ Ҡi∊ff⌇↯ 02:23, 8 March 2006 (UTC)

If intelligence is the ability to come to conclusions without resorting to trial-and-error, then I don't see why this wouldn't be a significant benefit in terms of evolutionary gain. While it is often said that intelligence is not expected from evolution, it is certainly probably because of the possible benifits towards survival that it allows. If an ancient ancestor of a tree (a pre-tree organism) had been able to estimate an efficient size-ratio for a tree through the use of basic mathematics, they would have saved a lot of evolutionary time that could be spent evolving on other benificial things (like walking trees, talking trees, cocktails manufactured for tree-like sensibilities). POV: I don't believe evolution constitutes intelligent design because it doesn't have this ability to make a logical choice without significant stimulus. By some definitions of intelligence, though, it could be interpreted that way. You'd be pushing it though.  freshgavinΓΛĿЌ  02:37, 8 March 2006 (UTC)

Regarding the definition of intelligence: I agree that the biosphere doesn't fulfill the requirement of self-awareness or consciousness, but why should that be a prerequisite of intelligence? Consciousness is "the most profound mystery facing modern biology" (also Dawkins). If we do not even understand it fully, I think this allows us some latitude in defining intelligence. I think it's unfair (as in anthropocentric) to have such a narrow definition of intelligence as the one commonly accepted, with the restrictions imposed on it by both Kieff (conciousness) and freshgavin (a non-trial-and-error thought process). It seems as if we define intelligence for the express purpose of excluding all non-human entities from having it! --JianLi 02:40, 8 March 2006 (UTC)

If you use the definition "The capacity to acquire and apply knowledge" and you fudge a bit by considering encoded information to be "knowledge", then you could say that a biological system exhibits intelligence through the use of DNA and natural selection. If, however, you use the definition "The faculty of thought and reason", I don't think it would apply. Even in the first case, though, it's a bit of a stretch, semantically. Kaldari 02:53, 8 March 2006 (UTC)

I didn't mean to imply that a "non-trial-and-error thought process" equals intelligence, but merely that it's probably a subset of a few processes that when combined form a complete definition of intelligence. I agree that stating intelligence is conciousness or self-awareness is very presumptuous given our understanding, and it's inherent difficulty to justify, and I think it's more useful to define intelligence as a combination of ... abilities? which can each be (relatively) easily defined. You could liken it to Wikipedia, which is much easier to define accurately in WP:NOT than in Wikipedia:What Wikipedia is.  freshgavinΓΛĿЌ  04:23, 8 March 2006 (UTC)

I am not quite certain that humans have a non-trial-and-error though process. Certainly, we do not manifest every erroneous creation. But it is quite possible that we making leaps of imagination, we are simulating trial and error in our heads, and combining it with a processing engine that processes the consequences of each assumption - something really fairly identical to natural selection. -User:Fangz (not logged in)

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

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

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

You've asked "why not" without first considering "why".  freshgavinΓΛĿЌ  07:27, 8 March 2006 (UTC)

See Gaia theory (science). User:Zoe|^(talk) 16:48, 8 March 2006 (UTC)

BluePlatypus, I don't think vestigial organs or genes immediately disqualify the process that created it from being intelligent. Intelligent animals do many irrational things (for example, things which are done more out of habit than because of utility, and which may actually detract from utility). Yet, in the sense that I am talking about, people who are highly irrational are still "intelligent beings." Of course, you may call them "unintelligent" or "stupid" in the sense of "what a stupid/unintelligent person!", but of course that's a different usage of "intelligence." JianLi 23:26, 8 March 2006 (UTC)

'Intelligent' is a subjective term, and it's pretty useless to discuss what constitutes an 'intelligent' process or not. Do you want a semantic discussion or a biological one? My point is/was that it obviously costs energy to produce and maintain those vestigal traits and since they provide no benefit to the organism, they're a burden. That doesn't mean they're 'mistakes'. Vestigal traits are an unavoidable consequence of how evolution works. - It's an illustration of Steve's point, that evolution does not work towards a 'global' optimum, but towards the best it can do "working with what it has". --BluePlatypus 12:37, 9 March 2006 (UTC)

I feel I should add that even though the question won't be resolved here, it's a really beautiful idea, JianLi, and lots of fun to think about. Thanks for bringing it up.Adambrowne666 02:54, 14 March 2006 (UTC)

Big Bang

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

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

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

It is quite possible to create "something from nothing" - ie, ex nihilo, viz. quantum field fluctuations and such. Of course, this in itself raises a lot of peculiar issues. As for the original question, I think it is too general for it to be answered with any precision. I would like to see someday, someone publish a paper linking evolution and nonextensivity. Now that would be most wonderful. --HappyCamper 04:47, 8 March 2006 (UTC)

While it is quite possible to "create something from nothing," due to quantum effects, a common misconception of what the big bang theory presents is that all matter today came out of one point in time in a huge explosion. This is incorrect. The big bang theory presents that at some point billions of years ago, spacetime suddenly began expanding, greatening the distance between things, but without moving them. The big bang theory breaks no laws of thermodynamics.

A recent Gallop poll showed roughly 50% of Americans believe in creationism over evolution. People don’t generally reject evolution because of little or no evidence in support of it, they reject it because of their religious convictions, and because it’s not obviously intuitive, there is an illusion of design which people find hard to comprehend, so why bother with scientific evidence showing evolution to be wrong when you can simply refuse to believe in it out of a rigid mindset which rejects the possibility of accepting design without a creator? Evolution's illusion of design misleads even very smart, educated people. Lots of engineers, for example, will quote you the eye as something that is "obviously designed". Werner von Braun, father of both Hitler's and Kennedy's rocket programs, was of this opinion and was not shy about saying so. -- Mac Davis] ☢ ญƛ. 04:54, 8 March 2006 (UTC)

Since the nazis believed they were a "master race" of eveolved supermen, wouldn't that actually make them histories strongest supporters of darwin?--Somebodye6436346 05:15, 8 March 2006 (UTC)

Now that this topic has been Godwinned, can we pretend it's gone? Melchoir 05:23, 8 March 2006 (UTC)

I think so, but read my answer first. -- Mac Davis] ☢ ญƛ. 06:43, 8 March 2006 (UTC)

Re the Nazi's, I think that would merely classify them as people who have incorrectly applied Darwin's theory. Evolution has no "goal" (but if it did, I guess that would prove my argument ;-) ), so the supposed "Master Race" is just an accident of evolution. In addition, humans aren't the epitome of evolution anyway. Just the fact that both humans and cockroaches exist today puts us on about equal footing, I think. And if there were a nuclear holocaust, cockroaches would probably have a better chance of surviving. So, in that case, the "master race" would more likely be cockroaches than Aryans. JianLi 23:41, 8 March 2006 (UTC)

Or if you read Kafka, it could be both ;)64.12.116.74 23:47, 8 March 2006 (UTC)

Haha JianLi 00:10, 9 March 2006 (UTC)

Some points of clarification since we seem to have gone off track:

• The Big Bang is not an explosion. It is an inflation of space. Space itself expanded - not just a ball of matter within it.
• We don't know what there was before the big bang. In fact, it is fairly absurd to talk about such a notion. Theories about the origin of the big bang are currently really only just speculations, because we have no measurements whatsoever from such a time. In particular, it cannot be asserted that there was nothing before the big bang.
• Nothing itself is hard to define. Empty space is filled with all sorts of quantum weirdness. And even without that, we have the curvature of space to consider and so on. The big bang may simply break all laws of science, because these laws only came into existence with the big bang.

-User:Fangz (not logged in)

Sand ridges

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

• The answer is antimatter, it makes sand split in twos, because everyone knows antimatter doesn't split into fours--205.188.116.74 03:52, 8 March 2006 (UTC)

Well, a 3-split would quickly become two 2-splits when one of the three daughter ridges shifts a little. Then there's probably an effective repulsive force between ridges, which would in turn move the 2-splits away from each other until they don't coincide visually. Of course, I'm just making this up. Melchoir 04:05, 8 March 2006 (UTC)

I'm looking for an answer possibly related to fluid dynamics and criticality... --HappyCamper 04:32, 8 March 2006 (UTC)

Perhaps it's the other way 'round - two ridges approach each other and meld into one. hydnjo talk 04:48, 8 March 2006 (UTC)

Okay, I've done some research (try searching for "aeolian" on arXiv), and the ripples do tend to merge over time. There is little known about the two-dimensional dynamics, particularly the evolution of defects, but I found at least one reference:

• Blown by wind: nonlinear dynamics of aeolian sand ripples

See "Two-dimensional ripple fields" towads the bottom. Melchoir 05:10, 8 March 2006 (UTC)

How did you know to search "aeolian"? This was a key word that I was not aware of. --HappyCamper 17:20, 8 March 2006 (UTC)

The fifth paragraph in the Sand article starts with, "The study of sand is called arenology", an article which was started only a couple of days before HC started this section! A Google search of "Sand ripples" gets you this interesting study. hydnjo talk 19:46, 8 March 2006 (UTC)

Oh, I tried searching arXiv for more obvious words like "sand" first, which led me to the magic jargon. Melchoir 20:14, 8 March 2006 (UTC)

Chemical Engineering

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

Ethanol - Water - Ethyl Acrylate

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

If you're going to post your homework, could you at least not phrase it as a command? Melchoir 07:45, 8 March 2006 (UTC)

People who aren't creative enough to do their own homework also aren't creative enough to rephrase it when they type it into a reference desk service like this and "ask" someone else to do it for them. But don't complain; the blatant problem-set diction is a useful marker: it reminds us not to answer. —Steve Summit (talk) 15:49, 8 March 2006 (UTC)

Indeed. Melchoir 20:18, 8 March 2006 (UTC)

Good point JianLi 00:14, 9 March 2006 (UTC)

• I'm sure they asked you the question with the intention of teaching you how to look it up yourself. Either try the course book, or use a library reference like the "Handbook of Chemistry and Physics" or some "Physical chemistry" book. - Mgm|^(talk) 09:44, 8 March 2006 (UTC)

nuclear reaction

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

In a nutshell, the law of conservation of mass was superseded (it's no longer a strictly accurate "law") when Einstein discovered e = mc².

Our article on conservation of mass is a bit short, but might be of help to you. In brief, the principle of conservation of mass is an approximation - in chemical reactions, some mass is lost/gained, but the quantities are so infinitessimally small that they can be safely ignored, leading to the "mass is constant" rule, which for these works perfectly well. For nuclear reactions (such as nuclear fission or nuclear fusion), the mass gain/loss starts to become measurable, and so must be taken into account. The extreme case is matter-antimatter annihilation, where all mass is converted to energy, and so "mass is conserved" is obviously incorrect.

More accurately, energy is always conserved, if, by using E=mc² , you equate mass to its equivalent in energy. — QuantumEleven | (talk) 08:36, 8 March 2006 (UTC)

• With nuclear reactions the mass isn't lost either. It's just converted into energy. - Mgm|^(talk) 09:45, 8 March 2006 (UTC)

• The conservation of mass and conservation of energy laws must just be combined to say "the total of the mass and energy of a system is preserved, with respect to the equation E=mc²". This can be described by the following equation:

$E_{i}+m_{i}c^{2}=E_{f}+m_{f}c^{2}$

Where:

$E_{i}=$ initial energy of the system

$E_{f}=$ final energy of the system

$m_{i}=$ initial mass of the system

$m_{f}=$ final mass of the system

$c=$ speed of light

StuRat 20:46, 9 March 2006 (UTC)

StuRat, your terminology is... shall we say, nonstandard. What you call "energy" is really kinetic energy; what you call "total of mass and energy" is really energy. Melchoir 01:07, 10 March 2006 (UTC)

"Energy" would not just be kinetic energy, but would also include other forms of energy such as heat and gravitational potential energy. The equation I listed does convert everything (including mass) into energy for a quantity comparison. However, you could just as well divide by $c^{2}$ to convert everything into mass for a quantity comparison:

${\frac {E_{i}}{c^{2}}}+m_{i}={\frac {E_{f}}{c^{2}}}+m_{f}$

StuRat 01:54, 10 March 2006 (UTC)

Okay, yes, if you want to include those kinds of energy without calling them kinetic; I was thinking of simpler systems. My point is that in relativistic contexts, the symbol E and the word "energy" already include mass. So either you're using symbols in a way contrary to everyone else, or you're counting the mass twice. Melchoir 02:03, 10 March 2006 (UTC)

Well, I doubt if most people, including the person posing the question, are thinking in those "relativistic terms", thus the need for my explanation. StuRat 02:08, 10 March 2006 (UTC)

If most people think of the speed of light and mass-energy equivalence in nonrelativistic terms, then they're wrong, and we do them a disservice to perpetuate their ignorance. Energy is conserved, period. Melchoir 02:18, 10 March 2006 (UTC)

Using the term "energy" to include mass is just a linguistic choice, thus there is no right or wrong answer, only "more common" and "less common" usages. What exactly do you call energy excluding mass, then ? StuRat 02:28, 10 March 2006 (UTC)

It is, in fact, a linguistic choice that was made decades ago. For a single particle, energy minus mass is the definition of kinetic energy; for a complex system it's more complex. Melchoir 02:41, 10 March 2006 (UTC)

There is no body that "decides" what a word will mean in the English language, it means whatever people use it to mean. Dictionaries only report what it means, they don't chose what it will mean. StuRat 04:35, 10 March 2006 (UTC)

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

We\\\'re always told that on the Moon your gravity is something like 1/6th of its weight on Earth and you could effortlessly jump three metres high (or something like that). So why is it that in existing moon footage all the astronauts do is pussyfoot around with those tiny skip-hops? If I ever landed on the moon the FIRST thing I\\\'d do is jump around like I was on a trampoline. So why didn\\\'t they? Professional discipline? Risk of damaging the suits? Or is it proof the landings were faked? — Preceding unsigned comment added by 202.72.148.102 (talk • contribs)

Some reasons include:

• the suit had a mass of 180 pounds [4]
• the soles of the boots were (I think entirely) stiff, depriving the astronaut of all of the jumping power of his foot and ankle - try putting on a pair of snowboarding boots and see how high you can jump.
• I guess they\\\'d also be worried that, if they fell, they couldn\\\'t get up.

