Wikipedia:Reference desk/Archives/Science/2010 August 12

= August 12 =

Famous scientific hypothesis
I need to prepare for my science test a description of two famous hypothesis. Thus, I need your help to give me two science hypothesis (from any field), that is easy to understand and explain. Thanks! --Tyw7 (☎ Contact me! • Contributions)   Changing the world one edit at a time! 02:43, 12 August 2010 (UTC)
 * It would help if you'd explain what grade level you're dealing with. The theory of evolution can be made pretty simple or pretty complex depending on how deep you want to go with your explanation.  Dismas |(talk) 03:00, 12 August 2010 (UTC)
 * Grade 11. Easy means easy to remember and type in a closed exam. IE can be explained in a few simple words. --Tyw7 (☎ Contact me! • Contributions)   Changing the world one edit at a time! 03:02, 12 August 2010 (UTC)
 * DO they need to be correlated (i.e., one versus the other, opposing theories)? If not, I suggest the quantum field theory and effective field theory (disclaimer: I'm an engineering graduate student ;). If so, how about the accepted Darwinian model of evolution versus the Lamarck model? You'll have to come up with the descriptions yourself ofcourse; if we did that it would be equivalent to doing your homework for you. 76.228.193.68 (talk) 03:04, 12 August 2010 (UTC)
 * I'd go with Darwinian evolution and Lamarckian evolution, myself. Both famous, both related, both easy to summarize in a couple of sentences, and taken together, a good example of how hypothesizes can be tested, with ones that don't match reality being discarded. -- 174.24.200.206 (talk) 03:09, 12 August 2010 (UTC)


 * Spontaneous Generation was a long-held theory and was proven wrong by use of The Scientific Method. Also, Gregor Mendel held the hypothesis that traits are passed on to the next generation published in his work Experiments on Plant Hybridization. schyler (talk) 03:07, 12 August 2010 (UTC)
 * But I think it's fairly well established that Mendel forged a significant amount of his data to fit with his hypothesis. It might have been true in the end, but that's not real research.  DRosenbach  ( Talk 15:02, 13 August 2010 (UTC)
 * The phlogiston hypothesis would be another good one that also proved to be wrong. --Anonymous, 03:20 UTC, August 12, 2010.
 * How about one that was proven right? --Tyw7 (☎ Contact me! • Contributions)   Changing the world one edit at a time! 03:23, 12 August 2010 (UTC)
 * One rarely proves a hypothesis right. One only looks for disproof. The theory of natural selection, as noted above, is accepted as scientific fact, due to its lack of falsification and explanatory power. The Rhymesmith (talk) 03:27, 12 August 2010 (UTC)
 * Well, one very famous hypothesis which was tested and shown to be accurate was the experiment which proved the Gravitational lens prediction proposed by Einsteins' General Relativity. Arthur Stanley Eddington famously showed that the mass of the sun bent light so that objects behind the sun could be viewed during the Solar eclipse of May 29, 1919.  It was a simple observation which confirmed an unusual hypothesis, that large objects could bend space-time, and thus cause light to appear to bend around them. -- Jayron  32  05:44, 12 August 2010 (UTC)
 * That's why I said "rarely". The Rhymesmith (talk) 08:09, 12 August 2010 (UTC)
 * Prout's hypothesis is a nice example, easy to explain, easy to show how it was proved wrong (the atomic weight of chlorine), and nice because it's almost correct in modern terms. Physchim62 (talk) 11:59, 12 August 2010 (UTC)

