Wikipedia:Reference desk/Science: Difference between revisions
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:Not reliably -- people don't smell any different when they're awake than when they're asleep, and the one thing on which dogs beat people hands-down is perceiving smells which are undetectable to humans. So if someone is really good at pretending he/she is asleep (like me -- I have very long eyelashes, so I can pretend to have my eyes closed when in fact they're slightly open), then he/she can fool a dog just as easily as a human. [[Special:Contributions/2601:646:8E01:7E0B:E957:E363:9DD1:1743|2601:646:8E01:7E0B:E957:E363:9DD1:1743]] ([[User talk:2601:646:8E01:7E0B:E957:E363:9DD1:1743|talk]]) 06:36, 11 June 2017 (UTC) |
:Not reliably -- people don't smell any different when they're awake than when they're asleep, and the one thing on which dogs beat people hands-down is perceiving smells which are undetectable to humans. So if someone is really good at pretending he/she is asleep (like me -- I have very long eyelashes, so I can pretend to have my eyes closed when in fact they're slightly open), then he/she can fool a dog just as easily as a human. [[Special:Contributions/2601:646:8E01:7E0B:E957:E363:9DD1:1743|2601:646:8E01:7E0B:E957:E363:9DD1:1743]] ([[User talk:2601:646:8E01:7E0B:E957:E363:9DD1:1743|talk]]) 06:36, 11 June 2017 (UTC) |
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::How do you know? ←[[User:Baseball Bugs|Baseball Bugs]] <sup>''[[User talk:Baseball Bugs|What's up, Doc?]]''</sup> [[Special:Contributions/Baseball_Bugs|carrots]]→ 07:07, 11 June 2017 (UTC) |
::How do you know? ←[[User:Baseball Bugs|Baseball Bugs]] <sup>''[[User talk:Baseball Bugs|What's up, Doc?]]''</sup> [[Special:Contributions/Baseball_Bugs|carrots]]→ 07:07, 11 June 2017 (UTC) |
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:::How do ''you'' know if people smell different when they're asleep? [[Special:Contributions/2601:646:8E01:7E0B:E957:E363:9DD1:1743|2601:646:8E01:7E0B:E957:E363:9DD1:1743]] ([[User talk:2601:646:8E01:7E0B:E957:E363:9DD1:1743|talk]]) 07:57, 11 June 2017 (UTC) |
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== Using numbers to make something more believable == |
== Using numbers to make something more believable == |
Revision as of 07:57, 11 June 2017
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June 7
21st century inventions
My 11-year-old cousin said this about inventions: "In the 21st century, apparently nobody created any ***new*** inventions, they just made improved versions of things that already existed, like better computers and cellphones."
So, are there any ***new*** inventions created in the 21st century? Timeline of historic inventions does not seem to help, it only has inventions up until the 1990s. --Daniel Carrero (talk) 07:13, 7 June 2017 (UTC)
- Superjumbo jets? The design was finalized in early 2001 barely beating the deadline (just like Dracula 2000) Sagittarian Milky Way (talk) 07:31, 7 June 2017 (UTC)
- That's hardly a "new invention". It's a good question. Maybe the USB stick and the Segway PT just about qualify.--Shantavira|feed me 08:11, 7 June 2017 (UTC)
- Both are 20th century inventions. Sagittarian Milky Way (talk) 09:52, 7 June 2017 (UTC)
- If you search for something like 'recent inventions' you should get lots. I think you have a bit of a problem because you're looking I think for some earth shattering or widespread thing whereas it takes a while for anything to be adopted widely and we have only had 17 years so far of the 21st century. And your standards are very high if you consider something like a modern smartphone as just a better celllphone or the machine reasoning being used nowadays as simply better computers. Dmcq (talk) 08:16, 7 June 2017 (UTC)
- That's hardly a "new invention". It's a good question. Maybe the USB stick and the Segway PT just about qualify.--Shantavira|feed me 08:11, 7 June 2017 (UTC)
- It is increasingly hard to make a "big, obvious, new invention". We're still inventing, but they're often things that are either detailed or so sophisticated they're hard to explain. Yes, "better computers" is one of them - but "computer" is such a broad field that there are massive inventions within it, with large consequences, yet they're still just "some more computer stuff". Big Data is one of these with a huge impact on our daily life - the TV show Person of Interest is one. Silicon micro-machined accelerometers have been around for some time (at a cost of $10ks), but now they cost less than $1 and allow phone cameras that know which way is up, or when you shake them, or quadcopter drones that can hover and pilot themselves (and Segways too). When were these "invented"? SpaceX has a really reusable first stage rocket - yet was this invented by 1930s sci-fi? Except that now it works. Same with self-driving cars, or even just electric sports cars, with real performance.
- Some things are whole new inventions, but aren't visible as products yet. Quantum computers are one - what are they for yet? Graphene another.
- We're not far into the 21st century yet, and inventions do take time to go from idea, to invention, to product, to cheap commonplace product. Andy Dingley (talk) 09:10, 7 June 2017 (UTC)
- Tweeting? Social networks? Sagittarian Milky Way (talk) 09:52, 7 June 2017 (UTC)
- Netflix / Hulu streaming services? Google Maps? Facebook? Skype? Twitter? I'd argue XPoint memory is pretty new since it is based on an entirely different technology than previous computer memory. Andy mentions big data, one of the major applications of that is automated online recommender systems, which while not entirely 21st century, didn't really become useful till the 21st century. A similar example is facial recognition software. How about the recent (if still crude) invention of sight restoring retinal implants? Dragons flight (talk) 10:15, 7 June 2017 (UTC)
- I might argue that Gravitational-wave astronomy is a 21st century invention. Although, like virtually all human endeavours, it's an elaboration of previously known theory and apparatus, it only became a reality when more than one detector could observe the same astronomical phenomenon and thus narrow down its source (though not pin-point it, which will need three such detectors). {The poster formerly known as 87.81.230.195} 2.217.208.38 (talk) 10:47, 7 June 2017 (UTC)
- Not invented in 21c though! Graeme Bartlett (talk) 11:46, 7 June 2017 (UTC)
- Most every invention is derived from something prior. ←Baseball Bugs What's up, Doc? carrots→ 11:15, 7 June 2017 (UTC)
- Self-balancing scooter (which I call a hoverboard) Graeme Bartlett (talk) 11:46, 7 June 2017 (UTC)
- When was Wikipedia invented? ←Baseball Bugs What's up, Doc? carrots→ 11:49, 7 June 2017 (UTC)
- Is it not a better version of print encyclopaedias? ^_^ Double sharp (talk) 15:20, 7 June 2017 (UTC)
- A wiki could be called an invention but that was in the 20th century. PrimeHunter (talk) 20:26, 7 June 2017 (UTC)
- Is it not a better version of print encyclopaedias? ^_^ Double sharp (talk) 15:20, 7 June 2017 (UTC)
I'd say: a) exoplanet detection (or if you demand a gadget, a satellite like Kepler). You can quibble the first few were a few years early and the rest of the many detection methods were just "improved methods", but it seems a stretch. b) self-driving cars - if you say they're a refinement on the car, then wasn't a car a refinement on the steam car or the horse and carriage? c) Emdrive will absolutely count if it continues to come out looking real; there are some fascinating Arxiv papers, far beyond my capabilities, from Qingdi Wang in Unruh's group that seem, to my untrained eye, to provide some theoretical underpinnings. Wnt (talk) 18:58, 7 June 2017 (UTC)
- Thanks for the answer so far! I guess I'll have a talk with my cousin about how if we have standards unreasonably high, basically everything is "an improved version of something", and that in practice you actually managed to list quite a few "new" and important inventions. Personally I consider Wikipedia something "new" and important too, even though I see that it's technically an improved version of paper encyclopedias... and paper is an improved version of writing on stone or something. ;) --Daniel Carrero (talk) 19:32, 7 June 2017 (UTC)
- Wikipedia is a combination of Web 2.0 content sourcing from the users, C2 wiki software, Nupedia and eventually Diderot's encyclopedia. Andy Dingley (talk) 20:07, 7 June 2017 (UTC)
- I think AI experts consider AlphaGo to be so radically different from its predecessors as to be an entirely new invention. When the first Superintelligence compiles the history of its kind, it will identify some software invention, probably created between 2005 and 2020, as its seminal enabler. Some futurists think this SI will come into existence within the next 15 years. -Arch dude (talk) 20:15, 7 June 2017 (UTC)
- Ah, yes. Skynet. - Nunh-huh 23:35, 7 June 2017 (UTC)
- Skynet (Terminator) was activated in August, 1997, albeit in an alternate (and fictional) time-line. StuRat (talk) 03:53, 8 June 2017 (UTC)
- How about the glasses that allow the colorblind to see colors [1] ? (Do we have an article ?). StuRat (talk) 20:20, 7 June 2017 (UTC)
- Well, that's quite an opinion-based question, since any "invention" out there could easily be dismissed as an improved version of something else. A pitfire is "just" trapping thunder for longer burning time, flint is "just" on-demand thunder, etc. Do you have a semi-objective definition of "new"? TigraanClick here to contact me 08:16, 8 June 2017 (UTC)
Yawning
Biologically speaking, what is it about yawning that opens up the ears to sudden clarity (and louder)? not just on an airplane.Lihaas (talk) 09:39, 7 June 2017 (UTC)
- Yawning can open the Eustachian tubes, which equalizes the air pressure on each side of the eardrum, if it was unequal. (Most of the time it's already equal, in which case you won't notice the effect.) --69.159.63.238 (talk) 10:21, 7 June 2017 (UTC)
Calcium leaching - dietary risk
Some studies indicate that high protein intake can leach or otherwise interfere with calcium absorption / usage. The studies are stating that intake of dairy products with the intent of supplementing a person's calcium and preventing osteoporosis and other diseases is counter-productive. See here: https://www.theguardian.com/lifeandstyle/2003/dec/13/foodanddrink.weekend and here: http://ajcn.nutrition.org/content/89/5/1638S.full. However, is it accurate to say that the studies emphasize the risks of dairy products, but actually all animal proteins, such as meat, such be the focus? In other words, the findings support reducing consumption of meat in addition to dairy? Why does it appear that the reduction in dairy is emphasized (or over-emphasized)? --208.58.214.187 (talk) 10:38, 7 June 2017 (UTC)
- Science is supposed to be specific. Scientists may include overgeneralizing speculations in the Discussion, but I think that is intended for further research, not as a statement of fact. So, just because dairy products have been associated with some kind of risk doesn't mean any animal protein does as well. Lacto-ovo vegetarianism is the most common type of vegetarianism, because there are so many Indians in the world. In the United States, many vegetarian products include cheese. I suppose the producers assume that the consumers really like cheese. So, it's no wonder why vegetarianism is associated with and implicitly includes dairy products, and that scientific paper is criticizing that type of vegetarianism. 50.4.236.254 (talk) 11:51, 7 June 2017 (UTC)
Cambrian Explosion and the black holes.
