Wikipedia:Reference desk/Archives/Science/2017 July 6

Science desk
< July 5	<< Jun | July | Aug >>	July 7 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

July 6

Do astronauts have to follow any laws?

Is there a governing body for astronauts? Are they excused from paying taxes? How are food resources used? Do they have families in space too? 50.4.236.254 (talk) 03:41, 6 July 2017 (UTC)

Why would you think astronauts are immune from the law and from taxes? They're employees. What do you mean by "how are food resources used" other than by being eaten? And as far as families, there aren't any families together in space as such, although the Kelly twin brothers (Mark and Scott) have been astronauts. ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:20, 6 July 2017 (UTC)

The question is: what nation has jurisdiction over outer space? Ideally, a nation's laws should be restricted to the territory over which they have jurisdiction. But that would leave space lawless. I think it's fair to say that if the need arises, a law will be found to govern any crimes that occur in space. Various nations have extended their jurisdictions and have laws to govern income earned abroad, crimes against its citizens abroad, their vessels on the high sea, etc. I suspect astronauts committing murder aboard a spaceship would be governed by the laws of the entity that financed the spaceship. - Nunh-huh 05:31, 6 July 2017 (UTC)

There is an article called Space law. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:45, 6 July 2017 (UTC)

The country of origin of the spaceship has jurisdiction - this is based on the principles of maritime law. Roger (Dodger67) (talk) 07:05, 6 July 2017 (UTC)

Which for me was the first reference returned when one does a Google search of "Do astronauts have to follow any laws?". Might I suggest the pposter tries out Google search first? Dmcq (talk) 07:28, 6 July 2017 (UTC)

I do believe the poster is taking pleasure asking stupid questions and seeing how we react. --jpgordon^{𝄢𝄆 𝄐𝄇} 14:59, 6 July 2017 (UTC)

IQ tests (real, not Internet)

There was a question "circumference of Earth at equator": biased to those who live on the Equator (and amateur astronomers, (and people who tried to guess the most likely questions and intentionally memorized lots of those)).

"Distance from New York City to London": biased to New Yorkers and Londoners (and the rich who are more likely to have taken that flight(and against people from remote Kazakhstani farms)).

I don't think there were other "how far it is from X to Y questions". Shouldn't they've asked me something like LA to Tokyo instead since the test is in New York and I'm a lifelong New Yorker? Someone in Africa should be asked maybe Cape Town to London. Unless they're in the southern half of Africa then they should be asked Cairo to something and so on. Sagittarian Milky Way (talk) 15:39, 6 July 2017 (UTC)

I don't know what kind of test you took, but I don't think it was a proper IQ test. They don't have trivia questions, and they typically have almost no math.

There is still some concern about test bias, but it's not anything as crazy as what you're talking about.

ApLundell (talk) 15:43, 6 July 2017 (UTC)

It was a WAIS or a WISC or a Stanford-Binet. Trivia-like questions were only a small part of the test (the general knowledge section) and they weren't too hard. The non-humanities trivia questions didn't get harder than these and while the humanities ones weren't so easy to me maybe they'd be very easy if I was a humanities person (if the end of the section was a bit harder I'd be like "To Kill A Mockingbird author, wait what was that dude's name?") Sagittarian Milky Way (talk) 17:34, 6 July 2017 (UTC)

And they didn't need the exact distance. I said "3,000 or 3,500 miles" and don't know how off you could be and still get it right. Sagittarian Milky Way (talk) 17:36, 6 July 2017 (UTC)

Our article seems to conflate IQ with some military aptitude test - the U.S. has one that 25% of people fail, and it would seem reasonable to have questions like these on one like that. (the sort of people who randomly remember the circumference of the equator might turn out to be useful in a planning session) The article has an intriguing claim - sourced to some obscure book in Portuguese - that twice the military tried lowering the IQ standard from 85 to 80 as an experiment, but it didn't work out. I'd love to see a movie about that one ... comedy or tragedy, I'm not sure which. Wnt (talk) 17:43, 6 July 2017 (UTC)

