Wikipedia:Reference desk/Archives/Science/2010 December 2

= December 2 =

Scientific Child Rearing
Humans have been raising children since basically the dawn of time, so presumably we do an okay job of it on average. On the other hand, if you talk to ten different people, you are likely to get ten different opinions about how to deal with kids. Some people believe in being very strict, physical (e.g. spanking), or distant. Others will try to coddle their children and protect them from everything. Some parents assign lots of chores to their kids, and other parents do all the cleaning and work themselves. Some parents want to know everything about their kids lives and others leave them alone.

I could go on, but you get the idea. My question is this: Is there any objective evidence that certain parenting styles are more effective than others at ensuring that children grow up to be happy and successful adults? For example, do the kids of strict parents earn more over their lifetime? Do the kids of gentler parents have fewer (or more) psychological problems in adulthood?

I'm looking for references to scientific studies and other factual conclusions, rather than just personal opinion. Dragons flight (talk) 00:24, 2 December 2010 (UTC)
 * I think the problem is that I doubt you could even satisfactorily define happy and successful. Vespine (talk) 02:18, 2 December 2010 (UTC)


 * There are lots and lots and lots of studies of this sort. I don't know what the larger synthetic conclusions are, but surely there are some by this point, even if they are contested (and they certainly will be). --Mr.98 (talk) 02:50, 2 December 2010 (UTC)


 * Actually, that's pretty good, it gave me the idea to put meta analysis  and meta analytic into the search field after "parenting style" and that comes up with some pretty interesting sounding results. don't have the time to go through any now, but i've bookmarked it. Vespine (talk) 02:59, 2 December 2010 (UTC)


 * A couple thoughts:


 * 1) Different kids likely require different parenting styles. For example, some would benefit from permissive parents who let them do as they please, while other kids would get into serious trouble with such parents. Identifying which type of kids you have an adjusting your parenting style (sometimes for each sibling), may therefore be necessary.


 * 2) Parents tend to think they did a good job if their kids turn out like them. So, parents who value education will think they did a good job if they end up with educated children, while parents who value athletics will think they did a good job if they end up with athletic kids. StuRat (talk) 21:50, 2 December 2010 (UTC)

The Marshmallow Trick
By many accounts, marshmallows, inserted anally, act as a laxative. What causes this effect? -mattbuck (Talk) 00:53, 2 December 2010 (UTC)


 * That's not how I learned to make smores. :-) StuRat (talk) 00:10, 3 December 2010 (UTC)


 * There are herbal laxatives (to be taken orally), such as "Easy Mover", that contain marshmallow (Althaea officinalis) extract. I don't know whether the marshmallow extract is the active ingredient, nor how it works, though our laxative article provides plenty of plant-based examples.  Searching Pubmed did not provide any helpful leads, and I could not easily find reliable sources for the use of marshmallow rectally.  -- Scray (talk) 01:36, 2 December 2010 (UTC)


 * But the modern marshmallow confection no longer actually uses the marshmallow plant (althaea officinalis) as an ingredient. Red Act (talk) 01:49, 2 December 2010 (UTC)


 * Indeed, I was adding that as an edit when I encountered an edit conflict ;-) -- Scray (talk) 01:56, 2 December 2010 (UTC)


 * Anyone else got an idea? -mattbuck (Talk) 03:25, 4 December 2010 (UTC)


 * I think it's the sugar. A corn syrup enema would probably work, too. StuRat (talk) 19:31, 4 December 2010 (UTC)

Chemistry Laboratory technique
I'm looking for the name of a chemistry laboratory technique in which you "scratch" at the walls of a beaker to form a polymer. —Preceding unsigned comment added by David255 (talk • contribs) 00:57, 2 December 2010 (UTC)
 * Assuming you're forming a crystalline solid, and not a covalent polymer, I've always called the technique "scratching"! You basically form new nucleation sites on the inside surface of the beaker. Trituration (beating it into a solid) is similar in thermodynamic terms, but you usually work with much less liquid than for scratching. Physchim62 (talk) 01:58, 2 December 2010 (UTC)
 * Trituration is the term. Thanks! —Preceding unsigned comment added by David255 (talk • contribs) 02:33, 2 December 2010 (UTC)

Question from ANI
I don't know why ANI is trying to figure it out:, but someone there would like to know if Birds are Dinosaurs? 108.121.139.247 (talk) 01:30, 2 December 2010 (UTC)
 * That's me. See below. ←Baseball Bugs What's up, Doc? carrots→ 01:47, 2 December 2010 (UTC)

Birds = Dinosaurs?
OK, I would like to hear some expert opinions on this. According to one of the articles, birds are "an extant clade of dinosaurs". I understand birds are considered to be descended from dinosaurs, but is that the same thing as saying "birds are dinosaurs"? I don't think so, and have said as much at List of common misconceptions, but I'm no expert in this area. Thanks for any help you can provide. ←Baseball Bugs What's up, Doc? carrots→ 01:47, 2 December 2010 (UTC)
 * See here Origin of birds and Origin of birds.  He  iro 01:51, 2 December 2010 (UTC)