I wonder if the recent report about colliding black holes could be used as a springboard to explain the Cambrian Explosion. <Did I say it right? :-)> This is a quote from Wikipedia[2]:
The long-running puzzlement about the appearance of the Cambrian fauna, seemingly abruptly, without precursor, centers on three key points: whether there really was a mass diversification of complex organisms over a relatively short period of time during the early Cambrian; what might have caused such rapid change...
The reason might be the coalescent black holes which generated gravitational waves that reached the Earth some 500M years ago. The original event must be assumed to have happened closer to Earth than any of the three events observed during the past year or so, thus generating a more powerful vibrations and bigger displacements of the space.
It is my understanding that in Pre-Cambrian all biota was confined to the oceans or other bodies of water. There was no real diversification. Modern phyla did not exist. However, all those primitive organisms had two strands of DNA in all probability. The distance between the strands is 3.4 Angström[3].
The descriptions of mutations are given here[4] and many include well known mechanisms considered mundane, however I think one mechanism is missing here: tunneling of electrons. This mechanism can be a factor if the distance between two strands of DNA is very small. During such a cataclysmic event the space deformation must have affected ALL organisms on Earth and certainly penetrated deep into the oceans. Shaking the DNA of each organism could have produced necessary tunneling of electrons because the various molecules were brought closer together. --AboutFace 22 (talk) 15:06, 7 June 2017 (UTC)
- The article Cambrian explosion has a big long list of possible causes. I see no reason why black holes should be invoked without at least a shred of evidence. Dmcq (talk) 16:34, 7 June 2017 (UTC)
- Gravitational waves are very very weak. That's why they are so difficult to detect. The first gravitational wave detected by LIGO was produced by a black hole merger 1.3 billion light years away and produced a movement on Earth of one part in 10^21. If it were a billion times closer, only 1.3 light years away (much closer than the nearest star), it would produce a movement a billion times larger, one part in 10^12. That is still extremely tiny; the entire Earth would change in diameter by about 0.01 millimeters. The 3.4 Angström distance you mention would be stretched to 3.4000000000034 Angströms, a change of less than a millionth of the diameter of a proton. This would have absolutely no effect on biological systems. To be close enough that the gravitational waves from the merger would produce a measurable biological effect, you would need to be so close to the black holes that the tidal forces would rip you apart before the merger happened. CodeTalker (talk) 18:35, 7 June 2017 (UTC)
- Nitpick:
1.3 light years away (much closer than the nearest star)
- well, the nearest star is 8 light-minutes away, and the next one is 4 light-years away which hardly qualifies as "much further" as astronomical distances go. TigraanClick here to contact me
- Nitpick:
- (edit conflict)(before I read CodeTalker's analysis above) It's an interesting theory, but there are much more likely explanations. Perhaps, if the event is repeated, we could observe the effects on our DNA (before we are superseded by a host of new species). Sometime in the distant future, scientists might take some DNA to a distant event to observe any effects, but meanwhile I cannot see how quantum tunnelling of electrons would change the molecules in a DNA sequence. Have you read any papers on the possible process? Dbfirs 18:43, 7 June 2017 (UTC)
- The "reasoning" here is of the type, "A is weird" and "B is weird" so "A and B must be related". It's no different from fallacious claims that quantum mechanics "explains" consciousness. There's certainly no plausible mechanism whereby gravitational waves could cause a directional change in animal evolution.
- Much more likely is the development of genes allowing bilateral creatures with heads ("worms") which were much more efficient grazers and hunters than the radial and organisms of the Vendian and Ediacaran fauna, and the arms race that resulted from this development. μηδείς (talk) 18:58, 7 June 2017 (UTC)
- In the phrase "radial and organisms", should I drop the 'and' or ask what you meant to follow it? —Tamfang (talk) 06:06, 8 June 2017 (UTC)
- Sorry, @Tamfang: I meant to say "radial and branched or plant-shaped". There's also snowball earth to look at. μηδείς (talk) 22:00, 8 June 2017 (UTC)
- In the phrase "radial and organisms", should I drop the 'and' or ask what you meant to follow it? —Tamfang (talk) 06:06, 8 June 2017 (UTC)
- Tunneling is fun, but it doesn't provide a method of directed mutation. So the mutation rate could have been increased by some weird astrophysical phenomenon (not necessarily by gravity, could be radiation from such holes) but surely periodic exposure of naturally radioactive sediments could also provide mutations, and on a much longer scale. Or evolution could turn up the rate, simply by reducing the amount of effort organisms put into keeping DNA fidelity. All those things happen randomly all the time in geologic terms. So if they couldn't 'break the logjam', neither could the holes. Whatever the reason was, it was NOT a single black hole merger. Wnt (talk) 19:03, 7 June 2017 (UTC)
@CodeTalker, An event that is a billion times closer than the one you postulated will produce a displacement more powerful not more powerful. --AboutFace 22 (talk) 20:34, 7 June 2017 (UTC)
- No, the displacement is linearly proportional to the inverse of the distance. See [5] which says
The amount of shift caused by a gravitational wave is due to its amplitude, not its energy. While the energy of gravitational waves follow the inverse square relation, the amplitude of gravitational waves follows the inverse distance relation. In other words, if we were half as far away from the merger we'd have seen four times the energy, but only twice the shift.
To be close enough that the gravitational waves from the merger would produce a measurable biological effect, you would need to be so close to the black holes that the tidal forces would rip you apart before the merger happened. This is a rather strange statement. I am talking about a displacement in a 1-3 Å --AboutFace 22 (talk) 20:48, 7 June 2017 (UTC)
- I'm not sure what you mean by "a displacement in a 1-3 Å". If you mean the separation of 3.4 Å is being reduced by 1 Å (to 2.4 Å), that's a displacement of more than one part in 4! To get that displacement, you would need to be less than 25 miles from the source of the gravitational waves, assuming the same magnitude of event as the one detected by LIGO. Not to mention that a displacement of one part in 4 would probably be a large enough disruption to destroy the Earth and every other planet in the solar system. CodeTalker (talk) 21:37, 7 June 2017 (UTC)
My argument has been defeated. This paper did it: [6]. Thanks. --AboutFace 22 (talk) 21:42, 7 June 2017 (UTC)
Original meaning of "corn" in corn flakes?
Since when exactly have corn flakes been made exclusively or at least predominantly from maize? And since when exactly have they been known as "corn flakes"? (Per John Harvey Kellogg § Breakfast cereals, they were originally known under the trademarks Granula and then Granola, but the alleged date of invention 1878 conflicts with the date 1894 given in Corn flakes § History.) My understanding is that maize only became a staple food in the US in the course of the 20th century, especially after WWII, which was the reason why Indian corn was shortened to corn and the word corn, which originally referred to any cereal grain as it still does in British English, came to refer solely to maize in American English. So the idea that corn in corn flakes referred to maize originally appears to be wrong. The first "corn flakes" at the end of the 19th century were made of wheat and later diverse types of cereals were used. However, I can't find details about the chronology, only vague and contradictory statements as pointed above, so I cannot be 100% sure that my suspicion is correct. --Florian Blaschke (talk) 17:19, 7 June 2017 (UTC)
- Interesting. I don't know. It's true that the corn flakes article says that the first flakes were made from wheat, but it doesn't say that the wheat flakes were marketed as "corn flakes"; it does note that they experimented with other grains. I'm not sure I'm convinced by your chronology as to when Americans started eating corn; do you have a source for that?
