Wikipedia:Reference desk/Archives/Science/2006 November 5

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November 5

Name of anti-depressant that makes people walk around a lot as a side-effect?

I'm not sure if its still in use, but I would like to know what its name is.

Thanks.

Hmmm. There are certain antidepressants that have various weird side effects, for instance spontaneous orgasm whenever the taker yawned, but I haven't heard of one that causes the behaviour you describe. --Robert Merkel 02:03, 5 November 2006 (UTC)

Is it still available? Im just interested.. thats all 8-)--Light current 03:03, 5 November 2006 (UTC)

Yes. However, this side effect only occurs rarely. A partial or complete loss of libido is a much more common side effect. --Robert Merkel 10:27, 5 November 2006 (UTC)

Well, according to a quick google search, all of them. The effect, BTW, is called akathisia. Anchoress 02:55, 5 November 2006 (UTC)

Not ALL OF them. For example Clozapine has minimal EP Adverse Effects.  Doctor Bruno  16:16, 5 November 2006 (UTC)

Why do they euthanize horses after they break a leg?

I understand that in the Distaff today Pine Island dislocated her front leg, which caused infection, and as a result she was euthanized. Why can't they save the horse, give it antibiotics or something, and rehabilitate it? I understand such a horse would never be raceable again, but even so, for becoming a stud and breeding, it could have some utility... 207.200.116.204 01:55, 5 November 2006 (UTC)

For fun and profit. Chris 00:54, 8 November 2006 (UTC)

When a human being breaks a leg, s/he can get around with a cast and a crutch; if s/he needs to have the fracture under tension, s/he can rest in bed during that time. Unfortunately, a) a horse needs to be upright and moving around in order for its digestive and circulatory system to work, and b) its limbs are so delicate and specialised that i) the horse often can't last long on only three legs, ii) a cast is insufficient to take pressure off the break, and iii) it can seldom heal well enough to support the horse's weight. Which isn't to say that a horse can never survive a break or dislocation, but it's uncommon. Anchoress 02:46, 5 November 2006 (UTC)

The Barbaro case.--JWSchmidt 05:13, 5 November 2006 (UTC)

So what the article is missing is how much semen was extracted from Barbaro while it was recovering. Obviously they primarily wanted to save its life but secondarily I suspect its offspring would be extremely valuable and they worked vigorously to extract as much semen as they could in case it died. --Tbeatty 06:09, 5 November 2006 (UTC)

Hmmmm. That never happened to me when I was in hospital the other year - *and* more than one person had remarked to me "if you were a horse, they'd have shot you by now". Maybe it's just that you don't get that on the NHS... ;) --Kurt Shaped Box 11:04, 5 November 2006 (UTC)

Yeah, well, I wonder how much semen they'd have been able to extract from you after a compound fracture and a bone-deep foot infection. It might have required the same extraction method used in Road Trip, or even Hannibal. Anchoress 11:19, 5 November 2006 (UTC)

I believe there have been some attempts to develop a method of saving horses with broken legs. While a plaster cast is insufficient for the forces placed on it, an external stainless steel brace can be added for that purpose (much like what polio victims used to use). Keeping the horse from licking or biting the area is also a problem, but one that can also be dealt with. StuRat 06:41, 5 November 2006 (UTC)

Keeping up with scientific discoveries

How can I keep up-to-date with scientific discoveries? for example how research on cures for various diseases is going. Are specialist journals the best option? Jack Daw 03:05, 5 November 2006 (UTC)

You could subscribe to Nature, New Scientist, Scientific American, The Lancet etc or read them in your local library.--Light current 03:12, 5 November 2006 (UTC)

That's the best option if you're a scientist. If you're not, the journals may be a bit difficult to read. I suggest searching Google for things like "medical news", "astronomy news", etc. For example, you can use http://www.medicalnewstoday.com/ to keep up-to-date with medical developments. --Bowlhover 03:17, 5 November 2006 (UTC)

It's not on the same level as some of the science journals listed, but I find THIS SITE a very accessible and reliable source for a wide variety of science news. Anchoress 03:31, 5 November 2006 (UTC)

This one too. Anchoress 05:16, 5 November 2006 (UTC)

Scientific American also seems to strike a good balance between technical detail and readability; the text is aimed at someone who is generally conversant with science, but not the specific topic under discussion. --ByeByeBaby 07:33, 5 November 2006 (UTC)