 * Our Dinosaur article says: Consequently, in modern classification systems, birds are considered a type of dinosaur — the only group of which that survives until the present day.  I rather randomly examined the October 3 edit from the history and verified the sentence (as ungrammatical as it looks) has been in the article at least since then, so it isn't a recent addition to confound the discussion mentioned at AN/I.  Comet Tuttle (talk) 01:52, 2 December 2010 (UTC)


 * The Dinosaur intro goes on to talk about dinosaurs in the present tense, because of birds; but then later says: From the point of view of cladistics, birds are dinosaurs, but in ordinary speech the word "dinosaur" does not include birds. Additionally, referring to dinosaurs that are not birds as "non-avian dinosaurs" is cumbersome. For clarity, this article will use "dinosaur" as a synonym for "non-avian dinosaur". The term "non-avian dinosaur" will be used for emphasis as needed. Comet Tuttle (talk) 01:55, 2 December 2010 (UTC)


 * The origin of birds article begins by saying "The origin of birds is a contentious and central topic within evolutionary biology." It goes on to say that "most" scientists, etc., etc., which in my opinion is sufficient to keep the flat-out contention that "birds are dinosaurs" out of the misconceptions article. ←Baseball Bugs What's up, Doc? carrots→ 01:58, 2 December 2010 (UTC)


 * If one defines "dinosaurs" as members of superorder dinosauria (in class reptilia) and "birds" as members of class aves, then "birds" are not "dinosaurs". Note that this is a taxonomic argument (i.e. based on how we have historically assigned words), which is different from a cladistic argument.  A clade includes all of an organism's descendents, even if they aren't in the same taxanomic groups.  The evidence is quite good that birds are in the dinosaur clade, even though they aren't in the superorder dinosauria.  Personally, I would agree that "birds are not dinosaurs", even though "birds are descended from dinosaurs".  In other words, I think the linguistic / taxanomic arguments are more relevant in this case.  Dragons flight (talk) 02:01, 2 December 2010 (UTC)


 * Similarly, humans are not fish, bacteria, or rodents, even though humans are almost certainly descended from all of these. Dragons flight (talk) 02:15, 2 December 2010 (UTC)
 * I hate to nit-pick, but that's not exactly correct. Humans, fish, bacteria, and rodents all share a VERY distant common ancestor that was neither human, fish, bacteria, or rodent but had descendents that evolved into those four very different groups of organisms.  Evolution is confusing enough to people without muddying the waters like that... --- Medical geneticist (talk) 14:35, 2 December 2010 (UTC)
 * I hate to nit-pick your nit-pick, but didn't our ancestry spend quite a bit of time as fish, most famously as Tiktaalik or other sarcopterygii? --Sean 19:38, 2 December 2010 (UTC)
 * Precisely. Here's the issue: The misconceptions list states to contrary to popular misconception (e.g. in The Flintstones, B.C., Alley Oop, etc.) humans and dinosaurs did not co-exist. The editor called TheThomas added the statement that birds are dinosaurs, which contradicts the alleged misconception. The question is how to resolve it. Seems to me the real "misconception" is that humans interacted with "classic" dinosaur species depicted in those cartoons, e.g. brontosaurus, t-rex, etc. ←Baseball Bugs What's up, Doc? carrots→ 02:22, 2 December 2010 (UTC)
 * If you're just worried about the practical problem, how about saying "In fact, most dinosaurs died around 65 million years ago after the Chicxulub event, whereas the earliest Homo genus (humans) evolved between 2.3 and 2.4 million years ago. A few dinosaurs survived the Chicxulub event, and we call their descendents birds." Physchim62 (talk) 02:35, 2 December 2010 (UTC)
 * It isn't really correct to say that a taxonomic argument is different from a cladistics argument. Different biological taxonomy systems exist; see Biological classification.  Linnaean taxonomy has been around for close to 300 years, and is easily still the most widely used system, but the more modern cladistics is also a branch of taxonomy; see Phylogenetic taxonomy.  According to Linnaean taxonomy, birds are not dinosaurs, since aves and reptilia are different classes.  According to cladistics, birds are dinosaurs, because aves is a subclade of dinosauria (see the "Scientific classification" panel of Avialae).  Neither one is "correct" or "incorrect"; they're just different systems, each with their own advantages and disadvantages; see Cladistics and Cladistics.  Red Act (talk) 03:46, 2 December 2010 (UTC)
 * Red Act has the most important thing to remember here: These are all human-created classification systems. Hypothetically, we could trace the ancestry of all life back to the first self-replicating molecule, and then move forward from there, creating a branching tree of life which includes every individual living thing to ever live; including me, my neighbors cat, and one of the little bacteria in my colon.  How we classify those trillions and trillions of individual living things, how we group them, is ultimately done for our own convenience, and isn't indicative of anything more than that.  We're pretty sure that, if you take that robin in my front yard, and go backwards through its parents and back and back and back, you eventually get to a dinosaur of some kind.  Whether that means that the birds are dinosaurs or they are descendend from dinosaurs is a minor, and mostly moot issue.  We use whatever definition is most convenient or useful. -- Jayron  32  04:05, 2 December 2010 (UTC)
 * (edit conflict with Dragons flight) I will second this. This question is not a science question, but rather a question of linguistics.  There are two different (main) ways to classify organisms.  Under one of them, birds are a part of the group that also includes dinosaurs.  Under another, they do not.  A Cladist would say, without any irony, that there is no such thing as a "reptile".  There are Sauropsids, which include almost all of what are considered reptiles under the Linnaean system (including dinosaurs, but excluding a few, mostly extinct, "mammal like reptiles"), and also include birds.  Up a level, there are Amniotes, including all creatures considered to be reptiles, as well as mammals and birds.  Questions like this really highlight a flaw in the traditional Linnaean taxonomy: it's easy enough to define when creatures have evolved sufficiently to form a new group, but at what point does a creature cease to be a member of a group?  Why don't we consider birds to be reptiles?  Is it the feathers, the wings?  Birds still have many of the traits we assign to reptiles: an Amniotic egg, and scales.  To be fair, even mammals are still an awful lot like reptiles.  We've lost our scales, and we regulate our own body temperature, but we've still got the important amniotic egg, as well as the older backbone and 4 legs. Buddy431 (talk) 04:28, 2 December 2010 (UTC)
 * Of course, at that level of precision, it's no longer a "tree" of life, strictly speaking. It's a directed acyclic graph.  Now that I think about it, the usual (if not as precise as it might first appear) definition of species, in terms of being able to interbreed in such a way that the descendants breed true, may be specifically designed to allow the use of trees rather than DAGs whenever you look at the species level or coarser. --Trovatore (talk) 04:12, 2 December 2010 (UTC)


