Wikipedia:Reference desk/Archives/Science/2015 February 15

= February 15 =

Need a Picture of Evolutionary Biologist Robert Trivers
Robert Trivers is one of the most significant biologists currently alive. His Wikipedia page is pretty sparce. One thing I want to do is to add a picture to his Infobox. I looked in the Commons but no luck. I sent an email to the web master on Trivers' personal web site and got a good immediate response but then no follow up. (WP:BLP info removed). If anyone has a decent image of Trivers that is in the public domain please let me know. Thanks. --MadScientistX11 (talk) 02:58, 15 February 2015 (UTC)


 * I have redacted BLP info, possibly defamatory, and irrelevant to the question at hand. μηδείς (talk) 05:07, 15 February 2015 (UTC)


 * I looked high and low on this, because I agree with you that Trivers' contributions cannot be understated, especially to the vital and broadly relevant fields of sociobiology and evolutionary psychology that he helped define.  Unfortunately, everything I came across seemed to be commercial.  I did find the photo on this page, apparently from a commencement address, and found the facebook page of the photographer.  Perhaps, given the generally non-commercial nature of the photo, he'd be willing to release it an open license? It's possibly worth looking into in any event; it's a less than ideal photo but better than nothing I'd say.  Good luck in any event and do feel free to message me if you need an extra set of hands with sourcing or building up that page.  S n o w  talk 04:23, 16 February 2015 (UTC)

Seeing the curvature of the earth from land
Some people claim to see the curvature of the Earth from a plane flying above 35,000 ft. There are scientific studies that show that this is the case. However, there are claims that there are only a few places on Earth where one can actually see the curvature of the Earth from land. Is it really scientifically possible to see the curvature of the earth from very flat land? If so, why would that be the case since we are too close to the ground level and the Earth is so big? If not, why do many of these claims come from official sources?

It is said that the Bonneville Salt Flats in Nevada near the border with Utah is so flat that from the top of Wendover Hill, you can actually the curvature of the Earth. The same claim is said for the Mundi Mundi plains from the top Broken Hill near Silverton, Australia. Some people claim you can actually see the curvature of the Earth in Black Rock Desert in Nevada because it is so flat. However, this time others question this claim. One source says, “Within the Black Rock, the most striking and prominent feature is a silt alkaline Salt Pan, commonly referred to as a playa. The Black Rock Playa, elevation 3,848 ft, is the second-largest flat region in the Northern Hemisphere….The longest stretch of playa is 27 miles along the west arm. South of the intersecting arms, the widest spot is 12 miles. The playa has a ‘bulge’ in the middle that is widely reported to be the visible curvature of the earth; this is actually the result of water pressure and the expanding clays that make up the playa fill….”. Willminator (talk) 03:12, 15 February 2015 (UTC)


 * Yea, seeing the curvature of the Earth really requires that you be up high, next to an ocean, because you know the ocean isn't "lumpy", while land certainly can be. StuRat (talk) 03:21, 15 February 2015 (UTC)


 * But these places I mentioned aren't next to an ocean. Willminator (talk) 03:25, 15 February 2015 (UTC)


 * This is my point. You may think you are seeing the curvature of the Earth, while you really are only seeing a local bulge.  (Holding a staightedge, like a yardstick, up to the horizon will tell you if there is an apparent bulge, but you still won't know the cause of this bulge.) StuRat (talk) 03:35, 15 February 2015 (UTC)
 * I know that as mentioned previously that for the Black Rock Playa in the Black Rock Desert of Nevada, some sources do mention that there is a bulge in the middle that is often mistaken as being the natural curvature of the Earth, but I can't find a source that says that there is a bulge in the Bonneville Salt Flats or in the Mundi Mundi Plains. This article says that the broad expanse of the Bonneville Salt Flats allows you to see the curvature of the earth from Wendover Boulevard above town. The curvature is visible both day and night but is easier to see at night because of the lineal trail of headlights on Interstate 80. Why do some sources say that the Bonneville Salt Flats and the Mundi Mundi plains are the only two places on Earth where you can actually see the curvature of the Earth from the land? Why those 2 places only without being questioned? Willminator (talk) 20:22, 15 February 2015 (UTC)
 * The 8.7 km straight on the Ehra-Lessien test track is so flat that the far end is hidden from view by the curvature of the Earth.--2A01:E34:EF5E:4640:B59C:3923:4D06:7BC1 (talk) 10:18, 15 February 2015 (UTC)
 * I just found another place on Earth where it is said to be so flat you can see the curvature of the Earth, the Salar de Uyuni in Bolivia Willminator (talk) 00:16, 16 February 2015 (UTC)

I believe one can see the curvature on 90 Mile Beach in New Zealand - the beach is almost perfectly straight for 90 miles ... Collect (talk) 00:30, 16 February 2015 (UTC)


 * It is said that one can see the curvature of the Earth from the top of Burj Khalifa in Dubai. 71.98.168.49 (talk) 22:06, 19 February 2015 (UTC)

About Schizotypal Personality Disorder
1. Are there paid clinical trials for SPD patients?