Yes SciAm is a popular magazine and not a peer reviewed journal.--Light current 09:34, 5 November 2006 (UTC)

Yeah, reading the popular science magazines would be a good way to keep up with some of the things that are going on. However, if you want more detail, you can then try digging up the relevant scientific papers. Be warned, some of them may be virtually indecipherable to an outsider. --Robert Merkel 10:25, 5 November 2006 (UTC)

Personally I would recomend New Scientist. I keeps up with all aspects of scientific advancements; it is a good mix, as it has some pretty deep articles, and some more light-hearted ones. Englishnerd 13:32, 5 November 2006 (UTC)

I like very much News@Nature, a web service by the well-known Nature journal, which explains significant new research results in a laguage understandable to the eductated layman (by which I mean somebody who has paid attention in biology and physics at high school). They post about three to five short articles per week, and seem top manage to not only cover stuff published by their own journals. If you are especiall interested in physics, you might also like Physical Review Focus, a similar service of the American Physical Society, to be found here. Simon A. 19:50, 5 November 2006 (UTC)

The site Anchoress mentioned is one of the best. Click on [1] Sciencedaily every day and you can stay on top of every scientific discovery, since they link to press releases from universities and research centers, and basically give press accounts of discoveries and research grants. In other words, it is not filtered through a science writer at a paper. The science section of the New York Times is also good, where it IS filtered through a science writer. Edison 14:43, 6 November 2006 (UTC)Edison 14:39, 6 November 2006 (UTC)

canine cognitive dysfunction

canine cognitive dysfunction - symptoms, treatments, homeopathic remedies

<sarcasm> Yes sir, I'll drop everything and get right on it! </sarcasm> Aaadddaaammm 04:24, 5 November 2006 (UTC)

I have seen a drug advertised for canine depression in older dogs, so this isn't any weirder than this, I suppose. StuRat 09:17, 5 November 2006 (UTC)

Have you tried searching on Google? --ByeByeBaby 07:30, 5 November 2006 (UTC)

Q. Will a homeopathic placebo make a dog smarter if it is the owner who believes in the efficacy? A. Only if the only evidence that the dog was getting dumber was in the mind of the owner. alteripse 12:05, 5 November 2006 (UTC)

On the other hand, the owner might think the dog is smarter: "Oh my God, I asked him how sandpaper feels and he said 'Rough' !" StuRat 23:06, 5 November 2006 (UTC)

Autoclave

Can we use autoclave to sterile graduated cylinder?218.137.224.220 04:47, 5 November 2006 (UTC)Phunsiri Suthiluk

Yes. According to the article, autoclaves are used to sterilize medical equipment. So I guess you can sterilize a graduated cylinder with it, too. --Bowlhover 05:08, 5 November 2006 (UTC)

Assuming it's made of glass, and not plastic or something else that doesn't like heat, I can't see why not. Then again, what do I know? —Ilmari Karonen (talk) 05:59, 5 November 2006 (UTC)

Many I've seen do have a plastic base, so that could be a problem, unless the base is removable. Of course, the base would then need to be sterilized in some other manner. StuRat 06:27, 5 November 2006 (UTC)

Depends on what temp you autoclave at although it seems unlikely you are going to damage pyrex 8-)--Light current 09:39, 5 November 2006 (UTC)

Why don't you ask your supervisor? If you are the supervisor, er no comment... In any case, I've autoclaved graduated cylinders before. Not one's with plastic bases of course. Do remember to cover up the top with foil and don't forget the autoclave tape so you know it actually got autoclaved. Oh and don't forget to close the autoclave properly. Oh and don't burn yourself when your done Nil Einne 15:39, 6 November 2006 (UTC)

Sound smearing and size hop of a vocoder

I often read these terms in papers but I don't understand 'em..can you help me? --Ulisse0 19:05, 5 November 2006 (UTC)

I've used a couple of vocoders but am far from any kind of authority. I've never heard of the exact terms you mention. As far as synthesis and vocoding go, I don't believe there is a 'standard' to which these devices follow, in other words the terms you have heard my be propriety terms used by one vocoder manufacturer to define parameters they have used in their device, they could be similar or different to the names and parameters used by a different company. Some times these aren't very well explained even in the device's manual, depending on the target market of the device, most DJ gear doesn't go beyond: 'changes the timbre of the sound'.