 * I would tend to quibble that "cladistics" is mostly an organizing principle and not really a taxonomy, since cladistics is about specifying relationships and is only rarely used to specify new names for things beyond "the clade of X". You could even accept cladistics as a starting point and define multiple different types of taxonomies on top of the relationship tree it generates.  All quibbles aside though, I understand your point. That said, I don't think even strident cladists would want to embrace a system where all descendants of X were given the same name as X. It isn't conducive to either common or scientific communication to have a nomeclature system that allows for humans to also be called rats, fish, and bacteria. For the same reason, I would tend to think that saying "birds are dinosaurs" actually makes communication more opaque rather than less, and should be disfavored. That's my opinion anyway. Dragons flight (talk) 04:18, 2 December 2010 (UTC)
 * Birds are more closely related to dinosaurs then anything else alive today, including crocodiles; the "next" most closely related species. A rough analogy might be that birds and dinosaurs are to crocodiles like what humans and chimps are to mice. There are very few major morphological differences between dinosaurs and birds, funnily enough a long tail is one of them, which is also a difference between humans and chimps. Vespine (talk) 04:51, 2 December 2010 (UTC)
 * What humans do you know that have long tails? Cuz I've never met one...  Do you have a long tail?  Weird.  -- Jayron  32  04:59, 2 December 2010 (UTC)
 * You know, all those chimps with tails. *face palm*... i was thinking monkeys when i wrote that.... I work in I.T., forgive me... lol. Vespine (talk) 05:21, 2 December 2010 (UTC)

clade n. A group of animals or other organisms derived from a common ancestor species. The clade Dinosauria includes all dinosaurs as well as birds, which are descended from the dinosaurs. I think the linguistic argument that has arisen would be avoided if the definition were rephrased: clade n. A grouping of animals... Cuddlyable3 (talk) 10:34, 2 December 2010 (UTC) updated


 * Birds are dinosaurs in the same way that humans are monkeys. Wnt (talk) 11:41, 2 December 2010 (UTC)


 * No, birds are dinosaurs in the same sense that humans are primates. Matt Deres (talk) 14:52, 2 December 2010 (UTC)