It is common for tests to have deduction questions. Is the circumference of the Earth around 250 miles, 2,500 miles, 25,000 miles, or 250,000 miles? In your head, estimate how far it is from one side of something you know about to the other. For example I know I have to drive 4 days, 8 hours each, to get from one side of I-10 to the other. That means that I-10 must be about 4*8*70 = 2240 miles long. That means that 250 and 2,500 are not the correct answer. Now, how many I-10's does it take to wrap around the Earth? Imagining a map in my head, I'd guess about 10. That makes the circumference of the Earth about 22400 miles. So, 25,000 must be the correct answer. 209.149.113.5 (talk) 19:03, 6 July 2017 (UTC)

Further, I wouldn't claim that people who live near the equator have a better idea of how big the Earth is. Similarly, why would someone who lives in New York know exactly how far away London is? Do you know how far it is from your home to London? They have to use major cities that everyone should know. That leaves very few: New York, LA, Tokyo, Beijing, Paris, and London. You can't, for example, use Moscow because I expect far too many people really don't know where it is. It is somewhere in northern Asia, maybe a little west or maybe a little east. Could it be very far north? Maybe. 209.149.113.5 (talk) 19:12, 6 July 2017 (UTC)

But they only asked for about how far it is. I strongly doubt the test's so harsh as to not accept my educated guess of 3,250 miles (they probably average your cover your ass wavering?). If you remember how many airline reward program miles you got for a flight between the 2 cities or anything from the East Coast to Europe then you probably know enough to guess within the allowed margin of error (whatever that is). Poor people like me are less likely to have been on transatlantic flights or gas guzzling 4-day roadtrips. If you live in a mundane town where being on the equator is the only interesting thing about it (Singapore and Manaus are the only big things near) maybe the curious would find out it's length. Or you might have a guess how long it takes to drive or fly 1 time zone east or west from home and know that there's 24 time zones and have a better chance of guessing close enough than someone that has to adjust for how much fatter the Earth is at 0° than their home latitude (these were the hard part of the general knowledge section so no generous multiple choice). I think they only specify the Equator to make sure no one thinks they want a more average length around the mid-latitudes (like USA to Europe to China to USA) Sagittarian Milky Way (talk) 22:10, 6 July 2017 (UTC)

To think that the equator is relevant in that question is showing that you don't understand how the circumference of a sphere is calculated, so that is normal to dock points for failing to answer that. It doesn't matter where you are on Earth, there are always an infinite number of circumference lines going through you and your antipodes. If they allow for + or minus 70 kms, the fact that the Earth is an oblate spheroid is not relevant. --Lgriot (talk) 15:14, 7 July 2017 (UTC)

Edit: I am now pretty sure circumference is not the right word here above, but I guess everyone will know what I meant --Lgriot (talk) 15:18, 7 July 2017 (UTC)

Great circle. Iapetus (talk) 15:28, 7 July 2017 (UTC)

Yes, I'm aware that a sphere has infinite number of circumference lines per point and the small circles aren't real circumferences. For whatever reason they specified the Equator. Maybe they just want to be clear exactly what they want so if someone answers a few miles under 80% the equatorial circumference (or whatever the allowance is) he can't make an excuse "but I thought you meant the average of the polar and equatorial circumference!" Sagittarian Milky Way (talk) 15:41, 7 July 2017 (UTC)

A planet's oblateness could be indirectly expressed by the ratio by which its longest great circle (the equator) exceeds the shortest. —Tamfang (talk) 05:46, 10 July 2017 (UTC)

What happens at the atomic level when two objects touch each other ?