Having said that, if I was going to have to guess, vocoding generally changes a sound by slicing the input and processing the slices. Smearing could possibly refer to the amount of one slice that 'smears' into the next one, and hop could be the size of the slice it self. Vespine 00:30, 6 November 2006 (UTC)

Thank You! --Ulisse0 09:15, 6 November 2006 (UTC)

sinusoidal oscillators(electronic)

i read that sinusoidal oscillators produce a sine wave output by amplifying noise signals through positive feedback loop. my question is that how can a noise(which is generally random and non periodic),produce a sine wave output...? and furthermore, how does the oscillator produce a sustained oscillations inspite of positive feedback...? if anyone can answer my questions i'd be eternally grateful to them...

Noise is what starts the loop but the frequency of oscillation is determined by other elements. The other elements resonate at a particular frequency. Since noise contains the full spectrum of frequencies, it "seeds" the positive feedback loop. The resonant frequency is reinforced until the oscillation is at the desired magnitude. --Tbeatty 16:35, 5 November 2006 (UTC)

The articleElectronic oscillator is not very clear when it talks about an oscillator producing noise when it is "first switched on". In practice they produce a sinusoid without any apparent period of noise production. Edison 14:52, 6 November 2006 (UTC)

Science (various)

What is science - i love it but don't really know how to define it thanks

Hi! Why don't you start by reading science, then come back with specific questions? Anchoress 10:52, 5 November 2006 (UTC)

There's also Wiktionary:science for a plain dictionary definition. -- Consumed Crustacean (talk) 10:55, 5 November 2006 (UTC)

Well, the definition in the opening sentence of the science article is just as good and at least as plain. Anchoress 10:58, 5 November 2006 (UTC)

Science in the broadest sense refers to any system of knowledge attained by verifiable means.--Light current 22:09, 5 November 2006 (UTC)

how to plant hybrid apple seeds

can you get the seeds from a fuji apple and plant them and them become a tree and produce fruit even though they are hybrid apples? thank you

• Apple seeds do not reproduce true to type. Apples are cross-pollinators. --jpgordon^∇∆∇∆ 15:29, 5 November 2006 (UTC)

environment

how the air is produced? from where it comes

• Try reading Earth's atmosphere. It comes from a variety of places. Plants release oxygen in photosynthesis, most of the nitrogen comes from bacteria, anything that respires release carbon dioxide, water vapour from evaporation, stuff like compounds of sulphur and lots else come from volcanic activity, methane largely from animals, and so on, plus all the junk that humans are now pumping into the atmosphere. It's quite complex. The Earth's gravity helps prevent these gases from escaping to space. --jjron 15:41, 5 November 2006 (UTC)

Also, comets and volcanoes contributed a lot to the current atmosphere. StuRat 19:29, 5 November 2006 (UTC)

The third most abundant gas in the atmosphere, argon, is created when calcium loses two protons and two neutrons (an alpha particle) via radioactive decay. (Our article on Argon also says it can be produced when a potassium atom captures a neutron, though I don't see how.) Since alpha particles are actually helium nuclei, this also explains how helium is produced; by radioactive decay, mostly from uranium and thorium. --Bowlhover 20:12, 5 November 2006 (UTC)

If my memory serves me well, a nucleus of a potassium-40 atom captures an electron, not a neutron. As a result, the nucleus charge decreases by one, so it's an argon-40 atom now :) --Dementios

A nucleus does not absorb an electron and change to another element. Only absorbing a proton will do that. Absorbing a neutron changes the isotope, and capturing an electron in an orbital changes the charge only. StuRat 23:02, 5 November 2006 (UTC)

Or, after the neutron is captured, it can decay into a proton, an electron, and a neutrino (beta decay). This way, the nucleus's isotope number won't change, but it will become another element. However, potassium has 19 protons; argon has 18. So potassium can only change into calcium (with 20 protons) after neutron capture, not argon. --Bowlhover 23:11, 5 November 2006 (UTC)

Actually, Dementios is right; electron capture can occur. In electron capture, an electron "merges" with a proton in the nucleus to form a neutron. So potassium-40 can capture an electron to form argon-41. (Our argon article claims the decay product is argon-40, but I don't understand how this could be.) --Bowlhover 23:37, 5 November 2006 (UTC)