 * The issue seems to center on how broadly the term "dinosaur" is used or perceived. It looks like we've got a misconception within a misconception. The average citizen has been told over and over that "dinosaurs went extinct 65 million years ago." That statement appears to be an oversimplification of the situation. When people think of "dinosaurs", and of the fantasy of early hominids interacting with them, they think of T-rex and Brontosaurus and like that; not birds. ←Baseball Bugs What's up, Doc? carrots→ 15:04, 2 December 2010 (UTC)
 * The word "dinosaur" was coined to describe ancient very large animals discovered as fossils. Birds are not "terrible lizards" - they are birds.  The later use of the word "dinosaur" by scientists does not alter the fact that the word is in practice used, by most people most of the time, in a sense very close to that originally intended.  Ghmyrtle (talk) 15:14, 2 December 2010 (UTC)
 * Good point. So perhaps the root issue of the misconception-within-the-misconception is a dichotomy between what the public thinks of as dinosaurs vs. what the scientists think of as dinosaurs. That opens another can of worms. ←Baseball Bugs What's up, Doc? carrots→ 15:20, 2 December 2010 (UTC)
 * And to further muddy the waters, according to Mammal our own mammalian ancestors were indeed around during the dinosaur age. ←Baseball Bugs What's up, Doc? carrots→ 15:23, 2 December 2010 (UTC)
 * Perhaps, but homo sapiens weren't. Birds were actually around during the late cretaceous as well (though theories exist they evolved twice etc.), so if birds aren't dinosaurs then all the dinosaurs did go extinct at KT. Chipmunkdavis (talk) 16:34, 2 December 2010 (UTC)
 * Trying to factor in what the average citizen thinks is a little pointless. The average citizen thinks that pterosaurs were dinosaurs. The average citizen thinks that ichthyosaurs were dinosaurs. The average citizen thinks a lot of things that are outdated, inaccurate, unbalanced, or just plain crazy. Matt Deres (talk) 17:23, 2 December 2010 (UTC)
 * But ... Until recently* the word "dinosaur" had no scientific definition! It was a word entirely for average citizens. Until recently, some sources would include pterosaurs and/or ichthyosaurs and others wouldn't and neither view was more "correct" than the other.  Sure, most sources agreed that anything from Saurischia or Ornithischia could be called a dinosaur, but other stuff from that time period would also be included in many definitions. It didn't help that Saurischia and Ornithischia were not thought (at the time) to be closely related, so the whole thing was considered to be too arbitrary and contrived for formal use.
 * Even definitions that discounted pterosaurs or ichthyosaurs often wouldn't do so in a satisfying way, resorting to even more arbitrary qualifiers like "ground based" or "non-flying".
 * Later when it was realized that Saurishcia and Ornithischia were closely related they were able to come up with an actual scientific definition of "dinosaur" that included most of the animals everyone "knew" were dinosaurs.
 * So, don't criticize too harshly people still using the informal, layman's definition of the term. The layman's version came long before the scientific version.
 * * The 90s still count as "recently", right?
 * APL (talk) 17:58, 2 December 2010 (UTC)
 * I hope so. :( Keep in mind this has to do with "common misconceptions". Obviously, paleontologists are going to know the details of the current theories. The general public is not necessarily so well informed. The goal here is to try to come up with a better way to deal with the "misconception" that humans and dinosaurs interacted. A major part of that is defining just what a "dinosaur" actually is. ←Baseball Bugs What's up, Doc? carrots→ 18:02, 2 December 2010 (UTC)


 * This is not a unique situation and we already have words to describe it. If we are talking about the monophyly of dinosaurs, then birds are dinosaurs.  If we are talking about the paraphyly of dinosaurs, then birds are not dinosaurs.  In official taxonomies, we are usually use the paraphyly, but in casual conversation we sometimes are talking about a monophyly.  The same is true of whales and dolphins.  The monophyly of even-toed ungulates includes hoofed mammals and whales and dolphins, whereas the paraphyly of even-toed ungulates only includes the hoofed mammals.  Going even farther back, you could do the same humans and their fish ansestors. --—Arctic Gnome (talk • contribs) 23:54, 3 December 2010 (UTC)

Draft
It's much warmer inside my house than outside. So, I expected that opening the windows would cause the air inside to blow out, because the warm air inside should be at a higher pressure. But instead, I get a draft coming from the outside. What gives? 74.15.138.27 (talk) 05:57, 2 December 2010 (UTC)
 * If you heat air in a fixed volume the pressure goes up, but that doesn't mean that warmer air is inherently at a higher pressure. The difference in pressure inside and out isn't going to be related to the temperature difference.  Instead it's going to depend on what the weather is doing outside (for example if the wind is blowing toward your window). 24.98.193.82 (talk) 06:04, 2 December 2010 (UTC)
 * To expand on 24.98's answer a bit; since your house is not perfectly airtight, it is likely at the same pressure as the outside, though at a different temperature. If you want to cool your house efficiently by opening the windows, your best bet is to open two windows on opposite sides of the room; this will allow for the air to move through your house; such that the cooler air can enter and the warmer air can escape.  Placing an electric fan in the window will speed the process.  -- Jayron  32  06:08, 2 December 2010 (UTC)
 * If you don't want a through-house draft, then opening a window at the top and bottom of the room is fairly effective at setting up internal-external convection currents. This is how sash windows work, see the bottom of that article. CS Miller (talk) 06:51, 2 December 2010 (UTC)
 * The reason you get a draft is the Chimney effect. The warm air inside the house is lighter than the cold air. So if you open a window at the bottom, you let cold air enter the house, and the warm air rises and exits through openings at the top (attics are usually ventilated). Ariel. (talk) 08:10, 2 December 2010 (UTC)
 * The draught flowing into the OP's house must be counteracted by an equal draught flowing out otherwise the house would explode. The two air flows may simply be through the lower and upper parts repectively of the window opening. Cuddlyable3 (talk) 10:06, 2 December 2010 (UTC)

Thanks. 74.15.138.27 (talk) 15:45, 2 December 2010 (UTC)

Evolution of the wavefunction
If you knew the current wavefunctions in a system, is it possible to determine the future wavefunctions? The time evolution of the wavefunction is deterministic in an isolated system BUT that does not account for wavefunction collapse - Is wavefunction collapse deterministic or stochastic, and does that mean that it is possible or not to determine the future wavefunctions with certainty? 220.253.217.130 (talk) 10:52, 2 December 2010 (UTC)