--Finlay McWalter | Talk 12:05, 8 March 2006 (UTC)

I\\\'d assume they\\\'d also be worried about landing badly and ripping the suit on a rock or something, which would ruin one\\\'s day rather. Sum0 16:40, 8 March 2006 (UTC)

Also, the legs of the spacesuits were rather stiff - they would have trouble bending their knees very far. You try jumping very high if you\\\'re only allowed to bend your knees a little way (and barely using your arms for balance and momentum). — QuantumEleven | (talk) 12:40, 8 March 2006 (UTC)

You may also be interested in reading our article on the moon landing hoax. In a nutshell, most \\\"hoax\\\" arguments are the result of drastic simplifications or sheer ignorance. — Lomn Talk 15:08, 8 March 2006 (UTC)

I read once that in addition to all the other hinderances of the suit, it was nearly impossible to bend at the waist considering the suit stiffness and pressures involved, so they had to use a pulley mechanism just to lean over. Think of it this way, you are bound in nearly every way except the ability to wiggle your arms and legs a minimal amount. The fact that they got around as much as they did is amazing in itself.

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

LOLZ!!1!1 onely noobs r \\\'fraid of xpl0siV d-comPr3ssi0n!1!1!! NOOB! rofl Black Carrot 20:00, 9 March 2006 (UTC)

They would have needed thicker wires in the studio for higher jumps. For great justice. 21:58, 9 March 2006 (UTC)

Why are computers so flaky?

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

I blame the parents.
Slumgum 13:03, 8 March 2006 (UTC)

Did you buy a cheap computer, or look for a highly reliable one? For example, most hard disk manufacturers sell premium lines that go into servers and have a much higher MTBF. In fact, hard disks are the only thing I've seen much of failing, and they inherently will fail one day: reliable computers are designed to accept this and make sure it does not matter. But people don't look for reliable computers, by and large: they look for the cheapest one with the list of features that they think they need. Notinasnaid 13:07, 8 March 2006 (UTC)

Computers are seen as consumer products, and are sold to the masses who, by and large, have absolutely no idea what they're buying. They look at a few of the numbers in the spec (speed, HD space, RAM...), then buy the cheapest one for a given spec. This drives the PC manufacturers to build cheaper and cheaper components - they can't sacrifice performance, so they sacrifice quality, especially knowing as computers become obsolete so fast anyway that they often don't even reach component failure.

It's certainly possible to build computers that are tough and durable - look at the computers on deep-space probes, those things are designed to run for decades in a radiation-filled environment, extreme cold with no maintenance whatsoever. They're ridiculously tough. And, of course, ridiculously expensive, for the same reason.

Bottom line - if you know what you're buying, you can certainly buy a computer which is much less likely to die (for whatever reason) than that $899 super-deal PC at the local supermarket. But you'll pay for it. — QuantumEleven | (talk) 15:22, 8 March 2006 (UTC)

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

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

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

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

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

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

Righty-o. I've never EVER had any hardware problems with my last three Apple computers. Well, one time I dropped my Apple Pro mouse on the tile floor too many times. :| -- Mac Davis] ☢ ญƛ. 07:35, 10 March 2006 (UTC)

• Personal computers are consumer products, and as such they're made to be as cheap as possible, even if that means occassional hardware failures. For applications where failure is more important there are correspondingly Workstation machines and at the top end, there are Mainframes. Mainframes are almost invunerable to hardware failure, because there are backup systems for just about every component. --BluePlatypus 19:54, 8 March 2006 (UTC)

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

I think this question suggests the wrong approach. Hard drives will fail, and unless you prepare for it, then it will be a nuisance in a week, or a nuisance in 2 years: still a nuisance. You should be looking for ways to avoid hard drive failure being a big deal. Backups, of course, but restoring can still be an annoying waste of a day, so why not add mirroring. Not a hugely expensive option, and I tend to specify it on any computer I value. Notinasnaid 21:09, 8 March 2006 (UTC)

Hmm, what is a mirroring option? hydnjo talk 21:59, 8 March 2006 (UTC)

Mirroring is basically installing two identical hard drives, and setting up either a hardware or software solution that makes sure that every disk write goes immediately to both drives. If one drive fails, the other drive is used - nominally automatically, but especially with IDE drives a failed drive may lock up the PC so you might still need to disconnect it. Then you put in a replacement as quickly as possible and resynchronise. Key thing to watch out for: if you don't have a system for checking whether one mirror has failed, you might as well not have bothered! I use a hardware solution from Promise, preinstalled by Dell. Monitoring options are poor: you have to do it manually. Notinasnaid 22:13, 8 March 2006 (UTC)

Emphasize what Notinasnaid said about monitoring! There is nothing so embarrassing as losing all your data because your backup drive fails also (i.e. when a second drive fails after you failed to notice that the first had failed). It's like discovering that your spare tire, when you need it, is flat, or that your fire extinguisher is empty, or that your UPS doesn't work. —Steve Summit (talk) 03:51, 9 March 2006 (UTC)

I'd say the basic answer to this question is that computers are based on principles that were invented 100 years ago. The basic structure of a computer has hardly changed at all in the last 30 years (or even 50). We just keep on inventing cooler parts, and adding them to a very old model (that works pretty well). The computer industry would benefit hugely from a completely re-thought computer model, one that didn't have you navigating through things like the BIOS, valence/integrity checking, memory permission errors, priority issues in IDA ports, and peanut butter on your CD-ROM tray. They've got a lot of new principles (like true plug-and-play and modular systems), but since they're all based on really old structures that weren't initially intended for such fancy shmancy gidjits, there's always going to be weird errors popping up, backdoors, and headaches.  freshgavinΓΛĿЌ  01:42, 9 March 2006 (UTC)

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

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

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

Yes, mirroring is one particular type of RAID, specifically RAID 1. --WhiteDragon 17:14, 10 March 2006 (UTC)

Going back to the discussion of software, that is where I find most of the trouble. I rarely have hardware fail but on a daily basis run into an "illegal operation" type error. The basic concept of a PC, that many programs will run simultaneously, some originating locally and some from over the Internet, and that they will each work together nicely, is flawed. This allows one program, whether maliciously or accidentally, to mess up all the other programs and bring the computer down. Each program should run in total isolation, with no ability to affect the others. I envision a parallel computer with, say 32, old, dirt-cheap processors, each with it's own old, dirt cheap hard drive. These programs could run independently so that even the most virulent could not possibly affect anything beyond it's processor and hard disk. One of the 32 processors would run a master control program which would kick off the others and control which programs have control of the monitor and accept input from the keyboard and mouse. Too bad we can't convince Bill Gates to come out with something like this (he prefers coming out with "new and improved" versions of windows with "new and improved" bugs, since each new O/S of his is based on the same flawed model of programs "cooperating nicely"). StuRat 20:26, 9 March 2006 (UTC)

This would be possible if somebody went back and thought about how to build a computer from scratch, and build it in a way that programmers wouldn't have to worry about system specs and fidgities. I don't even think we need to bother with the concept of a conventional "processor".  freshgavinΓΛĿЌ  07:25, 10 March 2006 (UTC)

To answer your questoin - yes, for people who are willing to pay for it, you can get a computer that has extra reliability. A blade server, for example - you can literally rip pieces out of it while it's running and it will keep on humming fine. On the other hand, it's going to cost you a pretty penny. If you want to insulate yourself from hard drive crashes, you can pay for full drive mirroring (Raid level 1, I think -- two hard drives doing exactly the same actions in paralllel - if one of them fails, you have a perfect copy already handy without worrying about data loss).

As to your more general - why are they prone to destructoin question - it depends on what you mean. Hardware destructon is relatively rare - certainly much less so than an automobile, for example. Software screwups are quite a bit more common, owing to the huge general purposes for which computers are applied, and the number of possible bad interactions increases in proportion to the factorial of the number of tasks a computer is running. Raul654 07:31, 10 March 2006 (UTC)

BTW if using mirroring or raid it may be worth mixing the makes/models. You will like lose in performance and waste some capacity (as the drives will never be exactly the same size) but you will protect yourself from batch faults. Plugwash 01:34, 14 March 2006 (UTC)

Searching For Research Groups

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

Nope. I'd suggest you either A) Just ask someone in the field. They should know. B) Check some review papers on the subject and check the reference list for such groups or C) Look for representatives from those places in conference schedules on the subject. --BluePlatypus 18:53, 8 March 2006 (UTC)

As BluePlatypus said, check existing papers on the subject. Most will be written by professors at other universities. One problem I've found about working in research for the past fifteen years is that it is very hard to get into if you aren't either a professor or a student. So, I decided to get my PhD and become a professor so I can keep doing research easily. --Kainaw ^(talk) 19:03, 8 March 2006 (UTC)

Conservation Of Momentum In Time-Demension

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

• It depends, what does that question mean??--64.12.116.74 20:17, 8 March 2006 (UTC)

Oh, you're going to love this. Check out Noether's theorem. Symmetry under translations in space leads to conservation of momentum, and symmetry under translations in time leads to conservation of energy. —Keenan Pepper 20:22, 8 March 2006 (UTC)

Dang, beaten to it! Well, also check out the article Four-momentum. Melchoir 20:25, 8 March 2006 (UTC)

well, 2 edit conflicts later, all I have left to offer is fourth dimension, I feel so inadequate );64.12.116.74 20:30, 8 March 2006 (UTC)

Thirteen minutes to post a sub-adequate reply, that must be a record!  freshgavinΓΛĿЌ  01:36, 9 March 2006 (UTC)

So if something explodes, the products of the masses and the amounts they are accelerated through time will equal those of the particles deccelerated and/or sent back in time? --Username132 02:31, 9 March 2006 (UTC)

If you interpret "acceleration through time" as a change in the Lorentz factor of a body, and you carefully also take into account changes in mass, then yes: you can make this into a meaningful, true statement. Ultimately it's still just conservation of energy. Melchoir 02:44, 9 March 2006 (UTC)

Cold shock and free radicals

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

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

Thanks for your help! --Nick123 ^(t/c) 21:35, 11 March 2006 (UTC)

March 9

animals that are consumers and producers

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

A grey seal and a grey lion? Or a lion and a grey seal? Or possibly a grey seal and a sea lion?  freshgavinΓΛĿЌ  01:33, 9 March 2006 (UTC)

It depends. If they are middle class, they are consumers. If they are upper class, they are predators. If they are lower class, they are a safety net for the middle class and the source of all society\'s problems for the upper class. Wait... isn\'t this your sociology homework? --Kainaw ^(talk) 01:44, 9 March 2006 (UTC)

Following the link in Consumer to the biological form of the word, I get Heterotroph, which links to Autotroph, the scientific word for producers. Those go into comfortable detail about what each is and isn\'t. In case you actually meant to include the word \"predator\" and it wasn\'t a typo, you might try Predator and Prey as well. Black Carrot 13:05, 9 March 2006 (UTC)

Chewing Gum (CareFree)

What is florason?

She's the Roman goddess of Spring dad. Grutness...wha? 07:17, 9 March 2006 (UTC)

Floraison is the French word for "flowering." My guess is that it is artificial fragrance in the gum. -- Mac Davis] ☢ ญƛ. 10:10, 9 March 2006 (UTC)

The Moon

Why is the flag waving if theirs no gravity.

• Cuz they obviously faked the moon landing, and you've discovered the one long lost bit of proof that we've been looking for ever since 1894 when the aliens first landed in the hills of MT.BOGATAWOGASFEILD, at last we can expose their secret, moon-landing-faking, alien agenda, and the MT.BOGATAWOGASFEILD aliens will be defeated forever!--64.12.116.74 00:38, 9 March 2006 (UTC)

• See moon landing hoax. Also, the reason why the flag is waving is because there's an atmosphere in the sound stage where they faked the landing. Both Earth and the Moon have gravity—which is necessary for the flag to hang properly. TenOfAllTrades(talk) 00:40, 9 March 2006 (UTC)

There is gravity on the Moon, but little wind. If you're talking about Image:Buzz Aldrin with U.S. flag.jpg, I can only assume that when you jostle a hanging piece of cloth in the absence of air resistance, it doesn't settle down until its internal friction absorbs the energy, which will take a while.

Also, it's a fake. Melchoir 00:44, 9 March 2006 (UTC)

Dang, TenOfAllTrades' link kicks my ass. Melchoir 00:47, 9 March 2006 (UTC)

Has anyone considered that the Moon Landing hoax goes even deeper? What if the Moon itself is a hoax? The Moon Landing was just there to reinforce the propoganda that there is a Moon and not a huge spy satellite floating around above our heads. --Kainaw ^(talk) 01:41, 9 March 2006 (UTC)

No, don't be crazy, it was the aliens--64.12.116.74 01:44, 9 March 2006 (UTC)

The 'Moon Landing Hoax' was itself a hoax. They wanted to prove to the Russians that they could do a really good hoax, and have them quiver in their vodka. Unfortunately, they couldn't make convincing enough and actually had to go to the moon for the pictures, while still saying it was done in a sound studio. --Zeizmic 02:40, 9 March 2006 (UTC)

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

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

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

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

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

Gravity doesn't make the flag wave, wind does (and it doesn't wave), it is rigid. -- Mac Davis] ☢ ญƛ. 10:12, 9 March 2006 (UTC)

• Here's why the flag was moving:

1. There is gravity on the moon, just less than on earth.
2. There was something sewn in the top to keep it up.
3. No gravity doesn't mean no wind.