You're right, I never heard of that process before. I thought electrons and protons only combined to form neutrons inside a neutron star. StuRat 16:34, 6 November 2006 (UTC)

Object for contemplation for Bowlhover:

     40                       40
       K(19p , 21n) + e-  -->   Ar(18p , 22n) +  neutrino

see also Electron capture, Positron emission --GangofOne 02:23, 6 November 2006 (UTC)

Oops. I thought the "40" in front of the element symbol means the number of neutrons. Sorry for the careless mistake. --Bowlhover 03:47, 6 November 2006 (UTC)

Also oops. I said, but have now corrected, above where I put antineutrino, I now believe it should be neutrino. (This conserves Lepton number.) See also Beta decay --GangofOne 04:47, 6 November 2006 (UTC)

This has always puzzled me. If neutrinos have no charge, what in the world is an "antineutrino"? --Bowlhover 05:02, 6 November 2006 (UTC)

That has to do with Subatomic particles. You know quarks (no not him Quark (Star Trek)) and stuff like that. I've never gone very advanced in physics, not to the level of particle physics or quantum physics so it's not something I really understand either but if you ever come across a antineutron, run like hell! Nil Einne 15:43, 6 November 2006 (UTC)

Actually, neutrinos are leptons, and leptons are not made up of quarks. (They're fundamental particles, i.e. not made up of anything.) --Bowlhover 21:50, 6 November 2006 (UTC)

Patenting of agricultural products

What is the current status on patents pertaining to the following products - Tulsi, Neem, Basmati rice, Bitter gourd, Turmeric, Brinjal. Please provde a brief update on each

That can require a fair bit of research. Read the Wikipedia articles on each and then do a few google searches. Weregerbil 15:48, 5 November 2006 (UTC)

Well at least two of articles on the topics listed have sections on attempted patents. Anchoress 15:59, 5 November 2006 (UTC)

In general, in order to patent a life form you must have changed it in a significant way, say by genetic engineering. StuRat 19:26, 5 November 2006 (UTC)

Not true. You can patent a conventionally developed hybrid or a new variety, and IIRC the DNA of humans was patented a few times, the actual DNA of particular people. And IIRC new species have been patented when they have been discovered. I don't know if it's still happening, but there was a big kafuffle about it in the early 1990s. Anchoress 20:11, 5 November 2006 (UTC)

Developing a hybrid is another way to have changed a life form in a significant way (relative to the two starting life forms). As for patenting the DNA of people and discovered species, do you have a source on those ? StuRat 22:57, 5 November 2006 (UTC)

To StuRat; I don't know that I agree that a hybrid is a significant change to a life form, but that's just me. I don't have sources for the other info, it was big in the Canadian news back in about 1991, and I'm too lazy to look it up. Anchoress 13:29, 6 November 2006 (UTC)

You can't patent human DNA (in the US) so much as you can patent processes which require knowledge about DNA and can patent diagnostic tests and things like that (i.e. I can patent the a process for diagnosing cancer likelihood by looking for such-and-such a string in DNA). I don't think you can patent new species—it was explicitly rejected by the patent office some time ago that you could just patent something new that you "just" found (you could, of course, patent processes relating to said plant, but not the plant itself — I don't remember the case in particular where it came up but the USPTO said that to impose such a monopoly would be like someone being able to claim that all of the ore in the ground was theirs before it was even extracted). The legal history of plant patenting is pretty different from the biotech stuff, though (the Plant Patent Act goes back to 1930!). --Fastfission 13:21, 6 November 2006 (UTC)

Yeah variety patenting and variety rights is an interesting area. So many people seem to think it has something to do with GM when in reality it's something that has existed for a long time. Nil Einne 15:48, 6 November 2006 (UTC)

Biopiracy covers the subject in some detail. The Traditional Ecological Knowledge Prior Art Database has a biopiracy hotlist which lists mosts of the plants you mention. --Salix alba (talk) 21:41, 5 November 2006 (UTC)

Anyone from the legal department of monsanto? I'm sure they'd be expert. Vespine 02:38, 6 November 2006 (UTC)

An expert at BS you mean? Nil Einne 15:45, 6 November 2006 (UTC)

scientific degree

What does it mean "college Ph.D and college MD?"