- As a side note, the terms maize and Indian corn, in vernacular American speech, both refer specifically to hard-shelled, deeply colored decorative varieties and not to the sort you eat. They are not really available to refer to sweet corn, though educated people can figure out what you mean, especially in the context of a technical report or something. --Trovatore (talk) 17:52, 7 June 2017 (UTC)
- Our article on what Americans think of when they hear "maize" seems to be at flint corn. --Trovatore (talk) 19:11, 7 June 2017 (UTC)
- Our article cites the original patent p1 p2, which includes the text "In carrying out my invention I use the material from which to produce my improved alimentary product wheat, which is preferably in its natural state, although it may be slightly pearled without affecting the desired result, barley or oats prepared by the removing of a portion of the outer husks, corn and other grains." From this it is clear that "corn" was not wheat, barley, or oats, and I assume, precariously, he meant Indian corn. Wnt (talk) 19:40, 7 June 2017 (UTC)
- European settlers had Sweet corn in 1779, a hundred years before the [1878 or maybe 1894] invention of corn flakes. [Dent corn]] was introduced in 1846 and quickly became popular, winning a prize at the 1893 World's Fair. Either of those are more likely candidates for eing in the first corn flakes than Flint corn. --Guy Macon (talk) 20:59, 7 June 2017 (UTC)
- It means maize and, for Kellogg's part in this, always did. He believed in a fairly novel (but not unique) manner for the time that whole grains were crucial to health (although his reasoning was as crazy as a bag of theosophists). In particular he saw the popular cooked, milled grain breakfasts of porridge or grits as being almost harmful. He was especially vituperative about hominy grits because they had the germ coat stripped off and even worse had been treated with alkali chemicals for nixtamalization. So he sought a breakfast food that was a whole grain, not cooked at the time of consumption, yet was milled by some process, so that he had a business from it. His answer was maize and corn flakes. Andy Dingley (talk) 22:43, 7 June 2017 (UTC)
- That's great. Do you have a source though? Articles already linked are very clear, as mentioned, that Kellog experimented with many grains, and that others before him specifically experimented with corn, but that the original "corn flakes" contained no "corn" as we'd call it today. Someguy1221 (talk) 22:50, 7 June 2017 (UTC)
- Thank you, Wnt and Guy. So the first corn flakes that were marketed as corn flakes (or even the corn flakes from the original patent, which I'm not sure were marketed under the term corn flakes already) had a mix of cereals, including but not limited to (nor even necessarily dominated by?) corn, and that's why they were called corn flakes? (Not sure about the content of current corn flakes.) I mean, again, the original "corn flakes" from 1894 were made of wheat and did not contain any corn, apparently (else I'd never questioned the meaning of corn in corn flakes in the first place!), but they weren't explicitly called corn flakes (also apparently), so they don't really matter (I guess).
- The text of the patent does indicate that by 1895, corn had already come to refer to maize in American English, as the author did not feel it necessary to specify Indian corn, and clearly meant a specific variety of grain. I grant that. I'm still confused by the text of the patent since it seems to say that just about any grain can be used (or a mixture?) – which is the point Andy is missing, as Someguy1221 correctly notes. (Maybe corn was simply the prototypical grain to use in Kellogg's mind, that's why he went for corn flakes even if in 1895 he still thought any type of grain was fine?) But then, I don't know from which point on the product was explicitly marketed as corn flakes. --Florian Blaschke (talk) 23:36, 7 June 2017 (UTC)
- I actually don't see anywhere in the linked articles that flakes made from grains other than corn were marketed as "corn flakes". It does say the first flakes were made from wheat, but not that they were sold as corn flakes. Or maybe I missed it? --Trovatore (talk) 23:41, 7 June 2017 (UTC)
- John's brother William was calling them "Corn Flakes" at least by 1906 [7]. John mentions the possibility of using corn in the original patent from 1895. I have not found a source to say whether John ever called them corn flakes, though that term does not appear in his patent. Someguy1221 (talk) 23:59, 7 June 2017 (UTC)
- I didn't interpret the rather confused sentence from the patent to mean that the corn flakes were necessarily a mix - I thought it was saying that the flakes could be made from this, that, or the other thing. The article on corn flakes mentions some things like Granula - my impression from both the patent and the article was that initially it was assumed that wheat would be the most successful thing to make flakes out of, and corn was a bit of an afterthought, but I don't know that. Wnt (talk) 07:27, 8 June 2017 (UTC)
- I actually don't see anywhere in the linked articles that flakes made from grains other than corn were marketed as "corn flakes". It does say the first flakes were made from wheat, but not that they were sold as corn flakes. Or maybe I missed it? --Trovatore (talk) 23:41, 7 June 2017 (UTC)
- Nothing offhand I'm afraid - it's in my pile of CrazyBooks, along with such classics as Personal Magnetism (which is mostly about diet, not electromagnetism). John Money, the sexologist, did a good recent (1980s) book on Kellogg though (coming at it from the "bland food cures masturbation" angle) and that would be worth a look (although Money is more or less a hate figure these days).
- AIUI, Kellogg found a process that "worked" with a bunch of grains and patented it on a broad basis (I hate it when patent lawyers stretch patents such that they no longer resemble the reality of the invention). However his own commercial production was purely maize. I think this may have been a taste issue - he certainly had complained about the taste of Shredded Wheat, which was an earlier attempt to make a wholegrain, uncooked breakfast. The inventor of Shredded Wheat was originally an engineer and had started out trying to sell the machine for making it, rather than the product; I think Kellogg had bought one, he was certainly aware of "baked cereal flakes" as a breakfast concept. Kellogg was also, quite early in his commercial production (so later than the invention), playing up the Midwestern cornhusker schtick with artfully draped Ceres figures waving stalks of Good Ol' US-of-A maize on the box.
- As an example of "corn flakes made from wheat", Force (cereal) is the only one I can think of. They avoid sugar but have malt (added ? formed as a by product?) to give more flavour than Shredded Wheat (they're a really good cereal, but went out of production a couple of years ago). Andy Dingley (talk) 00:39, 8 June 2017 (UTC)
- Any American supermarket will have various choices for wheat-flake cereals. See Total (breakfast cereal), for example. But of course we don't call them "corn flakes". --Trovatore (talk) 00:48, 8 June 2017 (UTC)
- Sorry, Force is contemporaneous, Total is modern. I'm sure there are others around today. Andy Dingley (talk) 09:56, 8 June 2017 (UTC)
- Any American supermarket will have various choices for wheat-flake cereals. See Total (breakfast cereal), for example. But of course we don't call them "corn flakes". --Trovatore (talk) 00:48, 8 June 2017 (UTC)
- Maize was certainly a staple food far before WWII. Stealing corn from the natives was about the first thing the Pilgrims did in America.[8]. Baker, O. E., A Graphic Summary of American Agriculture, Based Largely on the Census of 1920: "In the Corn Belt it is dominant, contributing nearly two-fifths of the acreage and half of the value of all crops. Hay, associated with spring oats in the northern portion and with winter wheat in the southern portion, are the other important crops in the Corn Belt." [9] See also Pellagra#history. Perhaps you are confusing sweet corn with field corn which is used to make corn meal, not generally as a fresh vegetable. Rmhermen (talk) 05:18, 8 June 2017 (UTC)
- I'm well-aware from reading the article Corn Belt that maize was the predominant staple grown in that region as early as the 1850s, but there are other regions of the US where maize might not have been thought of as the predominant staple by 1906 yet. However, over at Wikipedia:Reference desk/Language#When did the meaning of corn shift to maize in American English?, I'm pointed to a source that does say that the "Indian" was dropped already in the early 19th century. So by the time corn flakes were marketed as such (by 1906 at the latest), the Kelloggs must already have settled on corn. It just would have been nice to have precise dates, but oh well. At least now I'm positive that already by 1894, the ambiguity was almost certainly completely gone and nowhere in the US would any native ever called any other grain but maize call corn; certainly the Kelloggs didn't. Thanks, everyone. --Florian Blaschke (talk) 11:58, 9 June 2017 (UTC)
Please be specific
I keep seeing comments about Maize, as if that name identifies the specific grain that Kellogg used. But, as our article on Maize correctly points out,
Many forms of maize are used for food, sometimes classified as various subspecies related to the amount of starch each has:
- Flour corn
- Popcorn
- Dent corn
- Flint corn
- Sweet corn
- Waxy corn
- Amylomaize
- Pod corn
- Striped maize
According to this:[10] corn flakes are made of dent corn. --Guy Macon (talk) 16:43, 8 June 2017 (UTC)
- I think the point is that our British friends still use corn to mean "any cereal grain" (including wheat, barley, and oats). Maize is at least more specific than that, though as I mentioned, it has the risk on this side of the pond that your listener may think you're talking specifically about flint corn.
- To an American city boy like me, corn means "sweet corn" by default. I don't know whether it had ever occurred to me, prior to Wikipedia, that the "corn" in cornbread or beer was probably not sweet corn, but rather field corn. --Trovatore (talk) 21:44, 8 June 2017 (UTC)
- I see I had a confusion above involving "Indian corn". My impression was that Indian corn was distinguished from other sorts of "corn" (old sense) like wheat and barley. But we currently redirect this to flint corn, the particularly hard-shelled variety. And this actually seems to be a widespread usage. The crazy part though is that the Indians had already developed a range of varieties of corn before anyone else had a chance to get involved, so we have some "cultural appropriation" built into the language - I suspect kids mostly assume that the colorful and (they wrongly think) more ornamental than edible Indian corn was the only thing the natives of America were able to come up with, and all the rest must have been clever white men. Wnt (talk) 10:42, 10 June 2017 (UTC)
- I think you are correct that some speakers use Indian corn to distinguish from grain in general. This I think is a Commonwealth usage (because Americans see no need to distinguish; corn in the sense of "grain" is not used, and not very likely even to be recognized, by AmE speakers).