Why people are so hell-bent on claiming anything to be a hoax, I'll never know. - Mgm|^(talk) 10:18, 9 March 2006 (UTC)

Well one reason they keep on huffing about is because a lot of the explanations given are a little bit weak. There's some flaws in the way you worded it. a) The flag was moving because there's gravity on the moon. If you think of from the perspective of a human being, gravity is the thing that causes everything to STOP moving (when it hits the ground). An absense of gravity causes things to coninue moving forever (from a relative position) and so this doesn't make sense as an argument. b) It moves because there's something on the top to keep it up. Again, something stiff on the top was put there to keep it from moving (e.g. keep it up) so it sounds strange to use this as a reason. c) No gravity doesn't mean no wind. Actually, it does. Without any gravity, particles will not gather together in one place (let's say, the atmosphere) and thus there will be no substance around to create any wind, just empty space. What I think you meant to say was: 1) The gravity on the moon caused the flag to ruffle as it was being set. 2) There is a bar sewn at the top of the flag to keep it from falling down. #3 doesn't really need to be said.  freshgavinΓΛĿЌ  07:18, 10 March 2006 (UTC)

OK, since it seems people want every T dotted and every eye crossed, let's put it this way. The wire at the top of the flag kept the top rigid. The flag would therefore have been stretched to its full length from hoist to fly, rather than hanging limply. Since the flag would need to have been moved into position in order for it to have been erected on the lunar surface, it would have been in motion to get it to that position. The bottom edge of the flag was not wired, and was hanging freely. Due to inertia, it would not have automatically been in direct position below the upper edge of the flag the second the flag was erected. Thus, the bottom edge would have acted very much like a pendulum - it would have moved backwards and forwards until it came to rest due to gravity at its lowest possible point. Due to the lower gravity of the moon (as compared to the Earth) and the lack of air resistance to the flag, this slight motion would have taken quite a long time to subside. What was seen as the "flapping" of the flag was nothing more than this - the bottom edge of the flag acting as a pendulum beneath the rigid upper edge. Happy? Grutness...wha? 10:09, 10 March 2006 (UTC)

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

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

Evolution

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

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

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

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

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

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

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

Yeah. As far as classical evolution is concerned, environment cannot have such a direct effect. On the other hand, there are exceptions to such a rule. For example, exposure of some organisms to stress can cause a faster rate of mutation - not exactly the same, but close. Some research may also be concerned with feedback effects between organisms and their habitats - as an organism's phenotype changes, it may cause changes to its environment that continuate its own phenotype. (If we use rather broad definitions, we can speak of human society and education in particular as an example of this) - User:Fangz (not logged in)

There's still an ongoing debate on directed mutation (which might need an article), as Fangz noted. I seem to recall that there was a study involving exposing fruitflies to high heat. This may be it, the various references on this are also interesting.

Supporters indicate that there is experimental evidence of certain cellular mechanisms for repairing 'damage' mutations which may be suppressed under environmental stress; this is posited to be a fitness trait of another order which allows a species to 'speed up' selection by increasing mutations when there is high environmental stress. Detractors usually mis-identify directed mutation with Lysenkoism by defining it as "the hypothesis that mutations that are useful under particular circumstances are more likely to happen if the organism is actually in those circumstances."[5] However, there is some very interesting experimental evidence that the cell may be able to "choose" the mutation.[6]

I also browsed a science fiction book called Darwin's Radio by Greg Bear which seemed to have a plotline along this angle. KWH 17:42, 9 March 2006 (UTC)

The gender ratio of offspring can be affected by the environment, such as the average temperature of the father's testicles. StuRat 19:53, 9 March 2006 (UTC)

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

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

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

The oscillation is interesting, but there are cases where life has changed the Earth in a negative way for it's own survival. Early plants gave off oxygen and thus filled the air with it. However, free oxygen was toxic to these early plants, so later plants, and then animals, needed to develop a defense against free oxygen. Our layer of dead skin on the surface protects us nicely. A current example might be global warming, which may be disastrous for human life. StuRat 10:29, 10 March 2006 (UTC)

I haven't read Ender's Game, but that sounds a lot like the Daisyworld simulation of James Lovelock's Gaia hypothesis. KWH 14:59, 10 March 2006 (UTC)

Yes, yes that's it! So they were daisies after all. I highly recommend the books, anyway. Mostly written in the 1980s, they're not perfect sci-fi books (Card is not a scientist, but a religious man), but if you can imagine it as an adventure series they can be quite inspiring.  freshgavinΓΛĿЌ  05:51, 13 March 2006 (UTC)

Effect of bodies of water on surrounding areas

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

See continentality, which is the opposite of oceanity or oceanicity, which is something like what you're talking about. If you do a google search for "climate", "body of water", and "specific heat" you'll find more. —Steve Summit (talk) 06:20, 9 March 2006 (UTC)

Moderation. The water moderates the climate. --Anonymous, 08:48 UTC, March 9.

I looked around. There's a little bit on microclimate. Googlize and you find a bit more. --Zeizmic 12:36, 9 March 2006 (UTC)

Lake effect snow, Orographic lift, http://www.noaa.gov/questions/question_011602.html ,http://meted.ucar.edu/norlat/snow/lake_effect/1.2_instability.htm. WAS 4.250 14:55, 9 March 2006 (UTC)

Parabolic hotdog cooker

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

May I suggest the Solar death ray? :) --Obli (Talk)^? 06:40, 9 March 2006 (UTC)

Did you see solar cooker? And there are some interesting links from there. --Shantavira 08:25, 9 March 2006 (UTC)

I remember when I did that in 8th grade, I shared my two hotdogs with my friends. *tear* A Frensel lens off Ebay is what you want to do. You can find directions for building the box and doing the right math (if you are doing this for school). Have fun! Also try cooking other things, and things that aren't food. (Shotgun shells don't work well). Ow. -- Mac Davis] ☢ ญƛ. 10:05, 9 March 2006 (UTC)

I believe you meant to say a Fresnel lens. StuRat 19:45, 9 March 2006 (UTC)

Loperamide

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

• What did the packaging say about dosage? - Mgm|^(talk) 10:19, 9 March 2006 (UTC)

To intially take two 20mg pills and then another one every time I had a loose bowel movement (which I haven't had so the initial dose was the only one). Looking at the infobox in the article, the elimination halflife is ~10 hours so I should still have about 5mg floating around my system, which makes me a bit less worried. (And my stomach just rumbled, which makes me thinks might be coming back to life.) --Bth 10:29, 9 March 2006 (UTC)

By the way, don't take anti-diarrheals if you think it's being caused by an infection. Diarrhea is a good thing since it flushes out the organisms. Just be sure to stay well-hydrated with an oral rehydration solution preferably or a sports drink like Gatorade. --Uthbrian (talk) 19:21, 9 March 2006 (UTC)

PC catastrophe

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

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

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

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

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

Wow! I just got a mirror delivered by UPS. It was dropped on my porch (I think they waited for me to go away a few minutes). It looked liked it had bullet holes through it. The box was falling apart, so it looked like the guy tipped it to stop glass shards from falling out. Does this answer the question? No -- shit happens. --Zeizmic 12:38, 9 March 2006 (UTC)

I had a server delivered by FedEx about 10 years ago. It was in fine condition if you ignored the steel rod going through the package (and server). I brought this to the delivery guy's attention and he replied, "So, you're saying the rod isn't yours?" Does that answer the question? No. But, an answer could be: The card is apparently an AGP card. Windows failed on an AGP library. A hard reboot was apparently done, which messes up the Windows files. A reinstall is required. See if you can disable AGP in the BIOS and use the card like it is a PCI card. If you have an LCD display, ensure you are using a resolution it can display - otherwise you will get a blank screen even when the card is working perfectly. Expect 90% of what you purchase through cheap discount dealers to be garbage. If it was actually a great deal, someone would have bought it before you saw it. --Kainaw ^(talk) 13:22, 9 March 2006 (UTC)

Is it possible that you might have inadvertently loosened the heat sink on your CPU when you swapped graphics cards? Poor contact between the CPU and heat sink will result in inefficient cooling; a processor that's running hot will cause the PC to behave erratically and hang periodically (whenever the CPU warms up). Running for extended periods with a poorly-attached heat sink will eventually cook your CPU (possibly leading to the smell of burning and the release of the magic smoke.) TenOfAllTrades(talk) 13:55, 9 March 2006 (UTC)

What is the material that actually burns to produce this smoke? --Username132 22:28, 9 March 2006 (UTC)

The smoke is installed when the chip is produced. We can only speculate as to what it's actually made of.  freshgavinΓΛĿЌ  03:50, 10 March 2006 (UTC)

:D I assume it's actually the plastic casing of the chip melting. Sum0 09:21, 10 March 2006 (UTC)

Good thinking, TenOfAllTrades. The heat sink appears to be fine, but the CPU fan isn't spinning. I think what has happened is that when I was putting the new card in I invadventantly damaged the connection between the CPU fan speed controller (a knob on the back) and the fan. So... sorry Dabs, seems like it was my fault all along. Just need to get a new fan. Either way, thanks to everyone for the replies. Sum0 16:07, 10 March 2006 (UTC)

Hopefully you just need a new fan! You may need a new motherboard and processor too! I mean you smelled the thing burning... Good luck anyway. --Username132 17:15, 12 March 2006 (UTC)

Thanks for your concern! I installed a new fan yesterday and everything is now working swimmingly. I'll be sending the card back, incidentally. Sum0 23:03, 12 March 2006 (UTC)

I'd imagine the burning smell was dust or something. You get it all the time when something gets hotter than normal but not hot enough to destroy itself or when stuff that normally runs hot has been in storage for a while. I can't imagine a fan failure alone killing any modern chip (most have protection systems and whilst they are sometimes a bit slow to deal with complete heatsink removal fan failure is a much more gradual overheat).

Horsepower

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

Confused pilot?

EHP is the horsepower that the engine produces, equal to torque times angular speed. THP is the horsepower required to push the aircraft along, and is equal to drag times speed (assuming constant speed). The difference between the two is due to losses such as heating of the air [7]. --Heron 21:33, 9 March 2006 (UTC)

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

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

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

Eyes are unique to each person. So, distance to a monitor is unique to each person. If your monitor position makes your eyes hurt, movie it. If your neck hurts, the monitor is usually too far away or too low. There is no "well known fact" about specific monitor distance. There are only assumptions based on poor science. --Kainaw ^(talk) 15:46, 9 March 2006 (UTC)

I can tell you that the top of your monitor should be roughly at eye level, so you never have to look up to read pages.

If I do that, I get severe migranes. I keep the bottom of my monitor at eye level. As I stated before, monitor position is dependent on the person looking at the monitor. Any "rule" can, at most, be applied to most people, not all people. --Kainaw ^(talk) 17:26, 9 March 2006 (UTC)

In my iMac's manual I think it said I should have my eye level a few inches above the bottom of the monitor. -- Mac Davis] ☢ ญƛ. 07:29, 10 March 2006 (UTC)

• Further on this point, the desirable height may be different for people who use bifocal/multifocal glasses, or have (say) neck problems affecting what position they can hold their head in. --Anonymous, 23:33 UTC, March 9.

I think you need to invest in a larger monitor, 10 inches is pathetically small. I use a 19 inch monitor, so almost 4 times the area, and wish I had a larger one. Also, I would avoid traditional cathode ray tube monitors and go with a plasma screen. That technology can produce a bright, high contrast image with a minimum of electromagnetic radiation, unlike a CRT. The size, brightness, and contrast of the screen are more critical to preventing eyestrain than your distance from it. StuRat 19:15, 9 March 2006 (UTC)

I don't think radiation is an issue in modern monitors. I'd go for a 17-19 inch CRT off ebay or something. If you're using a 10" monitor, you probably havn't got money to spend on a plasma anything. I certainly don't. Vive le CRT! --Username132 22:20, 9 March 2006 (UTC)

Well, that's the reason it's called a "plasma" screen, you need to sell blood plasma until you can afford it ! :-) StuRat 10:20, 10 March 2006 (UTC)

Only in America... The UK (at least) blood service don't pay for blood products. --Username132 13:36, 10 March 2006 (UTC)

Possible allergy?

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

First, a disclaimer: Wikipedia is not a medical doctor. All responses should be treated as random hearsay. Anyway, I've had similar stuff (in my case, red meat, which I didn't eat as a poor college student) where my tolerance could fluxuate. However, in my case, it was simply said tolerance and the need to develop one. — Lomn Talk 16:27, 9 March 2006 (UTC)

I can think of a possible mechanism for this observation: perhaps a helpful bacteria exists in the digestive system initially in insufficient quantities to digest large quantities of that food. However, the bacteria quickly multiplies by eating that food, and thus the numbers become sufficient to properly digest the food after a few days. Then, when you abstain from eating the food for a long period they are flushed from the system. The appendix seems to serve the function of allowing at least a few of the bacteria to stay in that pouch and not be flushed out. I would be interested to know if you each still have your appendices. Four possible solutions are:

• Avoid that food entirely.
• Eat the food more continuously to avoid flushing out the good bacteria.
• When you start eating it after a gap, only eat a small amount the first few days.
• Consume the needed bacteria with the food (much as lactase is taken by the lactose intolerant).

StuRat 19:00, 9 March 2006 (UTC)

Did you just invent a function of the appendix? Or did I miss a new discovery? And what is TFP? Is it some food brand or fatfood chain? Suitly emphazi (there, now I'm talking in riddles too, for those not native to this ref desk :) ). DirkvdM 19:16, 9 March 2006 (UTC)

No, I've heard that theory before, especially with respect to storing bacteria necessary for the digestion of raw meat by cave men, who would likely go for long periods betweens "kills" and thus need a way to preserve the helpful bacteria. If our appendix article omits this info, that's just one of Wikipedia's shortcomings, I guess. Also, they were using TFP to refer to any food which causes the problem in question, not any specific food. StuRat 19:32, 9 March 2006 (UTC)

Appendix intact and in place here, and "TFP" is just a catch-all for "whatever food is responsible here". — Lomn Talk 19:33, 9 March 2006 (UTC)

Thanks for the advice. I still have my appendix, and the food in question is soymilk. --Original Poster

acute renal failure

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

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

operational amplifiers

why level shifting is necessary in operational amplifiers?---61.1.127.74 18:31, 9 March 2006 (UTC)

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

RENAL FAILURE

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

I think your analysis is correct, and they are just trying to protect themselves from a costly lawsuit. If you have samples of the materials he was exposed to, say from those could be analyzed to find the toxic agent. StuRat 18:50, 9 March 2006 (UTC)

Wow! Two people with renal failure caused by ptomaine poisoning in the same day! --Kainaw ^(talk) 19:10, 9 March 2006 (UTC)

I bet they both had salami too, without getting sick with a question mark. DirkvdM 19:21, 9 March 2006 (UTC)

I don't understand what either of you are saying? Only one person got poisoned - his son? And why did Dirkvdm verbalise his question mark? --Username132 22:12, 9 March 2006 (UTC)

The question got asked twice, both times unsigned. Of course it's obvious that it was the same person who asked it but we were just having a bit of fun. And this version of the question had an oddly placed question mark; "Dry Salami and no one got sick?" so I made a little 'joke' about that? Aren't we having a lot of fun here! (in case you wonder about the misplaced exclamation mark - it's intentional?). DirkvdM 12:42, 10 March 2006 (UTC)

StuRat is right, you should probably consult a lawyer; if your son is in a union he should probably speak to the union people as well. --Robert Merkel 01:48, 10 March 2006 (UTC)

That would be hantavirus, btw, not hunta virus. - Nunh-huh 09:36, 10 March 2006 (UTC)

Well, if you don't know where a virus is, you need to hunta virus, right ? :-) StuRat 10:17, 10 March 2006 (UTC)

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

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

You need to find lawyers who are willing to do the work for free (pro bono), such as Legal Aid. StuRat 03:04, 14 March 2006 (UTC)

analogy of rotational equilibrium

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

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

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

Fiber in Tropicana "Lots of pulp" juice

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

The pulp does contain fiber, and other carbohydrates, but probably the pulp makes up a small enough proportion of the total juice that one serving contains less than a gram of fiber. (0 grams, really means less than one gram per serving). What's the benefit of pulp? Maybe some people just like the pulp because it makes the juice seem more like fresh squeezed, rather than processed, juice. Edgar181 21:59, 9 March 2006 (UTC)

Have you ever poured a jug of Tropicana into a sieve just to see how much pulp there actually was? There's lots of it, a lot more than 1 gram per serving. By your logic, it should at least get a "traces" rating for fiber. I'd say the answer to this Tropicana mystery is that the company figures that people don't really care about the fiber content, and rather just like getting their faces sloppy, and it puts the same specs on the box for "Homestyle" and "Original". I personally prefer the pulp.  freshgavinΓΛĿЌ  07:07, 10 March 2006 (UTC)

I'm confident that if you filtered a serving of juice, collecting the pulp, and then completely removed all the water, the remaining dried solid would weigh less than a gram. Edgar181 13:24, 10 March 2006 (UTC)

I hate those chunks of pulp that stick between my teeth. I once bought "homestyle", not knowing that apparently means "nothing but pulp" ! StuRat 08:57, 10 March 2006 (UTC)

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

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

Hard disk

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

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

Generally, hard disks can be unplugged, removed, placed in another computer, etc. without damaging data. Doing it too much shouldn't be dangerous, but it increases the chance that something might go wrong. Hope this helps! Sum0 20:51, 9 March 2006 (UTC)

As long as you treat your HD with care as you do this, there shouldn't be any problems. — TheKMan^talk 21:15, 9 March 2006 (UTC)

It may go without saying, but I'm going to say it anyway—don't remove the hard disk while the computer is running. This will often result in data loss, and may result in physical damage to the drive.