Doctor of Philosophy has a much wider meaning than you would normally assign to "philosophy". It comes from a time when most of science was called philosophy.

Natural philosophy actually. 8-)--Light current 02:46, 6 November 2006 (UTC)

Doctor of Medicine means pretty much what it sounds like.

Another major doctorate is a JD, or Doctor of Jurisprudence (law).

StuRat 19:10, 5 November 2006 (UTC)

Exactly. See PhD and MD for more details on the differences. Rockpocket 20:37, 5 November 2006 (UTC)

The phrase is a strange one, though. What does "college" mean in that context?, since in a sense all legitimate degrees are conferred by a "college" of one sort or another. alteripse 02:42, 6 November 2006 (UTC)

As opposed to one you bought off the internet?--Light current 02:45, 6 November 2006 (UTC)

No, I'm old enough I got my doctorate by responding to an ad in the back of a magazine many years ago, just like my ordination certificate. alteripse 14:11, 6 November 2006 (UTC)

The meaning of "college" can change depending what country one is in. A "college PhD" doesn't really make sense in an American context — universities grant PhDs, colleges don't, generally speaking. --Fastfission 13:23, 6 November 2006 (UTC)

Isotopes

What is the total number of known isotopes? How many of them are natural and how many are artificial? Thank you in advance.

I mean all elements.

--196.202.92.86 20:16, 5 November 2006 (UTC)

Isotopes of which element? Did you mean all the known elements? This might be a large number, and I don't know if all the possible isotopes of the heavier, radioactive elements are known. --V. Szabolcs 20:22, 5 November 2006 (UTC)

This table might be of some help, if you feel like counting them.--Russoc4 20:50, 5 November 2006 (UTC)

According to Wikipedia, Isotope table (divided): "The data for these tables came from Brookhaven National Laboratory which has an interactive Table of Nuclides with data on ~3000 nuclides." --GangofOne 21:38, 5 November 2006 (UTC)

Theoretically, any random positive integer number of protons and neutrons glommed together is an "isotope" all the way to infinitely number of protons or neutrons. One could think of a neutron star with many powers of ten of neutrons as a single isotope, if it makes you happy. --18.214.0.144 23:51, 5 November 2006 (UTC)

Actually, it doesn't make me happy. The ~3000 known nuclei are held together by the strong force, neutron stars are much more massive, so massive that gravity, not the strong force, dominates-- a very different situation. Any nuclides outside of the ~3000 known to exist are not known to exist--they are science fiction, so far, so it doesn't make much sense to talk about them. --GangofOne 05:10, 6 November 2006 (UTC)

As far as natural goes, we find only those which have a long enough lifetime to remain since they were created in the supernova that created our solar system, approximately 5e9 years ago, or so. Presumably, in the supernova some of every kind were created; but then many isotopes have decayed completely by now so are not found. Like technetium for example. According to Wikipedia, Technetium: "No isotope of technetium has a half-life longer than 4.2 million years (98Tc), so its detection in red giants in 1952 helped bolster the theory that stars can produce heavier elements. On earth, technetium occurs naturally only in uranium ores as a product of spontaneous fission; the quantities are minute but have been measured." Natural, or artificial? you decide. --GangofOne 05:10, 6 November 2006 (UTC)

Mobile phones in airliners

As I know, many (maybe all) airlines prohibit the usage of mobile phones. But is it even possible to use a cell phone at an altitude of 10000 m? The transmitter towers don't broadcast upwards. I don't think a mobile phone could work in an airliner, except when the plane is equipped with a transmitter of some kind. I never tried a mobile phone in an airliner, but piloting a sailplane I observed that above 1000 m my phone could rarely find any signal, and at 2000 m it found nothing. Calls received from Flight 93 had also low quality and were interrupted often. (and the aircraft was flying below its service ceiling) --V. Szabolcs 20:18, 5 November 2006 (UTC)

Mobile phones constantly emit signals when they are trying to connect ot the network, so even if there was no connection, they still generate a lot of interference. Philc _T^E_C^I 21:05, 5 November 2006 (UTC)

I think it is very unlikely to cause an interference. I know, it's better safe than sorry, so they prohibit it. The question was wether it is possible to communicate via mobile phones at such an altitude. Some technical info, or maybe personal experience... --V. Szabolcs 22:10, 5 November 2006 (UTC)