Quark
Does the atomic theory deals with quarks? Is atoms made of quarks? What is the smallest unit of matter as of today? --Tyw7 (☎ Contact me! • Contributions)   Changing the world one edit at a time! 03:25, 12 August 2010 (UTC)
 * Have you read our articles on quark and atomic theory? Dismas |(talk) 03:26, 12 August 2010 (UTC)
 * Reading... The article does not mention quarks, so I presume its covered by another theory (not atomic theory)? --Tyw7 (☎ Contact me! • Contributions)   Changing the world one edit at a time! 03:27, 12 August 2010 (UTC)
 * To put it shortly: Atoms are made of electrons orbiting a nucleus of protons and neutrons, which in turn are made of quarks, the smallest known subatomic particle. --The High Fin Sperm Whale 03:36, 12 August 2010 (UTC)
 * In case the previous sentence was ambiguous, protons and neutrons are made of quarks, while electrons are not. The phrase "Atomic Theory" generally only refers to looking down to the level of atoms, and sometimes of the particles that make up atoms (protons, neutrons, and electrons).  The "Standard Model" would be the "theory" that includes quarks.  "Particle physics" would be a general term used to describe the physics of Elementary particles, including quarks.  Obviously, these fields are not strictly defined, and there is a considerable amount of overlap. Buddy431 (talk) 03:58, 12 August 2010 (UTC)
 * There are likely particles smaller than quarks: Electrons, gluons, leptons, muons, tauons, gravitons, neutrinos, photons, singularities, etc. ~ A H  1 &lt;sup>(TCU) 00:15, 13 August 2010 (UTC)
 * Our articles don't seem to mention size. I assume that this is because the effective diameter depends on where the particles are, and what they are doing, and how we try to measure size.  For most practical purposes, quarks and all of the particles mentioned by Astro above have zero size (i.e. they are all singularities in a general sense), so the comparison cannot be made.  One could claim that they all have zero size.  Perhaps, sometime in the future, when we find a way to measure distances less than a tenth of a millionth of a millionth of a millimetre, we might compare their effective sizes in some way, but, at present, we regard them all as point masses, charges, colours etc.
 * Actually the particles have a de Broglie wavelength which defines their size. Calling them "singularities" seems sort of pointless (they're not black holes, you can't fall in, and you can never measure them as points, but as fuzzy clouds of probability that affect their collisions and interactions)  But to measure the de Broglie wavelength of a quark, you need to have one to measure its mass ... and having one is the problem (see free quark). Wnt (talk) 14:53, 14 August 2010 (UTC)

Superfluids and conductors
Does anyone know of a compound that, when cooled, is both a superconductor and a superfluid, preferably above the freezing point of nitrogen (63.153 K)? --The High Fin Sperm Whale 03:34, 12 August 2010 (UTC)
 * How about the core of a neutron star ? Probably not what you meant...  Sean.hoyland  - talk 06:01, 12 August 2010 (UTC)


 * No. It's speculated that hydrogen might do that at extremely high pressures and extremely low temperatures, but it has never been observed.  I believe all known superconductors are solids.  Dragons flight (talk) 07:01, 12 August 2010 (UTC)

Prince Rupert's Drop Gun ?
Is it possible to build a gun like this ? The drop is tightly fit in the breech. When the firing pin hits and drop is exploded the ball rushes out and do the usual gun thing ? Jon Ascton   (talk)  05:07, 12 August 2010 (UTC)
 * I'm not sure that Prince Ruperts Drops explode with all that much force. Its a rather spectacular splash of glass, but the "explosion" is many orders of magnitude smaller than any combustable material or high explosive.  It doesn't really explode as much as crack very fast.  It may generate enough force to make the ball dribble out of the barrel of your gun, but little more.  -- Jayron  32  05:35, 12 August 2010 (UTC)
 * Build - yes. Use - no. These things, by definition, cannot be stabilized for safe handling in the field. East of Borschov 05:47, 12 August 2010 (UTC)
 * Glass contracts as it solidifies so the inside of the Prince Rupert's Drop is under tensile stress. I conclude that the drop implodes rather than explodes, and would not expel the ball. Cuddlyable3 (talk) 14:56, 12 August 2010 (UTC)
 * When something implodes, fragments can still fly outwards -- the ones that happen to pass through the center without hitting other fragments, or as a result of fragments colliding elastically. But it is true that they'll tend to lose kinetic energy as they come together, of course.  --Anonymous, 17:52 UTC, August 12, 2010.
 * Gunpowder would be a better option! Alansplodge (talk) 23:13, 12 August 2010 (UTC)

a better option might be a Prince Rupert's Drop Bomb, if your looking for glass weaponry...