Many scientists would claim that there is no such thing as wavefunction collapse, since any "measurement" (i.e. interaction) can itself be described by deterministic wave function evolution. See many worlds interpretation. Obviousely, any measurement of an isolated system is an interaction with the outside world and thus, the system is no longer isolated. 157.193.175.207 (talk) 12:25, 2 December 2010 (UTC)


 * The outcome of a measurement is not deterministic, and this is pretty much true across the various QM interpretations except for hidden variable theories. When you make a measurement, the probability of which value the wavefunction will collapse to is determined by the value of the wavefunction, but the outcome is still stochastic.  In terms of quantum decoherence, you become entangled in the state of what you're observing (which happens in a deterministic way) so that your wavefunction is a combination of all the different possible outcomes of the measurement.  However, only one of those "you"s is the "you" that you experience, and you can't tell which one that's going to be, so in that sense it's still not deterministic.  In other words, how the possible worlds will branch out is determined, but not which branch you'll seem to take. Rckrone (talk) 14:41, 2 December 2010 (UTC)

Can you safely drink rusty water?
Na, I'm not planning on doing it. This comes from a discussion I was having with someone yesterday about Irn Bru. He asserted that Irn Bru was originally just water that had sat in a vat with an iron girder in the bottom for a few weeks, sugared, carbonated and bottled (which is, I believe is a commonly held, albeit incorrect belief). Drinking rusty water (basically a suspension of iron(III) oxide, right?) as a regular beverage would make you rather sick, wouldn't it? --Kurt Shaped Box (talk) 12:12, 2 December 2010 (UTC)


 * Why would it make you sick? Iron poisoning is possible I guess, but iron oxide does not absorb very well in the body. Ariel. (talk) 12:16, 2 December 2010 (UTC)


 * Well water is known for being relatively highly mineralized, often with an "iron" taste, but I don't know that it's much of an issue. The issue with any water source is the possible presence of dangerous bacteria. ←Baseball Bugs What's up, Doc? carrots→ 15:17, 2 December 2010 (UTC)


 * Rust itself is pretty harmless, I believe, but may be associated with other contaminants that are not. There are many possible issues other than bacteria:  arsenic, lead, PCBs, etc, etc. Looie496 (talk) 18:17, 2 December 2010 (UTC)


 * I doubt your friend's assertion, though, as iron has a rather unpleasant taste and smell. I believe that's what you taste in blood or marrow, and most people don't like the taste of those much. StuRat (talk) 05:19, 4 December 2010 (UTC)

Objective scientific evidence for PMS?
What verified scientific evidence is there that pre-menstrual tension actually exists objectively? I ask because firstly, I get all the symptoms listed here http://www.womenshealth.gov/faq/premenstrual-syndrome.cfm#c except the second one, but I'm a man. Secondly, isnt expression of irritability because the behavioural standards expected of women in office etc situations are more indulgent that those expected of other men - men get just as irritated but have to bottle it up? Thanks 92.24.186.163 (talk) 17:39, 2 December 2010 (UTC)


 * You feel intense bloating, pain, cramping, and resultant irritation on a regularly monthly pattern, as a man? You really ought to see your doctor about that, if so. --Mr.98 (talk) 00:24, 3 December 2010 (UTC)
 * Yes, although not just monthly. I don't think the physical pain or cramping is considered part of pre-mentrual tension. 92.29.114.35 (talk) 11:45, 3 December 2010 (UTC)
 * Do you have a female significant other whose cycle your symptoms coincide with? Possibly you're feeling sympathy pains - although in the more general sense, not the specific case (pregnancy) covered by the article. It need not be a SO in the usual sense either - my wife claims ( WP:OR, not WP:RS ) that her twin brother used to feel some symptoms each month just before she got her period. 124.169.215.32 (talk) 01:23, 3 December 2010 (UTC)


 * And where on earth did the OP get the idea that "the behavioural standards expected of women in office etc situations are more lax that those expected of men"? Surely the opposite is true. All sorts of extra demands are made of women, and not just in offices. Men have much greater leeway to behave aggressively, callously, selfishly, precipitately, and irresponsibly; they are not expected to display very much tact or sympathy; they are never expected to make themselves "available" in an altruistic, motherly fashion. The average male personality would, in a female body, invariably lead to a diagnosis of "bitchy", "crazy", or "stupid". But perhaps this is off-topic. L ANTZY T ALK 01:40, 3 December 2010 (UTC)
 * I've countless times witnessed women being treated favourably and indulgently by men, compared with the standards they expect of other men. The most macho men are the worst at this. Its part of the tradition of male chivalry to women I suppose. For example Silvio_Berlusconi. 92.29.114.35 (talk) 10:58, 3 December 2010 (UTC)

Nobody read PMS then? 92.29.114.35 (talk) 11:00, 3 December 2010 (UTC)