Right. In fact, no experiment has ever provided evidence that cell phone signals can interfere with a plane's instruments. The Mythbusters did a show on this, in which they used a special radio-wave producer in a small plane to see if it has any effect on the instruments. Even when they produced radio signals thousands of times more powerful than a cellphone's, there was no noticeable effect on the plane. So the chances of a cellphone interfering with navigational/communication instruments is about the same as the chances of winning a lottery. --Bowlhover 23:02, 5 November 2006 (UTC)

I'm an airline pilot. It happens all the time, usually from my cell phone in my front pocket when I forget to turn it off. Don't pay any attention to Mythbusters. Mexcellent 04:04, 6 November 2006 (UTC)

Hmm, but what about interference with communications equipment? I'm sure that can be dangerous if it does interfere. I was rowing last weekend when someone nearby had a mobile which went off. You could definitely hear loud interference through the on-board boat speakers. The speakers themselves just get their signal from a microphone connected to an amplifier. Also, I'm sure I've heard interference with car radios in the past. Richard B 23:49, 5 November 2006 (UTC)

Probably not a problem. Navigation frequencies for VORs are almost the same as for communication (they even share radios). HTey are from around 110 MHz to ~140MHz so just above a normal FM radio. I suspect the interference you heard was AM since FM super-het receivers are very immune to interference from side channels. Cell phones operate near 1 GHz. If you can use your cell phone in your car when the FM radio is on, it should be similiar to using it in an airplane. --Tbeatty 00:55, 6 November 2006 (UTC)

Yes, they can and do interfere with communications equipment, despite whatever speculation you might be reading on here. Mexcellent 04:07, 6 November 2006 (UTC)

In small planes, it's not prohibited and the navigation equipment is pretty much identical (ILS, GPS, VOR, etc). I am much closer to the instruments, too. I have never seen a problem. --Tbeatty 22:22, 5 November 2006 (UTC)

1. Yes, it's definitely possible. That's how the Flight 93 passengers found out what was going on.
2. However it's difficult for the equipment on the ground to keep up with signals changing location so quickly. That's supposedly the real reason for the ban at the current time, not interference with flight equipment.
3. I personally dread the day when the ban is lifted. All the business flyers will be conducting business in the air, lots of other people will just be yakking with friends, and flying will become even more of an ordeal than the tiny seats and hub-and-spoke model have already made it. --Trovatore 22:30, 5 November 2006 (UTC)

So it has nothing to do with the altitude? How is the connection established at a service ceiling of 10000 m? Some equipment in the airliner? Comm satellites? --V. Szabolcs 23:39, 5 November 2006 (UTC)

I'm just guessing here, but it might be the case that transmitter towers broadcast in all directions (much like radio) and both the buildings and the curviture of the Earth block these signals from going very far horizontally but straight up there is little in the way. Then again, your experiences on the sailplane probably negate this answer. Ƶ§œš¹ _{[aɪm ˈfɻɛ̃ⁿdˡi]} 02:04, 6 November 2006 (UTC)

Phone towers (like any well constructed RF communication device) only transmit/receive in the direction they expect to make a connection on (they do no waste energy transmitting straight up or down). The advantage in a plane is Line of Sight. Unperturbed signals in the 1GHz range travel easily for many many miles, and reach cellphones. If you are interested in researching more there are many problems with using phones on planes NOT related to aircraft instrumentation interference, such as the load each phone puts on all of the towers within range (which is a LOT when you have sight of a 50mi area). Cell networks are designed to work WITH terrain to control what signals go where, and when you negate that things get messy. To the person claiming that he was a pilot and that phones certainly interfere with aircraft systems, prove it pal. Yes, some phone bands interfere with cheaply constructed audio amplifier circuits, but real aircraft grade equipment is beyond the reach of such a signal. --Jmeden2000 16:12, 6 November 2006 (UTC)

You may believe whatever you wish. I'll give people in here the benefit of my experience, but if you chose to remain ignorant then that's your problem, not mine. Mexcellent 22:32, 6 November 2006 (UTC)

What I've done is explain (with specific examples) how this particular technology works. What you have done is made several attempts at refuting the common knowledge displayed here by providing absolutely no counter-argument whatsoever. GJ! --Jmeden2000 19:13, 7 November 2006 (UTC)