Colloids
Do viscous substances have more Surface tension than non viscous substances?? How does Lyophilic colloids have less surface tension than the solvent??Rohitbastian (talk) 06:03, 12 August 2010 (UTC)


 * Viscosity and surface tension are unrelated to each other. Water has a relatively high surface tension, and a relatively low viscosity, for example.  And lots of mixtures have lower surface tension than the pure solvents they are based on.  See Surfactant for more.  -- Jayron  32  06:33, 12 August 2010 (UTC)

Erectile dysfunction drugs
Did the makers of Cialis and Levitra copy and modify the chemical structure of Viagra or did espionage occur? It seems like they came out right after Viagra did. It would be understandable if they came out years later, but I believe they came out within a short period of time after Viagra (but I may be wrong). Would it be really possible to find or make a similar medication within such a period of time if they didn't copy it? —Preceding unsigned comment added by 76.169.33.234 (talk) 06:09, 12 August 2010 (UTC)
 * While Sildenafil (Viagra) and Vardenafil (Levitra) share some similar chemical structure, Tadalafil (Cialis) appears to be quite different. The first of these, Viagra, was not originally marketed for use in fixing erectile dysfunction, rather as a hypertension medication.  The erection was basically a side effect which ended up becoming the actual intended use.  Both Cialis and Levitra were developed, at least in part, by GSK, so that explains some of their connection.  The general class of drugs is discussed at PDE5 inhibitor.  -- Jayron  32  06:30, 12 August 2010 (UTC)
 * I actually worked at an Eli Lilly site when Cialis appeared, and hadn't known the GSK connection until now. (Checking Jayron32's answer, I found that it was discovered by an SK/ICOS joint venture, but developed & marketed by an ICOS/Lilly one.) Apparent coincidences like this are partly explained by the very long times it takes to develop newly discovered "candidate molecules" all the way to market (assuming they make it - only around 1 in 10 do): up to 10 years (and a cost of around half a billion US$) is typical. A Company might be able to speed up the process a little by devoting more resources to a given candidate, and might be inclined to do that if a competitor is known to be in the works, so as not to concede more market advantage that they have to by allowing more of a head start: thus the release dates can converge. 87.81.230.195 (talk) 11:46, 12 August 2010 (UTC)
 * BTW if you read the obvious articles, which Jayron32 has helpfully linked above, you'll find Sildenafil i.e. Viagra received FDA approval in March 1998 and the other two in August and November 2003 or over 5 years later. I'm not sure whether you consider that 'short period of time' or 'years later' but I would say it isn't an unresonable length of time just for fairly normal development, particularly since the drugs were already in development even if not for the specific purpose and as 87 has mentioned a company may devote more resources if they see it as important or likely to be a success. Nil Einne (talk)

PROGESTERONE
Progesterone:- would the use of progestrone, used in the form of an transdermal cream, have an effect on a person who has high colesterole? —Preceding unsigned comment added by Gilpill (talk • contribs) 08:56, 12 August 2010 (UTC)
 * Could you clarify the question? Are you asking whether progesterone has its normal effects even if the person has high cholesterol? Or if progesterone affects cholesterol levels? Or if the specific transdermal application has specifically different effects related to cholesterol? As a starting point, Bioidentical hormone replacement therapy suggests that--at least in the cases considered there--route/form of administration of progesterone does not have an effect consistent with altered cholesterol levels. DMacks (talk) 13:12, 12 August 2010 (UTC)

"Smotl."
Hi all,

One of my pet peeves is binomial authorities without articles or at the very least a full name. So far only Boletus rhodopurpureus cites one "Smotl." as binomial authority. Google results would suggest that he or she is apparently eminent in Mycology... but not even a trace of ""Smotl."'s family name, let alone his or her full name. So, who was that masked mycologist? --Shirt58 (talk) 11:22, 12 August 2010 (UTC)
 * And why did s/he leave name this silver fir-associated boletus? 87.81.230.195 (talk) 11:25, 12 August 2010 (UTC)
 * Francis Smotlacha  Sean.hoyland  - talk 11:49, 12 August 2010 (UTC)
 * Or was it Miroslav Smotlacha who is a famed Czech mycologist who died at age 86 back in 2007? According to his obituary, his entire family are mushroom experts - so it could have been any of half a dozen people with the same surname. SteveBaker (talk) 14:05, 12 August 2010 (UTC)
 * Ummm... it appears I might have made an oopsy here --Shirt58 (talk) 12:56, 13 August 2010 (UTC)
 * Or not, it's hard to tell. :) Maybe you could expand it to cover the family ?  Sean.hoyland  - talk 13:02, 13 August 2010 (UTC)
 * It would appear that Miroslav Smotlacha is František Smotlacha's son. The dates the species were described, and that the author abbreviation is "Smotl.", not "Smotl.f" / "Smotl.p", would suggest the article about Smotlacha-the-person-whose-author-abbreviation-is-Smotl. should be about Miroslav Smotlacha.  I am indeed mistaken.--Shirt58 (talk) 06:11, 14 August 2010 (UTC)