2. Will SPD render me ineligible for a DOT medical card (and therefore, to drive commercially?)

3. Why would life insurance exclude me from coverage for having SPD?

4. Now that I'm with a new mental health office waiting for a new diagnosis, is it best to not have records transferred from the old mental health office so that I can stand a chance of being diagnosed with something better? (I think Asperger's Syndrome / ASD was the better diagnosis, that I was re-diagnosed from in 2010.)

5. How common is homelessness for SPD sufferers?

6. What say I just hide my SPD from life insurance agents during the interview? After all, how would they find out anyhow?

Thanks for the help. --2602:306:B8A5:26B0:4D5C:381C:5357:6070 (talk) 08:42, 15 February 2015 (UTC)


 * I'm very sorry to have to say only the following in response to your question, but I'm afraid we have a policy here which prohibits us from giving advice on personal medical and/or legal circumstances, and unfortunately it extends to psychiatric matters. The best we can do is recommend you seek a professional to help you sort out these issues.  I know that response is less than useful to you in your particular circumstances, since you are largely seeking guidance in how to approach your medical providers about this issue in the first place, but unfortunately those very questions combine two types of advice we are barred from giving here.   The only one of your questions which we may be able to answer is #5, since it is a statistical matter that does not reflect on your specific circumstances.  Unfortunately I don't know the answer to that question, but I will see what I can find.   S n o w  talk 08:59, 15 February 2015 (UTC)


 * 1 and 5 can be answered with facts and without knowing anything about the OP, but only before a certain user with a Greek name, that I don't want to mention, appears and closes the question.Noopolo (talk) 13:22, 15 February 2015 (UTC)


 * Technically you're right -- you could answer #1 without giving direct advice, with a simple yes or no. But by clinical studies I took the OP to mean drug trials and mentioning a particular study would start to get into the territory of diagnostics and treatment.   Unfortunately, with regard to #5, I was only able to immediately find this source as regards the specific correlation between this condition and homelessness.  Needless to say, there's a fair bit of research into the prevalence of personality disorders in general amongst the homeless, and an absolute mountain of it with regard to the prevalence of mental health issues broadly amongst such populations.  But with the borders between specific personality disorders being an ongoing area of inquiry and debate, I think specific figures on SPD are going to be few and far between.  S n o w  talk 13:51, 15 February 2015 (UTC)


 * I think if you're expecting to make significant money as a research guinea-pig, you're likely to be disappointed. I've volunteered in the past, and the pay is not great. I probably walked away with a maximum of $50 per research project. Then again, for you, this may be a significant sum. As you don't mention which area you're in, I'm afraid I can't assist. Clinical trials usually look to recruit locals in the area of the university / research center. (Sorry, but no, they will usually not pay for your airline ticket or hotel bills to fly you in).
 * As to the life insurance questions - life insurance companies do sometimes offer individual policies to people with pre-existing conditions, but there may be specific exceptions (such as, in your case, they would quite likely specifically and permanently exclude death by suicide or drug overdose), and you should expect higher premiums (a "loading", to use insurance-industry lexicon). I'm unfamiliar with the area. Can anyone provide the OP with some links to organisations which advocate for or assist disabled individuals in general in dealing with insurance matters? I presume this could be done without constituting legal or medical advice (just advice on where to get proper medico-legal advice).


 * EDIT: For information specific to Australia, you might find a useful read. It covers some of the questions you ask, such as how the insurer may find out, and what cover may be offered. I presume the USA insurers may have similar rules. 121.214.50.54 (talk) 13:28, 17 February 2015 (UTC)

Who am I -- ungulates(?) in Slovakia
{{answered|text= Welcome to the latest instalment of my occasional requests for help with animal ID. Today's entrants are from Bratislava, Slovakia, but they live in a fenced area, so may not be native. I would guess deer of some kind, but they're suspiciously hairy. Any ideas gratefully received! Henry{{sup|Flower}} 08:45, 15 February 2015 (UTC)


 * Looks like a variety of musk deer to me. But the morphology of the jaw and ears doesn't fit with any species I've seen before.  Alternatively, a muntjac is another possibility. I'm fairly sure it's one of those genera or the other.  Certainly it seems to be a deer (that is cervidae) of some sort.  S n o w  talk 09:02, 15 February 2015 (UTC)