- I could have said "... use Indian corn to mean 'maize'", except that I think a lot of Americans interpret maize to mean "flint corn" as well.
- Basically anything you say about Zea mays mays and its cultivars, in a cross-pondial setting, has potential for confusion, no matter what term you use. Keeping this in mind, the best advice seems to be to use the term you want, but explain clearly what you mean by it. --Trovatore (talk) 22:03, 10 June 2017 (UTC)
'Fold' in motorcycle helmets
Why do motorcycle helmets have a fold on the the back? I suppose this has some aerodynamic reason, but fail to understand which. Why aren't helmets even, as close to a sphere as possible? --Clipname (talk) 19:02, 7 June 2017 (UTC)
- One factor that doesn't explain the need, but does make it less "expensive", is that the rider is unlikely to land on the back of his head, so concentrating forces with a non-spherical back is less likely to result in injury than it would elsewhere. StuRat (talk) 20:26, 7 June 2017 (UTC)
- [citation needed] As far as I can understand the Hurt Report, impacts affecting the rear of the helmet represent about 10% or more [11] (page 278 of the document or 288 of the PDF). I'd note that most intepretations of the data e.g. [12] [13] [14] generally consider regions containing the rear side including the rear I'm guessing because this makes the most sense (i.e. it isn't uncommon that impacts will affect at least part of the rear). If you did want a region of the helmet not generally impacted, try the top. Nil Einne (talk) 11:30, 8 June 2017 (UTC)
- I don't know if this is the reason (some) helmets are shaped like that, but I'll note that a sphere is not the most aerodynamic shape. A "teardrop" or airfoil shape, with the point at the rear, has less aerodynamic drag than a sphere.[15] Some helmets approximate that type of shape. CodeTalker (talk) 15:58, 8 June 2017 (UTC)
- I don't have references to hand; someone can probably find them by an easy search, but I think it might be worth mentioning that often the function of aerodynamic-looking stylings is simply to look aerodynamic (and be stylish).
- For some time, a lot of new cars had spoiler-like things in back, like you would put on a race car to provide negative lift and keep the car from launching into the air. These passenger cars had no use for that feature whatsoever. But buyers liked the look. --Trovatore (talk) 21:54, 8 June 2017 (UTC)
How fast could a human swim in an infinite universe made of STP air?
How many minutes or hours of swimming would it take to accelerate till air resistance equals average swimming power? Would his air disturbances and/or body mass cause a black hole to form? How long would that take? He starts at zero airspeed. Sagittarian Milky Way (talk) 22:26, 7 June 2017 (UTC)
- Bees tread air like swimmers tread water, but their top speed will not possibly be much faster than the speed that they can rotate their wings or arms or undulate their bodies since one has to be able propel the air with respect to the zero air speed to at least their current speed or more in order to have thrust. Otherwise their effort will simply serve to act as a net drag (like sticking your hand out of a car window). To look at this another way, what is the top wind speed of the air leaving their cupped hands when they slap at the air or from their lungs when they are stationary. They will never exceed that speed and become fast and massive even if the air resistance was negligible due to an aerodynamic suit. --Modocc (talk) 23:38, 7 June 2017 (UTC)
- Could random turbulence and the tiny high density seed (a human) at the center of the initially isotropic, windless universe cause a positive feedback loop of gravitational collapse? (maybe long after he's dead?) Or would air flowing from high pressure to low prevent any gravitational accumulation of an air planet that becomes a nitroxygen star that becomes a white dwarf that becomes a neutron star that becomes a black hole? Air pressure changes only travel at the speed of sound so maybe gravity can overcome it? Sagittarian Milky Way (talk) 23:53, 7 June 2017 (UTC)
- Gravity is so weak the local pressure gradient due to the displaced air would be negligible. Thus, I don't see that happening. The long-term outcome would certainly depend on how independent and random the air molecules' trajectories actually are. Nevertheless, I'll conjecture that they don't have sufficient independence to spontaneously sustain localized disturbances as such. However, I could be very wrong on that as I'm not a physicist or a cosmologist. --Modocc (talk) 01:26, 8 June 2017 (UTC)
- Could random turbulence and the tiny high density seed (a human) at the center of the initially isotropic, windless universe cause a positive feedback loop of gravitational collapse? (maybe long after he's dead?) Or would air flowing from high pressure to low prevent any gravitational accumulation of an air planet that becomes a nitroxygen star that becomes a white dwarf that becomes a neutron star that becomes a black hole? Air pressure changes only travel at the speed of sound so maybe gravity can overcome it? Sagittarian Milky Way (talk) 23:53, 7 June 2017 (UTC)
- STP may be "The Racer's Edge" but I wouldn't recommend swimming in it. ←Baseball Bugs What's up, Doc? carrots→ 23:41, 7 June 2017 (UTC)
- The question is meaningless (to say the least); velocity is relative, there would no point of reference against which to measure the speed. There does seem to be a black hole involved here, but not a cosmological one. μηδείς (talk) 02:15, 8 June 2017 (UTC)
- We are each at rest relative to the average velocity of the air molecules we are now breathing in the rooms we are in. Simply ignore or remove the movement of the celestial sphere and extend your walls to infinity and we are still at rest to their average velocities for an infinite amount of air with the gravity evenly distributed thus canceling. Move very fast relative to that reference and you will suffer from air resistance. Period. It's a thought experiment, so your mileage may vary. --Modocc (talk) 02:29, 8 June 2017 (UTC)
- No, this is simply college dorm bullsittery. You are now adding ad hoc assumptions to deal with possible objections. If all the air is still, then all that will happen is the creation of eddies local to the flailing body, not "swimming" and not any objectively measurable velocity. μηδείς (talk) 17:48, 8 June 2017 (UTC)
- The OP's thought experiment is simply an infinite universe filled with breathable air and with a swimmer in it. From the swimmer's perspective it would be little different than living in a dark space station filled with air that is several miles in diameter where there is no gravity so they are floating in the middle of it of it all. Then they can get the ground pepper (inspired from the more recent thread posts below) and sneeze a lot in one particular direction such that they move in the opposite direction. Better yet they can use a rapid down stroke such as with the breaststroke and since there is not much to kick wear the flippers that divers use. I wore them for fun and for swimming speed when I was a kid. Boat propellers such as what's on airboats work on the same thrust principle. It's basic Newtonian mechanics, and at some point, some knowledge about air molecule velocities of the Maxwell–Boltzmann distribution. When the molecules' velocity vectors are summed the mean amplitude is near zero because the stationary swimmer is being impinged equally by air molecules from all directions; half the molecules velocities are negative and the other half are positive. As the swimmer gains velocity this is no longer true and they experience a net force due to the air resistance. In this case, changing to a reference frame in which the swimmer is always stationary, the mean amplitude of the molecular velocities will become nonzero in the direction opposite of their movement. Since the air resistance is a drag force they will eventually slow down such that the mean amplitude is zero again (in their reference frame). Unless, they come into possession of a perpetual motion machine. Now that would be an invention! -Modocc (talk) 19:39, 8 June 2017 (UTC)
- No, again, there is nothing to measure one's velocity against, and the simplest assumption is that the air surrounding your body would simply move in local vortices as you flailed about. Everything else depends on smuggling in assumptions the OP has not made. This is why we don't engage in speculation or debate. There's no definable "location" in this universe, and at STP any single molecule of air is moving in a random walk at 1,000's of kmph. Again, the premise is pre-scientific, one might as well argue about the clinamen, phlogiston, and aether. μηδείς (talk) 21:41, 8 June 2017 (UTC)
- I adequately answered the OP's question with my first post and the only reason this thread is continuing is to rebut your unfounded assertions. Molecule collisions happen to conserve momentum so they are not as random as one might think. Nevertheless these molecules do move relative to one another and the swimmer so it's not like there is nothing to measure. Your first post here was to assert "there would no point of reference against which to measure the speed" which is a misconception that you are still repeating with "there is nothing to measure one's velocity against" although I've gone to great pains to debunk this. Let's give the swimmer a rocket so they can create sonic booms when they are not at rest. --Modocc (talk) 21:51, 8 June 2017 (UTC)
- Averaging the velocity of all the air molecules out to infinity gives a frame of reference to measure speed against. Sagittarian Milky Way (talk) 23:00, 8 June 2017 (UTC)
- Sagittarian Milky Way, that is very well stated and there are times when I wish could be that succinct and didn't delve into peripheral tangents and be misunderstood. :-) -Modocc (talk) 00:05, 9 June 2017 (UTC)
- At the other extreme, swimming in a highly resisting medium has been put to the test [16], though this addresses only ultimate velocity and not the time needed to approach it,--catslash (talk) 01:18, 9 June 2017 (UTC)
- Consideration of dimensionless numbers in fluid mechanics and dimensional analysis might provide an estimate of the ultimate velocity and time needed to approach it. --catslash (talk) 01:32, 9 June 2017 (UTC)
- Sagittarian Milky Way, that is very well stated and there are times when I wish could be that succinct and didn't delve into peripheral tangents and be misunderstood. :-) -Modocc (talk) 00:05, 9 June 2017 (UTC)
- No, again, there is nothing to measure one's velocity against, and the simplest assumption is that the air surrounding your body would simply move in local vortices as you flailed about. Everything else depends on smuggling in assumptions the OP has not made. This is why we don't engage in speculation or debate. There's no definable "location" in this universe, and at STP any single molecule of air is moving in a random walk at 1,000's of kmph. Again, the premise is pre-scientific, one might as well argue about the clinamen, phlogiston, and aether. μηδείς (talk) 21:41, 8 June 2017 (UTC)
- The OP's thought experiment is simply an infinite universe filled with breathable air and with a swimmer in it. From the swimmer's perspective it would be little different than living in a dark space station filled with air that is several miles in diameter where there is no gravity so they are floating in the middle of it of it all. Then they can get the ground pepper (inspired from the more recent thread posts below) and sneeze a lot in one particular direction such that they move in the opposite direction. Better yet they can use a rapid down stroke such as with the breaststroke and since there is not much to kick wear the flippers that divers use. I wore them for fun and for swimming speed when I was a kid. Boat propellers such as what's on airboats work on the same thrust principle. It's basic Newtonian mechanics, and at some point, some knowledge about air molecule velocities of the Maxwell–Boltzmann distribution. When the molecules' velocity vectors are summed the mean amplitude is near zero because the stationary swimmer is being impinged equally by air molecules from all directions; half the molecules velocities are negative and the other half are positive. As the swimmer gains velocity this is no longer true and they experience a net force due to the air resistance. In this case, changing to a reference frame in which the swimmer is always stationary, the mean amplitude of the molecular velocities will become nonzero in the direction opposite of their movement. Since the air resistance is a drag force they will eventually slow down such that the mean amplitude is zero again (in their reference frame). Unless, they come into possession of a perpetual motion machine. Now that would be an invention! -Modocc (talk) 19:39, 8 June 2017 (UTC)
June 8
The pleasure of sneezing
Hardly a day ever goes by when I don't sneeze at least once. It never bothers me; in fact, I like it a lot. Just before the expulsion of breath I experience a feeling that is intensely pleasurable; it's up there with orgasm in terms of pleasure. I'm sure others have this feeling too.