how can that possibly be true???
It says 1.5 million facebook users die every year!! How can that possibly be true??? That can't be just a coincidence, but what could possibly explain this, it just doesn't make sense! Is it just a lie?! Or how is it true!!! 84.153.200.162 (talk) 14:54, 12 August 2010 (UTC)
 * The world death rate is something like 8 deaths per thousand people per year. Facebook has something like half a billion active users. Thus if Facebook users are as likely to die as anyone else, we would expect about four million to die every year. So if your figure is accurate, then Facebook users are in fact much less likely to die than people on average – as we would expect, given its target demographic. Algebraist 15:01, 12 August 2010 (UTC)
 * Cool! Use facebook - live 2.7 times longer! SteveBaker (talk) 15:36, 12 August 2010 (UTC)
 * This discussion reminds me of how some people were surprised ~350 people die in Moscow every day Nil Einne (talk) 15:54, 12 August 2010 (UTC)
 * Given that average life-expectancy is around 70 years, then 500million / 70 year = 7 million/year. This of course assumes that facebook's user demographics is about the same as the average person, which probably is not accurate. CS Miller (talk) 16:48, 12 August 2010 (UTC)
 * Except, as I'm sure we're all aware, it's not that simple. I'd suggest that Facebook has a lot more users in the 16-40 years old range than elderly 70 year olds. If 1.5 million Facebook users die every year, I'm sure a lot of those will be unfortunate accidents. Regards, --— Cyclonenim | Chat 21:05, 12 August 2010 (UTC)
 * Oops, just noticed I basically reiterated CS Miller above. My bad :) Regards, --— Cyclonenim | Chat 21:32, 12 August 2010 (UTC)
 * When Facebook first started, the largest group of users was likely young adults in post-secondary education such as college or university. Currently the fastest-growing demographic group on Facebook is women over 55. ~ A H  1 (TCU) 00:09, 13 August 2010 (UTC)

How much does an aluminium soda can tab weigh?
(This is an offshoot of a question on the misc ref desk - but I'm hoping someone with an accurate laboratory scale can get me a better answer).

How much does the ring-pull 'tab' on a typical soda can weigh?

SteveBaker (talk) 15:16, 12 August 2010 (UTC)
 * Just so we know, what degree of accuracy are you expecting? Vimescarrot (talk) 15:19, 12 August 2010 (UTC)
 * For clarification... are you referring to the old style that completely comes off the can or the new style that stays on the can, but you can remove if you bend it back and forth a lot? If it is the old style, that will be hard to answer. If I can locate a can, I can do the new type. Everyone around here appears to use bottles now. -- k a i n a w &trade; 15:20, 12 August 2010 (UTC)
 * The newer kind that you have to bend back and forth to remove...to a very rough precision (I guess tabs from different manufacturers are a bit different)...+/-20% should be fine. Thanks! SteveBaker (talk) 15:29, 12 August 2010 (UTC)
 * I thought this would be trivial to do, but there are no cans here. Our vending machines only have bottles and the convenience store across the street only has bottles.  If nobody answers, I will do my best to remember to bring in a few tabs tomorrow and weigh them on one of the drug scales which go to 1/1000th gram. --  k a i n a w &trade; 16:49, 12 August 2010 (UTC)
 * As a completely random aside primarily arising because it's something I've been looking at recently. You can get cheap high precision scales from China/HK eBay sellers, something like US$6.00 shipped for a 100g/0.01g or US$8.50 shipped for a 300g/0.01g scale isn't uncommon. I wouldn't use these for serious work but from what I've read the precision is usually fairly good, i.e. they will give about the same value for the same weight and neither where you put the mass nor the temperature (within reason) have a significant effect. However the accuracy on these scales is likely to be far more questionable and there is a possibility they may drift over time (I read one person saying their one did). They can usually be calibrated and you can buy cheap calibration weights but of course the accuracy of cheap calibration weights is also questionable. However if you do have access to a accurate high precision scale, you could test them or for that matter make your own calibration weight to hopefully give you a resonably accurate high precision scale (you can also test it with various masses after calibration). I've seen some people use coins but I'm dubious that will give you an accurate enough calibration or test weight. Of course the precision is useful if that's all you need, I think some people use them for balancing RC helicopter rotors blades. There are also 0.001g ones but they're a fair bit more, like US$15.00, and while I haven't looked in to them much, I do wonder whether that precision is worthwhile on something so cheap. Nil Einne (talk) 18:34, 12 August 2010 (UTC)


