Wikipedia:Reference desk/Archives/Science/2010 March 13

= March 13 =

Sodium bicarbonate
I noticed that if you burn a chlorate, you get the chloride (with oxygen gas), and if you burn a carbonate, you get the oxide (with carbon dioxide gas), so what does burning a bicarbonate, such as sodium bicarbonate, produce? --70.250.214.164 (talk) 00:25, 13 March 2010 (UTC)
 * I don't think you really mean "burn" &mdash; more like "heat" or perhaps "pyrolyze". If I recall correctly, heating sodium bicarbonate will first drive off water, producing sodium carbonate.  This reduces the question to the previous case, which you have already solved. --Trovatore (talk) 00:34, 13 March 2010 (UTC)
 * You could try reading the article; it answers the question directly. Looie496 (talk) 00:37, 13 March 2010 (UTC)

The mass of a singularity
Don't give out to me now. A principle of the singularity, in the big bang anyway, is that the mass could be fit into an infinitely small space. To say "infinitely small", there is no requirement of the word small, right? There is zero size, right? If that follows, could there be a singularity of some sort that requires zero mass? Could they peel open a quark, for instance, and a singularity or something pops out? Is there interesting theories or anything like that? ~ R.T.G 02:45, 13 March 2010 (UTC)
 * Quarks do have mass, so I'm not sure what you mean. However, singularities are usually just interpreted as a sign that we've made a mistake rather than as a genuine physical object. When the maths results in a singularity it is basically saying "I don't know". When we get a good working theory of quantum gravity, hopefully the singularities in black holes and the big bang will disappear. --Tango (talk) 03:03, 13 March 2010 (UTC)


 * Often in sci-fi there is something about where they have cracked open an atom or interfered with the density of a star opening a rift which could destroy a universe. Couldn't that sort of potential be a basic element? I suppose trying to write into it I am thinking well maybe pigs will fly too but the theory about it is hardly going to be in aerodynamics. Maybe if a butterfly flaps a bit all these storms will stop for the summer. Oh well never mind me. Thanks for answer anyway. ~ R.T.G 04:21, 13 March 2010 (UTC)
 * Tango, this is the second time recently that you've stated (in so many words) "singularities are usually just interpreted as a sign that we've made a mistake rather than as a genuine physical object. When the maths results in a singularity it is basically saying "I don't know"." First, what is your source for this?  Second, the overwhelming consensus is that, e.g., the singularity of a black hole has infinite density; literally dozens of sources for this statement could be found in one bookshelf of one library.  If you personally believe singularities are nonsense, that's fine -- but it is not the overwhelming consensus ... which equals the "truth" for our purposes here. 63.17.60.8 (talk) 05:33, 13 March 2010 (UTC)
 * It's very well known that general relativity, which predicts singularities in black holes and for the Big Bang, breaks down at such extreme energies. This is what's behind the search for quantum gravity, and is not at all controversial.
 * Also, to the OP: white hole? --99.237.234.104 (talk) 07:13, 13 March 2010 (UTC)
 * Gravitational singularity, for reference. Indeterminate (talk) 09:50, 13 March 2010 (UTC)
 * Indeed - Tango is correct. Our gravitational singularity article says "Many theories in physics have mathematical singularities of one kind or another ... This is generally a sign for a missing piece in the theory, as in the Ultraviolet Catastrophe and in renormalization". In the case of gravitational singularities the canonical view, which I believe originated with Penrose and Hawking, is that the physcially unrealistic conditions predicted by general relativity can only be resolved by an as yet unknown theory of quantum gravity. Gandalf61 (talk) 10:04, 13 March 2010 (UTC)
 * If something had zero mass but finite space, then it would either be considered a vacuum or nothing, but even a pure vacuum contains energy in the form of dark energy and vacuum energy. However even a singularity may have "volume" in the sense that it contains a geometrical shape but possibly in a different dimension as in the case of a ring singularity. Also, you may be interested in micro black holes. ~ A H  1 (TCU) 23:24, 13 March 2010 (UTC)
 * Indeed, it remains unsourced. "This is generally a sign for a missing piece in the theory" ... according to whom and based on what evidence?  One can speculate that singularities are non-existent.  But here the standard for "true" is the academic consensus at present, and the consensus is that singularities are consistent with the math and the physics and no better theory or evidence has emerged to render them imaginary.  Again: scores of references for this are available on literally one shelf of any decent library.  Just to pick one at random (from the internet, where, again, sources for this are endless):  "We must rely on our untestable theoretical predictions.  At this point they tell us the singularity has all the matter in the black hole collapsed to a geometric point. This singularity has a mass comparable to a star compressed to a zero volume and infinite density."  See the words:  "We must rely."  That's what a scientist says, without resorting to speculation, in the present tense.  (Here's THAT source, selected at random in ten seconds from among thousands on the internet: google "black_hole_singularity" (at a site WP blocks), by Paul Heckert, who writes:  "I am a university professor who has been teaching physics and astronomy for over 25 years. I have a Ph.D. in astrophysics specializing in observational astronomy. My work has led to over 60 published research articles in journals such as Astronomical Journal, Astronomy and Astrophysics, Astrophysical Journal, The Monthly Notices of the Royal Astronomical Society, and The Information Bulletin on Variable Stars.")  So, again:  Besides the UNsourced WP article cited above, what are your sources for the statement about singularities? 63.17.64.195 (talk) 11:29, 14 March 2010 (UTC)


