Wikipedia:Reference desk/Archives/Science/2013 September 13

= September 13 =

Chemical terminology
What is the term used to describe a chemical species, that is practically unaffected by water between pH 0-14? For example, Na+, Ne, etc. That is, disregarding solvation shells, they do not spontaneously react with water to produce new species. HO−, NH4+, etc. are not examples. Is the term 'unhydrolyzable'? Plasmic Physics (talk) 02:12, 13 September 2013 (UTC)
 * It sort of depends on how you define your terms. If you read Ligand, you find statements like "Metals and metalloids are bound to ligands in virtually all circumstances"; a "solvation shell" is just water molecules bound as ligands to the metal ions (though highly labile ligands).  Some species will bond stronger to H+ ions and other will bond stronger to OH-.  Lewis bases (like ammonia) tend to do the former, while lewis acids (like Fe+3) tend to do the latter.  By Le Chatelier's principle the fact that Lewis bases or acids will bond strongly to H+ or OH- ions is what tips the equilibrium and changes the pH.  Species which are neither Lewis acids or Lewis bases is what you are looking for.  I'm not sure there is a word for that.  -- Jayron  32  19:51, 13 September 2013 (UTC)

Oral masturbation question
I note that autofellatio is quite possible, and was curious if there had been any documented cases of women who could perform "autocunnilingus", or if it's even physiologically possible. — Crisco 1492 (talk) 07:14, 13 September 2013 (UTC)
 * Why not... You just need to be real flexible. ☯ Bonkers The Clown  \(^_^)/  Nonsensical Babble  ☯ 07:26, 13 September 2013 (UTC)
 * I haven't really been able to find a reliable source for any of this. At most there are porn feeds, which are not necessarily scientifically accurate (I recall one which had a three-breasted woman, so it could be niche). Our article on oral sex mentions autocunnilingus, but no reference. — Crisco 1492 (talk) 07:31, 13 September 2013 (UTC)
 * These seem useful In theory it is possible, that is for certain. ☯ Bonkers The Clown  \(^_^)/  Nonsensical Babble  ☯ 07:35, 13 September 2013 (UTC)
 * Dicdefs, mostly. This is the only one that is somewhat helpful, but that seems to be (non-human) primates. — Crisco 1492 (talk) 07:37, 13 September 2013 (UTC)


 * Here's a blog devoted to the topic discussing the possibility: . In it they mention Zlata, we don't have an article on her, but here is her site:, two other pages about her: , (it mentions something about her having some form of condition). Here's a video of her doing a Frontbend to let you form your own opinion. Zlata aside, you may want to take a look at Contortion, Hypermobility, and Ehlers–Danlos syndrome, and a link to the Dutch Wiki on the matter: . That's the most reliable bit of info I could find, the rest was just porn clips, which aren't too helpful.Phoenixia1177 (talk) 09:55, 13 September 2013 (UTC)


 * That's interesting (noticed the Dutch Wikipedia article already). Thanks for the blog, didn't see that pop up in Google. — Crisco 1492 (talk) 11:10, 13 September 2013 (UTC)

Naegleria fowleri — what does it normally eat?
Piecing together various things I've heard, it seems that the spectacular, usually lethal, human infection is a dead end for the microbe, and not a reflection of its normal life cycle. A recent news article says that it's not truly an amoeba, but calls it a parasite; our article, on the other hand, says it's a "free-living protist", but that it's related to trypanosomes and to the organisms that cause leishmaniasis, which certainly are parasites.