 * I get 0.300 grams. I wouldn't be surprised if that can swing at least a few milligrams up or down depending on precisely where the tab tears when it is removed from the can.  (I don't know what the distribution is; I only conducted one measurement.) TenOfAllTrades(talk) 18:22, 12 August 2010 (UTC)
 * That's plenty good enough! Many thanks. SteveBaker (talk) 19:17, 12 August 2010 (UTC)


 * By the way, the tab is (or was, when last I checked) a tolerably accurate inch in length. I was fiddling around with a vernier and noticed that the tab from my Coke can was almost exactly one inch. My friend scoffed at the accuracy of the vernier and used a more accurate device only to come to the same conclusion. Which is of little use to anyone practically, but which may prove useful to someone stranded in the desert with an empty Coke can and a desperate need to measure whether something is exactly an inch wide... Matt Deres (talk) 13:50, 16 August 2010 (UTC)

What did Edward Teller die of?
The article on him doesn't say... 148.168.127.10 (talk) 19:16, 12 August 2010 (UTC)


 * It is usually stated in his biographies and obitiaries as "unspecified". When someone dies peacefully in their bed at age 95, there isn't generally any cause of death listed.  "Natural causes" or "Old age" is the best you're going to get.  Of course, something very specific did kill him - heart failure or something - but nobody is gonna being doing an autopsy to find out. SteveBaker (talk) 19:21, 12 August 2010 (UTC)


 * If you really want to know, it looks like you can go here and get his death certificate. --Sean 21:29, 12 August 2010 (UTC)


 * He had suffered a stroke on September 7, 2003, and died two days later. (Goodchild, Edward Teller, The Real Dr. Stranglove, 394.) At age 95 he suffered from a whole host of old-age related maladies. I think "old age" or "natural causes" is probably whatever his certificate said; they probably did not bother doing an autopsy. I've added the basic info to the article.--Mr.98 (talk) 00:00, 13 August 2010 (UTC)

Magic
Does magic really exist? I heard that in about 16th century in Europe, there are many witches got burned to dead.75.73.152.238 (talk) 19:30, 12 August 2010 (UTC)


 * No. See Witch hunt and more specifically Witch trials in Early Modern Europe and North America, sometimes melodramatically referred to as The Burning Times. 82.24.248.137 (talk) 19:42, 12 August 2010 (UTC)
 * What caused the witch-hunt. Are they really witch? If not, why did we kill them?75.73.152.238 (talk) 19:52, 12 August 2010 (UTC)
 * Panic, mass hysteria, paranoia. Plus the ordinary run of the mill mistakes in the justice system that allows innocent people to be executed to this very day.
 * This is all explained pretty well in the Witch hunt article. APL (talk) 19:57, 12 August 2010 (UTC)
 * It seems likely to me that there were at least a few people around who thought they were witches and could cast spells. After all, there are people today who think that, in this far more rational age.  But of course the great majority who were burnt were completely innocent. Looie496 (talk) 21:25, 12 August 2010 (UTC)
 * And, let's be clear, unless those people who thought they were witches were actually poisoning people or animals, they were also completely innocent. You can't be guilty of actually casting evil magic spells that cause your neighbour's cows to dry up. 82.24.248.137 (talk) 00:09, 13 August 2010 (UTC)


 * Magic is usually defined as "Powers outside of nature", but as soon as someone discovers how to do something, it's automatically part of nature. So by that definition magic can never exist - because as soon as it's discovered, it's no longer magic. But, if we change the definition to "Unexplained phenomena" then magic did (and does) exist, because there were (and are) lots of unexplained things. In the search for explanations for the unexplained (especially the tragically unexplained) people accused those that were different. Ariel. (talk) 21:24, 12 August 2010 (UTC)