 * Here are some sources for the fact that the presence (and, indeed, inevitability) of singularities in general relatviity is generaly taken as evidence that the classical theory of general relativity is incomplete:
 * Stephen Hawking, A Brief History of Time, Chapter 8: "All the known laws of science would break down at such a point. One might suppose that there were new laws that held at singularities, but it would be very difficult to even formulate such laws at such badly behaved points ... the gravitational field becomes so strong that quantum gravitational effects become important: classical theory is no longer a good description"
 * Roger Penrose, The Road to Reality, Chapetr 27: "...it seems unavoidable that the realm of quantum gravity (or whatever is the appropriate term) will be entered, so that these expectations of the classical theory will have to be modified in accordance with this".
 * F. David Peat, Superstrings and the Search for the Theory of Everything, Chapter 8: "These singularities are points at which the very structure of space-time breaks down and the laws of physics no longer apply".
 * Matts Roos, Introduction to Cosmology, Chapter 10: "In a singularity, the field equations of general relativity break down, so one can only say that 'the theory predicts that it cannot predict the Universe'".
 * Abhay Ashtekar, One Hundread Years of Relativity, Chapter 14: "...it is clear that the singularity does not so much present a boundary to the universe as a boundary to the classical theory. The theory predicts conditions under which it has to break down and is thus incomplete". Gandalf61 (talk) 14:41, 14 March 2010 (UTC)

the frog still alive
how possible?

http://www.youtube.com/watch?v=QLz8RK4teHM&feature=related —Preceding unsigned comment added by Thekiller35789 (talk • contribs) 04:46, 13 March 2010 (UTC)


 * Twitching is not the same as living. See the article Galvanism which mentions the 18th century discovery that a severed frog's leg can be made to twitch. Cuddlyable3 (talk) 23:42, 13 March 2010 (UTC)
 * Frogs are pithed before dissection, severing the spinal column so they don't kick their legs. Nerve impulses from the spinal column can cause the legs of a dead/dieing frog to kick. All it takes is a volt or so. In the early 19th century, 1804, a hanged and dead man, Mr Foster, was used with his spine severed for electrical experiments., , , by Giovanni Aldini. A battery connected to muscle groups could make the dead man move his arms and legs, move his eyes around, and extend his arm. Frankenstein, anyone? Mary Shelley doubtless read of these experiments.  A dead horse would kick its leg when a battery was applied, A chicken with her head chopped off can run around flapping her wings for a minute or so. Still dead. Edison (talk) 04:43, 14 March 2010 (UTC)

yes im aware but i think the frog was alive because iv seen suicide vids where they live when others would die —Preceding unsigned comment added by 67.246.254.35 (talk) 07:51, 14 March 2010 (UTC)
 * Did you read the part about how muscle from an absolutely dead animal can twitch? If parts of the brain were still functioning, or if the swimming movement in a frog can proceed from lower nerve centers like in a headless chicken, then the movement could occur without the animal being "alive" in any meaningful way. I did not intend to suggest that someone was electrically stimulating the shredded frog like Dr. Aldini did to his Franken-victim in 1803. Edison (talk) 18:17, 14 March 2010 (UTC)