So if it doesn't normally eat brains, then what? Does it have a facultative parasitic life path when the opportunity presents itself, one that's not a dead end? --Trovatore (talk) 09:10, 13 September 2013 (UTC)


 * It definitely has a "normal" life cycle that does not involve eating human brains. See this CDC page, with references to three recent science papers, all of which call it an Amoeba. Compare to Clostridium_tetani, which normally just hangs out in the soil doing bacteria things, but causes big problems if it gets inside right/wrong bits of a human body. The pathogenicity in both cases, is, to my knowledge, basically just bad luck, or perhaps an accident of history. SemanticMantis (talk) 13:14, 13 September 2013 (UTC)
 * Hmm, don't really buy the bit about tetanus. Elaborate high-molecular-weight peptide neurotoxins don't happen by chance.  My guess is that C. tetani (and C. botulinum) kill animals so that their corpses provide a nice anaerobic growth medium. --Trovatore (talk) 19:17, 13 September 2013 (UTC)

Synthesizing elements 119 and 120
Why hasn't it succeeded yet? Theoretical studies indicate that we should be capable of doing this already, and indeed experiments have already been started. Why have they all failed? The half-lives predicted are long enough that the resultant atoms should survive the journey to the detector. And why can't we just keep using 48Ca projectiles on Es for element 119 at least? Double sharp (talk) 11:53, 13 September 2013 (UTC)


 * We have articles on Ununennium and Unbinilium - in both cases, about half of the possible routes to synthesis have been tried - but simply failed - and not for any well-understood reasons. Using  48Ca projectiles on Es has been tried, and failed to produce a single atom...so unless there is credible reason to suppose that the superHILAC team at Berkeley screwed up, experimenters are going to want to try the other predicted synthesis route just because it has a higher chance of succeeding.  There might even be some actual successes - but the results have not been announced, so the teams may be waiting for confirmation or something. Element 120 is a more promising target than 119 because it's predicted to like on the island of stability - and because there are many more routes to synthesis to explore. SteveBaker (talk) 15:27, 13 September 2013 (UTC)


 * A credible reason might be that it's very old results (1985!)? This paper thinks that the 254Es reaction should be about as effective as the reactions that made elements 117 and 118: if that's the case, then why not do that? It seems the only obstacle is getting enough of it!
 * (Just realized this possibility: Maybe the isotopes are less long-lived than we previously thought and hence we are making them, but they are decaying before they reach the detector. Is there some way to increase detector efficiency and beam intensity by at least an order of magnitude?) Double sharp (talk) 04:11, 14 September 2013 (UTC)

Kidney bruising
How do most kidney bruises occur? It seems to be common in footballers but how much force is required? Wouldn't fat and muscle protect it unless it was a very strong force? Can kidney bruising be seen? Clover345 (talk) 14:51, 13 September 2013 (UTC)

Your kidneys are generally well protected by muscles of the back and rib cage but injuries can occur as a result of blunt or penetrating trauma. (Urology Care Foundation ). Most Kidney injuries occur from blunt force due to motor vehicle accidents, falls, or sports injuries. The kidney is actually injured more often than any other organ along the urinary tract..(The Merck Manual Home Health Handbook ) A bruised kidney is characterized by bleeding within the kidney.(The Livestrong Foundation). The bruise cannot be seen, but blood in the urine is an important indicator of a kidney injury. Pain in the upper abdomen and flank are further indicators of a kidney injury. Ljtr222 (talk) 19:17, 13 September 2013 (UTC)
 * Ljtr222 I have taken the liberty of re-formatting your references to make them available to readers without a 'references' template. (they all had which is unnecessary, in fact undesireable as it gives all your refs the same ref name--220  of  Borg 19:40, 13 September 2013 (UTC)

Physiology behind eating certain types of food
Is there a scientific consensus on what causes the rejection of certain non-meat types of food (like onion, garlic, scallion, mushrooms, olives)? I've recently found that I can't stand cooked zucchini, as well as eggplant, which while in mouth trigger vomiting in me, whereas all other members of my family eat them. Is it something different from food intolerance like lactose intolerance?--93.174.25.12 (talk) 17:27, 13 September 2013 (UTC)


 * I strongly suspect that this isn't a chemical intolerance like lactose intolerance - but a psychological matter. However, we're not allowed to give medical advice here - so we can't discuss your personal situation.  SteveBaker (talk) 17:33, 13 September 2013 (UTC)


 * It is well known that if you have been vomiting after eating some food with a non neutral taste, this can cause your brain to flag that taste as disgusting later. Patients on chemotherapy are adviced not to eat their favorite food during the time they experience nausea. Count Iblis (talk) 17:44, 13 September 2013 (UTC)


