Wikipedia:Reference desk/Archives/Science/2019 April 16

= April 16 =

How to prove flat Earth
believers really mean it, and are not an elaborate parody of, say, Creationists? That is, besides our gut feeling about someone being a real crank and not a caricature of a crank, what scientific method do we have to test this? The question can be extended to Earth representations. How could we conclude whether the author of a drawing believed on a flat Earth? Nowadays, we also draw maps on flat surfaces, but without any intention of making a flat-Earther claim. --Doroletho (talk) 00:02, 16 April 2019 (UTC)


 * If there were a scientific method to prove when someone is being sincere, the world would be a very different place. Someguy1221 (talk) 00:08, 16 April 2019 (UTC)


 * Well, sometimes you can prove whether someone truly believes in some crazy stuff. Some HIV infected AIDS denialists didn't get anti-viral treatment. Some breatharians starved to death. --Doroletho (talk) 00:14, 16 April 2019 (UTC)


 * I would challenge your premise that this constitutes proof. I am completely ready to believe that some people will allow themselves to die for the sake of pride. But if you are simply asking for that degree of commitment, well, I'm certainly not aware of any flat earthers who have made realistic efforts to fund a private spaceflight or navigate to the edge of the world. Considering that freakin' teenagers have circumnavigated the globe by sail, one might conclude they are deliberately avoiding feasible tests that could prove their hypothesis wrong, similar to how most pseudomedical and pseudoscientific studies are designed in such a way that no conclusions can actually be drawn. Make of that what you will. Someguy1221 (talk) 04:22, 16 April 2019 (UTC)
 * Those teens made sure to stay away from the edge. ←Baseball Bugs What's up, Doc? carrots→ 04:50, 16 April 2019 (UTC)
 * Well there was this infamous example which failed spectacularly [//www.bbc.com/news/blogs-trending-41399164] www.gofundme.com/showBoBthecurve. However to be fair, even if I did believe in a flat earth and wanted to prove it, I'm not sure that giving money to B.o.B is something I'd consider. Especially since it's not really clear he had a coherent and realistic plan of how to spend the money. And although the media may sometimes overplay it, [//www.newshub.co.nz/home/travel/2019/03/reports-of-flat-earth-cruise-to-antarctica-is-blatantly-false-conference-founder-says.html], it's not like flat earthers aren't willing to spend money attending conferences and such although the travel and socialisation may be sufficient perks for the money spent. The OP is correct it can be difficult know what people are really thinking when they make outrageous claims e.g. [//www.thedrive.com/opinion/20084/the-strange-short-flight-of-flat-earth-rocket-man] [//www.forbes.com/sites/trevornace/2018/03/27/flat-earth-rocket-man-finally-blasts-off-in-homemade-rocket-to-prove-earth-is-flat/] Nil Einne (talk) 01:36, 17 April 2019 (UTC)
 * We have a well-referenced article on pseudoscience, citing dozens of books and papers that analyze and describe pseudoscience at large. If you don't find our encyclopedia sufficiently detailed, the Plato Encyclopedia also has a well-referenced article, Science and Pseudo-Science.
 * What more do you think we can we say on this topic that hasn't already been said elsewhere?
 * Nimur (talk) 00:41, 16 April 2019 (UTC)


 * Related to this topic, there is a blog "100 Proofs that the Earth is a Globe" currently being written by physicist and web-cartoonist David Morgan-Mar, which as of this date has got up to Proof #10. Necessarily he analyses claimed proofs of a flat Earth in the process. {The poster formerly known as 87.81.230.195} 2.122.2.132 (talk) 06:26, 16 April 2019 (UTC)


 * I read the OP to question about more ancient maps and the discovery that the earth was indeed a globe at a later stage in history and thereby how would one prove if the aforementioned map maker had been aware of the earth being a sphere, or if they had believed the earth to be flat. — Preceding unsigned comment added by 81.131.40.58 (talk) 08:19, 16 April 2019 (UTC)