Was there sex in the biosphere?
? —Preceding unsigned comment added by 67.246.254.35 (talk) 05:30, 13 March 2010 (UTC)
 * If you're talking about this biosphere, then the answer is an unquestionable "Yes". If you're referring to Biosphere 2, then the answer is still likely "yes" as this source suggests.  Dismas |(talk) 07:14, 13 March 2010 (UTC)
 * Or if you are asking about sex in space, see that article. ~ A H  1 (TCU) 23:19, 13 March 2010 (UTC)

Cylindrical Fuels rods??any
I have made an characterisation and optimisation study on flames with open top enclosures.It is already selected for an international Conference.I have problem in finding s field of application for it.Please anybody suggest.

Thanks in advance —Preceding unsigned comment added by SCI-hunter (talk • contribs) 05:41, 13 March 2010 (UTC)


 * If you can describe these fuel rods better, we may be able to help. Is this just a cylinder of flammable material ? StuRat (talk) 13:42, 13 March 2010 (UTC)


 * If it it can achieve  a clean burn, then you have my vote to use it as a neat and nifty heat source for my  one gallon Bagna càuda and save filling the  room with the oily smell of burning paraffin wax. --Aspro (talk) 14:11, 13 March 2010 (UTC)

Yes i have modelled the situation with a candle flame.hence it is a cylinder of flammable material.Any way what is banga cauda stated by Aspro.Some more application preferably in industries would be welcomed. Thanks SCI-hunter (talk) —Preceding undated comment added 15:20, 13 March 2010 (UTC).


 * You are the same guy who thought a common candle was somehow related to a "CANDLE nuclear reactor" - which I think we can conclusively say it isn't. So somehow this confusion has resulted in you getting this "study" into an international conference!?!  OMG!  That's too funny!  I strongly recommend that you call up the conference panel, apologize profusely and withdraw your paper ASAP. SteveBaker (talk) 15:40, 13 March 2010 (UTC)


 * Steve, I don't think English is their first language, so mistakes like that don't mean they are an idiot, it just means they don't speak English well. StuRat (talk) 15:54, 13 March 2010 (UTC)


 * OK, assuming you are talking about something with the characteristics of a candle, namely burning at one end by combustion with environmental oxygen, let's see what applications we can come up with. I would assume that this would be more expensive than fuel sources such as propane or natural gas.  The advantage may then be that it's more portable, and stores well.  If so, uses where other fuel supplies aren't available come to mind, such as camping or for emergencies (in a car road kit, for example).  Perhaps this could be used to start a camp fire in damp weather ? I wouldn't think there would be much industrial use, as industry is likely to have cheaper sources of energy avaialble. StuRat (talk) 15:54, 13 March 2010 (UTC)


 * How about using as a heat source for a Fondu (that is also is like a Bagna càuda but more popular with trailer trash and nouveau riche )… A better  fondu heat source could be the biggest advance in human dinner party experience  since Boy Scouts  first sat  around the camp fire together and roasted their  nuts.--Aspro (talk) 16:44, 13 March 2010 (UTC)

Thanx a lot for positive responses and let me tell "Steve" that my paper has not mentioned anything about the nuclear reactor.The innovative study methodology and subject has won a place in international conference.So i am nothing to apologize and withdraw.Looks some problem in communication. Thanx to aspro and others 220.225.98.251 (talk) —Preceding undated comment added 15:01, 14 March 2010 (UTC).