Intelligent prey
Pigs are far more intelligent than dogs and cats, but to eat them is acceptable, whereas dog and cat meat is contraband in many places. What is the most intelligent animal that is regularly eaten, either by humans or by other animals? By "regularly" I mean that being eaten, or almost being eaten, is a part of its daily routine. L ANTZY T ALK 19:49, 2 December 2010 (UTC)


 * Pigs are not an acceptable source of meat in many places: see Kosher and Islamic dietary laws. On the flip side of the coin, dogs, and to a lesser extent cats, are an acceptable source of meat in some areas: see Dog meat and Cat meat.  What you consider an acceptable and unacceptable diet is not universally held. Buddy431 (talk) 19:58, 2 December 2010 (UTC)


 * That's true, but I don't think Jews and Muslims object to pig-eating on ethical grounds. They regard pigs as unclean, not as sentient pink friends. L ANTZY T ALK 20:11, 2 December 2010 (UTC)


 * Probably whale. Looie496 (talk) 20:01, 2 December 2010 (UTC)


 * Agreed. StuRat (talk) 03:57, 3 December 2010 (UTC)


 * Monkey is eaten in many parts of the world. See this oddly-titled National Geographic article, New Monkey Species Discovered, Then Eaten.  (Notably, this article has an addendum that addresses the cultural and ethical issues about meat, bushmeat, and defining which animals are "acceptable" to eat).  I will point out that there is no authoritative "ranking" of intelligence amongst the animal world - classifying a food-animal as "intelligent" or not depends entirely on various definitions of intelligence.  Nimur (talk) 20:02, 2 December 2010 (UTC)


 * An intelligent prey? A pig that wants to be eaten --Aspro (talk) 20:07, 2 December 2010 (UTC)


 * Of the most commonly-eaten animals (cattle, lambs, pigs, etc.), pigs are surely the most intelligent. In the less-commonly-but-not-too-uncommonly-eaten category, I'd say octopus.  Wiki Dao  &#9775;  (talk)  20:13, 2 December 2010 (UTC)


 * That National Geographic blog post from 2010 is eerily similar to this Onion article from 2005. -- BenRG (talk) 23:01, 2 December 2010 (UTC)


 * It has nothing to do with intelligence, but rather with friendliness to humans. No animals are intelligent enough for intelligence to make any difference, but the emotional relationship to humans does matter. Ariel. (talk) 21:15, 2 December 2010 (UTC)


 * Make any difference to whom? I know people who definitely wouldn't eat animals they thought were as intelligence as pigs or even cuttlefish. --Mr.98 (talk) 00:33, 3 December 2010 (UTC)


 * Those people are not doing that based on intelligence of the animal, but rather things like ability to feel pain, or that they don't think it's right to eat animals at all. Ariel. (talk) 02:01, 3 December 2010 (UTC)


 * There's many other cultural factors besides intelligence. Muslims don't eat non-marine carnivores. I believe other people avoid carnivores based on the idea that they accumulate toxins because they are higher on the food chain. Also, dogs, cats, and horses have a companion status much more than other animals, which my explain why most cultures don't regularly consume them. Similarity to us is another big factor culturally. Intelligent non mammals dont get the same status for the purpose of eating them and experimenting on them as mammals, even if they are more intelligent than many mammals. Apes, monkies, and other simians also get a higher level of that respect in most cultures simply based on their perceived similarity to us. Roberto75780 (talk) 00:57, 3 December 2010 (UTC)


 * Yes, I imagine we consider factors other than intelligence when deciding which animals to eat. Succulence, for instance. If cognitive powers were the only relevant factor, I suppose Ariel Sharon and Terri Schiavo would be regarded as foodstuffs. Anyway, I was more interested in looking at it from the animal's perspective. I'm not so interested in our obligation towards intelligent lifeforms, I'm interested in the usefulness of intelligence to its possessor. I'm curious whether intelligence always coincides with the ability not to get eaten, in which case predators would always be more intelligent than prey. That's why I'm less interested in the animals humans eat than in the animals animals eat. Humans can eat anything, and probably will. But if there were a highly intelligent species being preyed upon (with great regularity) by a less intelligent species, that would be very interesting. Are there any instances of that in nature? L ANTZY T ALK 01:21, 3 December 2010 (UTC)


 * Hmmm... such as humans being consumed by viruses, bacteria, and other microbes? ←Baseball Bugs What's up, Doc? carrots→ 01:36, 3 December 2010 (UTC)


 * That's true, but somehow it doesn't really rattle my faith in intelligence. Perhaps it should. You're right, parasites regularly prey upon much more intelligent organisms. It's just that this kind of predation isn't quite as striking as if, say, orangutans were to be eaten by butterflies. L ANTZY T ALK 01:47, 3 December 2010 (UTC)


 * Sharks eat dolphins (or try to). Intelligence is not a way to rank who eats who. Ariel. (talk) 02:01, 3 December 2010 (UTC)


 * If you had a disabled ape and an undending supply of butterflies that had developed a taste for primate flesh, that orang might indeed be in trouble. Every living thing gets eaten eventually, or "recycled" if you will. No matter how smart pigs are, in general they haven't gotten smart enough to figure out how to unlock the pens they're kept in. The proscription against eating things like hogs and bottom-feeding marine creatures has to do at least in part with the idea that they are "unclean" because they are scavengers, and there is some reasonable basis for that argument, at least in older times when nothing was known about biochemistry other than what could be observed with the naked eye. ←Baseball Bugs What's up, Doc? carrots→ 02:14, 3 December 2010 (UTC)


 * It's an interesting notion, a discrepancy on average in intelligence between predator and prey. Our Predation article does not say directly, but has some interesting "food for thought" along those lines.