 * To wit, any sufficiently advanced technology is indistinguishable from magic, and any sufficiently advanced magic is indistinguishable from technology :) --Dr Dima (talk) 22:59, 12 August 2010 (UTC)
 * I take issue with your comparisons, Dr Dima. From a Jewish perspective, while technology is reproducible and morally neutral, magic is not.  You mustn't pray, "Oh Awesome Computer, please send my email!!"  Rather, you click on the button, and whether you're an old lady who executes cats in her basement after torturing them or an upstanding member of the community, the computer will send your email.  But cauldrons of potion require incantations and the like, beseeching the (non-existent) power of magic.  If one is worthy, one's virgin in the volcano is accepted and the magical request may be granted.  Thus, magic and technology are examples of two distinct and non-overlapping magisteria.  DRosenbach  ( Talk 15:14, 13 August 2010 (UTC)
 * That's just a fancy term for the god of the gaps. 67.243.7.245 (talk) 03:52, 14 August 2010 (UTC)
 * That would be incorrect. Intelligent design is incompatible with Judaism, whilst what I asserted above is compatible.  Science is descriptive and religion is proscriptive -- they need not be made to reconcile because a true religion is reality.  DRosenbach  ( Talk 03:22, 15 August 2010 (UTC)
 * History is replete with religious claims, including Christian ones, that have been laid by the wayside. Good luck keeping the two magisteria separate. 67.243.7.245 (talk) 20:44, 15 August 2010 (UTC)
 * Speaking of witches, wicca may be relavent. ~ A H  1 (TCU) 00:06, 13 August 2010 (UTC)


 * In the Old Testament there is an explicit instruction that women who are witches or sorceresses are to be put to death. It is found in Exodus 22:18.  Different versions of the Bible translate this instruction in different ways, but the central message is the same – a woman is to be put to death if she might be a person who practices magic.


 * Thou shalt not suffer a witch to live (King James Version)


 * Put to death any woman who practices magic (Good News Version – makes one wonder what the Bad News Version would say!)


 * You shall not permit a sorceress to live (Revised Standard Version)


 * For other translations, see Ex 22:18


 * There is no similar instruction regarding the execution of men - only women!  And there is no opportunity for tolerance or a lesser punishment such as counselling or even a curfew – death is the only acceptable outcome!


 * In past centuries, prior to the broadcast of science and education, people relied heavily on ancient scriptures to guide them in their daily lives. As a result, all manner of injustice and foolishness pervaded human communities that practised loyalty to these ancient scriptures. The murder of women, and particularly old women, out of fear of witchcraft and sorcery is merely one of the injustices that persisted for thousands of years as a result of the unquestioning loyalty to ancient scriptures.  Dolphin  ( t ) 03:46, 13 August 2010 (UTC)


 * It's 22:17 not 18. And your rant about women is wrong because you forgot about Deuteronomy 18:10 which uses the male version of the female word used in Exodus. The rest of your rant has nothing to do with scriptures and everything to do with people who simply wanted to, due to fear of "other", or "strange", scriptures were just an excuse. Just look at Africa today where such executions are still carried out and have nothing to do with scripture. Ariel. (talk) 06:09, 13 August 2010 (UTC)


 * I did not forget about Deuteronomy 18:10 because I know nothing about it. However, the nineteen persons (or groups of persons) responsible for the nineteen translations listed at Ex 22:18 might have forgotten about it, but I doubt it because to translate the Bible, and have it published, one must be an expert.  In those nineteen translations no masculine word, or male version of a female word is used.  The female word sorceress is used many times, but the male equivalent sorcerer is not used in any of the nineteen translations (except in the expression female sorcerer.)  I concede that the gender-neutral word witch is used in two of the translations, and the word witchcraft once, but no unambiguously male word appears.  I agree that many executions of alleged-witches would have been because people just didn't like the person and were motivated to murder that person, but the existence of Exodus 22:18 provided many of the murderers with re-assurance and justification that what they were doing was not only legitimate but an explicit commandment from holy scripture.  Dolphin  ( t ) 07:39, 13 August 2010 (UTC)


 * Considering they got the verse number wrong I don't think they are a reliable source. Ariel. (talk) 19:55, 13 August 2010 (UTC)
 * Chapters and verses of the Bible are numbered slightly differently in different versions.
 * —Wavelength (talk) 20:09, 13 August 2010 (UTC)
 * Thanks Wavelength. Regardless of the verse number, and regardless of the gender addressed in the verse, it is undeniable that the book of Exodus gives a peremptory instruction that if a person practises magic (or sorcery or witchcraft) that person is to be put to death.  Consequently it is not surprising that in less-enlightened times than at present, people who were suspected of practising magic were killed. Dolphin  ( t ) 03:16, 16 August 2010 (UTC)