 * The main "proof" of a flat earth, as a cultural phenomenon rather than geodesy is that, "NASA says it is, I disbelieve everything The Government tells me on principle, I am supported in this by my group of friends and our venal leaders."  So any appeals to logic or measurement are largely irrelevant to that.
 * There is very little simple 'ignorance' in the FE movements, certainly not in the more vocal advocates. Andy Dingley (talk) 09:11, 16 April 2019 (UTC)
 * Jonathan Swift, in 1721, said "Reasoning will never make a Man correct an ill Opinion, which by Reasoning he never acquired". 300 years later, humanity has not gotten much better at this. Here's a decent article from a neuroscience perspective that explains why actual facts aren't that relevant to changing people's minds on anything.  -- Jayron 32 12:25, 16 April 2019 (UTC)
 * The kind of "thinking" on the flat earth is the same as the claims that we never went to the moon. ←Baseball Bugs What's up, Doc? carrots→ 17:16, 16 April 2019 (UTC)

"Any fool can look out his window and see that the earth is flat." --Guy Macon (talk) 14:50, 16 April 2019 (UTC)


 * There are experiments such as the Bedford Level experiment, which Flat-Earthers claim shows that the Earth is flat. The Bedford Level is a slow flat canalized river, 6 miles (10km) long. It is long enough to show the horizon distance, when there is no wind. A strong wind can force water from one end of a lake to the other, causing a slight difference in height. If the experiment is done correctly, then it does show the expected curvature. LongHairedFop (talk) 20:49, 16 April 2019 (UTC)
 * Like the Universe, the Earth is approximately flat. Wnt (talk) 03:45, 17 April 2019 (UTC)


 * Some people believe their own lies . 2A00:23C2:B80:4500:E5AF:BD7B:5868:3521 (talk) 12:19, 17 April 2019 (UTC)


 * I don't have a good idea how flat-earthers handwave away time zones (etc.), but two sets of simultaneously-taken images, one set from several points on Earth at similar latitudes but widely spaced in longitude, and a second set at a spread in latitude from sites at the same longitude, showing the Sun's (or Moon's) altitude and azimuth from those positions, could in principle provide data that would be awkward for the approximately-spherical Earth model. Such data does in actuality give results which are incompatible with a flat-Earth model, of course.  I also would need to think about how they handwave away the rotated appearance of the Moon seen at very different latitudes; if you are used to living at around 40 degrees N, when you arrive at 30 degrees S for the first time and look at the sky, the Moon "is upside down". BSVulturis (talk) 05:37, 19 April 2019 (UTC)

hibernation
Hibernators need to put on weight before undergoing hibernation. But what happens to the unfortunate animal that didn't manage to build up enough body fat before winter hits? I'm guessing it could be one of the follow scenarios:

1. The body's internal mechanisms knows there's not enough body fat to hibernate, so it skips/delays hibernation until enough food is found.

2. The body doesn't know or doesn't care that there's not enough body fat, and enters hibernation anyways. The animal quietly dies during hibernation.

3. The body doesn't know or doesn't care that there's not enough body fat, and enters hibernation anyways. Hibernation continues for as long as possible until all the available body fat is used up, and the animal exits hibernation early. There's not enough fat to continue hibernation, so the animal's only choice is to find food in the winter. This similar to scenario 1 except delayed by a few months.

Which scenario is the closest one?

I'm interested in the behavior of hibernators in general and the American black bear in particular. Thanks. Mũeller (talk) 07:38, 16 April 2019 (UTC)


 * Keep in mind that bears are not the only kind of hibernator. Hummingbirds have a form of hibernation that happens every night. and one human supposedly hibernated for 32 years. --Guy Macon (talk) 12:13, 16 April 2019 (UTC)
 * For the human part, emphasis on "supposedly". (She was drinking milk and trimming her nails... even "sleeping" sounds unlikely, let alone anything else close to "hibernating".) Tigraan Click here to contact me 08:32, 19 April 2019 (UTC)


 * Not direct answers, but what I've found implies 1 or 3. Bears do not usually die of starvation in dens, most deaths from starvation are before or after hibernation and involve primarily cubs and yearlings; In northeastern Minnesota, where food is unavailable for about seven months and bears hibernate for five to seven months, it was noted that while no Ursus americanus - American black bears died of starvation while hibernating, some died in spring after emerging from the den.