When two objects touch each other, do the electrons of their atoms collide? Do the protons touch each other? Or neither of both? --Hofhof (talk) 17:40, 6 July 2017 (UTC)

If the protons touched and it was light elements you would see this: . Sagittarian Milky Way (talk) 17:49, 6 July 2017 (UTC)

• WRONG! That's a fission explosion you're showing, not a hydrogen bomb. And fusion will only occur when the products have a lower mass than the reagents. Not all light elements can be made to fuse. μηδείς (talk) 16:04, 7 July 2017 (UTC)

I couldn't find a gif of a fusion explosion on Wikipedia. Sagittarian Milky Way (talk) 00:06, 8 July 2017 (UTC)

(edit conflict) Like they say in the Matrix, Buckle your seatbelt Dorothy, cause Kansas is going bye-bye... ;) You're looking to understand quantum mechanics, which involves a lot of very strange concepts. The lighter something is, the more it acts like a wave of probability rather than a particle. Electrons are like big clouds of probability and atomic nuclei are like little clouds of probability. Protons and neutrons are stuck closely together inside nuclei. The charged particles - protons and electrons - exert tremendous amounts of long range force (electromagnetism) while protons and neutrons are held together by strong force that is short range.

The protons almost never touch - that would be nuclear fusion. They push each other away so hard that even though every particle is in motion, at room temperature or any non center of the Sun like temperature they don't move fast enough to get close enough to touch and stick like in a nucleus. (Even then, the definition of "touch" is iffy -- what I mean really is that they go from being pushed away by electromagnetic force to being pulled together by strong force, but a hypothetical point particle can never touch anything, and the clouds of probability theoretically extend out forever, they just are astronomically, absurdly weak beyond a certain point. Trying to define a surface is done with units like barn (physics) that ... well, they don't readily appeal to intuition.

The electrons "collide" in the sense that they push each other away according to the Pauli exclusion principle if they are in the same quantum state ... which is a weird idea. Something like: You look at the two atoms and how electrons could orbit them in theory ... then you say, the two can't really be moving the same way at the same time, and that means ... they're somewhere else, which means ... they've pushed each other away. But if they get into a state where they are spinning or circling differently, then they can overlap and it may even be attractive to do so, which is where we get chemistry.

Don't let the complexity of some of these links discourage you - but do try to find online courses like Khan Academy or Wikiversity (honestly theirs is way better but Wikiversity you can edit like Wikipedia) that go through in order because there is a lot to learn. Wnt (talk) 17:54, 6 July 2017 (UTC)

Yes, the short answer is that thinking of subatomic particles as "touching" is your ape brain attempting to make sense of what happens at such scales in terms of the familiar macroscopic world that it evolved to understand. Protons, electrons, etc. aren't little tiny solid balls. They're weird (to us) things that behave sometimes like waves and sometimes like particles. They don't have a defined "place" you can point to and say "here's the electron". All you can say is it has a certain probability of being found in a certain space at any given time. As Wnt touched on above, electrons are fermions, meaning it's forbidden by the Pauli exclusion principle for two electrons to have the same quantum state, and this is what gives rise to the "solidity" of normal matter. Bosons, such as photons, aren't subject to this; this is why light doesn't "take up space". Introduction to quantum mechanics is, I think, a decent introduction if you're just dipping your toe into the subject. Also, PBS Space Time is in the middle of a series on quantum mechanics right now. And there are plenty of other good resources. Don't worry if this all seems crazy and counter-intuitive, because it is. --47.138.161.183 (talk) 20:06, 6 July 2017 (UTC)

It's really not necessary to understand all the ins and outs of QM to get an answer to this at a qualitative level. Basically two macroscopic objects "touch" when you get them close enough that their respective electrons start interacting directly. The electrons are not perfectly localized, but they're pretty well localized at the nanometer scale. So the force that one object exerts on the other, as a function of distance, has such a sharp slope (move it out a nanometer and the electrons essentially don't interact, move it in a tenth of a nanometer and they interact much more) that on our scale it appears to be a discontinuity. --Trovatore (talk) 22:16, 6 July 2017 (UTC)

Van der Waals force pretty much explain all, i think it more of interest here than previously mentioned links.