 * Please see my comments in the discussion Reference desk/Archives/Humanities/2010 March 27.
 * —Wavelength (talk) 04:38, 13 August 2010 (UTC)

See the Copenhagen interpretation. When the First Man looked up into the sky, the stars coalesced from formless chaos. Is that not magic? But be wary of pursuing the paranormal - you may find that you harm all you encounter, and lose the capacity of meaningful choice, and that your "talent" is nothing but a disease, and a crime, and an abomination, and an art of the damned. Look to Diocletianic Persecution for a remedy. Wnt (talk) 14:42, 14 August 2010 (UTC)
 * Stop making up stories. 67.243.7.245 (talk) 18:17, 17 August 2010 (UTC)

pizza condiments
where do i get pizza condiments like they have in pizza hut in the glass shakers —Preceding unsigned comment added by Tomjohnson357 (talk • contribs) 20:28, 12 August 2010 (UTC)
 * You mean parmesean cheese and crushed red pepper? Most grocery stores carry those.  Googlemeister (talk) 20:35, 12 August 2010 (UTC)
 * You might have to buy the glass shakers separately (supermarkets usually sell in plastic, but I've seen pretty good ones at a 'restaurant supply store' that is open to the public.) RJFJR (talk) 21:12, 12 August 2010 (UTC)


 * Here you can get the shakers for about a buck. The green stuff is usually stale oregano, and there's parmesan and red pepper flakes, as mentioned. --Sean 21:31, 12 August 2010 (UTC)
 * That article is at crushed red pepper. Maybe add a redirect. Ariel. (talk) 22:08, 12 August 2010 (UTC)

Seeing What People Are Thinking
I was watching this episode of House, and they did an experiment where they where able to see what a person was thinking by reading brain waves while look at pictures so the computer knows what triggers what in the brain. Is this actually possible? 99.114.94.169 (talk) 20:31, 12 August 2010 (UTC)
 * To a very limited extent, yes. You can see what areas of the brain are being used at any given time with various forms of functional neuroimaging (read that article and the articles it links to for details). While that isn't enough to work out what someone is thinking from scratch, you can compare it to previous scans of the same person and find a match and know that they are probably having the same kind of thoughts (eg. you show them a bunch of pictures and see what parts of their brain are active when they consider the picture and then show them one of the pictures again at random and you can work out which one it is by comparing the brain scans). While there are general areas of the brain that do the same thing is everyone, there is enough variation that you do generally need to establish a "baseline" using scans of that particular person's brain before you can use new scans to determine anything substantial about their thoughts. Also, the best you can do is work out what kind of thinking they are doing (for example, thinking about something they enjoy, thinking about moving their body, thinking about hearing something, etc.). You can't work out specific thoughts. --Tango (talk) 21:07, 12 August 2010 (UTC)
 * If our article's description of the episode is correct, the things they do (mapping the thoughts of an unconscious person) go vastly beyond anything that is currently possible. Current technology is at the level of things like trying to read brain waves well enough to let a person to use them to move a lever back and forth. Looie496 (talk) 22:35, 12 August 2010 (UTC)


 * If I recall the episode correctly, they show the patient a huge number of reference images, and have the computer create a sort of database of what this patient's brain looked like when they were looking at each of the images. Only after hours of that did they start trying to reverse the process. They don't dwell on it, but I got the impression they were relying on the computer running some sort of algorithm, possibly like facial recognition software, making up the new image out of combinations of basic features from the huge database of images. Do I mean eigenfaces? It was the sort of thing that seemed probably not possible with current technology, but plausible in the not-distant future. (In fact, the characters in the episode are all a bit surprised it works) But I'm no expert. 82.24.248.137 (talk) 00:04, 13 August 2010 (UTC)


 * I'm going to call on your claim it's plausible at all.  The episode was the worst House episode in memory when it comes to plausibility.  Comet Tuttle (talk) 15:12, 13 August 2010 (UTC)