What is the biological purpose of this intensely pleasurable feeling? -- Jack of Oz [pleasantries] 07:06, 8 June 2017 (UTC)
- Not every biological phenomenon has a 'purpose' (which in itself is an ontologically loaded term); sometimes they are just side effects of some other process, or arise by chance. If they are neutral in terms of survival, they will neither be selected for nor selected against. {The poster formerly known as 87.81.230.195} 2.217.208.38 (talk) 07:19, 8 June 2017 (UTC)
- (ec) Googling "sneeze pleasure" gives a few interesting results, showing that you're not the first to wonder about this, though they seem to be more about what makes sneezing pleasurable rather than "why". And WP:WHAAOE: Sexually induced sneezing. AndrewWTaylor (talk) 07:23, 8 June 2017 (UTC)
- Great. What I need now is a sneezing induced erection. :) -- Jack of Oz [pleasantries] 08:03, 8 June 2017 (UTC)
- So when someone says you "sneezed hard", it wasn't about the strength of the lung action? DMacks (talk) 08:09, 8 June 2017 (UTC)
- Hmm. Maybe a drug-free cure for erectile dysfunction is in the offing: Sneeze yourself hard. Worth a try. Hand me that pepper shaker, please. -- Jack of Oz [pleasantries] 09:50, 8 June 2017 (UTC)
- I guess snuff film needs to become a DAB page. DMacks (talk) 13:54, 8 June 2017 (UTC)
- Hmm. Maybe a drug-free cure for erectile dysfunction is in the offing: Sneeze yourself hard. Worth a try. Hand me that pepper shaker, please. -- Jack of Oz [pleasantries] 09:50, 8 June 2017 (UTC)
- So when someone says you "sneezed hard", it wasn't about the strength of the lung action? DMacks (talk) 08:09, 8 June 2017 (UTC)
- Great. What I need now is a sneezing induced erection. :) -- Jack of Oz [pleasantries] 08:03, 8 June 2017 (UTC)
Unknown Antilope
May you please help me identifying this Antilope species?--Erasmus Wolfgang Blivet (talk) 10:18, 8 June 2017 (UTC)
- Unfortunately the park's web site doesn't contain anything like a list of all the species they have. But it does mention that they have elands, and while I'm no expert, I'd say that creature looks a lot like the ones shown in the common eland article. --69.159.63.238 (talk) 10:41, 8 June 2017 (UTC)
- I agree. Definitely a Taurotragus of some sort. Note the dewlap and the distinctive horn spiral. Quite common where I live. 196.213.35.146 (talk) 12:54, 8 June 2017 (UTC)
War stories
Why does my grandfather constantly talks about the war? He's 94 and for the past 20 or so years, ever since I remember actually, he's been telling WW2 stories to everyone willing to listen.
He always talks about 1941-1945, very rarely about the this life before or after the war.
Its like the granpa Trotter from Only fools and horses.
How come some people always talk about the war even though it's such a small fragment of as opposed to the rest or their lives? Is there a scientific explanation ? — Preceding unsigned comment added by 212.200.247.175 (talk) 16:26, 8 June 2017 (UTC)
- For many of that generation, the war was by far the most extraordinary experience of their lives. Cut him some slack. And maybe record what he says, because you may find it useful once you've grown up. ←Baseball Bugs What's up, Doc? carrots→ 17:40, 8 June 2017 (UTC)
- Agreed; and many of them feel that it's their duty to pass on their experiences to the younger generations. There's not many of them left now. Alansplodge (talk) 22:47, 8 June 2017 (UTC)
- From the perspective of a daughter of a survivor of the worst of World War 2, your grandfather probably had untreated PTSD, for which we now prescribe talk therapies. He is undergoing his own self-treatment of his PTSD, even 70 years later, as it was not treated at the time. You could also think of it this way: there is a proverb "he who does not learn from history is condemned to repeat it". The best way to ensure the mistakes of history are not learned is to ensure that they are forgotten. So from that perspective, your grandfather is anxious that you and your generation don't suffer like he and his generation did. Be gentle, and as others have said, cut him some slack and make notes of what he says. Your future self will thank you for it. --TammyMoet (talk) 16:08, 10 June 2017 (UTC)
- We're not really qualified to make diagnoses. An alternative explanation is that war is obviously interesting; otherwise why are there so many war movies? A religious person might say that God made Nazis for the sole purpose of allowing us to watch them die in entertaining ways. (Then again, maybe not...) It is entirely possible that if he had not been in a war, he would have gotten involved in a World of Warcraft game or a Civil War reenactment or something and bored you to death with stories about that instead. So be thankful (but not too thankful) for our Axis friends. But we don't know scientifically why any one person does what he does, and generally the actions of a crowd are even less logically explicable. Wnt (talk) 16:43, 10 June 2017 (UTC)
What solvent to rejuvenate a solvent resistant pen?
When I was a kid and a felt tip pen dried out, it could be revived by adding just a couple of drops of water from the back end of the pen. I have a marker pen which is solvent resistant and won't come off with ethanol but will come off with some solvents such as methanol. What can I add a couple of drops of to rejuvenate my pen? (I know I can't do this forever) — Preceding unsigned comment added by 129.215.47.59 (talk) 16:33, 8 June 2017 (UTC)
- I've woken up dried-out VWR lab markers with a histo-grade mixture of xylenes. Wnt (talk) 18:14, 8 June 2017 (UTC)
carbon monoxide
Is CO heavier or lighter than air? — Preceding unsigned comment added by 2601:601:8600:F1:15D3:932D:A7F8:B18F (talk) 19:41, 8 June 2017 (UTC)
- For most practical applications carbon monoxide is essentially the same as air. Dragons flight (talk) 20:02, 8 June 2017 (UTC)
- You are likely referring to molar mass. Carbon Monoxide is 28.01. Air tends to be around 29. While lighter than average air, the difference is so slight that, as Dragons flight stated, carbon monoxide is essentially the same as air. 209.149.113.5 (talk) 20:24, 8 June 2017 (UTC)
- Our Carbon monoxide#Molecular properties notes, "Carbon monoxide has a molar mass of 28.0, which, according to the ideal gas law, makes it slightly less dense than air, whose average molar mass is 28.8." DMacks (talk) 21:36, 8 June 2017 (UTC)
Where can I get reliable info about LDL and HDL in quail eggs?