 * You might be interested in reading what we have at selective eating disorder. SemanticMantis (talk) 18:12, 13 September 2013 (UTC)


 * The negative conditioning model is a good potential explanation, yet... it surely doesn't cover everything. For example, I never encountered durian in any form until one day, well into adulthood, I encountered a container of durian-flavored cookies left in a lunchroom as an exhibit.  I was blissfully ignorant of what to expect, yet, O-my-God is that repulsive, like cannot be believed, merely to smell from a distance!  The weird part was that I kept sniffing at the bag at intervals, racing to the sink out of fear of an incident, then trying again, because the scent is such as cannot be remembered a minute after it is smelled ... indeed, it is almost as if it cannot be experienced even as it is perceived.  Memory cannot contain it.  I can only recall how I reacted to it. Wnt (talk) 21:55, 13 September 2013 (UTC)

What happens when you place a Crane Fly in Sulfuric acid?
If I was to place a live crane fly in a bottle of sulfuric acid, can I have a basic scientific explaination to what would happen to the crane fly? Would it die painfully? --LiebeisBesser (talk) 19:11, 13 September 2013 (UTC)
 * Depending on your definition of pain, yes or no. See Pain in invertebrates for some of the controversy surrounding whether invertebrates feel pain as we understand it.  It's probably not the best idea to gratuitiously kill just to see what happens, regardless of whether it can or cannot feel pain; experiments on animals are also controversial, but should only be properly carried out under they auspices of a proper governing body who maintains ethical standards for animal experimentation; you just screwing around and seeing what happens is not under such a governing body.  -- Jayron  32  19:17, 13 September 2013 (UTC)


 * It's hard to know whether such primitive animals experience pain per-se. Also, the fate of the beast will depend entirely on the concentration of the acid.  So-called "acid rain" is weak sulfuric acid - and crane flys seem to survive that OK.  In concentrated acid, they'd doubtless die very quickly because the acid will dissolve most (if not all) of their tissues. SteveBaker (talk) 19:19, 13 September 2013 (UTC)


 * Why would you want to torture a crane fly, or any other living thing? ←Baseball Bugs What's up, Doc? carrots→ 21:09, 13 September 2013 (UTC)
 * This was my reaction as well. What is you specific curiosity here: the experience of pains in flies, the effect of acid on living things, or something else entirely?Phoenixia1177 (talk) 21:26, 13 September 2013 (UTC)
 * The moralism here is laughable, and may well deserve a separate Humanities thread. Either it is good to put up flypaper to kill hundreds of flies, spray insecticide on a farm to kill millions, or it is bad.  Either way one fly in sulfuric acid does not matter.  You act as if it is only ethical to kill something if you do it with your eyes shut.  I suppose I know why - because there is rampant infection with brood parasites, dubbed "pets", which have evolved to fill a fantasy that they are human children, and people desperately contort their theories to match their infestation.  Sometimes it is pretty clearly science itself that is regarded as wrong - for example, to kill a mouse horribly in a snap trap or starving in glue is everyday home maintenance, but the slightest mistreatment for the sake of curing cancer is severely punishable.  (Perhaps the moral is that it is wrong to cure cancer)


 * As for the question, it is not so simple to figure out from first principles. Insects can survive a few minutes in vacuum, much of an hour underwater, you can clean their eggs with a fairly concentrated bleach solution, etc.  They are evolved to survive extremely dry conditions despite an absurdly high surface-to-volume ratio.  Nonetheless, chitin, despite being one of the most resistant biomolecules to degradation, will succumb to concentrated acid, releasing oligosaccharides.   So you can indeed punch holes through the exoskeleton, with ordinary protein and other components succumbing to the acid just as they do in a human. Wnt (talk) 21:44, 13 September 2013 (UTC)
 * I think the "moralistic" impulse in the responses is not so much about some particular crane fly suffering, as it is in response to the idea that the OP might be specifically wanting to cause suffering in a crane fly. Of course we don't actually know whether the OP wants that, or even enjoys thinking about it, but if he/she did, then it's a natural response to wonder why, and to try to discourage wanting such a thing.
 * What came to my mind was, why a crane fly, specifically? They're almost totally inoffensive, except for being sorta ugly, but they probably don't think I'm pretty, either.  If it were a mosquito I would understand (not exactly approve, but I'd have to admit that the impulse was not exactly foreign to me). --Trovatore (talk) 08:08, 14 September 2013 (UTC)