On a practical note, IDE connectors have a lot of fiddly little pins that don't like being repeatedly plugged and unplugged. Moving a hard drive between computers too often may result in premature failure of these pins. TenOfAllTrades(talk) 21:20, 9 March 2006 (UTC)

External USB harddisks maybe a better solution. Theresa Knott | Taste the Korn 21:43, 9 March 2006 (UTC)

Treating with care includes full anti-static precautions. The vulnerable part of a hard disk (unless you drop it) is that circuitry on the outside. Consider an external hard disk, though, may be much easier, or a memory key. Notinasnaid 09:14, 10 March 2006 (UTC)

Oh yes, and make sure the computer was shut down normally before you take the disk out, NOT just crashed or switched off. That can reduce the chances of damage. Notinasnaid 09:15, 10 March 2006 (UTC)

That's a tricky one - in my experience, shutting down 'normally' is not normal for msWindows. DirkvdM 12:45, 10 March 2006 (UTC)

And sing to it - and care for it - and love it. Celcius 11:39, 10 March 2006 (UTC)

At the risk of being pedantic, SATA hard drives (as well as external USB or FireWire ones) are hot-swappable. However, the operating system needs to be aware of this capability, so for instance in linux, be sure to umount the hard drive first. In Windows, SATA drives don't seem to be considered removable storage, so you don't have the handy safely remove hardware icon for it, so you must shut down windows before removing or reconnecting the drive. --WhiteDragon 17:33, 10 March 2006 (UTC)

I like my apples waxy... or not

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

Take a look here. Hope this helps — TheKMan^talk 21:16, 9 March 2006 (UTC)

Oh thanks. Perfect. :) --Username132 22:21, 9 March 2006 (UTC)

In future, if you ever come across a mystery waxy or oily substance that you're not sure if you're supposed to eat or not, I recommend you eat it. Not because I wish any harm on you, but because waxy and oily substances are hydrophobic, and will (generally) cluster (more or less) in your stomache, and won't cause any damage (probably, if you're lucky). On second thought...  freshgavinΓΛĿЌ  03:06, 10 March 2006 (UTC)

lol, that's the best advice I've ever heard. =P —Keenan Pepper 04:52, 10 March 2006 (UTC)

Bile salts may emulsify the wax... Plus being hydrophobic/lipid soluble, they should be able to freely cross cell membranes into the blood. --Username132 13:34, 10 March 2006 (UTC)

DARPA??

What did this have to do with the formation of the internet? Just wondering??Do any of you know?--205.188.116.11 06:32, 24 February 2006 (UTC)

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

March 10

Evil Gene Patenting

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

The evil gene cannot be patented; for national security reasons it is subject to a government monopoly. --Trovatore 03:21, 10 March 2006 (UTC)

Patenting genes is patent nonsense - so a lot of countries want it stopped. Celcius 03:35, 10 March 2006 (UTC)

Then why did the legislation get passed in the first place? --Username132 04:08, 10 March 2006 (UTC)

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

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

Or you can't actually claim anything over natural expression of the gene. But that's not the point. The point is, some corporation discovers the gene involved in, say, I don't know, some kind of cancer. The fat business executives who couldn't care less about people's welfare (they studied business and finance, not biomedical science) can then charge anyone who tries to distribute a treatment for that disease. --Username132 13:32, 10 March 2006 (UTC)

The businessman would say, "Listen, this isn't about people's welfare. I have a big company and spend a huge amount of private money in searching for genes related to disease. Of course I try to make a profit off of this once I've discovered something useful -- if I didn't, how would I ever get the money to look for genes in the first place? Sure, it'd be great if governments ponied up the dough for this, but we all know that it doesn't always work out. We'll try to set things at a fair price, to guarantee our future research abilities. And hey -- we all know that most of the money from these treatments is paid by insurance anyway, so what's the big deal?" I'm not saying that's the last word on the subject, but viewing it as just about "fat business executives" is a very one-sided and unfair approach. --Fastfission 01:52, 11 March 2006 (UTC)

Sounds like something a fat business executive would say... I'm in this gig for the people and what do I get? Exploited. It's fine to make money to cover future expense etc. but they're in it for their flash cars, homes and swimming pools. When my mum was younger she had to boil her asthma cartridges (to pressurise any remaining medicine) SO SHE COULD BREATHE. --Username132 16:57, 12 March 2006 (UTC)

Computer program equation input

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

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

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

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

Yay procedural programming! Not specific to FORTRAN but I learned a little about this in compiler theory (which I didn't enjoy too much), so you might want to check out a book on that. It's possible that someone has made a library that can recieve code as a parameter and parses it into instructions, but they probably did the exact same thing that you said in (1), though likely with a low-level language. High level langauges aren't very good at analysing their own code, which is why many of them have their own scripting languages (I assume FORTRAN doesn't). Does FORTRAN have Assembly commands?  freshgavinΓΛĿЌ  05:25, 10 March 2006 (UTC)

Not that I'm aware of, but it can make system calls, so if assembly language commands are available at the O/S level they could be accessed via a system call. StuRat 08:43, 10 March 2006 (UTC)

This would be relatively trivial in Matlab, but whether that's a real language or not is open to debate. moink 06:01, 10 March 2006 (UTC)

It wouldn't just be trivial, it wouldn't require any programming at all!  freshgavinΓΛĿЌ  07:01, 10 March 2006 (UTC)

Just look for almost any interpreted language. These tend to show off by having a function like "eval" which takes a string in the same language and execute it. They may be slower than compiled code, but this sort of thing is cute. Believe me, writing an expression parser is not simple, especially if you've never studied formal grammars and parsing techniques. Actually executing the functions is the trivial part. Notinasnaid 09:12, 10 March 2006 (UTC)

Yea, it looks like a lot of work to me. I was actually leaning towards option 2, which requires that the code be recompiled and linked after the user enters the equation to graph. StuRat 10:12, 10 March 2006 (UTC)

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

Expanding on what enochlau said: yes, option 1 is straightforward, though a certain amount of work. But you don't have to do all the work yourself; there are libraries which can do it for you. The C FAQ list mentions a few, although they're pretty dated. And if you know what you're doing, an expression evaluatior really isn't that much work, after all; you can write a simple one in an hour or two. Here's a condensed, mildly obfuscated one I coughed out once: eval.c.

Back in about 1987 I was thinking about precisely the problem you describe -- I wanted the user of a graphing program to be able to enter expressions using FORTRAN-like syntax. I wrote an expression parser and evaluator which I'm still using for various things. Like so many personal projects, it's not quite packaged and documented well enough for others to use easily, but you might take a look at http://www.eskimo.com/~scs/src/#med . That package includes the expression evaluation library and a command-line tool to exercise it. I just entered the expression

 c1**(pi**e) + abs(sin(X**3))/log(1/sqrt(c1))

into that tool (where I substituted the FORTRAN ** for your ^, and c1 -- meaning "column 1" -- for X) and it worked fine. Your function blows up pretty fast:

X	Y
0	divide by 0
1	divide by 0
2	5.76607e+06
3	5.19687e+10
4	3.32476e+13
5	4.99203e+15

Finally, a few more words about your option 2. You don't need to write the entire program out to a file and recompile it; typically you just need to write and compile a stub function containing the user-entered expression, then use dynamic linking to call the just-compiled code from the main program. The C FAQ list talks about this, too. (You didn't say you're using C, but both of the links I mentioned contain information that might be useful no matter what language you're using. Oh: you did say you're using FORTRAN. Hmm. I don't know how much of this stuff even a modern FORTRAN compiler would let you do.)

—Steve Summit (talk) 16:06, 10 March 2006 (UTC)

Wow, what a fortunate coincidence ! That math editor function looks quite useful. A few questions:

• The documentation says "in some versions" repeatedly. Do you have any documentation on what the version you are offering specifically does ?

• Do you have a FORTRAN stub that calls the function ? This would be useful to overcome all those silly FORTRAN-C function compatibility issues.

• Is there any support for +/- ? For example, if I give it Y = +/-sqrt(4), I want to get both +2 and -2 as output.

Thanks a lot for your help ! StuRat 20:30, 10 March 2006 (UTC)

Answering these on your talk page. —Steve Summit (talk) 16:45, 11 March 2006 (UTC)

I would like to note that most of these suggestions are good if you're only using the program yourself, maybe if only for a department of a few dozen users, but the concept of using eval statements or open ended compiling is a Really Bad Idea from an information security perspective, if the program is destined to become a software product or mission critical system in any sense. Best case is that an errant user could enter an equation that could crash or drag the processor to a halt, worst case is that you give a malicious hacker the keys to the kingdom (by letting them compile and run any code they want on your system). This of course depends highly on the systems environment you are in, but it is a word to the wise.

If you want to do this in any serious environment (where money or lives are on the line), you will want to know the appropriate compiler theory to parse the equation and build the code yourself, with appropriate boundary checks. KWH 19:11, 10 March 2006 (UTC)

It's just for my own use. I saw many glaring deficiencies in most graphing programs that I wanted to fix:

• Can only graph an equation in Y = f(X) form. Mine handles Y = f(X), X = f(Y) and equations in neither form.

• Can only use constant X increments for point sampling. Mine allows constant X increments, constant Y increments, or both.

• Can't handle inequalities. Mine does.

• Can't handle Boolean operations on multiple equations. Mine can handle unions, intersections, subtractions, etc.

• Limited size output. Mine can create a graph any size up to the memory limit of the computer.

• Can't handle polar equations. Mine can, in R = f(theta), theta = f(R), and general forms.

• Limited grid lines. Mine can create up to 5 levels of rectangular or polar grid lines.

• Can't do 3D graphs. My program can.

• Can't do derivatives and integrals. Mine will do these using numerical methods, although I haven't written this code yet.

I've already created several graphs with this program that are used in Wikipedia [8], but must edit and recompile the program each time I change the formula. This is annoying. StuRat 20:20, 10 March 2006 (UTC)

Look at free software that already does equation parsing. No need to write your own (although you may be the type who likes to DIY) PARI-GP computer algebra system, Euler, YACAS (Yet another computer algebra system) come to mind. Probably others. List of computer algebra systems , Category:Free mathematics software --GangofOne 21:33, 10 March 2006 (UTC)

BIN and CUE files

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

Let's hope it's not illegal then. BIN and CUE files can be opened using a "virtual drive". This is a program which emulates a CD drive on your computer. Of course you could just burn the files onto a CD for same effect but it is easier to use the CD drive emulator method. I usually use Daemon Tools - which you can download here - but that's a religious choice - there are many simulators out there. Celcius 11:14, 10 March 2006 (UTC)

An alternative to Daemon Tools is the equally popular Alcohol 120%.

I hope it is one of the many .bin files I've put my remote desktop server hack in. I can always use another bot! --Kainaw ^(talk) 13:52, 10 March 2006 (UTC)

I highly recommend Alcohol 120% over Daemon Tools, it's much more user friendly I think. Once you got Daemon Tools or Alcohol 120% just mount and unmount the image file(.ISO,.BIN). It's not a very good ideo to have a virtual drive on at all time because it will really slow down your computer, use it only when neccesary. If you want to use the image file constantly just burn the image file to CD using Alcohol 120% but if it's illegal, which i'm guessing it is, it may detect emulation and that you've stolen software, just hope that your OS doesn't send a report.--154.20.89.16 21:16, 12 March 2006 (UTC)

Telescopes

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

I don't know anything about telescopes - but I do know something about computers. It seems like a fairly simple job to hook up a computer and a small motor to a telescope and let it follow the stars automatically. Technically it wouldn't be very difficult. Celcius 11:36, 10 March 2006 (UTC)

The basic principle is that the sky appears to rotate around the pole (north or south). You have a wheel axis pointing to the pole, and have the telescope turn very slowly on it. These days, this can be coupled with a starfinder computer, which knows the location of celestial objects and will automatically use the motor to track to find them, before settling down to following the stars around. It is less expensive than I would have feared. I've been tempted to upgrade my old telescope with one of these. Notinasnaid 11:40, 10 March 2006 (UTC)

Okay. Thanks for both answers! Blueiris 11:46, 10 March 2006 (UTC)

This is very common for all except the smallest and cheapest telescopes, and is called an equatorial mount - for a simple version, all you need to do is set one of these up with the right ascension (also called polar) axis pointing at the celestial north pole, lock the declination axis, and rotate the polar axis so that it makes one revolution every 24 hours. Pretty much every equatorial mount comes with a little motor that does this job for you.