 * Worst. Episode. Ever. I'm afraid my criteria for 'seems plausible in the not-distant future' is that I can imagine the mechanism by which it would work, using merely more-advanced versions of technology we currently possess. It seems probably not possible with current imaging, although with enough care and a large enough database of examples for that individual, I wouldn't be wildly surprised by a much vaguer result being achievable. The sort of result that might let you tell whether they were thinking of a round thing or a tall thing, a dark thing or a light thing, a single shape or many shapes. 86.164.66.83 (talk) 22:23, 13 August 2010 (UTC)


 * It's definitely quite impossible right now. I'm skeptical that the approach suggested in House would actually work - it presumes a lot of things about the brain that we simply do not know to be true. SteveBaker (talk) 02:23, 13 August 2010 (UTC)


 * I think it might work in principle, but current functional imaging techniques don't come close to the spatial resolution or signal-to-noise ratio that would be needed. Correlation-based reconstruction is pretty robust -- it can work well even if you don't have any idea what the activity patterns actually mean. Looie496 (talk) 03:07, 13 August 2010 (UTC)


 * Thanks for the responses, it seems it would make an interesting field of science. 99.114.94.169 (talk) 04:33, 13 August 2010 (UTC)


 * I don't know the episode of House in particular (don't watch it) but from what's been discussed so far some may be interested to know various companies are developing fMRI lie detector tests. These have even been (controversially) used in Indian court cases www.policyinnovations .org/ideas/briefings/data/000172 (black listed site) Nil Einne (talk) 17:35, 13 August 2010 (UTC)


 * Also don't know the episode, but P300 (neuroscience) may interest you. Wnt (talk) 14:26, 14 August 2010 (UTC)

Ca2+ as a lewis acid
There is nothing in the calcium chloride article about its use as a Lewis acid. Is it NOT a Lewis acid? John Riemann Soong (talk) 22:11, 12 August 2010 (UTC)
 * Ca2+ It coordinates well with lewis bases such as crown ethers. In a similar way, it can bind to various sorts of structures during a reaction to allow one part of a molecule to serve as a template for another. For example, residual calcium ions from one step were critical in stabilizing a structure by two hydroxyls and an ether cause a subsequent reaction to proceed a certain way. DMacks (talk) 23:41, 12 August 2010 (UTC)

Pulse deficit
Why in atrial fibrilation there is pulse deficit while in very rapid supraventricular tachycardia there is not? Moh1988has (talk) 22:33, 12 August 2010 (UTC)
 * Where did you get that information, please? Looie496 (talk) 01:01, 13 August 2010 (UTC)


 * Supra-ventricular tachycardia is caused by a group of cells on top of the ventricle going haywire nad is not the same as fibrilation.--JyzzCannon (talk) 23:02, 14 August 2010 (UTC)

Thank you guys.....I know that AF is not the same as SVT..but i mean why there is no pulse deficit in SVT(where the pulse is so rapid) as in AF Could you tell me what is the mechanism in which the AF produce pulse deficit? And thank you so much109.70.70.5 (talk) 01:48, 15 August 2010 (UTC)

Who's good with chemical nomenclature?
Going to start proof reading and cleaning up the Glimepiride article, and have noticed two different sources stating the following IUPAC names. I can't distinguish between the two, so could someone who's good with naming large molecules have a look? Here are the two options:

-3-ethyl-4-methyl-N-(4-[N-((1r,4r)-4-methylcyclohexylcarbamoyl)sulfamoyl]phenethyl)-2-oxo-2,5-dihydro-1H-pyrrole-1-carboxamide

OR

-4-ethyl-3-methyl-N-[2-[4-[(4-methylcyclohexyl)carbamoylsulfoxo-2H-pyrrole-1-carboxamide

Thanks guys. Regards, --— Cyclonenim | Chat 22:55, 12 August 2010 (UTC)
 * I'm not quite in a mental state to confidently name a molecule quite that nightmarish, but do bear in mind that with molecules of that level of complexity you can very easily have more than one completely equivalent, and hence completely correct, name. If the sources are decent they may both be correct. ~ mazca  talk 23:09, 12 August 2010 (UTC)
 * Second one is at best incomplete, as it's missing stereochemical information about the cyclohexane ring. DMacks (talk) 23:21, 12 August 2010 (UTC)
 * The second name is missing a whole chunk in the middle, as you can see from the three opening brackets without closing brackets. The first name agrees with the name on ChemSpider (apart from the minor point of "phenethyl" vs. "phenylethyl"). Physchim62 (talk) 07:30, 13 August 2010 (UTC)