 * Thanks for the second paragraph, It's a good, referenced answer. No need for the initial diatribe though. I don't want to spiral into a needless debate here, so I'll try to head that off by weighing in in the middle.
 * Jayron's response wasn't exactly condemning all insect death, and he gave some good refs. Indeed there are and have been some animal experiments that I wouldn't want to approve, and I do generally support the aims of Institutional_review_boards for human and animal experimentation. However, it's also a too broad to say that animal experiments are always controversial. We kill all kinds of flies, bees and ants everyday in the name of science, and that research is seldom attacked on ethical grounds.
 * Finally, the article above clearly states that pain in invertebrates is contentious and problematic. My WP:OR suggests that very few practicing entomologists have any qualms about it. If the OP has specific questions about what "pain" might exist in the insect experience, s/he should ask another question.
 * p.s. Calling pets a "rampant infection with brood parasites" did make me laugh :) SemanticMantis (talk) 22:10, 13 September 2013 (UTC)


 * What now? I didn't realize I used mouse traps in my house, nor was I aware that being bothered by the possibility of arbitrary pain in a fly had something to do with my feelings on cancer research (both, obviously, yield the same amount of useful results). You seem to be making a lot of assumptions to reach your conclusion for a "defender" of science.Phoenixia1177 (talk) 21:54, 13 September 2013 (UTC)


 * For the part about the mice I was referring to this sort of 'claptrap'. Wnt (talk) 22:14, 13 September 2013 (UTC)


 * I'm very sleepy and am not sure who is addressing who- that said, I think if there is no useful purpose to something that can potentially inflict pain, then that something should not be done. It makes me sad knowing that mice die for research, but feeling sad is not inconsistent with supporting such research out of necessity. I don't think anyone here has raised an objection to cancer research, at most the objection is to an image of the op pointlessly dropping various living things in acid for the hell of it (whether that's their interest, or not).Phoenixia1177 (talk) 22:23, 13 September 2013 (UTC)


 * Simulating the brain of insects is a task than can in principle be executed by modern PCs, so if we assume computationalism, insects being able to feel pain would imply that using your PC could lead to pain being felt by some program it executes. Count Iblis (talk) 23:18, 13 September 2013 (UTC)
 * Interesting assertion. (this is why I refrain from powerpoint) SemanticMantis (talk) 23:37, 13 September 2013 (UTC)


 * Which is, in and of itself, virtually a complete refutation of computationalism. --Trovatore (talk) 07:47, 14 September 2013 (UTC)
 * Not really, the computer doesn't have all of the other biochemical pathways that are implicated in pain. Also, while computers are beginning to have the same computational complexity as an insect brain, they aren't organized the same way with all of the nerve endings and such that transmit pain to the brain and all of the physical processes that go on besides.  We would need a more comprehensive simulation of the entire insect to produce this kind of effect.  But it's not inconceivable that a computer program could "feel pain" in the way that (we believe) some or perhaps all non-human animals can.  But this is never going to be an easy question - we can't decide whether insects feel pain - so how could we decide whether a computer simulation of one does?  SteveBaker (talk) 12:53, 14 September 2013 (UTC)
 * I believe that considering "computer pain" would make it a lot easier to solve this problem, because it would force people to consider the problem in terms of well defined concepts. So, what matters is the computational state of a system; there is some the set of systems that are capable of perceiving pain, but algorithms executed by these systems can be totally different. Therefore, pain must be a universal phenomena. It will probably eventually be understood in terms of the world as perceived by some algorithm, pain obviously must have something to do with the discord between what the algorithm itself says it wants to do (which is an objective thing as it can be extracted from the information encoded in the algorithm) compared to what it actually is capable of doing under the circumstances it finds itself in. Count Iblis (talk) 14:09, 14 September 2013 (UTC)
 * There is no way to define qualia in terms of externally observable anything. They are inherently subjective (yet objectively real).  No, the computational state is not what matters.  I think that's just absurd on its face. --Trovatore (talk) 19:01, 14 September 2013 (UTC)
 * Yet, according to quantum mechanics, the exact physical state of a system can be specified by specifying the eigenvalues of a complete set of commuting observables. So, if I have Trovatore in an isolated box, whatever you experience must be describable in terms of a suitable set of Hermitian operators. Count Iblis (talk) 23:14, 14 September 2013 (UTC)
 * Your mistake is that you assume I'm a physical system. --Trovatore (talk) 01:33, 15 September 2013 (UTC)
 * Good point. You could be an Organian, or one of their cousins. ←Baseball Bugs What's up, Doc? carrots→ 02:43, 15 September 2013 (UTC)
 * No, my body is a physical system. That's different from saying I am.  --Trovatore (talk) 02:59, 15 September 2013 (UTC)