Gem fr (talk) 09:47, 7 July 2017 (UTC)

The Scanning tunneling microscope works (very roughly) by placing a small pointer very close to a surface (within a few tenths of a nanometer) and measuring the interactions between the electrons in the pointer and the electrons in the surface that is being scanned. Gandalf61 (talk) 10:01, 7 July 2017 (UTC)

Brown Pelican

Hi! The article Brown pelican needs a taxonomy section. The HBW pages in English for Linnaeus' original work on the species would contain a lot of information on that. So, it would be really helpful if the source could be provided. Thanks in advance! Adityavagarwal (talk) 18:54, 6 July 2017 (UTC)

Pseudoscience?

I was shocked to have read recently that the Facebook is developing telepathy as a way to communicate their Facebooky pictures or whatnot. This is one of the links[1]. Part of what this article describes is not extrasensory perception (ESP) at all but it has also been tried and failed as I remember. I mean, they want to read brain waves (EEG) and convert them to characters we type on keyboards. But the article also mentions true ESP. They want us to be able to read their minds, it seems. What kind of world do they envision?

Anyhow, there exists a very long history of failed ESP attempts. It seems the Journal of Parapsychology (biannual publication) still exists. Programs at Duke University have apparently been shut down after years of fruitless attempts. Militaries of Russia and the US have tried to harness the non-existing waves for their purposes and to my knowledge have failed also. Does Zuckerberg do any background checks before plowing billions into the impossible? --AboutFace 22 (talk) 19:10, 6 July 2017 (UTC)

It's dated April 19. I had expected it to be April 1. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:12, 6 July 2017 (UTC)

See BrainGate. That is the technology being discussed. It has absolutely nothing to do with ESP (Extra-Sensory Perception). 209.149.113.5 (talk) 19:18, 6 July 2017 (UTC)

Are you sure? The article says they're using Neuroimaging. ApLundell (talk) 19:30, 6 July 2017 (UTC)

BrainGate is an invasive form of the device. There are non-invasive forms as well. From what I've read, the technology that Zuckerburg is interested in is the invasive form. It isn't for playing games. It is to allow people who have absolutely no means of physical movement the ability to control a cursor and interact with a computer. 209.149.113.5 (talk) 19:34, 6 July 2017 (UTC)

Another story that explains that they are working towards a non-invasive model and stating that right now the best model is invasive. If you want to find a lot of articles, search for Facebook Building 8. 209.149.113.5 (talk) 19:43, 6 July 2017 (UTC)

That story and others link those linked by Wnt don't seem to correlate with your idea that Zuckerberg is interested only in invasive BCI or it's only for people with serious disabilities. That may be the short term plan but the long term goal seems to be to work towards non invasive devices to allow people to be on Facebook without having to use a phone. Okay that may be a bit facetious on the part of the sources, but it does seem they are attracted by the augmented reality and brain control for everyone angles. See for example this video [2] which was posted by Zuckerberg. Not forgetting Facebook owns Oculus VR. I wonder if your conflating Zuckerberg's goals with that of Elon Musk's, who's involvement in the field in the form of Neuralink blew up at a similar time [3] [4] [5] [6] [7]. AFAIK Musk does seem interested in implants only although his goal isn't that this will only be for people with serious disabilities idea but his imagination of a transhumanist future. Nil Einne (talk) 07:56, 7 July 2017 (UTC)

There is of course another key difference between what Zuckerberg's doing and Musk. Namely while perhaps Zuckerberg has a big influenceon the project, it isn't really his project but Facebook's. Zuckerberg may be the CEO but Facebook is a public company now and Zuckerberg has Fiduciary Duty to all shareholders who can ultimately ask him to stop or kick him out if they think he's doing something dumb. By comparison Musk started a new company with his and others investments solely for the purpose so it matters a lot less there is any actual plan to somehow gain something significant from their research and they're largely free to plow more of their money into it as they want to and have the money. Nil Einne (talk) 08:57, 7 July 2017 (UTC)

Who says it's impossible? It could just be something mundane described in overly optimistic marketing terms. That's normal enough.

Controlling technology via Brain-computer interfaces is not new. Multiple companies are competing to make Low-cost_BCI-based_interfaces and marketing press releases invariably describe it as "the computer reads your thoughts!".