MATERIALS USED IN BATHROOMS
I WANT THE FULL DETAILSSSSSSS —Preceding unsigned comment added by Waqasiqbal175615 (talk • contribs) 08:05, 13 March 2010 (UTC)


 * Tile, porcelain, metal, wood, drywall, paint, glass. Do you have a more specific question?  Comet Tuttle (talk) 08:26, 13 March 2010 (UTC)
 * Fiberglass, layered acrylic, and iron are often used for tubs. Marble, slate, and other forms of stone.  Copper and PVC pipes. Chrome. --Normansmithy (talk) 13:12, 15 March 2010 (UTC)

is it possible to boil water through the power of the mind alone?
If I put a pot of room temperature water on the stove, which is cold and turned off and to remain off, is it possible for me, or for anyone, to focus mental energy and bring the water to a boil through the power of the mind alone? If so, how would I go about developing this ability? 82.113.121.167 (talk) 11:15, 13 March 2010 (UTC)


 * No. If you can do it, and consistently, then get in touch with James Randi for your $1 million prize. --Mark PEA (talk) 11:28, 13 March 2010 (UTC)


 * You might consider asking this question on our yet to be created Reference desk/Nonsense. DVdm (talk) 11:30, 13 March 2010 (UTC)
 * I believe this has been proposed. :) Zain Ebrahim (talk) 17:30, 13 March 2010 (UTC)
 * You must have lived such a sheltered live, DVdm. Here, for your edification, is an example of actual nonsense:

j6eZiebr4-choayoahOaspi4JlU7i&hlaxl$CetL4nlevluSwlarluThOuroumIdoa+oaf51Eqla!rlen$swIudlEthluthlUgo*sp?u?
 * Or even:

Isn’t it always the heart that wants to wash the elephant, begging the body to do it with soap and water, a ladder, hands, in tree shade big enough for the vast savannas of your sadness, the strangler fig of your guilt, the cratered full moon’s light fuelling the windy spooling memory of elephant? (That's from the New Yorker).
 * By comparison, my question is extremely sensible, and very specific. You've lived a sheltered life. 82.113.121.167 (talk) 11:52, 13 March 2010 (UTC)


 * Well, I guess you can run a Stirling engine off the temperature difference of a brain and the environment and use that mechanical energy to drive a heat pump to concentrate heat to boil water, or convert it to electricity to drive an electric heater. It will require very many brains and probably the application of the Spherical cow theorem to work, though, and it's not what you would usually call "mental energy". It would, however, be a strong testament to the "power of the mind" ;-). --Stephan Schulz (talk) 11:36, 13 March 2010 (UTC)
 * See A. W. Underwood. He claimed to be able to set things on fire using the power of his mind (with only a _little_ assistance from white phosphorus).  Paranormal powers do show a distressing tendency to have such explanations - I can't imagine why. ;) Tevildo (talk) 11:54, 13 March 2010 (UTC)
 * I can. - DVdm (talk) 12:00, 13 March 2010 (UTC)


 * Spontaneous human combustion Graeme Bartlett (talk) 12:29, 13 March 2010 (UTC)
 * :-) Quoting (emphasis mine):
 * "While there have been about 200 cited cases worldwide over a period of around 300 years, most of the alleged cases are characterised by the lack of a thorough investigation, or rely heavily on hearsay and oral testimony. In many of the more recent cases, where photographic evidence is available, it is alleged that there was an external source of heat present (often cigarettes), and nothing occurred "spontaneously.""
 * For the other desk. DVdm (talk) 13:30, 13 March 2010 (UTC)


 * What you don't understand, DVdm, is that in a scientific investigation, at least one time in a hundred, you are likely to see a statistically significant effect at the 99% confidence level. The only thing paranormal scientists now need to do, is take that 1 case out of 100, and somehow hone in on it, isolate it.  That is the work that everyone who is rigorously interested in the paranormal must focus all of their mental energy on. 82.113.121.167 (talk) 14:20, 13 March 2010 (UTC)
 * Perhaps this is where I must emphasise that I'm not really all that "rigorously interested in the paranormal". I am however somewhat interested in the psychology of those who are. As this is a rather less interesting case, I think I'll sign off here. Sorry if was unable to help, but anyhow, the pleasure was mine :-) - DVdm (talk) 14:40, 13 March 2010 (UTC)