 * Bears, incidentally, are not a very good example of hibernators, as their state of torpor is not the same as classic hibernation (although definitions vary). HenryFlower 14:51, 16 April 2019 (UTC)

When was and for how long was the background radiation around room temperature?
I have heard but can’t find remark by some famous scientist that the universe was once at room temperature. Does this refer to the presently cold microwave background radiation? Anyway, how long ago and for how long did the temperature last between about 100 fahrenheit to 70 fahrenheit? Was the universe made ip of atoms at that time? How dense/large was the universe? I don’t remember if the famous scientist said that was a good time for organic chemicals to form and biochemistry to happen, but I got the impression that was what he or she was thinking about.Rich (talk) 14:03, 16 April 2019 (UTC)
 * See Chronology of the universe. According to the chart there, the universe was on the order of 103 K (which is the ballpark of "room temperature" as close as we can get) sometime during the "cosmological Dark Ages" which would have been about 380,000 - 150 million years after the big bang.  This time frame is when the universe cooled from 6000K down to about 60K, and given that room temperature (basically 300K or so) is between those numbers, there's you time frame, probably closer to the end than the beginning of that time period.  -- Jayron 32 14:09, 16 April 2019 (UTC)
 * The current temperature of the microwave background is about 2.7 K. So, the room temperature (~ 300 K) was at z ~ 100, which corresponds to the age of the universe of about 10-15 million years. At that time there was no stars, galaxies or any other celestial objects. The universe consisted of cool hydrogen-helium gas with small admixture of deuterium and lithium. So, no organic compounds could exist at that time. Ruslik_ Zero 20:53, 16 April 2019 (UTC)
 * Well couldn’t carbon have been created by cosmic rays striking beryllium or lithium?Rich (talk) 07:40, 17 April 2019 (UTC)
 * How so? In order to get a larger atom, you need to have extremely high-pressure inside-of-a-star type situation, where nuclear fusion can happen.  A "cosmic ray" striking a smaller atom cannot magically make it become larger!  See Stellar nucleosynthesis.  For carbon, you need the Triple-alpha process.  In Big Bang nucleosynthesis, you don't get any atoms larger than beryllium, and you don't get any stable nuclei larger than lithium.  There are some wacky hypotheses that carbon-based life could have evolved in a narrow epoch when liquid water could have formed in the ambient universe and where there was a nearby star to provide a source of carbon, see Chronology of the universe in the section titled Speculative "habitable epoch", and I think the emphasis on that is "speculative".  I don't know that anyone much takes it seriously. -- Jayron 32 12:00, 17 April 2019 (UTC)
 * The beryllium article says energetic alpha particles can make a beryllium nucleus into a carbon 12 nucleus.Rich (talk) 05:06, 18 April 2019 (UTC)
 * So it does. However, that is beryllium-9.  There wasn't enough stable beryllium-9 around prior to star formation for that to be a thing.  Any beryllium created would be Be-7, and that would have decayed into lithium.  And that also would not have formed carbon in the method described in the beryllium article, which requires Be-9.  See Big Bang nucleosynthesis.  I quote "Essentially all of the elements that are heavier than lithium were created much later, by stellar nucleosynthesis in evolving and exploding stars."  -- Jayron 32 12:30, 18 April 2019 (UTC)
 * Very very very thin gas right? Sagittarian Milky Way (talk) 02:20, 17 April 2019 (UTC)
 * actually gives some figures for density at several points. Already, when the universe was about 20 minutes old and Big Bang nucleosynthesis ceased, the spherical volume of space which will become the observable universe is about 300 light-years in radius, baryonic matter density is on the order of 4 grams per m3 (about 0.3% of sea level air density). --47.146.63.87 (talk) 07:28, 17 April 2019 (UTC)

Effect of path of Bluetooth cable on signal strength
I'm making a mount for my Bluetooth antenna to attach it to my desk. I have a question regarding the cable that connects the USB Bluetooth dongle to the amplifier. Does it matter what shape it forms? In [my first attempt] (I will have to scrap this for unrelated reasons), the cable forms an S or N shape, but I could also design a mount to produce a U shape or, much less conveniently, a straight line. Does the shape of this cable have an affect on the signal? Thanks. 78.149.180.132 (talk) 21:16, 16 April 2019 (UTC)
 * Assuming the Coaxial cable has Characteristic impedance that matches the dongle and amplifier (usually 50 or 75 ohms) at Bluetooth frequencies 2.400 to 2.485 GHz, its shape will have very little effect ( not affect ). DroneB (talk) 00:31, 17 April 2019 (UTC)