I would argue (but this is rather controversial) that in the formalism of quantum mechanics, the complete set of Hermitian operators for a system should in general refer to the qualia the system can experience. If Trovatore measures the z-component of the spin of an electron that is polarized in the x-direction, his state after performing the measurement is 1/sqrt(2) [|Trovatore measures spin up>|up> + |Trovatore measures spin down|down>] The measurement problem in quantum mechanics is solved by talking into account that any measurement involves experiencing qualia and these must define a preferred basis. So, there exist qualia for experiencing things that when put toghether point to the measurement outcome being spin up or spin down. The totality of available observables for Trovatore must correspond to precisely what Trovatore can subjectively experience (besides knowing what the outcome of the measurement was, you can also have pain in your knee and experience the taste of your lunch). Count Iblis (talk) 14:07, 15 September 2013 (UTC)
 * So you think that, say, hydrogen atoms must have qualia? I can't prove they don't, of course.  But it seems bizarre to me to assume they do. --Trovatore (talk) 18:15, 15 September 2013 (UTC)
 * Perhaps, but the system has no degrees of freedom when in the ground state (or two (qu)bits if you consider the spin of the proton and electron). I think some of the philosphical objections can be addressed by carefully considering a system that needs to be described by an astronomically large number of bits. Then consider what I said above about the system observing itself, the qualia won't form a "complete set" in the sense that what you experience won't pin down your exact physical state, there will be a huge degeneracy. You can never know exactly what state you are in, as the amount of information required for that would never fit in your available memory. But then, if you accept the Many Worlds Interpretation (MWI) of quantum mechanics, this means that you should always think of yourself as smeared out over some astronomically large number of macroscopically similar states.


 * Such a set of states contains information about the time evolution of the system, e.g. that you did something in response to something else implies that there is non trivial causation. This then addresses a well known thought experiment where one imagines replacing neurons by transitors and then one says that since the output to the actual input was what it was, you can replace the transitor by a fake transitor that always has that output and then the qualia would have to remain the same. That would seem to imply that a static representation of your brain would have your consciousness. Obviously, this argument fails in the MWI picture because you do have counterfactual states inside that large group of states over which you are smeared out. So the information that you would have done something slightly differently had the input been slightly different, is present in the set of states.


 * So, I believe that there is room within quantum mechanics to deal with some of the objections against computationalism (but without invoking non-classical quantum phenomena). Count Iblis (talk) 19:33, 15 September 2013 (UTC)

@Wnt above, there's a huge difference between killing out of necessity pest insects which have invaded your house and torturing to death a harmless non-pest. Admittedly, it is an abstract distinction that requires the self-control not to swat at and the discrimination to differentiate between harmless and harmfull critters. Surely as empathetic adults that's not above us. Or are we all trolls? μηδείς (talk) 22:06, 14 September 2013 (UTC)