 * Presumably this would not be supernatural but indeed, some kind of natural phenomena. The brain really doesn't seem built to transmit the amount of energy required. It's also unclear to me how it would boil water at a distance without boiling the water in your head simultaneously (a microwave transmitter would not work if it was immersed in a bunch of water—it would heat itself). The only way I can imagine doing it (though I don't pretend to be the most imaginative) is to suppose that our brains are somehow tied to some very strange physics, the likes of which our pretty reliable theories have given no hints of, and of which an evolutionary explanation is conspicuously absent. One would also presumably expect that if concentrating on something could cause it to be physically manipulated or heated or whatever, that people who spend long periods of time in, say, solitary confinement, would have had ample time and opportunity to develop these abilities. Anyway—the answer seems pretty clearly to be "no, sorry," even if one does not necessarily believe that scientists "know everything." It simply seems implausible from a number of viewpoints, and there seems to be no reason to assume it is true other than "it would be cool" in a comic-book way.
 * Alas, don't be sad, your brain can accomplish much more than boiling water if you apply it in useful ways. Human brainpower, coupled with manpower and technology, have moved mountains, destroyed cities, healed millions. The human brain is a powerful thing in and of itself, with no need to appeal to the paranormal. --Mr.98 (talk) 15:28, 13 March 2010 (UTC)


 * This is exactly why I find it hard to believe. The human mind, of all the plants, mushrooms, and animals on Earth, literally in the millions, has the power to form coherent sentences, can formulate exquisitely abstract notions.  The power of the human brain alone has allowed us to pierce the very fabric of the Universe and extract from it the secrets of electricity, which the power of the human brain has fully dominated and put at the command of every modern household; the power of the human brain has discovered and devised ways to apply atomic theory to split the atom, putting at our disposal not only vast amounts of energy in the form of nuclear fission power plants, far beyond what any plant or animal comes within many, many orders of magnitude of being able to produce, singly or in groups, but also what at this moment we are working on producing on Earth: the very process by which Sol our sun produces fusion energy, all invented, targeted, and worked upon through the power of the human brain; the human brain alone has cracked the secret of the atomic structure, the key to modern chemistry, and the human brain has realized ways of producing materials that have never appeared anywhere on Earth and have supremely useful functions for everyone.  The human brain has devised magnetic levitation, wholly absent in all of nature, and uses it for locomotion at a speed that is literally orders of magnitude faster and at distances that are orders of magnitude farther than the fastest animal can sustain.  Verily the human brain has cracked the cosmos; the genetic structure; problems of energy; of materials; of electricity and electronics; of land, air, sea, and space.  Yet it cannot bring a pot of water to a boil? 82.113.121.167 (talk) 16:30, 13 March 2010 (UTC)


 * The mind can "bring a pot of water to boil", as it can do all those other things you listed. What it can't do is boil a pot of water alone, and as it happens, it can't do any of those other things alone either (one needs to be taught literacy skills to form sentences = mind not working alone). --Mark PEA (talk) 20:03, 13 March 2010 (UTC)


 * Again, sure it can. It's way of doing so is to instruct the body to take the pot to the stove and turn it on. --Stephan Schulz (talk) 16:52, 13 March 2010 (UTC)


 * Yes, we human are very clever. However, there's no reason to think that the ability to do complex maths or think in the abstract would also give the power of telekinesis. In a nutshell, just because you can imagine it (or you really, really want it), does not make it so. – ClockworkSoul 16:53, 13 March 2010 (UTC)
 * Right, we can boil water just fine, in a dozen different ways. The mind does this. It understands heat and fire and boiling points and everything. But it cannot impose its intentions on the world with sheer thought alone. In every case of it "doing" something, it uses a medium to translate computation into physical effect—be in hands, voice, movement of feet. It is not set up to broadcast radio waves or microwaves or lasers or large amounts of heat. Neither is your computer. The human brain computes. It does a great job of that. As I.I. Rabi said in a different context: "What more do you want, mermaids?" --Mr.98 (talk) 19:33, 13 March 2010 (UTC)