 * On the separate point of animal consumption by humans: domesticated animals tend to be selected and bred for docility, which can resemble unintelligence. Wiki Dao  &#9775;  (talk)  03:59, 3 December 2010 (UTC)


 * A bird spider's diet includes birds and mice, both of which I assume to be more intelligent. StuRat (talk) 03:57, 3 December 2010 (UTC)


 * There's a related question I had about the intelligence of prey, which I think I've now figured out. It always seemed odd to me that large herds of prey animals (say antelope) will run from a small pack of predators instead of turning and attacking them together. They could easily defeat the predators, if they worked together, so why don't they ? My conclusion was that prey animals rely on predators to weed out the weak and thus allow only the strongest genes to get passed on. Thus, any herd which learned how to defend itself from predators would find it's genetic health deteriorate and might eventually disappear, leaving behind the other herds that didn't defend themselves. StuRat (talk) 04:03, 3 December 2010 (UTC)


 * I think we're throwing around words like "intelligence" rather loosely. These animals aren't doing calculus or reading Sun Tzu here.  When we're comparing the intelligence of pigs to antelopes to chihuahuas, its on an entirely different scale than human intelligence.  One must take care not to anthropomorphize non-human animals to the point of assigning human motivation to them or attempting to justify behavior on human standards.  The reason antelopes don't turn and attack predators is likely because they lack the faculties to strategize in that manner.  Animal group behavior can be complex and still the animals can lack individual intelligence; witness ant colonies for example.  "Turn and run from threat" is a hardwired response for even some of the least intelligent animals out there; "organize an effective counteroffensive" is somewhat more nuanced strategy usually requiring attendence of a military college of some sort.  -- Jayron  32  07:27, 3 December 2010 (UTC)


 * Many such herd animals already know how to fight with each other, it's just a matter of turning that instinct against the predators. The same head down, straight on attack that works against another antelope would also work against the predators, if the entire herd did it.  There's also the problem, though, that the first animal to defend the herd like that would be taking an increased risk, which would mainly benefit others, so his genes would be less likely to be passed on than the coward's. StuRat (talk) 05:07, 4 December 2010 (UTC)


 * AFAIK, some corvid species actually do launch coordinated counterattacks against their predators, working together to distract, harass, drive away and/or kill (if the opportunity arises). Stuff like creating a noisy distraction in front, whilst other birds outflank and attack from the rear. --Kurt Shaped Box (talk) 07:43, 3 December 2010 (UTC)


 * Yes, see animal mobbing behavior. While many birds perform this behaviour, crows are the standard example and it's probably no coincidence that they're also widely regarded as being extremely intelligent. Matt Deres (talk) 14:40, 3 December 2010 (UTC)


 * What about parrots? Some species (the African Grey Parrot or the large Macaws and Cockatoos for example) are thought to have a level of intelligence comparable to the non-human great apes - yet they often fall prey to various raptors. --Kurt Shaped Box (talk) 07:18, 3 December 2010 (UTC)


 * A Grey Parrot might have the intelligence of a child age 3-5, but honestly, that level of intelligence is not a decisive advantage in preventing you from getting eaten. If the parrot had the intelligence of an adult human and could figure out how to use tools extensively that would be a huge help, but even some humans get eaten by wild animals from time to time.  Googlemeister (talk) 14:47, 3 December 2010 (UTC)


 * If the parrot had the intelligence of a human, it would recruit a bunch of other parrots from the flock, find out where the predator lived was and 'do' it whilst it was sleeping. --Kurt Shaped Box (talk) 18:02, 3 December 2010 (UTC)


 * I thought people avoided eating dogs, cats, foxes, crows and other carnovores because the meat did not taste very nice. Although dogs are eaten in Thailand (?). 92.29.114.35 (talk) 11:10, 3 December 2010 (UTC)


 * I always thought that it was more that case that animals which turn vegetable matter into meat directly are more efficient to farm than an animal (say, a dog) which converts meat into meat. If you wanted to farm dogs for meat for instance, you'd need to farm something else (cows, for example) to provide meat to feed the dogs. I think it works out that you'd need a larger number of cows to feed the dogs to feed the people than the number of cows needed to feed the people directly... --Kurt Shaped Box (talk) 11:38, 3 December 2010 (UTC)


 * Yes, you would need far more cows to feed dogs to feed people, maybe 10X as much, due to the inefficiency of our digestive systems. An exception to that problem is if the predators can find their own food.  For example, if cats are finding rodents on their own, then eating them doesn't require you to raise rodents for them.  Another exception might be if you supply them with food that people would find unacceptable, like roadkill.  However, there's another problem in that toxins tend to accumulate in predators, with apex predator's being the worst.  That's one reason why there's more mercury in some fish than others. StuRat (talk) 05:14, 4 December 2010 (UTC)