 * It gives one pleasure to have a house free of the buzz of flies; it gives one pleasure to investigate the rough science of flies in acid. Difference?  Jainism is thataway. Wnt (talk) 22:39, 14 September 2013 (UTC)


 * No, there is no sadistic pleasure to mature adults in killing flies. They are disease-spreading pests that have evolved to plague and feed upon us.  We don't kill them by slowly dissolving them.  A crane fly is a harmless accidental visitor.  Given the amount of advice you dispense I would be shocked to find you don't understand the difference.  Or maybe you enjoy feigning ignorance, which tells us about you as well. μηδείς (talk) 22:57, 14 September 2013 (UTC)
 * You're categorizing someone else's pleasure as sadistic or not. Moreover, you're telling me there's no "sadistic" pleasure in swatting a fly that's been buzzing around the room?  Really?  And that it must be sadistic to experiment with a crane fly in acid?  Really?  I'd think the former might be more "sadistic" than the latter.
 * I suppose there's a broader issue here: this notion that it's OK to do anything unless you take pleasure in it. Ever since the bland functionaries of the Holocaust I don't think that kind of reasoning should fly.  If harming an insect were unethical it should be unethical whether you do it out of sadistic glee or in order to get an extra dollar an acre out of farmland. Wnt (talk) 14:40, 17 September 2013 (UTC)

Underground stream of water
Is there a name for an underground stream of water which emerges in times of rain (and forms pools of water)?

To be more specific: in the Sand River in St Francis Bay, South Africa water flows underground, over a hard rocky substrate that underlines the dunes. The water emerges in times of rain, when the river stops flowing a number of pools of water remain.

I was just wondering what this phenomenon is called. Servien (talk) 20:06, 13 September 2013 (UTC)


 * An underground stream that emerges from the ground is called a spring. See Spring (hydrology).  -- Jayron  32  20:18, 13 September 2013 (UTC)
 * Losing stream, subterranean river, and wadi might be useful articles, but I don't think there's a specific name for a river that is normally underground but rises above ground occasionally. Rivers which dry out completely for most of the year (such as the Todd River in Australia) are called "ephemeral rivers", but the river type you describe would always have a flow of water, even though it's not usually visible.  (Incidentally, we have articles on four Sand Rivers in South Africa, but not the one you mention.  Is it part of a larger system?) Tevildo (talk) 20:22, 13 September 2013 (UTC)
 * My favorite is the intermittent Mojave River. It's always running underground except for a couple of year-round surface flows, but it's above ground when there's enough rain. --jpgordon:==( o ) 22:08, 13 September 2013 (UTC)


 * I also found Lost River (Indiana). Alansplodge (talk) 09:51, 14 September 2013 (UTC)


 * Several streams or stream courses mostly in the south-west of England are called "Winterbourne" as all or part of their name because they generally only ran in the wetter winter season. Annual variations, more gradual climate changes, and alteration of water tables by artificial extraction may have affected this one way or another, so now some may run permanently while some others may be permanently dry. {The poster formerly known as 87.81.230.195} 90.213.83.178 (talk) 22:45, 15 September 2013 (UTC)
 * Thanks for your responses. Quite weird that there is no name for such a river/stream, since the term spring doesn't quite cover it. It is not part of a larger system as far as I know, there are no nearby rivers where the water could come from or run to. I've added it to the Sand River disambiguation page. Servien (talk) 17:41, 17 September 2013 (UTC)

wireless keyboards/mice
hello, I'm probably not the first one to whom this idea has occured and who wonders if it's true, but are (non-Bluetooth) keyboards and mice, on the physical level, actually Bluetooth systems where the transmitter (you know that tiny thingummy that goes into the USB port) and the device have been pre-"paired" in advance and the computer interface of the dongle modified so that the operating system sees a keyboard/mouse rather than a generic Bluetooth module? I mean, both types of devices (BT and non-BT) transmit at 2.4 GHz, the dongles look the same, so can't the hardware manufacturers have "reused" parts of the BT physical protocol (along with the respective circuitry)? Asmrulz (talk) 23:30, 13 September 2013 (UTC)