This is extensively discussed in the web. From memory, there is no evidence phones cause problems. However there is no conclusive evidence they don't cause problems either so I believe there is at least partially the believe people should err on the side of caution. I believe there are some estimates which suggest there is an average of 1-2 phones on which people forget to turn off. However mobile phone interaction with tranmission towers is a major concern. The phone is hopping between stations a lot which is not good for the networks and one reason, I believe, why they're banned. I think someone has proposed they develop a in-plane transmission system whereby the plan has a 'tower' and then relays it to the ground. Obviously you'd pay the plane for the service so don't expect it to be cheap. Nil Einne 16:13, 6 November 2006 (UTC)

The simple truth is that if something as relatively low power could negatively impact an aircraft's critical systems, we would have BIG trouble on our hands as terrorists (of any form) disrupt air travel nationwide with a few cheaply made transmission devices. The only possible impact that has been identified is interference with GPS navigation systems, since they rely on very low power signals to begin with. While it's true that these could be impacted by *certain* phones in *great* quantities, even if they are completely knocked out there should be no reason the pilots cannot operate the plane normally, they will just be reduced to an old fashioned Aeronautical chart since they technically cannot rely on GPS to begin with. --Jmeden2000 19:30, 6 November 2006 (UTC)

Cannot rely on GPS to begin with? Where do you get this crap from? Mexcellent 22:34, 6 November 2006 (UTC)

I think it is always like this for all new stuffs.For example when we first used PC's in early eighties, it was told us to put our shoes outside the room so that no dust particles could harm the computer system.But now we use them without such care and nothing bad is happening.In those days the computers were kept only in air conditioned rooms but now anywhere.

202.70.64.41 16:20, 6 November 2006 (UTC)

I'm sure in the day computers were a lot more delicate than today. Splintercellguy 04:33, 7 November 2006 (UTC)

Energy Dissipation in Vibrating Solids

Does anyone know what the mechanism of energy dissipation of a vibrating solid material is? Is it primarily by heating the air around it, or is most of the energy taken by the viscosity of the air, or is it primarily something else? Thanks

Well, the solid itself isn't perfectly elastic, so it heats up even without air. But you're right, sound is one of the ways. —Keenan Pepper 22:28, 5 November 2006 (UTC)

I would think that it would dissipate energy to change the direction of the vibration each time it goes the other direction. It's like a bouncing ball, where if you drop a rubber ball, it won't bounce as high because it doesn't transfer the energy 100%, and some is lost through sound and friction as well. But that also goes back to what Keenan said. --Wirbelwindヴィルヴェルヴィント (talk) 22:33, 5 November 2006 (UTC)

Changing direction does not dissipate energy. Think of the desk toy with the metal balls on strings that bounce back and forth. No energy is lost because of changing direction, but some is lost due to heat and sound. StuRat 22:44, 5 November 2006 (UTC)

If you keep on squeezing a peice of Blu-tack it will get quite warm. This is a very lossy material. In materials that are more perfectly elastic, most of the energy is returned to the mechanism doing the squeezing. I dont know what this is called in mechanics (apart from resistive loss) --Light current 23:01, 5 November 2006 (UTC)

Maybe shock absorber has some info--Light current 23:16, 5 November 2006 (UTC)

Aside from sound, you have thermal conduction, and rearrangements at an atomic level. In fibrous materials, you have friction. I don't really understand it well enough to summarize it.. See "The Physics of Musical Instruments" Fletcher & Rossing, p713, for details. Pfalstad 00:39, 6 November 2006 (UTC)

Obviously if energy is being dissipated in a material, that material is called a damper or damping material. Also see dashpot--Light current 01:12, 6 November 2006 (UTC)