Fancier telescopes with star-tracking software often use a simpler kind of mounting (an altazimuth mount, you've seen them on most binocular tripods), but with motors linked to a computer controlling both axes. This kind of mount is harder to follow stars with manually (as you need to constantly adjust both axes), but the computer does that job for you, while also automatically pointing itself at any object you particularly want to see. — QuantumEleven | (talk) 12:34, 10 March 2006 (UTC)

I think two things get mixed up here. The question was about a little telescope and that may refer to the little one that is often attached to a big one to get the bigger picture. First you roughly aim the telescope, then you look through the small telescope for more precision and only the do you start looking through the big one (sort of like looking up from binoculars to get the bigger picture). Afaik automated star-tracking doesn't use such small telescopes (don't know the ins and out, though) and it will only be used for the more expensive (bigger) telescopes because the mount isn't really cheap (I guess). DirkvdM 12:57, 10 March 2006 (UTC)

(not directly related to the original question, but still) No, you're right, Dirk, automatic star tracking doesn't use the small telescope (often called a finder scope) - how it works is that the computer knows where every star is at any point in time (a very easy thing to store, as stars don't move relatively to each other, and the Earth's rotation is very well known). You set up the telescope by pointing it at a particular star (the computer can't really do this... yet... :)), and from that and the current time and latitude, the computer knows where every star is and will be at any point in time. Therefore, it can control the two motors controlling the axes, and point the scope at anything you want, as well as keep it in the field of view as the Earth rotates. — QuantumEleven | (talk) 15:52, 10 March 2006 (UTC)

By "little" I actually meant a hobbyist's telescope. Equatorial mount was maybe the thing I was looking for, because sometimes telescopes are said to be star-tracking and there's no computer nearby. But I thought it had something to do with gyroscopes because they keep pointing at the same star, too. Blueiris 13:15, 10 March 2006 (UTC)

Yup, I think you probably got that right - a "star tracking" telescope without a computer is most likely one on an equatorial mount with a small drive motor. It takes advantage of the fact that, because the Earth rotates, from the Earth it seems that the stars are spinning around a point in the sky directly above the north pole called the "celestial north pole" (you can see a nice photo of this at Astronomy Picture of the Day - the camera shutter was left open for a few hours, and the streaks you see are the stars apparently moving). If you have a telescope with one of its mount axes pointed directly at this north celestial pole, and you lock the other axis, by spinning the first at the correct rate your telescope will follow a star as it seems to spin around the celestial north pole. Have fun observing! — QuantumEleven | (talk) 15:52, 10 March 2006 (UTC)

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

Wouldn't a cheap fast spinning motor with a succession of gear-wheels eliminate the vibrations? DirkvdM 07:37, 12 March 2006 (UTC)

Equatorial mounts with a clockwork drive were around many years before computers came along. --Shantavira 19:50, 13 March 2006 (UTC)

Physics

We know that like charges repel(coulombs law) and two wires carrying current in the same direction attract. Suppose there were two independent like charges moving with same velocity parallel to each other in the same direction then what would the force acting on them???61.1.131.142 12:55, 10 March 2006 (UTC)

You appear to be asking: If you take two negative (or positive) ions, put them side-by-side, and send them flying down the road, what will happen? They repel. It doesn't matter how fast they travel. --Kainaw ^(talk) 13:50, 10 March 2006 (UTC)

To explain this you really need relativistic electromagnetism (electromagnetism in the context of special relativity). The electric repulsion dominates the magnetic attraction until the charges are moving at a substantial fraction of the speed of light, and then relativistic effects like length contraction and time dilation kick in, so that the force in a comoving reference frame is always that due to the electric repulsion alone (because the charges are at rest in that frame). —Keenan Pepper 13:53, 10 March 2006 (UTC)

"two independent like charges moving with same velocity parallel to each other in the same direction" if so, then there's no movement relative to eachother, and no magnetic force. ☢ Ҡi∊ff⌇↯ 18:11, 10 March 2006 (UTC)

Well, yes, but if you're in a second frame of reference that observes the particles zooming off somewhere, you would see the force between them divided into magnetic and electrostatic, but the combined force would be equivalent to the electrostatic force between them in their frame of reference. In other words, it's an "everybody's right" kind of answer :) Confusing Manifestation 13:01, 11 March 2006 (UTC)

Earth Orbiter

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

Before our resident astronomer comes along, Roche limit might help. Sum0 20:20, 10 March 2006 (UTC)

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

Processor spead

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

I am ill-aware of the highest processor speed, but the higher the speed does not necessary mean a quicker computer. Kilo-Lima ^{Vous pouvez parler} 20:26, 10 March 2006 (UTC)

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

Electrical Cost Calculations

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

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

Thanks, John

Well, the first step is to figure out the wattage, do you know how to do that ? StuRat 21:02, 10 March 2006 (UTC)

Not to mention how long the device in question will be working for. Here7ic 22:41, 10 March 2006 (UTC)

Like StuRat mentioned, the power consumption is best to go by. Power (Watts) = voltage x current, but the problem is many devices give their current reading as the maximum instead of average, so the 5A could well be the peak current load on the device. - Akamad 23:20, 10 March 2006 (UTC)

Rule of thumb - electricity costs (approximately) $1/watt-year. A 5 AMP device running continiously for one year would consume: 5 amps * 120 volts -> $600 in one year. (5 amps is *a lot* of current). This is the reason, in my field, that supercomputers cost more in the long term due to energy usage than it costs to build them. Raul654 23:27, 10 March 2006 (UTC)

Well, your rule of thumb isn't too far off, assuming a few things about the question. The voltage of the questioner isn't specified, which makes quite a bit of difference. Assuming he's in the US (probably a good guess, based on his use of a dollar sign), this device will draw about 600 watts. Given John's cost, that results in a cost of $0.06588 per hour. This assumes that the device draws a constant 5 amps. So, with all these assumptions, this device running all year would cost $577.1088. kmccoy (talk) 03:21, 11 March 2006 (UTC)

Space Based Radio Telescope

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

Sure, but why would you want to? -- Finlay McWalter | Talk 22:01, 10 March 2006 (UTC)

A) Self indulgance, B) A better, clearer, and cheaper grasp of our universe, C) Wouldn't it just look cool? Here7ic 22:36, 10 March 2006 (UTC)

Edit: plus, it'd help to make the Earth a more peaceful place. Here7ic 22:39, 10 March 2006 (UTC)

How's so? ☢ Ҡi∊ff⌇↯ 23:39, 10 March 2006 (UTC)

I think such a project would result in one of two outcomes. 1: The Earth governments would control it as a whole, and it would be one more step towards peace. 2: The Earth governments quibble about spying, good ole' cold war fears are back, and our home world buries itself deeper into political unrest. Here7ic 04:35, 11 March 2006 (UTC)

Arecibo is a radio telescope, placing a single radio telescope that size in space would not yield better results than the Earth-bound arrays we already use. In fact it would probably not be better than Arecibo itself as radio waves aren't as distorted by the atmosphere as visible light. Rmhermen 23:57, 10 March 2006 (UTC)

What if you set up an array of satellite receivers? i.e. VLA but with a diameter of the Earth itself? --Fastfission 02:20, 11 March 2006 (UTC)

Why use the diameter of the Earth ? If you put them in geosynchronous orbit you would have a much larger diameter and would avoid much of the local radio interference on Earth. StuRat 02:51, 11 March 2006 (UTC)

Indeed, there already is a VLA-type array on Earth that's thousands of miles across: the VLBA. The VLA looks cool because of all the dishes being close together, but the VLBA does way better on resolution. According to the NRAO web site, it "has an ability to see fine detail equivalent to being able to stand in New York and read a newspaper in Los Angeles." Of course, as StuRat says, a high orbit in space would do even better. On the other hand, there is the downside that you'd need a radiotelescope to receive the signals from your radiotelescope... --Anonymous, 03:57 UTC, March 11.

What if the Voyagers would have been used for this? That would have given a rather long baseline. DirkvdM 09:08, 11 March 2006 (UTC)

One problem with that is the speed with which technology advances. In the amount of time it took Voyager to get there, its capability is outstripped by new local deployable technologies. Who would invest in a long term scheme when new technology might surpass it before it started it work? Already adaptive optic technology rivals the Hubble Space Telescope. Rmhermen 15:37, 11 March 2006 (UTC)

A radio telescope isn't all that high tech. Actually, it's pretty low tech I believe. So that isn't a problem and they would have known then that that technology wouldn't improve much. But, not knowing that space exploration budgets would collapse, they might indeed have thought that later faster satelites would overtake them.

The precision of Hubble can't compensate for a lack of diameter (which is what this is about). And anyway, Hubble isn't a radio telescope. It wouldn't make sense to put a radio telescope in space because that radiation reaches Earth's surface almost unperturbed. And the corrections were needed to compensate for errors, not to improve on an already good system. DirkvdM 07:47, 12 March 2006 (UTC)

March 11

Hoodia

Is P57-isoberberine, the active compound in hoodia, likely to be as toxic as berberine? yes.

Combustion chamber

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

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

Color of overcast sky

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

First, color temperature is related to actual temperature only when you're talking about objects that are actually incandescent, like the Sun or a light bulb. That doesn't apply to sky light.

I think the answer is that sky light on a cloudy day is only bluish in comparison to direct sunlight. On a clear day, scattering in the atmosphere affects high-frequency light more than low, so the sky is bluish while the direct light from the Sun is depleted of blue and therefore is slightly yellow. On a cloudy day, all the light is further scattered in the clouds and as much of it as gets through also gets mixed back together. So it's bluer than direct sunlight, but less blue than the sky light you get in a shadow on a sunny day. --Anonymous, 04:10 UTC, March 11, 2006.

Earths Atmosphere

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

Try origins of life

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

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

Search for life on other worlds

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

I can understand on why some people may be afraid of a situation in which we make contact with an alien civilization. History on this planet shows us that when a more advanced civilization interacts with a lesser civilization, death and destruction follows. This was the case when Europeans first came to the Americas with their superior guns and wiped out much of the native Indian population. I do not know if the government or military has any plans for this. One would assume that if aliens ever came here they would be possesing some serious technology since they would have traveled many ligh years. I don't think aliens that may be a million years more advanced than we, would have any trouble dealing with "primative" human defense capabalities.

Actually, guns didn't do a great deal of damage to Native American populations. Smallpox and measles did. - MPF 21:53, 11 March 2006 (UTC)

Although we have sent some signals, most searches for extraterrestrial intelligence are passive. If we do find a radio signal, the aliens won't know that we know. As for dealing with them, there are other things that we might actually need to defend Earth against; see our stub on Planetary defense. It'd be sad if we spent our anxiety on aliens and then got creamed by a rock. Melchoir 05:27, 11 March 2006 (UTC)

The Earth has been blaring out radio transmissions to this sector of the galaxy for a century now - anyone looking for signs of civilisation that's within 100 light years could have picked us up. So if there are any alien civilisations out there, they may well know we're here. To be actively looking for alien life means meeting it on our terms, rather than have it suddenly arrive on our doorstep, enabling us to be just that little bit more prepared. If there are intelligent belligerent aliens out there, then whether we're seeking it or not is irrelevant, since it could easily find us (we're a very loud species) - but seeking it out at least gives us a chance of finding it and maybe parlaying with it rather than just have it move in. Mind you, the vast majority of the search for extraterrestrial life is simply looking for any form of life, intelligent or not. Just discovering primitive extraterrestrial life - even monocellular - would be one of the biggest discoveries in scientific history. Grutness...wha? 07:29, 11 March 2006 (UTC)

Then again, a 100 lightyears radius is nothing compared to the size of the universe, the edge of which is said to be at 78 billion lightyears away. And our won galaxy is about 100 thousand lightyears wide. A main reason it is assumed there is life somewhere else is that there are so incredibly many stars that it would be statistically unlikely that something that happened here will not have happened somewhere else. The nearest star is about 5 lightyears away. Does anyone know how many stars there are in a 100 lightyear radius around us?

Why would the aliens be interrested in the US alone? Or rather, why should the US alone prepare for this?

Our intellectual and technological levels would likely be so far apart that they wouldn't be interrested in us. Look at animals in nature. They either compete, eat each other or ignore each other, with the last option being by far the most popular. Animals generally only eat what they know. Something from a different ecosystem (in this case Earth) might not go down well and would be avoided. Humans compete (such as in America) because they are so similar and use up each other's sources (land, food). But we pretty much ignore ants (as long as they don't come in our houses) and the aliens would likely be so totally different from us that they'd probably treat us in the same way. They might not even notice our presence and we'd be able to live here side by side. And we might not even notice them. Maybe they're too minute (hey, maybe ants are aliens) or maybe they take a from we don't recognise as intelligent. Maybe they're made of some gas. Hey, maybe they're already here and that's where ghost stories come from. :) DirkvdM 09:35, 11 March 2006 (UTC)

There have been any number of theories advanced by science fiction writers and SETI researchers (who sometimes are one and the same) about what contact with an alien species might mean. here's an interesting discussion of the various possibilities, though the signal-to-noise ratio in the discussion occasionally gets a bit low. You might also have a look at SETI, Fermi Paradox, Drake equation, CETI, and First contact. The short version is that a) unless they're travelling faster than light it's not going to be our problem, b) if their technology is sufficiently advanced to permit interstellar travel, they're probably going to have kick-arse military abilities as well, c) we're already transmitting unintentionally, d) even if their intentions are benign, real contact with aliens could possibly cause all manner of societal ructions, as it has when more technologically advanced cultures have run into less technologically advanced ones, and e) as an actual threat goes, there are plenty of other things higher up the priority list than aliens, for instance near-Earth objects and random long-period comets heading our way. --Robert Merkel 12:00, 11 March 2006 (UTC)

Don't know how many stars are within 100 ly, I too would be interested in knowing. Our List of nearest stars only goes out to 16 ly. Rmhermen 15:30, 11 March 2006 (UTC)

Hold the horses people - why would aliens want to wipe us out? Earth dosn't contain anything of particular value to a space faring civilzation. All of our ressources could be mined more easily from the Kuiper Belt rather than the gravity well that is planet earth. Our planet will most likely not suit their living needs as they evolved in an entirely different enviroment - so what would they want with earth? Celcius 22:58, 11 March 2006 (UTC)

I think usually (in popular science fiction) the aliens want land. Let's face it: Earth is a sweet ride. Melchoir 00:50, 12 March 2006 (UTC)