I read the article quail eggs but no information about that. In one place on Google I found that it's without LDL at all, it has HDL ("good cholesterol") only. In another place I found that it has high levels of cholesterol which can damage. So I assume, based on the last site, that it has LDL as well, otherwise it's not dangerous to eat good cholesterol. Isn't it? 93.126.88.30 (talk) 20:23, 8 June 2017 (UTC)
- This looks promising.--Jayron32 20:27, 8 June 2017 (UTC)
- The USDA doesn't differentiate between types of cholesterol. They list a 9g quail egg as having 76mg of cholesterol [17]. It is less than 1% cholesterol. However, this leads to why you ask. If it is because you believe that consuming cholesterol will raise cholesterol in your blood, please look into where that concept came from and the years of research that has shown the concept to be completely wrong. 209.149.113.5 (talk) 20:30, 8 June 2017 (UTC)
- Low density lipoprotein and high density lipoprotein are not eaten. (Well, alright, alright, I suppose you do eat them in meat and the enclosed blood therein, but in any case, proteins that are eaten get cut up into pieces and don't usually make it into the body intact; they generally have to be rebuilt from scratch according to our blueprints) They are chylomicrons formed by the interaction of ingested fats with apolipoproteins, proteins produced mainly in the liver, to allow their distribution throughout the body. While in theory it would be possible for some food sources to encourage more LDL or HDL production by any number of regulatory means, the fats themselves, including cholesterol, can be found in either. I highly doubt that any one species of bird produces a haloed egg capable of producing only good cholesterol, but this is biology where anything is possible ... I'd have to do an experiment (or find one) to actually know. Wnt (talk) 23:30, 8 June 2017 (UTC)
Taxonomy confusion
Does a species scientific name encompasses all subspecies.
For example does the scientific name of the species called lion "panthera leo" means at the same time all subspecies it has?
To visualize another example:
Is panthera leo = panthera leo leo, panthera leo spelaea, panthera leo atrox, panthera leo asiatica...
If my question is answered with YES, Are there exceptions to this in taxonomy?
For example does the scientific name Canis lupus refers to all its subspecies including the dingo and the dog?
Gyrkin (talk) 20:29, 8 June 2017 (UTC)
- See subspecies. A subspecies cannot be recognized independently. It is always subordinate to the species. 209.149.113.5 (talk) 20:34, 8 June 2017 (UTC)
- and specifically for Canis familiaris vs. Canis lupus familiaris see Dog#Taxonomy. Dr Dima (talk) 21:06, 8 June 2017 (UTC)
- The basic rule is that all members of a singles species share the same binomial - so all lions are Panthera leo (always use a capital letter for the genus). Sub-species are considered to show variation within the species, but not such as to justify them being labelled as separate species. So for the lions the main differences are in the size and shape of the mane, but many current lions are probably hybrids of different sub-species, and there is uncertainty about just how many different sub-species there really are.
- The problems arise with groups like the wolf/dog/dingo. Taxonomists are clear that the dog is a domesticated form of wolf, and the dingo may be too, though that is less certain. What is debated is whether dogs and wolves have now diverged so far that they should be considered as separate species - so is the dog Canis lupus familiaris, or Canis familiaris. If you conclude that they are still the same species, then Canis lupus includes them all. If you conclude otherwise, then they each have their own binomial, sharing only the generic name. That is not an exception to the rule - just a case where there is uncertainty about how the rule should be applied. Wymspen (talk) 21:43, 8 June 2017 (UTC)
- My understanding of the biological species concept is that it works like this: suppose you have two islands, A and B, and you go on a tranquilizer darting spree and come back with 10 animals of each sex from each island, and you let them all loose in an enclosure with a suitable environment. If the animals freely breed with each other, so that in a few generations most are descended from both islands, they would be the same species. If just a few under forced circumstances interbreed, like if you put one male from A and one female from B in a cage, and produce offspring, then they are different species and the offspring are hybrids. Hybrids often work only in one direction (Haldane's rule) but that isn't mandatory for the definition - they might breed both ways, but if they don't do so freely in a natural-like environment where both species are present, then that doesn't make them the same species. If they are the same species, but you can look at one of the 40 original animals and tell which island it came from, then they are different subspecies. But... there are some caveats.
- To begin with, there is no guarantee of transitivity: if A will interbreed with B and B will interbreed with C, A may not interbreed with C. See ring species.
- The distinction between subspecies and landraces or just races seems poorly drawn and perhaps political. I have the impression that subspecies are said to exist that are distinguished by little more than molecular markers - like any ancestry - for purposes of conservation, though I should disclaim I haven't looked into these issues carefully enough to be sure.
- Environmental changes can cause two species to hybridize widely that would not have done so before. (this covers some examples) Under those circumstances the prevalent "species" level can quickly change. Wnt (talk) 01:39, 9 June 2017 (UTC)
Choosing between 3, 4, or 5 digit long chunks
I got a bunch of 15 digit player ID numbers that I need people to write down for future reference. I want to break down the number into either 3, 4, or 5 digit long chunks so that it's easier to communicate over the phone and in person. In other words, there are three possible formats:
1. XXX-XXX-XXX-XXX-XXX
2. XXXX-XXXX-XXXX-XXX0 (extra 0 for padding)
3. XXXXX-XXXXX-XXXXX
Has there been any scientific research done on which of these formats is faster/easier/more accurate for people to communicate with? Scala Cats (talk) 21:50, 8 June 2017 (UTC)
- Best I could find is THIS. Only deals with phone numbers and lists different formats by country with varying justification. 64.170.21.194 (talk) 23:14, 8 June 2017 (UTC)
- The Magical Number Seven, Plus or Minus Two would be an interesting read.--Jayron32 00:45, 9 June 2017 (UTC)
- I'm surprised that article doesn't list the criticism. That study was heavily American-centric. The "7" came from Americans being trained to memorize 7-digit phone numbers. When the study was repeated in other countries, the magic number changed. I doubt it pertains to anything anymore since people don't memorize phone numbers. They just just pull up names in a contact list. 209.149.113.5 (talk) 14:55, 9 June 2017 (UTC)
- Just an observation: in France, phone numbers are commonly broken into 2-digit groups. Because of the way numerals in French are formed, this means that a number like "97-16-51-72" is spoken like "4-20-10-7-16-50-and-1-60-12"! It really is a matter of what people are used to. --69.159.63.238 (talk) 20:35, 9 June 2017 (UTC)
- Go with the groups of 3. It divides into 15 nicely and is easy to read. ←Baseball Bugs What's up, Doc? carrots→ 22:11, 9 June 2017 (UTC)
- Most credit/debit card numbers are 15 digits long. They add one extra checksum digit to make it 16 and break it into groups of 4. Why not use a checksum like that? It will help ensure all the digits are correct. — Preceding unsigned comment added by 71.85.51.150 (talk) 01:17, 10 June 2017 (UTC)
- Specifically, they commonly use the Luhn checksum. (Hmm, I had to pipe that link. That should be a redirect. Should be a redirect. Anyone care to add it?) --69.159.63.238 (talk) 05:21, 10 June 2017 (UTC)
- Done, thanks for noting it. Nil Einne (talk) 13:49, 10 June 2017 (UTC)
- Thanks. --76.71.5.114 (talk) 23:17, 10 June 2017 (UTC)
- Done, thanks for noting it. Nil Einne (talk) 13:49, 10 June 2017 (UTC)
- Specifically, they commonly use the Luhn checksum. (Hmm, I had to pipe that link. That should be a redirect. Should be a redirect. Anyone care to add it?) --69.159.63.238 (talk) 05:21, 10 June 2017 (UTC)
- I imagine the need for a checksum depends on the application - I mean, if there is nothing wrong with the person just looking up the number and trying again, why bother making him learn it? Given latitude, I'm thinking the nicest way to code the number might be to use some dictionary (this is the most common 10,000 words according to Google...). (You might have to trim this list and add a few to avoid collisions, or else capitalize first letters or require spaces - TherapistISandy) For example, "97-16-51-72" mentioned above would be "scoop flexibility". But a company would hate this lest it say something "politically incorrect"... and bullying always trumps efficiency and reliability. Wnt (talk) 16:31, 10 June 2017 (UTC)
- My first thought was also using a dictionary, but unfortunately my player base is international and there's no good trans-lingual dictionary scheme out there (or at least I couldn't find one). Scala Cats (talk) 17:55, 10 June 2017 (UTC)
- They wouldn't have to be the same words, would they? You could have a player choice at the time the number is given between English, French, Dutch, whatever, and so long as you could find unencumbered or licensable dictionaries for each, you could translate the same numbers into code phrases with entirely different meanings in each language. (For bilingual players they might flip back and forth and see which phrase is easier to remember!) Wnt (talk) 18:28, 10 June 2017 (UTC)
- My first thought was also using a dictionary, but unfortunately my player base is international and there's no good trans-lingual dictionary scheme out there (or at least I couldn't find one). Scala Cats (talk) 17:55, 10 June 2017 (UTC)
June 9
If there are more Na+ ions in the extracellular space, then will raw red meat taste salty?
Disregard the possibility of catching a foodborne illness. Will raw red meat taste salty? 50.4.236.254 (talk) 03:44, 9 June 2017 (UTC)
- meat has lots of sodium to begin with apparently? 0164.170.21.194 (talk) 04:49, 9 June 2017 (UTC)
- Ever tasted blood? Abductive (reasoning) 05:51, 9 June 2017 (UTC)
- Raw beef isn't bloody. It's myoglobin from the muscle tissue itself. --Jayron32 05:53, 9 June 2017 (UTC)
- Ever tasted blood? Abductive (reasoning) 05:51, 9 June 2017 (UTC)
- "specifically in the red blood cells. In humans, myoglobin is only found in the bloodstream after muscle injury. It is an abnormal finding, and can be diagnostically relevant when found in blood".... right.. no blood... 64.170.21.194 (talk) 22:29, 9 June 2017 (UTC)
CG and crosswinds
How does a forward CG affect crosswind takeoffs and landings in a taildragger (not necessarily just the Electra 10-E, but any taildragger like for example a DC-3 or a Ju-52)? 2601:646:8E01:7E0B:4F8:7AED:9CA5:90AA (talk) 06:22, 9 June 2017 (UTC)
Is there a term for functional groups that are displaced during electrophilic substitution reactions?