 * They look like (relatively) short-eared dairy goats --Digrpat (talk) 12:35, 15 February 2015 (UTC)


 * Well, I'll grant you the heads do look a little goat-like, but everything else that can be seen about their external morphology is wrong for a goat (or any species within capra, I'd say). Observe the contours of the neck, back, and torso.  I'm thinking these have got to be deer of some sort. Only the ambiguity of the shot with regard to the head gives me any pause.  S n o w  talk 13:18, 15 February 2015 (UTC)


 * Thank you both for your thoughts so far. :) Henry{{sup|Flower}} 20:00, 15 February 2015 (UTC)

My money is on the Tatra chamois, Rupicapra rupicapra μηδείς (talk) 22:53, 15 February 2015 (UTC)


 * The markings do seem consistent, and the range would be right as well, apparently. They would seem to be juveniles if that is the case.  S n o w  talk 03:49, 16 February 2015 (UTC)

Unless someone (Henry especially) has a doubt, I think Medeis has the right of this; these seem to be a type of caprid called a chamois.  S n o w  talk 14:05, 16 February 2015 (UTC)
 * I hope they're being used for vegetation control. <:- {     S n o w  talk 14:22, 16 February 2015 (UTC)
 * Splendid -- thanks all. Henry{{sup|Flower}} 15:09, 16 February 2015 (UTC)

}}

Sustainability magazines
Are there any magazines that regularly feature sustainability issues? I know national geographic sometimes does but not regularly. 94.118.96.3 (talk) 13:36, 15 February 2015 (UTC)


 * Do you mean otherwise famous magazines with just incidental sustainability issues? Because there's no shortage of magazines devoted specifically to the topic of sustainability:, , , , , .  Those are just some general interest magazines.  Factoring in peer-review journals in areas of ecology, engineering, agriculture, economics and other areas with an environmental leaning and trade magazines geared toward sustainable businesses, there are surely scores if not hundreds of publications that gear in this direction.  S n o w  talk 14:12, 15 February 2015 (UTC)
 * Yes, I mean out of the major ones. As opposed to industry magazines. 194.66.246.52 (talk) 15:06, 15 February 2015 (UTC)

Planck times
''Theoretically, this is the smallest time measurement that will ever be possible, roughly 10−43 seconds. Within the framework of the laws of physics as we understand them today, for times less than one Planck time apart, we can neither measure nor detect any change.''

Quoted from the Planck time article. Why isn't 2 Planck times the theoretically shortest time measurement: one PT for the photon to go the Planck length, and one to bounce back to the observer? If we have something capable of measuring time in this order of magnitude, how would we be able to know that the photon had left one end of the Planck length; wouldn't our first indicator be 2 PTs later, when it bounced back? Nyttend (talk) 15:32, 15 February 2015 (UTC)


 * Your valid concern is whether we would need to account for time of flight of a particle. We already have equations for that.  In the context of theoretical mathematical physics, that kind of adjustment is a practical consideration - just like the sampling theorem, for that matter - even though it is clearly derived from application of pure principles of mathematics.  It only modifies the value by a constant factor; the mechanism is well understood; and theoretical physicists are so used to multiplying by 2, or 2π, or some other factor, that they will ordinarily ignore such details.  It's a completely weird mindset that ignores very important details - but keep in mind that this mindset is not intended for solving problems, only for exploring ideas.  Nimur (talk) 16:00, 15 February 2015 (UTC)
 * So basically we'd record the elapsed time and cut it in half? That makes sense, but I don't understand why then we couldn't use half-PTs by recording our observation and cutting it in four.  The article quote sounds like it's saying that we can't observe the passage of a shorter period of time, and observing 2 PTs and using half of the result doesn't sound like observing 1 PT to me.  Nyttend (talk) 20:00, 15 February 2015 (UTC)


 * Researchers at MIT have found the shortest time measurement.
 * They discovered that it was the interval between the lights turning green and the guy behind you blowing his horn.  Widneymanor (talk) 15:55, 15 February 2015 (UTC)
 * : -) Nyttend (talk) 20:00, 15 February 2015 (UTC)