They might want to eradicate the cancer called 'mankind' before it spreads into space (as it's starting to do now). This isn't eco-negativism but just a conjecture of what alien minds might work. When it comes to alien thinking I consider myself an expert. :) DirkvdM 07:54, 12 March 2006 (UTC)

The reasons for wars just between different human societies are not always about rational reasons like resources, and for an alien civilization, who knows? Maybe they are like Nazis and want to exterminate 'inferior' life? Maybe they are mutant ant men and want to eliminate anyone existing contrary to their regimented existance? Maybe they are an ambulatory plant species, which has an imprinted hostility to animals (who preyed upon them until the plants learned to fight back)?

transistor

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

Thank you

Mani reformatted from original all caps

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

I don't mean to be rude, but if you can't say anything useful... Sorry, it's nothing personal. Sum0 09:52, 11 March 2006 (UTC)

Well, my remark looks a bit silly now that someone has cleaned up the question. Fyi, it was all capitals and indented to draw a box around it. So my point was that it was the questioneer who was being rude. DirkvdM 07:56, 12 March 2006 (UTC)

You are forgiven, my child. Sum0 15:11, 12 March 2006 (UTC)

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

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

Can anyone tell me the purpose of this page?

http://www.pcnotdienst-muenchen.com/misc/intimating/unconcerned/incompatibility/macrospecies/apocryphalist

Adambrowne666 11:13, 11 March 2006 (UTC)

My eyeballs are behaving like the tumblers of a one-armed bandit after reading some of the pages on this site. Either it's the work of manic surrealists or someone is trying to reproduce Finnegan's Wake. I've no idea what it is, but I've bookmarked it. Actually, it does bear some resemblance to the sort of weird things you get in some spam mail, so perhaps there's a connection there. Many of the links are like that, too, as are the upper level pages (e.g., http://www.pcnotdienst-muenchen.com/misc/intimating/). On the offchance that it is spam related, I'd be wary of doing too many clicks on it, though... Grutness...wha? 11:30, 11 March 2006 (UTC)

Looks like an example of Markovian Parallax Denigrate to me. GeeJo _{(t) (c)} • 11:53, 11 March 2006 (UTC)

It is a randomly created website used to harass search engines and programs that search websites for email addresses. There is no specific name for it (yet). Some call it a quicksand pit. Some shorten that to sandpit. Some call it a stinger site. Others call it a honeypot. Regardless of the name, it is simply designed to appear like a real website to a program that automatically goes from link to link in search of content. Because it cross-links to itself with random links, the program gets stuck and never leaves. --Kainaw ^(talk) 15:15, 11 March 2006 (UTC)

In fact cf. Honeypot (computing).--Dell Adams 06:54, 12 March 2006 (UTC)

Is that to battle the likes of Google or spammers? Also, wikipedia links to itself, right? --Username132 21:50, 11 March 2006 (UTC)

Google is smart enough to leave one of those sites. Spammers write clumsy programs to harvest email addresses from web pages. Those could spend weeks on a randomized site going round and round and round... --Kainaw ^(talk) 22:43, 11 March 2006 (UTC)

I see. And how is wikipedia different from one of those sites? --Username132 07:40, 12 March 2006 (UTC)

In that it doesn't go around in circles linking to itself, I suppose.

Are all those English words? DirkvdM 08:01, 12 March 2006 (UTC)

What are you talking about? Of course it links to itself. Cheese > Cheddar > Cheese > Cheddar... --Username132 16:58, 12 March 2006 (UTC)

Trawlers are usually smart enough not to grab files that they have already grabbed.--Fangz 18:51, 12 March 2006 (UTC)

So you're saying the page in question doesn't actually hold on to the programs spammers use? --Username132 00:29, 13 March 2006 (UTC)

You're feeding the trolls again aren't you - now git you trolls and you kids come home right now! hydnjo talk 00:35, 13 March 2006 (UTC)

Well, it is apparent that the word "random" is not in the troll dictionary. Otherwise, it would be rather obvious what the difference is between Wikipedia and a site that randomly creates web pages with random links to more randomly created pages. --Kainaw ^(talk) 13:49, 13 March 2006 (UTC)

Raw rice

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

Well, first off remember the conditions that rice is usually grown in. If it's left completely untreated and eaten shortly after harvesting, it's likely to harbour all sorts of nasties. I also seem to recall reading about a form of torture involving raw rice, in which the torturers would force a victim to eat as much of the stuff as they could, and then force them to drink a portion of water. The rice would take up the water and expand, stretching the stomach and causing extreme pain. I'm not sure on how apocryphal that story is though, and in any case, the stuff bought in supermarkets won't cause you any harm if eaten raw. GeeJo _{(t) (c)} • 11:59, 11 March 2006 (UTC)

Apocryphal. When rice soaks up water, it doesn't expand to more than the volume that the water and unsoaked rice occupied in the first place. - MPF 21:57, 11 March 2006 (UTC)

Could be an urban legend but I heard its fairly common that you can't throw rice at some churches because birds eat it and subsequently "explode" - which is to say their stomachs crack open under the pressure of the expanding rice. Does anybody know if this is an urban legend? Does anyone have some birds and some rice and a keen mind to find out? Celcius 22:47, 11 March 2006 (UTC)

snopes.com says this isn't true. User:Zoe|^(talk) 23:21, 11 March 2006 (UTC)

Birds probably know quite well how much raw grain they can eat because that's what they normally eat. Right? Not sure about raw rice, though, because it may be dried. Is it?

Anyway, if you drink plenty of water it passes through your stomach. If that is filled with dry rice ,that will absorb it. And then you can keep on adding water with at least part of it being absorbed. So the riceball would expand to several times its original size. Then again, wouldn't that go down the digestive tract and come out before we get a Monty Python restaurant scene? DirkvdM 08:08, 12 March 2006 (UTC)

The version of this story I heard is the birds do not get enough stones in their crop to grind up the rice and have problems because of it.

Pluto

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

They don't know what they'll find, so they won't know the point until they find it. In general terms, however, investigating the outer regions of the solar system may help us understand the process by which the solar system was formed, which is a good thing. That can help us with issues such as how life arose, and where else it might have arisen. In any case, the amount of money spent is trivial compared to the amount spent on buying bombs for the army, or the amount of money spent on chewing gum each year. You can bet that if the money wasn't being spent on this mission, it wouldn't be spent on relieving world poverty. Mark^{your words} 12:02, 11 March 2006 (UTC)

Yes, and what tells you that the money would have been spent to support poor people, or anything useful at all? It's at least as likely that it would have been used to drop a few more bombs on random countries with difficult to pronounce names, so the Pluto mission might actually have saved innocent lives :p dab (ᛏ) 12:11, 11 March 2006 (UTC)

Tell your friend they are committing the logical fallacy of false choice which is a correlative based fallacy in which options are presented as being exclusive when they may not be. It is often used to obscure the likelihood of one option or to reframe an argument on the user's terms. There is nothing to prevent the government from doing both. This fallacy is also known as Morton's Fork. WAS 4.250 14:52, 11 March 2006 (UTC)

So, your friend's argument is to fire everyone at NASA, make them poor, and give their money to poor people? How is that a more intelligent thing to do than sending a probe to Pluto? --Kainaw ^(talk) 22:41, 11 March 2006 (UTC)

There's this silly idea that feeding the hunger is something terribly important for mankind, as if no money can be spend anywhere else until everyone is chubby. People just try too hard to "do a good thing" (and "feeding the hunger" is the stock "I care" idea) and forget there are other things that are also good for mankind, even on a higher level, such as scientific research. The issue with the poor people shouldn't be solved taking money from these other areas, but by correctly allocating resources and disappearing with corruption and white collar thieves. ☢ Ҡi∊ff⌇↯ 22:49, 11 March 2006 (UTC)

In about 200 years, when the Earth is uninhabitable, these probes will have given NASA or whatever other agencies which succeed it (and those in other countries) enough information to help to transport humanity into space, where they can survive instead of dying out. User:Zoe|^(talk) 23:18, 11 March 2006 (UTC)

Now that's just rubbish. The Earth will still be habitable in 200 years. In any case it's the most likely probability. The "last perfect day" is a good several billions of years from now. At least that's the general consensus. Here7ic 05:06, 12 March 2006 (UTC)

You guys seem to have crystal balls (no pun). One far-sighted, one short-sighted. DirkvdM 08:42, 12 March 2006 (UTC)

I don't need a crystal ball. My contribution is based on the observed age of our sun and it's predicted life. I'd really like to see his sources... Here7ic 18:31, 12 March 2006 (UTC)

I'm not talking about the sun burning out, I'm talking about the lack of energy sources and the soup of pollution. User:Zoe|^(talk) 00:20, 13 March 2006 (UTC)

Ever heard of expansion? Earth won't be our only home forever. Here7ic 04:12, 13 March 2006 (UTC)

That's my whole point. If we don't explore the solar system/galaxy, how will we ever be able to expand? User:Zoe|^(talk) 17:16, 13 March 2006 (UTC)

It is expected that a large amount of money will be spent on space exploration within the next decades. Here7ic 01:32, 14 March 2006 (UTC)

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

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

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

Suraj, you might like to think about why your own country is doing things like a) building the BrahMos cruise missile, buying (and building, I believe) Su-30 fighter jets, and hosting the 2010 Commonwealth Games, all of which are considerably more expensive than the New Horizons mission? Are they really more important than the 300-million odd Indians who still live in absolute poverty? And would cancelling any of them help those people? --Robert Merkel 00:48, 14 March 2006 (UTC)

Origin of life

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

Modern evolutionary synthesis? Mark^{your words} 12:04, 11 March 2006 (UTC)

friction

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

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

Pre-heat/warm oven?

Why do we pre-heat/warm ovens?

Regards, Reelstreets.

Are you talking about an oven you would have in your kitchen? If so, to pre-heat the oven just means to turn the oven on a few minutes before you are going to need to use it so that the oven is up to the desired temperature before you put the food into it. Dismas|^(talk) 15:22, 11 March 2006 (UTC)

It's because foods cook differently at different temperatures. Let's say you were baking a cake. Cooking it for 10 minutes at 300 degrees(F) is not the same as cooking it for 20 minutes at 150 degrees(F) (twice as long at half the temp). All things are cooked at a specific temperature to achieve the best results. We preheat ovens so that from the moment we put the food in there, it is cooking at just the right temperature. A good example of how things cook can be found in pretzels. Hard pretzels are the result of high temperatures and short cook times. Soft pretzels are the result of low temperatures and long cook times. See how much of a differene it makes? --Chris 15:59, 11 March 2006 (UTC)

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

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

• Preheating is useful if you are cooking something based strictly on time, for example, at 300 degrees for an hour. That is, without it you don't exactly know how long it takes for the oven to get up to temp and how much cooking was done while at the lower temps.

• Cooking based strictly on time and temp is akin to "dead reckoning", however, which is finding a location by moving a certain amount in a certain direction with no regard for landmarks. If you use landmarks, you can navigate much more closely to your target. Imagine the difference between driving home with your eyes closed and with them open ! In cooking, you can look for browning, use a thermometer, stick a fork in the food, use smell, etc., to gauge when the food is ready. This is much more reliable than going strictly by time and temp, which may vary by altitude, oven design, humidity, slight differences in proportions of ingredients, age of ingredients, how much of your yeast is alive, etc.

• I prefer to put food into the oven and take it out, when the oven is cool, to prevent accidental burns. Yes, you can use pot holders, but one slip and it's easy to severely burn yourself. I also like to open the oven door and let it cool down before removing the food. Most food needs a cool-down period before it's served anyway, so this is not a problem.

StuRat 20:47, 11 March 2006 (UTC)

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

multilingual webpage

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

You have to set up your web server to serve them a different page based on the "Accept-Language" field sent by the browser. Exactly how to do it depends on which web server you're using. —Keenan Pepper 18:33, 11 March 2006 (UTC)

Well, what if I don't have access to the server configuration? I was hoping for something I could include in the page. Basically I'm looking to replace a front page that says "choose your language". You know that wikipedia error page that you get when the site goes down? It's a single page, but it includes 5 or so different languages, which you can switch between (without loading a different page). Like, maybe it's Javascript? How do I see that page when wikipedia is not offline? -lethe ^{talk +} 18:40, 11 March 2006 (UTC)

So does the webserver have to know what translations to use for every single page it's going to serve? Seems a bit inefficient, doesn't it? Every time you add a page, you have to update the server config? -lethe ^{talk +} 18:50, 11 March 2006 (UTC)

The multilingual portal for wikipedia should appear here, and this page seems to address your 'automatic language selection' needs. Tzarius 01:25, 12 March 2006 (UTC)

Tracking Addresses

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

Short answer: in principle, yes, your IP address tells your physical location, but in practice, no, no one can find out your address. Yes in principle because your IP address is just that, an address. Packets on the internet use it to get to and from your computer, and if internet packets can do it, then so can people. Only, most people don't have access to all the routing information of the internet, so in practice, it's very hard.

On Wikipedia, if you have a user account, no one can get your IP address without developer or m:CheckUser access. Thus having a user account actually makes you more anonymous. If you edit wikipedia "anonymously", then anyone who cares to can see your IP address.

With email, email headers generally contain the fully qualified domain name (FQDN) of the machine they originated from, which is equivalent to the IP address. Emails from webmail services do not actually originate on your machine, they originate on the webserver, although the webserver can choose to add the client's IP address to the headers. Hotmail does this, gmail does not.

So what can people find out from your IP address? It depends on the address. When I'm in my office at university, my FQDN contains my last name, the department I work for, and the name of my uni. That's a lot of information; with that information, someone can look up my full name, see my picture, get my phone number, and my mailing address from the university's online directory. When I'm at home, my IP address contains the name of my internet service provider (ISP) and an abbreviation for the city, province and country that I live in. If I were using AOL instead, the IP address would contain less information; just the name of the ISP (AOL). It might also say whether I'm a broadband or a dialup user. In no case does your IP address contain information about your actual mailing address, though in some cases it can be almost as good.