Studies show that the human brain consumes oxygen from the bloostream at a rate that is equivalent to 100 Watts. However, the activity actually conducted by the brain accounts for only about 10 Watts. The remaining energy is lost as electrical signals. These can be measured by electroencephalography (the EEG machine everyone has seen). Different wave patterns are generated by different types of brain activity. Some individuals have trained themselves to focus this brain activity in such a way that the wave pattern matches the vibrational frequency of the hydrogen-oxygen sigma bonds in water. This matching resonance frequency increases the rate of vibration, and of course this type of intramolecular vibration manifests itself as heat. The 90 Watts of power lost from the brain as electrical waves and focused on H-O bonds is more than enough to boil a liter of water. 72.94.164.21 (talk) 16:58, 13 March 2010 (UTC) (Since DVdm's WP:RD/N doesn't exist yet, I decided to post here instead.)
 * What if this signal can be amplified to electrify a heat source? Yes I realise this is no longer done on the mind ALONE, but with some help. --Kvasir (talk) 08:07, 17 March 2010 (UTC)
 * The whole human body only uses 100 watts of power. The brain consumes 20-40 watts, but there's no way to "account" for any of it; our brains can be as inefficient as they want to be for the computations they perform.  You could warm water with a 30 watt lightbulb just fine from the waste heat.  But brain waves are super-weak; that's why you have to attach electrodes to someone's head just to detect them.


 * If brain waves were the right frequency, and strong enough, to boil water, we'd be in trouble, because the brain is mostly water... It would be a neat ability, though, other than that.  Paul Stansifer 17:21, 13 March 2010 (UTC)
 * Right. I don't see how the brain is going to boil water without boiling itself. A microwave would not work if it was immersed in water, presumably (in the sense that it would not be effective exclusively for a kettle of water kept at a distance). --Mr.98 (talk) 19:33, 13 March 2010 (UTC)


 * Side discussion moved to talk page – ClockworkSoul 18:08, 13 March 2010 (UTC)


 * ...specifically, to here: Wikipedia_talk:Reference_desk. StuRat (talk) 19:52, 13 March 2010 (UTC)


 * How about if we lower the pressure to where water boils right around body temp, put the person's skull in contact with the water, then have them concentrate really hard on some difficult problem ? Couldn't we then get their head to give off ever so slightly more heat, and therefore cause the water to boil ?  (Of course, we'd probably need to provide a higher than normal percentage of oxygen in the air, to compensate for the lower pressure.) StuRat (talk) 20:06, 13 March 2010 (UTC)


 * The pressure would have to be about 6% of the atmospheric pressure. I think I would have a hard time thinking under those circumstances. Why can't we give the OP the honest answer and let him know that the whole thing is ludicrous? Dauto (talk) 21:19, 13 March 2010 (UTC)


 * Wikipedia has an article on a relevant topic so far unmentioned: Pyrokinesis which is a kind of Psychokinesis. Graeme Bartlett (talk) 22:48, 13 March 2010 (UTC)


 * I doubt there's any direct credible scientific proof on this, but brain waves may be shown to have effects external to the brain itself. For example a robot that places balls into a container within a random number of moves may be "affected" by human thought causing it to reduce its number of moves (but correlation with brain activity is not shown directly). ~ A H  1 (TCU) 23:18, 13 March 2010 (UTC)


 * Um, what? Citation needed. --Mr.98 (talk) 00:08, 14 March 2010 (UTC)
 * I'm sorry, what did that comment add to this discussion? You say that something might happen but you doubt there is any evidence for it. You don't even claim that anyone before you has claimed it does happen or that you have observed it to happen. You are just knowingly spouting nonsense for the sake of it... --Tango (talk) 05:13, 14 March 2010 (UTC)
 * Can we not assume that something is nonsense just for the sake of it? By the way, the specific example given was shown in Mystery Hunters. ~ A H  1 (TCU) 02:20, 15 March 2010 (UTC)
 * In other words, a silly, nonsensical TV show. That it sounds like you half-remembered. Great contribution, thanks. Clarified a lot. --Mr.98 (talk) 16:45, 15 March 2010 (UTC)