Even small amounts of control could potentially be useful. Especially for wearable applications. (Sure they say they "want" users to be able to type that way, but I'm sure that's not where they're starting.) ApLundell (talk) 19:24, 6 July 2017 (UTC)

You are talking about "invasive devices." Is it something like drilling a hole in the scull and applying electrical electrodes for stimulation? That has been tried also. Many years ago an investigator, whose last name is Brindley, published an article in the Journal of Physiology describing how he stimulated visual cortex in a woman with life long blindness. I was able to find it: G.S. Brindley, W.S. Lewin The sensations produced by electrical stimulation of the visual cortex J. Physiol., 196 (1968), pp. 479–493 His and other related works are referenced here[8]. There is also a short abstract. As I recall he applied a matrix with 80 electrodes directly to pia mater. The woman certainly saw phosphenes which could be shaped as characters. The problem was that a glial deterioration of the underlying neuronal tissue quickly took place and she lost any ability to see again. I don't know how they do it in deep brain stimulation for Parkinsonism, but this is what happened to that experiment. It was a failure. I can imagine how the lawyers will be happy to sue practitioners who drill holes in the people's brains. --AboutFace 22 (talk) 22:05, 6 July 2017 (UTC)

See [9] and particularly [10]. The latter makes the odd claim that their team is somehow visualizing differences in neural activity by shining lasers through the brain, which is certainly not what I expected. Though Steve Jackson Games did. If neural activity can be visualized, then I have seen fMRI papers that get the rest of the way to "hearing thoughts". [11] Once companies have a choice between the compliant workers who let their brain be recorded so they can type while they're walking around the plant versus the ones who type more slowly only in front of a keyboard, the outcome will be obvious; after that, the company can sell them enhanced access to find out based on the conceptual map of what words are where what the employees' political beliefs and social propensities are, which is a thousand times more important than their work product anyway. Mix in a heavy dose of social credit that they're pioneering and they'll make it so if you don't literally spend two hours a day praying to the Company you might as well grab one of the last unconfiscated guns and end it all. Wnt (talk) 22:37, 6 July 2017 (UTC)

@Wnt, thank you. Your references [18] and [19] are hilarious. They should hire a single person who spent his life sorting bibliography to write a comprehensive literature survey like they did in old times. Zuckerberg, of course, could not wait. I'll tell you, however, that nobody could read my mind. I am sure your brains are safe also. There is another very sad aspect here to consider. Those 60 hired employees may eventually realize after years of fruitless research that they are butting their heads against a wall and will have to find something else to do to make a living. --AboutFace 22 (talk) 23:05, 6 July 2017 (UTC)

Their next project will be perpetual motion. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:25, 7 July 2017 (UTC)

Yes, Perpetuum mobile is a good project for them to apply their boundless wild energy. This is a report on the famous story with USS Nautilus[12]. Anecdotally I've always believed that it was all an American hoax to entice the Soviets to throw their resources int a bogus project. It probably worked. I've read some accounts over the years that they took it seriously. It is a fascinating story, not supernatural though at all. --AboutFace 22 (talk) 15:03, 7 July 2017 (UTC)

As with the so-called "Star Wars" defense system, the prospective cost of which contributed to the cracking of the Soviet Union. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:19, 7 July 2017 (UTC)

I'm not sure if Star Wars works or not, but thanks to the North Koreans we may soon find out. I wasn't expecting this degree of skepticism of the company's claims, given that we are approaching a "single payer publishing system" under their command. There are more bizarre claims out there, but I think something like this reflects where they are starting from, though measuring bloodflow in mice through "thinned skull" remains slightly short of noninvasive mind reading. Never be pessimistic about the odds of something awful to succeed... Wnt (talk) 19:00, 7 July 2017 (UTC)

Just what I need. All the employers asking to get your skull thinned so the mind reader can get through. Sagittarian Milky Way (talk) 21:21, 7 July 2017 (UTC)