Your ISP does know your mailing address, that's how they send you bills and do maintainence on the connection, etc. So people who work for your ISP can figure out your address if they know your IP address. This also applies to people who can break into your ISP's database or people who can get a judge to issue a court order to the ISP to release that information. -lethe ^{talk +} 18:27, 11 March 2006 (UTC)

In films people sometimes hide their location by being connected through several times (or something like that - I don't understand how that works either). But I suppose that is just to make it difficult to locate them, even for intelligence agencies. By the time the location is found they're gone. I suppose. DirkvdM 08:50, 12 March 2006 (UTC)

Antibiotic Sensitivity Testing (Antibiotic Discs)

Antibiotic sensitivity is tested with impregnated discs. The discs are available at a different antibiotic concentrations from the same company (e.g. Nofloxacin (10 mcg)-NF, Cefuroxime (30 mcg)-CR, Ciprofloxacin (5 mcg)-CI). Now is it fair to normalise the size of the clearance to the concentration of antibiotic on the disc - I mean is a clearance of 30 mm for 10 mcg of antibiotic A supposed to make it an equaly good choice as 30 mm 10 mcg antibiotic B? I mean antibiotic B could be lethal at a concentration of 10 mcg...

...so do they impregnate the discs at physiologically meaningful concentrations? Different companies even do different concentrations for the same antibiotics... how confusing! How does one decide what to give a patient? --Username132 20:05, 11 March 2006 (UTC)

Different disks are used for different purposes, or are used with appropriate variations of method. Obviously, the concentrations need to be clinically relevant. Patterns of infection and resistance in a hospital are closely watched and if the sensitivity testing results were not correlating with clinical responses to infections, it would be noticed and investigated. The sensitivity report is only one of the pieces of information considered in choosing an antibiotic. I suspect you could pay a visit to the microbiology lab of your local hospital and one of the lab techs would be happy to show you how it is done and answer your specfic questions. alteripse 03:05, 12 March 2006 (UTC)

In clinical use, you have to consider a number of things aside from antibiotic sensitivity, although it is definitely a good starting point. The antibiotic has to be able to reach the site of infection in an active form at adequate concentrations, and you have to consider possible side effects, contraindications, and drug interactions. For instance, tetracycline antibiotics may bind to a number of different metals such as magnesium, aluminium, iron, and calcium-- this will inactivate the tetracycline. Hence, they should not be taken with antacids or milk. Also, since they bind to calcium, they can also cause permanent stains in children's growing teeth, and the tetracyclines may also affect their bones.

Some bacteria may not show resistance at low concentrations; however, when you test at higher concentrations, genes for antibiotic resistance may be activated, and the bacteria is then resistant. This is known as "inducible resistance", and is associated with the SPICE organisms (Serratia marcescens, Pseudomonas, Indole-positive Proteus, Citrobacter, Enterobacter). In these cases, the disc method might not pick up on this form of antibiotic resistance, and you may have to resort to other techniques [9].

Additionally, some bacteria may form biofilms, which are aggregates of micro-organisms that can resist antibiotics-- this makes treatment of replacement joint infections difficult. Also, when you take broad-spectrum antibiotics, you usually end up killing a multitude of microbial species in your gut (i.e. gut flora). This may allow Clostridium difficile to take over, and you can get Pseudomembranous colitis as a result.

Hopefully, I haven't overwhelmed you! But as you can see, there are a number of factors that go into choosing the most appropriate antibiotic aside from antibiotic disc sensitivity. --Uthbrian (talk) 06:01, 13 March 2006 (UTC)

visual acuity testing using the stars

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

Hmm... Visual acuity and Zeta Ursae Majoris don't provide an immediate answer. It doesn't seem as if groups of dots are standard optotypes... Melchoir 21:02, 11 March 2006 (UTC)

I know that answering this question is futile, but I can't help it. :-\ The letters on the Snellen chart are based on a 5x5 grid. At 20/20, each letter subtends 5 minutes of arc, so each grid cell subtends 1 minute. Recklessly assume that resolving two stars is the same as perceiving a single black cell between two single white cells (which of course is not what happens in a real Snellen test). At 20/20, the centres of the two white cells are separated by 2 minutes of arc. 12 minutes of arc is six times bigger than this, so the Snellen fraction would be 20/120. However, with star-spotting, you are violating the standard illumination conditions of the Snellen test just a teensy bit, so I doubt that this result is meaningful. The only true way to equate the Snellen scale with the star-seeing test would be by experiment, which would be an interesting exercise. I wonder if anyone has done it. --Heron 18:32, 12 March 2006 (UTC)

Good response Heron. I think it would also the same as discerning 3 black cells in a row from two black cells separated by one white cell. I would guess that 20/120 would correlate quite well (at the very least it would be a rough estimate) with the star-example although it is true that experiment is the only way to tell. George, I'm wondering where you read about that being an acient test? Just curious, thanks. -Snpoj 07:08, 13 March 2006 (UTC)

Languages

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

Depends on what you mean by "foreign language support". If you want to read pages in other languages, it should just work automatically as long as you have the right fonts. If you want the browser interface to be in a different language, you have to download a regionalized build here: http://www.mozilla.com/firefox/all.html —Keenan Pepper 23:40, 11 March 2006 (UTC)

I meant the former, so I guess I don't have the right fonts...But there is nothing that automatically asks me to download the required fonts, like in Internet Explorer. For example, I can't read [10] -Anonymous

It doesn't have to be any particular font, just one that includes the required characters. For example, if you install Microsoft Office, it includes a version of Arial with characters for a wide variety of languages. If you don't have Office, you may be able to find a freeware font with the same characters, such as Code2000, but I haven't tried any of those.

By the way, that "Add Language" dialog is for something completely different. The list you enter there is sent to web servers, which can then decide which language version of a page to send you in case they have more than one of the same page. I don't think it's used much any more. —David Wahler (talk) 15:16, 12 March 2006 (UTC)

That's strange...I already have Microsoft Office. I even went to Microsoft Office Tools/Microsoft Language Settings and added the language (Chinese) but i still couldn't read [11] -Anonymous

Oh, wait, it works now. Thanks! -Anonymous

Problem with my mouse

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

If you haven't already done so, cleaning your mouse is a good idea. Take out the ball and scrape the grey gunk off the rollers (most mouseseses have three). If it's an old mouse, then the problem may be with the cable - if it's worn internally, it may not send a good signal to your computer. And of course, check the connection!
Slumgum 23:10, 11 March 2006 (UTC)

I'd suggest you to just go get an optical mouse instead. They're pretty cheap nowdays and they're just too much better than ball mouses. ☢ Ҡi∊ff⌇↯ 00:58, 12 March 2006 (UTC)

Alas you specified that it is about a computer mouse. Without that the question would have been a lot funnier. Especially the 'ball mouse' bit. DirkvdM 08:53, 12 March 2006 (UTC)

More seriously, it sounds like your graphical system is overloaded. In that case you should have other graphical problems as well, such as when switching between windows being slow. Having too many windows open (say, over 20) could be a cause. I also once had something like this with a mouse-pad, althogh I can't remember the details. I think I had both a normal mouse and the mouse pad connected and when I disconnected the latter all was fine. Does the problem persist when you use a normal mouse? DirkvdM 08:59, 12 March 2006 (UTC)

What about mice with a tracking ball - are they nice to use? --Username132 17:02, 12 March 2006 (UTC)

If you don't mind people making fun of you, and if you can get used to doing everything backwards.  freshgavinΓΛĿЌ  05:39, 13 March 2006 (UTC)

Download freezing my PC

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

I am assuming you use Microsoft Windows, and if so, then you could try their Malicious Software remover. I have not yet downloaded this, so, unfortunately, I am unable eto give you a mini rave-review. It's available here. Hope this helps. However, after reading a few details on the page, it appears it scans your ccomputer, so I doubt the file will come up becuase every .exe file will come up. Kilo-Lima ^{Vous pouvez parler} 23:20, 11 March 2006 (UTC)

(added after edit conflict) First off, a few specifics. What program were you trying to update? What was the name of the exe file? From where did you download it? It might be some sort of spyware mucking up your OS, so it'd be helpful to know what something about it.

Other than that, it sounds like there was a problem with your browser downloading it. Since it froze before it was even finished, it seems like it doesn't have very much to do with the exe itself, other than it got malformed during download. Have you tried simply downloading the file again?

As for deleting it, you may wanna try deleting it using the command line, instead of using Windows Explorer. Does this work? That is, open Run, type "cmd" browse to the correct folder using "cd", and typing "del [filename]". Hope this helps Oskar 23:23, 11 March 2006 (UTC)

It was an update to IrfanView. It isn't a .exe file, it's a .part file, because the download didn't finish. I can't delete it, that's the problem, the minute I single-click on the file name or the icon, the computer freezes. Maybe I'll try re-downloading it, see what happens there. User:Zoe|^(talk) 23:44, 11 March 2006 (UTC)

So, what you're saying is, probably not spyware? :P Try downloading again and/or deleting it using the command line, those should work. Oskar 23:48, 11 March 2006 (UTC)

Having more than one OS installed can often help in such situations. Preferably two different ones, so if you use msWindows, install Linux (takes about half an hour with a modern distro and you'll have all sorts of programs coming with it - unlike with msWindows). Then, from there, it should be no problem to remove the file (linux can access just about any file system, although ntfs is problematic). And then you can use Linux to download the program. That's what Linux is best at - internet stuff. And if things go wrong it won't freeze (well, extremely unlikely). DirkvdM 09:04, 12 March 2006 (UTC)

I find Ubuntu Linux useful because the Live CD enables complete access to Windows folders without having to go to the trouble of installing it all. Sum0 15:07, 12 March 2006 (UTC)

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

March 12

aromatic oils in citrus

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

Does the word purpose mean you support intelligent design, or are you really asking why the citrus tree evolved the genes to make those oils? —Keenan Pepper 01:23, 12 March 2006 (UTC)

the latter. sorry if that wasn't clear. —Charles P._(Mirv) 02:21, 12 March 2006 (UTC)

Many fruits are "designed" (the parentheses are there to keep that anti-Intelligent Design guy from chiming in again) to be eaten, then the well fertilized seeds grow into a new plant. Having a bright color and fragrance makes it easier for animals, including us, to find and eat the fruit. StuRat 06:51, 12 March 2006 (UTC)

Also, some of them might be chemical signals in the flowers, to bees or whatever pollinates them, that happen to remain in the fruit. —Keenan Pepper 07:04, 12 March 2006 (UTC)

Your comment on intelligent design was way out-of-order and I expect you to bow deeply and resign from your post. It doesn't matter if it was an intelligent purpose or not, it still functions in the same way and achieves the same results no matter what you think of evolution.  freshgavinΓΛĿЌ  05:38, 13 March 2006 (UTC)

Mustard oil

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

Have you read the article on mustard oil? —Keenan Pepper 01:18, 12 March 2006 (UTC)

Mustard oil is the best! deeptrivia (talk) 01:21, 12 March 2006 (UTC)

Moment in a bimetallic strip

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

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

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

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

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

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

Do I have to come up with my very own model format and write my own Blender exporter for it, all from scratch, if I want to write anything resembling a graphics engine? That seems to be what many videogame companies do anyway, using an in-house format that they no doubt wrote custom exporters for, but I really don't have time for that. Or is there some open-specification, well-documented, royalty-free, and pretty-much-fully-featured model/mesh file format out there supported by the majority of 3D modeling+animation programs that I haven't noticed yet? It's just frustrating that the only thing holding me back from writing an engine that does more than render flat-shaded, static models is the lack of information and availability of utility. --69.237.157.237 08:06, 12 March 2006 (UTC)

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

.m4a

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

iTunes can. Melchoir 10:30, 12 March 2006 (UTC)

To turn m4a into mp3, use iTunes. To do this go to prefrences, and make sure you are importing to mp3, with the bps of your choice (128 is CD quality), and right click (control-click on a mac) on the song(s) you want to change and select "convert to mp3." I am pretty sure you can't convert from m4a to wma, because of codec issues. If you want to convert from wma to mp3 or m4a, then you would want to use Easy WMA. Love, -- Mac Davis] ☢ ญƛ. 11:20, 12 March 2006 (UTC)

It's certainly possible to convert from m4a to wma. If nothing else, you could convert the m4a file to a wav file, then convert the wav file to wma. However any transcoding between lossy formats is going to do damage to the quality of the file, so should be avoided if at all possible. Mark^{your words} 11:39, 12 March 2006 (UTC)

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

Audio Conversion

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

Use any CD ripping program. ITunes is popular but very bad; EAC is harder to use, but gives the best quality. Mark^{your words} 12:28, 12 March 2006 (UTC)

Can't Windows Media Player simply do it? Kilo-Lima ^{Vous pouvez parler} 12:42, 12 March 2006 (UTC)

Newer versions can, but they're no better than iTunes. Mark^{your words} 13:02, 12 March 2006 (UTC)

Winamp Pro can. This costs $20. You can try this piece of freeware. Though, it doesn't look perfect. Computerjoe's talk 15:34, 12 March 2006 (UTC)

I use FreeRIP, my sisters use EasyCD-DA Extractor. In my opinion, they're both better than all these suggested so far. FreeRIP is the faster I know, too. ☢ Ҡi∊ff⌇↯ 01:12, 13 March 2006 (UTC)

There is a LAME plugin for iTunes that replaces iTunes crappy codex with a kick ass mp3 encoder. For great justice. 02:52, 13 March 2006 (UTC)

I've always used CDEX for ripping. Just another reliable option. It's small and freeware, allows plugins.  freshgavinΓΛĿЌ  05:33, 13 March 2006 (UTC)

I like to use DeepRipper. Its completely free and very easy to use. Try it out. You can download it from download.com or from the official website. If you use the official website, make sure you get DeepRipper and not DeepBurner. I suggest download.com though. Latest version is 1.1 for both sites. --Chris 16:14, 13 March 2006 (UTC)

Blood circulatory system

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

Wargsmon

Well, even although I don't have a specific andwer for this question, bu if coca-cola contains roughly the smae amount of sugar in honey, then it iwll take about 20 seconds for the suagr to get into the bloodstream. (Source: The Book of Useless Information.) Kilo-Lima ^{Vous pouvez parler} 14:52, 12 March 2006 (UTC)

Note this is probably the first appearance of sugar from honey in the portal blood, not full absorption or "diffusion" into the systemic circulation. alteripse 18:47, 12 March 2006 (UTC)

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

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

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

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

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

Unknown plant

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

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

Windows Media Player 10

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

March 13

noninteractive XML editor?