Congenital disorders causing abandonment of young by animal mothers

I was watching Planet Earth on TV earlier which was about life at the Poles. One part showed a group of penguin chicks that had become lost or left behind by the penguin troop with unknown cause (or at least none they told us). I was wondering how the penguin chicks had gotten so lost when I remembered another programme about an animal park that had a part on a wallaby joey that had been rejected by its mother; it turned out that the joey had a congenital disorder that the mother had sensed (presumably by smell) and it would've not survived anyway (or at least have been weak and sickly to a point that it was not worth expending effort on). Could this have been a cause of abandonment of the penguin chicks? Do penguins share this sense evidently present in the wallaby mother? It may be that they were just unlucky or had become left behind simply because of any congenital defects and not due to any active abandonment. And this might be nasty (I feel kinda bad in asking it), but could the wallaby's sense be present in humans? Has anyone done a survey on mothers of normal babies and those with congenital disorders, and the amount of maternal feeling felt after the baby is born? I apologise wholeheartedly if my questions have been covered already in an article, but Wikipedia is like a thicket and you cannot find anything unless you already have some idea where it might be found (I don't think there is an article about congenital disorders in animals, hint hint). Vitriol 22:41, 5 November 2006 (UTC)

A mother animal's ability to detect a serious congenital disorder or weakness in a single offspring would have adaptive value for species where a mother has only one or a couple of offspring at a time and then must devote substantial effort and resources to caring for them over an extended period. Being able to recognize that investing effort will not "pay off" may allow ovulation to resume sooner, or may enhance the ability of the mother to survive for another reproduction attempt. Detection could be olfactory for inborn errors of metabolism and other forms of major organ system failure, but might be depend on visual or tactile recognition of abnormal movement or diminished strength in other instances, or the sound of an abnormal cry. As to your question as to whether human mothers may fail to bond with a newborn infant with a congenital disorder, the answer is of course. Many cultures have practiced various forms of infanticide for infants perceived to be defective. There is nothing mysterious about it. Once in a while a mother may sense that an infant has a serious problem before it is apparent to a doctor (but there are also cases where a mother may be convinced erroneously that the baby has a serious problem that never materializes). alteripse 02:38, 6 November 2006 (UTC)

Do emperor penguins notice congenital conditions? And when I was asking about humans I did mean non-obvious problems... But it was a useful answer anyways. Vitriol 03:19, 6 November 2006 (UTC)

There is a folklore-level idea about the "runt of the litter" not surviving, say, a litter of pigs or dogs. The weakest "fail to thrive". I don't know if the mother acts differently toward it. As for humans, as mentioned above, they are heavily influenced by culture and norms, beyond instincts, so there is a lot of variety in behaviour. For one case, read Death Without Weeping: The Violence of Everyday Life in Brazil by Nancy Scheper-Hughes, U of California, Berkeley, anthropologist. 1993 ISBN 0520065374 From the Amazon.com page:

"From Publishers Weekly: In Brazil's shantytowns, poverty has transformed the meaning of mother love. The routineness with which young children die, argues University of California anthropologist Scheper-Hughes, causes many women to affect indifference to their offspring, even to neglect those infants presumed to be doomed or "wanting to die." Maternal love is delayed and attenuated, with dire consequences for infant survival, according to the author's two decades of fieldwork. Scheper-Hughes also maintains that the Catholic Church contributes to the indifference toward children's deaths by teaching fatalistic resignation and upholding its strictures against birth control and abortion. This important, shocking study resonates with the emotion of Oscar Lewis's ethnographic classics as it follows three generations of women in a plantation town. The compelling narrative investigates the everyday tactics of survival that people use to stay alive in a culture of institutionalized dependency ravaged by sickness, scarcity, feudal working conditions and death-squad "disappearances." Copyright 1992 Reed Business Information, Inc."

--GangofOne 04:01, 6 November 2006 (UTC)

Rubies natural processes

How do rubies naturally form? Also can you name a mineral that could be scratched by a ruby?

Rubies are a type of Corundum. In that article, it states that corundum has a hardness of 9 on mohs' scale, which is out of 10, so it's in the 'very hard' end. Glass, hardened steel, topaz, garnet, quartz are all less hard then Rubies. Please sign your posts. Vespine 00:09, 6 November 2006 (UTC)

The same as other gemstones: lots of pressure, plenty of heat. (The creation of artificial gemstones is described here.) However, according to a Nov. 2004 Discover magazine article, there is a mystery. The problem is that rubies can't form in the presence of silica or large amounts of iron. And both of these are very abundant in the Earth's crust. Clarityfiend 02:56, 6 November 2006 (UTC)

Abundant, but not uniformly distributed. So rubies just form in places without either of those. StuRat 05:37, 6 November 2006 (UTC)