 * The Planck time and Planck length get referred to as the smallest possible, but that's not really correct. It would be more accurate to say that they are values at which our present understanding of physics is obviously incomplete due to the unambiguous need to use both quantum mechanics and general relativity in order to describe the events occurring on that scale (i.e. the need for a theory of quantum gravity).  Without a theory of quantum gravity (or something like it), we can't really say what transpires on very short time scales and distances.  Maybe matter remains well-behaved on that scale, and maybe it doesn't.  A complete theory of quantum gravity might very well let us describe even finer times and distances.  On the other hand, the true limit of measurement might even be much larger than implied by the Planck units.  Our current limits of time measurement are roughly 1026 times larger than the Planck time, and our most energetic man-made particles are 1016 away from probing the Planck length.  To the best of my knowledge, space-time could become discrete on scales a billion times larger than the Planck length without interfering with any known observational constraint.  Without either a theory that works on the Planck scale, or an experiment that probes it, really the best we can say is that we don't know what goes on there.  Given that, worrying about hypothetical factors of two and time of flight measurements on that scale is rather pointless.  Dragons flight (talk) 20:20, 15 February 2015 (UTC)


 * I did some major surgery on the Planck time article. The quoted text (which was wrong) is no longer there. -- BenRG (talk) 20:41, 15 February 2015 (UTC)

Check valve with rubber plug?
Hi! .. Is it okey to call this: www.droh.de/artikel/12-afp-01-fingertip-verschlussstopfen/ a "check valve with rubber plug" (or bung, stopper?) rather than "fingertip"? Or is there even a specific term for this medical instrument? [carried from german refdesk Thanks advanced! --217.84.69.159 (talk) 16:30, 15 February 2015 (UTC)


 * (Disclaimer: I'm not familiar with device on the website you linked to. My answer is a layperson's educated guess.) I don't think the device is a check valve. (A check valve is a flow control device that allows fluid to flow in one direction only.) A machine translation of the German text into English suggests that the device is intended to be placed in the middle of some suction line. It appears that the plug in the middle, when unplugged, will "break" the suction by allowing air to flow into the suction line. This UK website carries a similar looking device. On the website, the device is called "suction control valve". --98.114.146.37 (talk) 17:20, 15 February 2015 (UTC)
 * Perfect! Sry for not translating the use of it! Exactly what it's used for. Thanks a lot! ✅ --217.84.69.159 (talk) 23:44, 15 February 2015 (UTC)

Why do Europeans are more diverse regarding hair and eye color?
Europeans seem to have specimens in the whole Fischer–Saller scale (hair color) or the whole Martin–Schultz scale (eyes). In other regions, genetics seems to have favored black hair and eyes, invariably. But Europeans have any hair color that exists: red, blond, brown, black, and any eye color that exists.--Noopolo (talk) 16:46, 15 February 2015 (UTC) Moved by Robert McClenon (talk) 17:04, 15 February 2015 (UTC)
 * melting pot. Central geographical location (other, than North-America). Many cultures on comparedly small space in a fertile land. Then, no less given variations of dark and black won't occur to you just as much, which makes the subsupmtion (of uncomparably greater variability) partly an optical delusion or selective conceiving. --217.84.69.159 (talk) 17:19, 15 February 2015 (UTC)
 * You asked about hair color and eye color. You didn't mention skin color.  Here is my guess, only a guess.  Dark skin and dark eyes are adaptations to the African tropical sun, and I would guess that dark hair also is.  In the middle to northern latitudes, there may no longer be any adaptive or maladaptive value for any particular hair or eye color, so that those scatter rather than being pulled back to dark.  Skin color is a little different.  In the northern latitudes, fair skin is adaptive, because dark skin is not necessary to protect against the northern sun, but fair skin absorbs the sun's rays to support vitamin D formation.  In the middle latitudes, e.g., the Mediterranean, medium skin is adaptive, with enough pigment to protect against the sun but with some vitamin D formation.  So, with less sunlight, skin color is pushed in the direction of fairer skin, and hair and eye color are not pushed in any direction, and so can scatter.  That may explain Europeans, who have been out of Africa long enough to be adapted to reduced sun.  By the way, it is my understanding that East Asians have lost dark skin via a different genetic change, giving them a differently distinctive light skin tone.  However, Asians, including East Asians, still have dark hair and eyes.  Robert McClenon (talk) 17:25, 15 February 2015 (UTC)

Light hair coloration map.png, from 2006 study European hair and eye color a case of frequency-dependent sexual selection? by Peter Frost

you might look at the works of Carleton Coon. While his theories are long outdated, his physical observations are acute. The Living Races of Man is a wonderful encyclopedic work of human diversity with scores of human subtypes with each depicted by a "typical" member. Unfortunately the work is in black and white. μηδείς (talk) 21:43, 15 February 2015 (UTC)
 * 250x250px]]
 * See Blond, especially Blond: "Natural lighter hair colors occur most often in Europe and less frequently in other areas. In Northern European populations, the occurrence of blond hair is very frequent. The hair color gene MC1R has at least seven variants in Europe giving the continent a wide range of hair and eye shades. Based on recent genetic research carried out at three Japanese universities, the date of the genetic mutation that resulted in blond hair in Europe has been isolated to about 11,000 years ago during the last ice age." The gene for blondism seems to have originated in or around the Baltic states, and has spread through sexual selection.  Blond hair is also found among the inhabitants of New Guinea. μηδείς (talk) 17:28, 15 February 2015 (UTC)