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

I use Kate. No annoying popups. No annoying auto-completes. Plus, you can open/edit/save on remote servers without doing any import/export garbage. --Kainaw ^(talk) 13:44, 13 March 2006 (UTC)

Thanks, but that looks pretty interactive to me! Anybody know of any noninteractive ones? —Steve Summit (talk) 16:s [16, 13 March 2006 (UTC)

I'm tempted to suggest rolling your own Perl program for whatever it is you want to do -- if you know sed then it's not much of a leap, and there'http://search.cpan.org/search?query=xml&mode=all loads of XML parsing modules available]. But then I love Perl and have a tendency to see everything as a nail that can be hit by its hammer. --Bth 16:31, 13 March 2006 (UTC)

Graphics of the PS3

Does anyone know if the PS3 will be able to achieve superior graphics than the XBOX 360? I have seen the technical specifications of both of the systems GPU's but I am not sure of the meaning of all those numbers. It seems that the PS3's GPU has higher spec numbers. —The preceding unsigned comment was added by 4.234.222.77 (talk • contribs) 02:35, 13 March 2006 (UTC)

I believe the XBOX 360 can pump out better graphics than the PS3. The 360's GPU is truly custom built. It was built from scratch by ATI while the PS3 uses a clone of the Nvidia GeForce 7800.

—The preceding unsigned comment was added by 4.234.222.77 (talk • contribs) 02:54, 13 March 2006 (UTC)

A few comments on this. If you're going to judge "superior graphics" as a direct relation to specs on benchmark testing (like 3D Mark), then don't expect a more concrete answer than "PS3 seems to be better than XBOX 360". Benchmarking works with hundreds of critera and there is often overlap between winners: XBOX 360 is likely the winner in some benchmark categories and PS3 is likely the winner in others. Tech specs are largely just part of the "numbers game" as well, because a lot of what is important is much more difficult to put into numbers that the public will understand. Sure 1 billion gigahertz is impressive, but it means absolutely nothing if there isn't efficient use of the cache system, or if the machine-code procedures are badly implemented.

The fact that the 360's GPU is custom built means very little. NVidia uses tried-and-tested, industry standard equipment, and they've been building quality products for decades. Unsigned's comments are rather a statement of his trust in the manufacturers employed by Microsoft, though POV is not un-welcome at the reference desk.

Besides, we all know that the games (and how they're built, who built them) matter a lot more than the system does (and I don't even play games anymore). This is especially evident when talking about the "ease of programming" that each system allows for it's programmers, something that PS2 had a huge leg-up on over Microsoft when XBOX was first released.  freshgavinΓΛĿЌ  05:04, 13 March 2006 (UTC)

Precisely. The PS3 is coming out a year after the Xbox 360, so presumably it'll have a year's worth of graphics advances. So I'd put my money on the PS3 having better graphics. But that's not certain, and it depends on the gamer's opinion and on the game itself. In addition, console graphics improve gradually as the console gets older (as programmers learn how to get the most out of the console), so the Xbox 360 may well catch up with the PS3 (especially if programmers find it easier to program for the Xbox 360 - I don't know if that's the case.) Sum0 20:09, 13 March 2006 (UTC)

Epistasis?

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

66.191.1.142 02:37, 13 March 2006 (UTC)

Sounds suspiciously like homework, but... Two genes, let's call them A and B. Both can be in one of two forms (say j and k), with a 50% chance of a gene being one or the other. So you can get Aj, Ak, Bj, Bk. A controls mouth shape. Aj gives thin, Ak gives oval - irrespective of what form of gene B is. BUT both genes have to be in the k form for the colour to be black. Anything else will give white (i.e., Black is a recessive gene). An average population of 16 would give four each of AjBj, AjBk, AkBj and AkBk. The first eight would have thin mouths, the last eight would have oval mouths, but only the four with AkBk would have black mouths - the others would have white mouths. Whether that would count as epistasis, though, I'll leave to others who know more about genetics... Grutness...wha? 06:01, 13 March 2006 (UTC)

Lethal Dominant Genes

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

As I understand that article, the hairlessness is dominant, but the lethality is recessive. That is, dogs with two wild-type (normal) genes will be normal, with hair. With one affected gene, they will be hairless but alive. With two affected genes, they will not survive. Does this make sense? — Knowledge Seeker দ 06:02, 13 March 2006 (UTC)

Ah, I didn't catch that, but upon further inspection you are certainly right! So "homozygous lethal for the dominant gene" is just a confusing way of saying, "the hairlessness is dominant, but the lethality is recessive." So what is the mechanism that relates (double-allele) hairlessness with lethality? Can it merely be two genes linked so close together that they appear as one?JianLi 01:18, 14 March 2006 (UTC)

Check out thanatophoric dwarfism for an example of a human lethal single gene disease: [12]. Obviously all cases represent new mutations as no one survives to reproduce. alteripse 06:11, 13 March 2006 (UTC) PS, as it is a red link, we obviously need an article on it.

Electricity

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

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

To answer Blueiris, there would be power cuts or power rationing. Water heating might be turned off, or power might be turned off in general between certain hours of the day. To see what happens when power gets close to completely running ut in a Westernised urban area, have a look at 1998 Auckland power crisis. Auckland was lucky - it happened there in mid-summer. In winter in slightly-less-than-tropical Finland, though...? Grutness...wha? 07:05, 13 March 2006 (UTC)

Okay, thanks. :) Blueiris 07:26, 13 March 2006 (UTC)

If there was no power rationing and everyone was still connected to and drawing from the grid, then I would say that lightbulbs would go dimmer because there is simply less power. I would also guess that voltage would remain constant and that the amps coming into your lightbulb would drop, making it dimmer. Whether a lightbulb would even go on or not is a more difficult question. That would require looking at exactly how much power is going into it and how much power is required for the filament to begin emitting black-body radiation (i.e. how much power it takes to get the filament to a certain temperature). -Snpoj 07:39, 13 March 2006 (UTC)

Harrumph. If the voltage remains constant, the current (amps) through a particular load (resistance) must also remain constant. Ohm's Law, you know?

In fact, the delivery of electric power requires a careful balancing of load and generating capacity. If the load increases beyond what the generators can supply, the voltage starts to drop, creating a "brownout". With lower voltage, the current delivered is also reduced. Light bulbs shine less strongly, motors don't deliver as much power. But the voltage isn't allowed to drop more than a few percent, because if it did, appliances might start to malfunction. If the generators can't maintain even the slightly reduced voltage, they'll automatically "trip offline" and shut down. It's also possible that an excess of "reactive load" (basically motors as opposed to lights) will cause the frequency to drop rather than the voltage, and again the genertor trips offline. (The same thing also happens if the load is reduced suddenly due to some problem and the generator is delivering too much power.)

Power utilities will try to avoid this sort of thing if they possibly can; for one thing, an unplanned shutdown can take longer to recover from, and if compounded by other problems it can propagate to a much larger area than the area of the actual shortage, as in the Second Great Northeast Blackout (where the actual power shortage was confined to northern Ohio). To avoid it, as noted, they will ration power: for example, they may use "rotating blackouts" where different districts deliberately have their power turned off in turn for predictable periods of time.

--Anonymous, 10:01 UTC, March 13, 2006.

Didn't exactly that happen in Russia a few weeks ago? People died. Well, that was a general lack of energy, not specifically electricity. I suppose that in Finland the decision was made that heating was so important in winter that energy sources weren't used for electricity. That way at least people won't freze to death like they did in Russia. We may have lived without electricity until just one or two centuries ago, but we've become so reliant on it that we wouldn't know how to deal with lack of it. People don't generally have a bunch of oil lamps to light the house. But domestically that's mostly a nuisance (in winter a fridge isn't necessary).

The biggest problem, I suppose, wuld be with certain computerised systems not running anymore, but the most essential systems will probably have their own backup with a generator. For which they'd still need fuel, though, so that's rather begging the question and those generators would be much less efficient, thus aggravating the problem. DirkvdM 09:50, 13 March 2006 (UTC)

Unfortunately, though, you can't always separate "electricity" from "heating". I don't know what the common types of heating systems in Finland are, but many of the ones I'm familiar with here require electricity also. For example, my house has a gas-fired boiler, but without electricity to run the pump to force the hot water through the radiators, I wouldn't be able to heat the house. (And of course this is one more reason for having rolling blackouts, as opposed to, say, shutting the electricity off for good.) —Steve Summit (talk) 16:13, 13 March 2006 (UTC)

Thanks all... these were exactly the things I wanted to know. :) Blueiris 11:05, 13 March 2006 (UTC)

Last column of elements

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

See the "Etymology" section of Noble gas. Melchoir 08:57, 13 March 2006 (UTC)

Blue blooded fart? DirkvdM 09:52, 13 March 2006 (UTC)

Wha? Melchoir 10:31, 13 March 2006 (UTC)

Don't worry - just Dirk thinking like an alien again :) Grutness...wha? 13:11, 13 March 2006 (UTC)

distributed compilers

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

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

Smoke inhalation

Yet another question from the Newcomer's help page:

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

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

"There must be some good quality of smokes which may be good." — That's not a logical conclusion. The best thing to breathe is pure smoke-free air. All kinds of smoke contain polycyclic aromatic hydrocarbons like benzopyrene and other nasties. —Keenan Pepper 13:18, 13 March 2006 (UTC)

Don't be a buzz killer man. Just tell him that smoking pot is good for him and everyone will be so much happier. --Kainaw ^(talk) 13:41, 13 March 2006 (UTC)

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

Note that essences of some plants are inhaled regularly in westrn medicine, too - notably eucalyptus. Grutness...wha? 22:39, 13 March 2006 (UTC)

Electolysis

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

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

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

Well, I have done this with filtered water and a lot of NaCl. I have also done it with mere tap water. With both, I never seemed to get oxygen. I know that chlorine more readily escapes from the solution that oxygen, but there are some salts that do not take part in the reaction, and are only there to conduct the electricity. I do not know which salts these are though. But I assume that what you are saying is that there isn't going to be too many secondary reactions. Just hydrogen, chlorine, NaOH, and remaining salt will remain. Thanks for your help. --Chris 21:58, 13 March 2006 (UTC)

Chimpanzee IQ

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

• Given my experience with a lot of the vandals here, I'd say, yeah, easily. --jpgordon∇∆∇∆ 17:35, 13 March 2006 (UTC)

The smartest ant is smarter than the least intelligent human. Therefore, the smartest apes are smarter than the least intelligent humans. Note - the least intelligent human is a human with no mental capacity. This may be caused by birth defect or brain damage. Some humans have no brain activity at all and are kept alive purely by machines. So, they are the least intelligent humans. Anything with a heartbeat is more intelligent. --Kainaw ^(talk) 19:56, 13 March 2006 (UTC)

I think it's a testament to all wikipedian's maturity, that no one has mentioned george bush yet

That doesn't mean we weren't thinking it.  :-) Dismas|^(talk) 22:46, 13 March 2006 (UTC)

The chimp is very good...at being a chimp, just as a human is good at being human. IQ is a general measure of human abilities, and by applying it to a chimp, you might suggest that a chimp with a very high IQ isn't actually a very good chimp. It's off putting a square plug into a square hole and solving equations instead of eating bananas. Just something to think about :)--inks^T 01:45, 14 March 2006 (UTC)

AIDS transmission

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

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

I always thought that the HIV virus died within a few minutes of leaving the body and being exposed to the outside world. Sum0 20:00, 13 March 2006 (UTC)

It dies shortly after leaving the blood. When a needle is used, blood is left inside the vial/needle. That infected blood is passed to the next user. So, the virus never has to leave the blood to get from one person to another with needle sharing. --Kainaw ^(talk) 20:08, 13 March 2006 (UTC)

Yes. But be aware there is nothing magical about blood in terms of HIV surviving. It needs moisture and warmth (ie dryness and cold and heat "kill" or denature it). It can survive in a warm moist vagina quite long enough. WAS 4.250 20:22, 13 March 2006 (UTC)

Mission to Mars

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

Well, NASA's Vision for Space Exploration doesn't set a date for Mars, but says 2020 for the Moon, while ESA's Aurora Programme says 2030 for Mars. These are both highly speculative, of course. See also Exploration of Mars. Melchoir 21:33, 13 March 2006 (UTC)

It's a programming, budgetary, and risk issue more than a technological one. If one were prepared to cancel the shuttle immediately and/or give NASA (or some other group) lots of money immediately, and were prepared to accept a greater risk of the astronauts not coming back (maybe 10-20% rather than the 2% the Shuttle astronauts face), the job could almost certainly be done within the decade. As a further example of a technology that could get us to Mars quickly (in both senses of the word) but which is likely to remain undeveloped for various reasons, have a look at Project Orion.

FWIW, I too hope to see somebody walk on Mars in my lifetime, and I'm 29. I remain reasonably confident that it will happen. --Robert Merkel 00:34, 14 March 2006 (UTC)

March 14

Pykecrete

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

Check out Pykrete, which recommends "approximately 14 percent sawdust or some other form of wood pulp (such as paper) and 86 percent ice by weight". Melchoir 00:20, 14 March 2006 (UTC)

Thank you. The spelling eluded me as well apparently!

Well, it's good you asked! Pykecrete is now a proud redirect. Melchoir 00:33, 14 March 2006 (UTC)

Er... it will be when a certain cache updates. Melchoir 00:35, 14 March 2006 (UTC)

Cutting Mirrors

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

To be clear, you are talking about using a series of small flat mirrors to approximate a paraboloid, not actually constructing a curved mirror, right ? You can cut mirrors with a glass cutter: [13] Typically you score the glass in a straight line, then break it off with one half supported by a table and the other half hanging over the edge. You should wear goggles and thick leather gloves when doing this. StuRat 02:01, 14 March 2006 (UTC)

Walking On The Moon

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

As I mentioned above, NASA's Vision for Space Exploration proposes manned Moon missions by 2020. Assuming that actually happens, I guess it depends on how old astronauts are supposed to be. Melchoir 01:47, 14 March 2006 (UTC)

Very interesting. Perhaps that info is in the Wikipedia on Astronauts. I must check this out. Here7ic 01:59, 14 March 2006 (UTC)

Well, good luck on your research! For such a visible occupation, Wikipedia has surprisingly little information about the astronaut career path, especially in the United States. Hopefully you can educate us all! Melchoir 02:49, 14 March 2006 (UTC)

Actually, on second thought, I should stop thinking about Wikipedia for a second and encourage you to ask your Marine recruiter the same question. Melchoir 02:55, 14 March 2006 (UTC)

Um, I wouldn't take the recruiter's answer at face value. He has a quota to fill. He probably won't literally promise you the Moon, but he might try to make it sound like joining the Marines is your best shot at it, even if it isn't. (Has there ever been an astronaut from the Marines? I think, at least in the early days, a lot of them came from the Air Force.) --Trovatore 03:05, 14 March 2006 (UTC)