I think the term leaving groups is reserved for functional groups that are displaced during nucleophilic substitution. OrganoMetallurgy (talk) 18:00, 9 June 2017 (UTC)
- Electrofuge. DMacks (talk) 19:17, 9 June 2017 (UTC)
- Electrofuges are a kind of leaving group; I've added IUPAC references to that effect in that article. Wnt (talk) 16:19, 10 June 2017 (UTC)
- Thanks. I've been terribly confused about that. OrganoMetallurgy (talk) 18:02, 10 June 2017 (UTC)
- I have the vague sense that a leaving group is simply a group that is "happy" with the structure and charge it ends up with, whatever the charge (or lack thereof) may be. So H+ and Cl- are good leaving groups - H- and Cl+, not so much (though I think the first does happen, and I'd be afraid to say the second is impossible...). Wnt (talk) 18:31, 10 June 2017 (UTC)
- A hyride leaving group is common in several sorts of reactions, but the only ones I can think of involve it transferring directly as a nucleophile onto some other substrate rather than merely becoming solvated (Cannizzaro reaction and some biological dihydroquinone oxidations, or even less distinctly Oppenauer oxidation). I wonder what the mechanism is for the formation of the I+ (-like reactive intermediate) in the "I2+HIO3" electrophilic halogenation protocol? DMacks (talk) 20:29, 10 June 2017 (UTC)
- I have the vague sense that a leaving group is simply a group that is "happy" with the structure and charge it ends up with, whatever the charge (or lack thereof) may be. So H+ and Cl- are good leaving groups - H- and Cl+, not so much (though I think the first does happen, and I'd be afraid to say the second is impossible...). Wnt (talk) 18:31, 10 June 2017 (UTC)
- Thanks for cleaning up the defs! DMacks (talk) 20:29, 10 June 2017 (UTC)
- Thanks. I've been terribly confused about that. OrganoMetallurgy (talk) 18:02, 10 June 2017 (UTC)
June 10
Feynman Lectures. Exercises PDF. Exercises 7-1...7-11
I have a general question. Feynman at the end of Section 7-4 describes the mechanism of tides. He says that centrifugal force balances gravitation force of the moon at the center of the earth. I assume we can prove that for moon free fall acceleration (at the distance 384 400 km) and centrifugal acceleration we can replace the earth by one point:
* for the centrifugal force:
we can divide the earth into 1 kg bricks and sum up the forces applied;
the centrifugal acceleration ω²R is linearly dependent from R , its x-projection is same for each section of the earth , its y-projections cancel each other png
during summation we see that lowering the centrifugal force on near side of the earth is just compensated by the growth at the far side of the earth. So the sum will not change if we replace all the forces by the mean force -- the force at the center.
* for the gravitation force:
for large distance from the moon (384 400 km) and for relatively small earth diameter (12 800 km) the change in the moon field (moon free fall acceleration) is almost linear (3.4×10-5 m/sec² on near side of the earth , 3.3×10-5 at the earth center, 3.2×10-5 at the far side )png. Neglecting moon's field direction, the same analysis permits to change all the forces by the mean force and collect all mass of the earth in a single point.
But from such reasoning I still can't see why do the mean forces balance each other. Is it because the Earth would otherwise have come down from the orbit (no more equilibrium in rotating reference frame)? Is such reasoning correct? Username160611000000 (talk) 12:54, 10 June 2017 (UTC).
- I might be misunderstanding, but I think you want the shell theorem. The idea is that a spherical shell of Earth of uniform density will orbit and attract like a point mass at its center. Note that since the Earth is not a perfect sphere or perfectly uniform in density at a given depth, your premise should not be perfectly true. Wnt (talk) 16:33, 10 June 2017 (UTC)
- Feynman explains "shell theorem" later [18] . According to him a spherical body and a point with equal mass generate identical fields. But nothing is said about objects affected by that field. In this problem the moon can be thought as a point. But this does not change either the formulas or the drawings. If Feynman gives this problem in Lecture 7, then we need not "shell theorem" to explain the phenomenon. Actually the tidal effect itself shows that earth cannot be considered as a point (it can be considered as point approximately and only for collecting the force, but not for further explanation ).
So no, "shell theorem" is out of place. Username160611000000 (talk) 17:25, 10 June 2017 (UTC)- This lecture is simply applying Newtons' law of action-reaction by balancing two forces, the reactive centrifugal force (which is not to be confused with fictitious centrifugal forces that are due to rotating reference frames) and the gravitational force that are said to be acting on the masses. That is all. This is not the modern view, but it is a traditional treatment of the problem. BTW, when I was introduced to the term "centrifugal force" I understood it in the sense of the reactive centrifugal force that acts on a string (or the other mass as the case here). Strings, flywheels and spinners are always under tension due to it. To make things even more interesting, the last section of the reactive centrifugal force article points out that with the gravitational two-body case (such as that is being considered here), the reaction to the centripetal force is also a centripetal force. So there you go. I hope that helps. --Modocc (talk) 19:51, 10 June 2017 (UTC)
- @Modocc:
BTW, when I was introduced to the term "centrifugal force" I understood it in the sense of the reactive centrifugal force that acts on a string (or the other mass as the case here).
First, it doesn't explain then why do both forces balance in the center of the earth, and not somewhere else (according to the rules we can move a vector along an axis). Second, these forces (gravitational attraction from the moon on the earth and reactive force from the earth on the source) are applied to the different objects. Yes, we can add forces on one axis, but I'm not sure that in this case it is possible.
Username160611000000 (talk • contribs) 04:30, 11 June 2017 (UTC)- OK. Reading further, I see he says "What do we mean by “balanced”? What balances? If the moon pulls the whole earth toward it, why doesn’t the earth fall right “up” to the moon? Because the earth does the same trick as the moon, it goes in a circle around a point which is inside the earth but not at its center." So he means any system's mass center. The common mass center between the Earth's water and the rest of it is its center in this case. Both of these masses are held in place by gravity as they rotate around the Earth's center. This also means that both masses pretty much happen to trace the same orbit around the Earth-Moon barycenter, more or less. --Modocc (talk) 04:57, 11 June 2017 (UTC)
- My original questions were:
1 Are the forces balanced at the center of the earth and how it could be explained?
2 If the forces are balanced at the center, then can it reason the tidal effect as consequence?
Using very accurate plotting I've found that the total effect of both forces gave lifting acceleration over the earth intersection by the moon orbit plane PNG. The lifting acceleration is a bit smaller on the Y-axis . Image can answer question 2. But I'm still in suspense about question 1. Are my arguments at the beginning correct.
Username160611000000 (talk) 07:56, 11 June 2017 (UTC).
- My original questions were:
- OK. Reading further, I see he says "What do we mean by “balanced”? What balances? If the moon pulls the whole earth toward it, why doesn’t the earth fall right “up” to the moon? Because the earth does the same trick as the moon, it goes in a circle around a point which is inside the earth but not at its center." So he means any system's mass center. The common mass center between the Earth's water and the rest of it is its center in this case. Both of these masses are held in place by gravity as they rotate around the Earth's center. This also means that both masses pretty much happen to trace the same orbit around the Earth-Moon barycenter, more or less. --Modocc (talk) 04:57, 11 June 2017 (UTC)
- @Modocc:
- This lecture is simply applying Newtons' law of action-reaction by balancing two forces, the reactive centrifugal force (which is not to be confused with fictitious centrifugal forces that are due to rotating reference frames) and the gravitational force that are said to be acting on the masses. That is all. This is not the modern view, but it is a traditional treatment of the problem. BTW, when I was introduced to the term "centrifugal force" I understood it in the sense of the reactive centrifugal force that acts on a string (or the other mass as the case here). Strings, flywheels and spinners are always under tension due to it. To make things even more interesting, the last section of the reactive centrifugal force article points out that with the gravitational two-body case (such as that is being considered here), the reaction to the centripetal force is also a centripetal force. So there you go. I hope that helps. --Modocc (talk) 19:51, 10 June 2017 (UTC)
- Feynman explains "shell theorem" later [18] . According to him a spherical body and a point with equal mass generate identical fields. But nothing is said about objects affected by that field. In this problem the moon can be thought as a point. But this does not change either the formulas or the drawings. If Feynman gives this problem in Lecture 7, then we need not "shell theorem" to explain the phenomenon. Actually the tidal effect itself shows that earth cannot be considered as a point (it can be considered as point approximately and only for collecting the force, but not for further explanation ).
What do people mean by "reversing diabetes/CVD"?