Radio waves
Is there a difference between radio signals and radio waves? —Preceding unsigned comment added by Fire2010 (talk • contribs) 20:26, 13 March 2010 (UTC)


 * The signal is the message that is being transmitted via waves. Zain Ebrahim (talk) 20:39, 13 March 2010 (UTC)


 * I not sure I understand. Can "signal" and "wave" both be used when describing the transmissions and receiving of music or television channels? Are they essentially the same concept with different names or are they totally different from each other? —Preceding unsigned comment added by Fire2010 (talk • contribs) 20:45, 13 March 2010 (UTC)


 * Yes, both words can be used when talking about TV/radio. So the signal (which is the message) could be a TV show and your television receives the signal sent from the TV company in the form of waves. So the signal is transmitted as waves. Does that make sense? Zain Ebrahim (talk) 21:03, 13 March 2010 (UTC)


 * The signal is usually encoded either as modulations of the radio wave amplitude (AM broadcasting) or as modulations of the radio wave frequency (FM broadcasting). Dauto (talk) 21:13, 13 March 2010 (UTC)


 * To help understand the difference, consider the SETI astronomers, who scan the skies looking at radio waves generated by astronomical objects, hoping to find a radio signal (from an alien intelligence) among them. StuRat (talk) 21:11, 13 March 2010 (UTC)
 * I think (feel free to correct me if I'm wrong) that the difference would be that a radio signal would be a radio wave that carries information. Vimescarrot (talk) 21:51, 13 March 2010 (UTC)

Thanks everyone, I think I understand now. The "signal" is the message, and the "wave" is how it arrives. Thanks! —Preceding unsigned comment added by Fire2010 (talk • contribs)

acid reflux
See WT:RD. Zain Ebrahim (talk) 20:44, 13 March 2010 (UTC)

Feigning death drug
I just watched an episode of the TV series "The New Avengers" - a guy injects a substance to feign death, later wakes and says "a drug that suspends the heart and the respiration" - isn't that impossible (brain death?) or do such substances exist? Thanks for info., --AlexSuricata (talk) 23:24, 13 March 2010 (UTC)


 * Well, potassium chloride stops the heart and thus causes death by cardiac arrest, yes. I believe the mythical drug you're describing sort of freezes the body's operations, allowing them to resume hours later, and the subject only has a hangover, presumably.  The same mythical drug was in The Dark Knight Returns graphic novel.  No, no such drug exists; as you note, a stoppage of the heart and breathing does kill people.  On a related note, the field of cryonics seeks to put people or other animals in suspended animation, but by means of chilling them.  Comet Tuttle (talk) 00:37, 14 March 2010 (UTC)


 * (edit conflict) Yes, it's impossible. You would suffer massive brain damage due to lack of oxygen to the brain. That could be reduced by inducing hypothermia, but even that would be very unreliable. There are ways to significantly reduce the heart-rate and respiration, but not eliminate them entirely. Someone would appear dead at a glance, but not if someone actually made a significant effort to check (hold a mirror in front of their mouth for a minute, say). --Tango (talk) 00:38, 14 March 2010 (UTC)


 * The toxin in the blue-ringed octopus paralyzes and can make a person appear dead, especially when they stop breathing. However, if artificial respiration is used until the toxin clears their system, they can recover.  So, while the heart continues to beat, the lack of any breathing could indeed make others assume the person is dead. StuRat (talk) 03:16, 14 March 2010 (UTC)


 * A similar drug like this was used in the play Romeo and Juliet. But I don't know if this mythical drug is modelled after any real substance. ~ A H  1 (TCU) 02:18, 15 March 2010 (UTC)


 * An induced coma might slow your breath and appear something like death, but not nearly enough to fool a doctor. APL (talk) 02:02, 16 March 2010 (UTC)