 * I recall reading that crow meat tastes horrible. And despite foxes being regularly hunted, there's never been any reports of them being eaten, as other hunted animals such as deer hares or rabbits are. People eat various animals in the far est for 'medicinal' reasons rather than enjoying the taste. 92.29.114.35 (talk) 11:56, 3 December 2010 (UTC)


 * I think that's a general feature of scavengers, they taste like the decomposing food they eat. They don't mind the toxins they absorb, but we do. StuRat (talk) 19:29, 4 December 2010 (UTC)

Split down the middle
Often people have survived the loss of a large portion of their brain, and there is also a procedure whereby the corpus callosum is severed, separating the two hemispheres. So what if a person's brain were completely split, all the way down to the spine, but left otherwise intact? Would the brain become, in effect, two brains? (Obviously, assuming a form of neurosurgery far beyond what we have today.) Without any means of interface, how could the hemispheres not diverge and become two distinct individuals sharing a skull? To continue the mad science, suppose we carry on down the spine, splitting the organism into two pieces, Mr. Right and Mr. Left. (Never mind the heartless Mr. Right - we'd have a cloned implant on ice.) Is it theoretically possible, given the general symmetry of chordates, to split one lengthwise into two living, functioning halves? Or is our symmetry specious and superficial? L ANTZY T ALK 20:07, 2 December 2010 (UTC)


 * I'm not sure where you're going with wanting to split even the spinal column, but you can do just fine (as an "individual" person) with only half a brain (with of course some impairment – though some people have been born with only one hemisphere, and they do much better than the surgical patients). And of course you may also find our Split-brain article of interest.  Wiki Dao  &#9775;  (talk)  20:35, 2 December 2010 (UTC)

Such a person would be completely, or almost completely, paralyzed. The great majority of the motor outputs from the brain control the opposite side of the body, and the crossings (decussations) occur inside the brain, in the midbrain and brainstem. Looie496 (talk) 20:37, 2 December 2010 (UTC)


 * Our article Hemispherectomy touches on Looie496's statement. Comet Tuttle (talk) 21:01, 2 December 2010 (UTC)
 * It is stunning that you can remove half the brain with little ill effect. :o --Sean 18:43, 3 December 2010 (UTC)

So, as one would expect, bisecting the lower brain is quite a different matter than splitting the cerebrum. It looks like it will have to remain just a beautiful dream... Of course, theoretically, the decussations could be untangled and rewired. What if we try something a little less ambitious, and just cut down through the brain to where the decussations begin? L ANTZY T ALK 21:04, 2 December 2010 (UTC)
 * decussation n. A crossing or intersection of lines etc. so as to form an X-shape. Cuddlyable3 (talk) 22:50, 2 December 2010 (UTC)

Forces in space
My friend told me that if you push against something in space, you will move away much more than you would on Earth. If this is true, is it something to do with Newton's Third Law? Or Momentum? I'd like this information to use it in something I'm working on. Thanks a lot! -- Editor510  drop us a line, mate  21:44, 2 December 2010 (UTC)
 * I think I've sussed it, but I'm looking for confirmation, here. Is it that in space, you and another object would be exactly the same weight, thus making the Third Law kick in on a much larger scale than it does in gravity equivalent to 1 Earth?-- Editor510  drop us a line, mate  21:55, 2 December 2010 (UTC)
 * No, it's not weight (not directly). The difference is whether you can brace against the earth, and transfer the reaction force there.  If you can brace, you can move something without moving yourself (relative to the earth).  In space, the third law still applies, but you have nowhere to put the momentum, so it must be you that goes flying.  --Tardis (talk) 21:59, 2 December 2010 (UTC)
 * Oh, I get it. So you absorb all the momentum the Earth would usually absorb? That makes sense! Thank you!-- Editor510  drop us a line, mate  22:02, 2 December 2010 (UTC)
 * Editor510 you still need to get the terms right. You and another object usually have different masses which never change. On Earth the masses are experienced as weights. In outer space there is no weight. If you and the object are both standing on a perfectly slippery ice rink, then Newton's 3rd Law operates similarly to being in space. If you push the object, both you and the object start moving apart. Cuddlyable3 (talk) 22:42, 2 December 2010 (UTC)
 * Exactly, and for example: Ever see a hockey fight? They tend to grab the jersey of their opponent with one hand and punch with the other. If they did not do so, half (roughly) of the energy of the punch would be used up in pushing the punch-er backwards. Same kind of thing would happen in space. Arakunem Talk 16:51, 3 December 2010 (UTC)
 * Exactly, and for example: Ever see a hockey fight? They tend to grab the jersey of their opponent with one hand and punch with the other. If they did not do so, half (roughly) of the energy of the punch would be used up in pushing the punch-er backwards. Same kind of thing would happen in space. Arakunem Talk 16:51, 3 December 2010 (UTC)