 * Unfortunately so were Coon's theories... AndyTheGrump (talk) 22:11, 15 February 2015 (UTC)


 * That's not justified, he was no more a racist because he studied race (we can call it physical anthropology, so as not to scare the children) than a detective is a criminal for studying crime. His writing is objective and his observations unchallenged. He died ('81) at a time when his work was attacked on political grounds, and he never had the advantage of the modern tools we have now. μηδείς (talk) 22:30, 15 February 2015 (UTC)


 * Having studied physical anthropology, I can assure you that it is not in any shape or form a euphemism for 'race'. And as for Coon, he evidently not only supported segregationist policies in the United States, but actively intervened in the debate over the issue. If he wasn't a racist, he certainly facilitated racism. AndyTheGrump (talk) 22:51, 15 February 2015 (UTC)
 * That source doesn't say Coon espoused racism. It says unnamed racists saw his theories as supporting them.  But plenty of people, like Darwin and Nietzsche's writings have been used by quacks. μηδείς (talk) 01:44, 16 February 2015 (UTC)


 * The article on Carleton S. Coon agrees with AndyTheGrump that Coon's views were criticized as racist in his own time. I agree with Medeis's comment that "his theories are long outdated" although not with her defense of his theories.  His support of the multi-racial hypothesis should not be held against him, but his views were white-supremacist.  (So were those of many reputable scholars at the time, but it doesn't mean that they weren't fairly criticized then or that they shouldn't be criticized now.)  Robert McClenon (talk) 00:23, 16 February 2015 (UTC)


 * One, there's Coon, and there's Coon's views. There's no allegation Coon himself was racist.  Believing in good faith a certain false idea is not the same as treating people immorally on the basis of race.  Coon's arguments on the origins of the races were wrong (and such ideas as the Alpine Race were around for a long time before Coon).


 * Nor, am I, as you say giving a "defense of his theories". I said his physical observations were acute.  That's an important difference I was very careful to make, and you've misattributed me.  The Living Races of Man is a masterful work if you read it purely descriptively, and are aware that his suppositions have long been proven false, largely due to genetic work that wasn't possible for ten years until after he died. μηδείς (talk) 01:44, 16 February 2015 (UTC)
 * I agree that his physical observations were acute. When you said that his images were in black and white, ATG said that his theories also were.  Some of his theories were just proven incorrect by modern science, but, in retrospect, some of them must be seen as having been racist.  Robert McClenon (talk) 01:57, 16 February 2015 (UTC)


 * Yes. When I use the term racist I mean making collective moral judgments (personally or legally) about people based on their physical characteristics, not their chosen actions.  Coon's work was racial, but no one has pointed to where he was a racist.  And of course racists would use his work.  But that can be done even now with other genetic work, like the discovery of the Cohen Y-chromosome.  That discovery is not racist, but it could be put to racist use.


 * In any case, this is off-topic. I wonder if there might not be a good, modern, color encyclopedia of human variation. μηδείς (talk) 03:18, 16 February 2015 (UTC)

I's probably easier to look a a species like dogs. Great expressions of variation is achieved through selective and isolated breeding, not a melting pot. The easiest way to suppress variety is to mingle purebred dogs for a few generations of mutts and all the variation of expression is gone and a generic mutt has very uniform features. Expressed variation in that case is the opposite of melting pot. --DHeyward (talk) 01:58, 17 February 2015 (UTC)

What is the farthest distance from Earth reached by a spacecraft that came back?
?--Fend 83 (talk) 21:36, 15 February 2015 (UTC)


 * The Apollo 13 mission, see also List of spaceflight records. μηδείς (talk) 21:48, 15 February 2015 (UTC)
 * Apollo 13 holds the record for a manned spaceflight. The unmanned record is probably held by the Hayabusa asteroid probe, although finding numbers for the exact distance it reached is proving tricky.  J002E3 might have been further out at some point in the 1980's, but only returned to the vicinity of the Earth, not to its surface.  Tevildo (talk) 22:04, 15 February 2015 (UTC)


 * Stardust (spacecraft) Not all of it, just the interstellar particle collector.--Aspro (talk) 22:06, 15 February 2015 (UTC)