Does it mean that the patient no longer has to depend on medications or be hospitalized or live with some kind of physical ailments (blindness, brain damage)? Or does it mean that the person no longer has to be restricted to diabetes-friendly food? By the way, what happens if a normal healthy person eats food made for diabetics? Is diabetic food safe for the non-diabetic? 50.4.236.254 (talk) 17:41, 10 June 2017 (UTC)
- Diabetic foods are generally safe for everyone. (Caveat: some varieties may be sweetened with weird sugar substitutes that cause some digestive unpleasantness, but if so, the diabetics feel the same)
- Putting type II diabetes into remission by weight loss and other therapies does happen; it's largely a matter of reversing insulin resistance. It's important to note though that diabetes is a common condition and many people, even those who don't have it, live close to the edge of it with standard Western diets. There is some evidence to suggest that even prediabetes thought not to be so bad ... is so bad. For example, prediabetics tend to prefer diet soda by taste, presumably having to do with higher blood sugar, and this study found a correlation between that and other serious problems that was not accounted for by diagnosed diabetes. Unless one goes for what seem like overblown theories about aspartame, anyway... Wnt (talk) 18:37, 10 June 2017 (UTC)
- Has anybody done research on the eating habits of African, Asian, South American, and Eastern European immigrants in a Western country and whether they have the same obesity prevalence as Westerners? With obesity on the rise and so many people trying new things, just how common/prevalent is the Standard Western Diet? 50.4.236.254 (talk) 19:16, 10 June 2017 (UTC)
- Not quite what you were asking but the rate among Inuit and First Nations in Canada is growing after the adoption of a western diet. See First Nations and diabetes, Inuit Type 2 diabetes gap worsens and Diabetes - First Nations & Inuit Health. CambridgeBayWeather, Uqaqtuq (talk), Sunasuttuq 00:09, 11 June 2017 (UTC)
- Has anybody done research on the eating habits of African, Asian, South American, and Eastern European immigrants in a Western country and whether they have the same obesity prevalence as Westerners? With obesity on the rise and so many people trying new things, just how common/prevalent is the Standard Western Diet? 50.4.236.254 (talk) 19:16, 10 June 2017 (UTC)
Grey hair
I've noticed numerous, isolated white hairs on people with otherwise dark brown or even black hair. Is the presence of such hairs, in any sense, distinct from greying, where, I believe, many more hairs have lost pigmentation, but only partially, and as such are grey rather than white?--Leon (talk) 17:53, 10 June 2017 (UTC)
“ | Each individuals hair colour is determined by the particular pigment they produce (called melanin - the same stuff in your skin that makes you tan).
As the body ages this pigment (produced by the melanonocytes - cells that reside in the hair follicle) is produced less and less, until the hair is no longer coloured, and appears grey. This is unique to each individual because it is a genetic (and therefore highly heritable) trait. Because it is in no way linked to mortality there is no selection pressure against greying hair. The reason that the pigment is not longer produced is the gradual depletion of the stem-cell pool with age. This is common to many tissues, hair follicles being just one. As the 'pool' of stem cells is depleted, the melanocytes are no longer replaced as frequently, and thus less pigment is produced as we age. |
” |
— Luke, Biology Stack Exchange |
50.4.236.254 (talk) 18:16, 10 June 2017 (UTC)
- I take issue with the statement "Because it is in no way linked to mortality there is no selection pressure against greying hair". A trait does not need to be linked to mortality to be subject to selection. For instance, it is quite plausible that grey hair has a negative effect on sexual attractiveness, and in that way is selected against. But one can also think of possible advantages: older looking individuals are seen as less of a threat or their opinions are more respected; this might benefit the grey haired individual directly or benefit their family members. Note that in our close relative the gorilla, the grey hair of silverbacks is clearly an adaptation concerned with signalling maturity and dominance. Note also that greying in old age seems to be a trait shared with other mammals, such as dogs. The loss of pigment in older humans might indeed just be an incidental side effect of no selective value, but my own hunches would be that it is not selectively neutral, and that it has some unrecognised positive selective value in signalling age.
- Some recent discoveries about the genetics of grey hair may be of relevance to the original question: http://www.ucl.ac.uk/news/news-articles/0316/010316-first-grey-hair-gene-discovered . Jmchutchinson (talk) 19:08, 10 June 2017 (UTC)
Is Zaus gland considered as a lacrimal gland?
Is Zeis' gland considered as lacrimal gland? Based on this picture it seems that it is, but I'm not sure how authorized or correct it is. 93.126.88.30 (talk) 22:52, 10 June 2017 (UTC)
- Judging by this abstract ( [19] ) I think not. I didn't check Sci-Hub for it, but it probably explains further. I think Zeis' gland secretes lipid while lacrimal gland secretes mostly saline solution, but I haven't looked into it enough to be sure. Tear film for the eye is really sophisticated technology at the biological level and shouldn't be underestimated. Wnt (talk) 00:28, 11 June 2017 (UTC)
Yellow mercuric oxide
When I were a lad, minor eyelid infections (styes) were treated with an ointment of "yellow mercuric oxide" (presumably mercury(II) oxide, HgO), which was sold over-the-counter. But the last time there was a need, I couldn't find the stuff. There was an ointment called Stye (trade name; we don't seem to have an article), which if memory serves used to have YMO, but it seemed to have been reduced to a lubricant with no antibacterial component.
Searching around, I find a paper that recommends it for a very particular condition, phthiriasis palpebrarum, not for styes in the usual sense. It doesn't seem to be available for pharmaceutical sale in the United States.
Presumably it was banned at some point, at least for over-the-counter sales? I didn't see anything specifically saying that, but it seems like the natural guess. When did that happen? Or was it something else, maybe product-liability concerns? --Trovatore (talk) 23:08, 10 June 2017 (UTC)
- Hum. Wonder if you're so old that your birth certificate is in Latin. Banned a long time ago. See your
quackDoctor. If he thinks it needs treating it will be with an antibiotic. Aspro (talk) 23:18, 10 June 2017 (UTC)- Oh, I don't have a need at the moment. I was reminded of it when clicking around in reaction to the question above, about "lacrimal glands". Do you have details on the banning, with particular attention to the United States? --Trovatore (talk) 23:23, 10 June 2017 (UTC)
- Apparently this is Pagenstecher's ointment. [20] A 1990 study called it safe and effective for treatment of bacterial blepharitis of the eyelid. Apparently in 1983 the FDA published a Tentative Final Monograph banning it from over the counter use on the basis that patients might have a more serious infection, therefore must be sent to see a doctor to find out if it is only trivial. [21] As always, medicine is a racket; it's only about the money. That said, this is true for both sides, and many sorts of blepharitis often respond nicely to warm wet compresses... [22] ... the risks of mercury are probably exaggerated, but still, of various drugs unjustly banned and restricted, this one seems less indispensable than some. Wnt (talk) 00:50, 11 June 2017 (UTC)
- Well, there's no longer any need for it -- antibiotics work just as well, and are safer (no need to worry about chronic toxicity). 2601:646:8E01:7E0B:E957:E363:9DD1:1743 (talk) 06:38, 11 June 2017 (UTC)
RfC Announce: Wikimedia referrer policy
In February of 2016 the Wikimedia foundation started sending information to all of the websites we link to that allow the owner of the website (or someone who hacks the website, or law enforcement with a search warrant / subpoena) to figure out what Wikipedia page the user was reading when they clicked on the external link.
The WMF is not bound by Wikipedia RfCs, but we can use an advisory-only RfC to decide what information, if any, we want to send to websites we link to and then put in a request to the WMF. I have posted such an advisory-only RfC, which may be found here:
Wikipedia:Village pump (policy)#RfC: Wikimedia referrer policy
Please comment so that we can determine the consensus of the Wikipedia community on this matter. --Guy Macon (talk) 23:28, 10 June 2017 (UTC)
June 11
Could a dog be trained ...
Could a (police/military) dog be trained to pick out an awake person from a group of asleep people or vice versa?Naraht (talk) 03:39, 11 June 2017 (UTC)
- Not reliably -- people don't smell any different when they're awake than when they're asleep, and the one thing on which dogs beat people hands-down is perceiving smells which are undetectable to humans. So if someone is really good at pretending he/she is asleep (like me -- I have very long eyelashes, so I can pretend to have my eyes closed when in fact they're slightly open), then he/she can fool a dog just as easily as a human. 2601:646:8E01:7E0B:E957:E363:9DD1:1743 (talk) 06:36, 11 June 2017 (UTC)
- How do you know? ←Baseball Bugs What's up, Doc? carrots→ 07:07, 11 June 2017 (UTC)
- How do you know if people smell different when they're asleep? 2601:646:8E01:7E0B:E957:E363:9DD1:1743 (talk) 07:57, 11 June 2017 (UTC)
- How do you know? ←Baseball Bugs What's up, Doc? carrots→ 07:07, 11 June 2017 (UTC)
Using numbers to make something more believable
I often see big headings that say, "Researchers say..." or "Scientists say..." or mention some kind of percentage or statistical information without really providing any source. It seems to me that the popular impression of science is that science is the ultimate source for knowledge, and nothing beats the scientific knowledge, so if anyone makes a claim appear like a formal scientific finding, then the claim is readily believed. Similarly, in résumé-building workshops, it is advised that the résumé should always use numbers to make the résumé stand out from the rest. Is there any support for the use of numbers as a rhetorical strategy? 50.4.236.254 (talk) 03:54, 11 June 2017 (UTC)
- You may find this of interest. ←Baseball Bugs What's up, Doc? carrots→ 07:06, 11 June 2017 (UTC)
Nuclear reactor
Is it possible to disable an operating nuclear reactor (not like Osirak, which was destroyed before it could be put into operation) without causing a Chernobyl-scale radioactive spill? For example, say that we needed to put Iranian or North Korean reactors out of action -- how could that be done? 2601:646:8E01:7E0B:E957:E363:9DD1:1743 (talk) 06:44, 11 June 2017 (UTC)