Wikipedia:Reference desk/Archives/Science/2017 August 25

= August 25 =

Eclipse on other planets
Do any planets in the Solar System besides Earth experience total (as opposed to partial or annular) solar eclipses? 2601:646:8E01:7E0B:84FD:477A:71AB:7A1E (talk) 06:16, 25 August 2017 (UTC)


 * Yes, every planet further than Mars. (except possibly X) Sagittarian Milky Way (talk) 06:39, 25 August 2017 (UTC)
 * Category:Solar eclipses by planet --47.138.161.183 (talk) 07:33, 25 August 2017 (UTC)
 * Mars's Moons are basically space junk. :)Naraht (talk) 15:23, 25 August 2017 (UTC)
 * One planet's junk is another planet's treasure. --47.138.161.183 (talk) 18:14, 25 August 2017 (UTC)
 * Jupiter, Saturn, Uranus, and Neptune can all have total eclipses from a variety of moons, which all appear significantly larger than the Sun in their skies. The moons of Mars are not quite large or close enough to do this, and Mercury and Venus don't even have moons. So it is really quite a coincidence that Earth's Moon has almost exactly the same apparent angular diameter as the sun, allowing total, partial, and annular eclipses. Double sharp (talk) 08:23, 25 August 2017 (UTC)
 * Which leads to an important point: it's because of this coincidence that, when there is a total solar eclipse on the Earth, we can see essentially the entire solar corona. If the Sun is eclipsed by a body that "appears significantly larger than the Sun", this won't happen.  The kind of eclipses we have would only be possible with suitably small eclipsing bodies, and would be quite rare, whereas total solar eclipses are common on the Earth if you take the whole planet into account. --69.159.60.147 (talk) 19:57, 28 August 2017 (UTC)


 * Extraterrestrial_skies discusses this to some extent. Ultimately it comes down to the sun appearing quite small - literally not much larger than a typical background "star" - once you get out to the orbit of Jupiter. With that small an angular diameter, even a very small chunk of "moon" can eclipse he sun. Matt Deres (talk) 13:05, 25 August 2017 (UTC)


 * Yes, when the Venus moves between Sun and Earth, we do no see anything. It is like a pin in front of a large head light. The light from the other side of the reflector in the head lamp spreads light behind the nail and no shadow is visible the no close enough to the nail. But projecting the sun on a white sheet, makes the Venus appear as a small dark round dot, moving though the light spot, called the transit of Venus. As the moon is close enough, its shadow reaches the Earth in an eclipse. On the other hand, Venus is a planet. The Moon is a moon of the Earth. Some other planets have moons, for example moons of Jupiter. -- Hans Haase (有问题吗) 09:25, 26 August 2017 (UTC)


 * When the first telescopes were turned on Jupiter its satellites were discovered and the times of their eclipses when they passed behind the planet calculated.  It was noted that these occultations arrived earlier than calculated for six months and then later for six months.   The finite velocity of light was discovered when it was found that the nearer the planet was the earlier these eclipses happened.   It was then noticed that however the bodies were moving the speed of light was always the same.   The Michelson-Morley experiment confirmed this and Einstein used the result to develop his theory of relativity, which was confirmed by the observation of a total solar eclipse in 1919. 92.8.219.206 (talk) 18:31, 26 August 2017 (UTC)

Tree with the largest shadow
What single tree or shade tree is known to give the largest shadow by area among all known trees? Both currently existing and theoretically, in terms of species. Thanks. 212.180.235.46 (talk) 14:52, 25 August 2017 (UTC)


 * Wikipedia has an article titled Tree crown measurement which would be a good place to start your research. The section titled "largest crown spread" has some contenders.  This article also has some possibilities.  -- Jayron 32 15:56, 25 August 2017 (UTC)


 * What is the maximum number of shade tree mechanics ever found under one shade tree? All the best: Rich Farmbrough, 18:25, 25 August 2017 (UTC).


 * Height will also matter, as will whether the foliage extends from the ground to the top, or is just at the top, as in palm trees. Then there's whether it blocks all sunlight or lets patches through. StuRat (talk) 22:01, 25 August 2017 (UTC)


 * As far as the theoretical limit for a "single tree", some species have multiple trunks, and that could extend to an entire forest being one "tree", theoretically. There's a clonal colony of aspens of interest here: "The Pando colony in Utah contains an estimated 47,000 stems and occupies 107 acres": . StuRat (talk) 22:05, 25 August 2017 (UTC)


 * Theoretically there is no limit, but currently existing, probably Thimmamma Marrimanu, a banyan tree. Looie496 (talk) 15:43, 26 August 2017 (UTC)

Insect identification
This [left] is an actual live bug in Missouri, U.S. Any help identifying this guy? &#8213; Mandruss  &#9742;  19:07, 25 August 2017 (UTC)


 * A cropped image leaving out the zipper would help, but almost certainly a Tiger Swallowtail caterpillar [right]. μηδείς (talk) 21:19, 25 August 2017 (UTC)


 * Thanks! &#8213; Mandruss  &#9742;  02:29, 26 August 2017 (UTC)

Study that involves babies that can chop long strings of gibberish into "words"?
What is the study that involves babies who are able to chop long strings of gibberish into "words"? Why do older people (past puberty) have trouble with this kind of chopping? 140.254.70.33 (talk) 21:53, 25 August 2017 (UTC)


 * What are you talking about? Can you cite any specific examples? Youtube videos or something? ←Baseball Bugs What's up, Doc? carrots→ 00:09, 26 August 2017 (UTC)


 * Children have the ability to recognize words and sounds that fit the structure of their own language as opposed to others with radically different phonologies before they speak it. I don't know the specific studies that address this, as it is not a topic that interests me.  As for older people, most become less facile at parsing the sounds of foreign languages as they age.  There's a colonel of fact in this question.  I'll look later if no one comes up with relevant material in the meantime. μηδείς (talk) 00:39, 26 August 2017 (UTC)


 * @Medeis More likely a kernel than a colonel methinks. Blooteuth (talk) 00:53, 26 August 2017 (UTC)


 * That's not a major mistake. ←Baseball Bugs What's up, Doc? carrots→ 01:00, 26 August 2017 (UTC)


 * Don't cucumber me with your textplaining! μηδείς (talk) 01:03, 26 August 2017 (UTC)


 * In general, I think Medeis knows what she's talking about. -- Jayron 32 02:01, 26 August 2017 (UTC)


 * So there will be no need for any corporal punishment. ←Baseball Bugs What's up, Doc? carrots→ 02:10, 26 August 2017 (UTC)


 * Actually, I'm kind of into corporeal punishment. μηδείς (talk) 02:34, 26 August 2017 (UTC)


 * Your private life may be first class, but does not necessarily warrant exposure. ←Baseball Bugs What's up, Doc? carrots→ 07:31, 26 August 2017 (UTC)


 * The above general comments are not particularly admiral. --   Jack of Oz   [pleasantries]  21:47, 27 August 2017 (UTC)
 * Ranked comments about one's privates may follow but are we to get seamen on our hands too? Blooteuth (talk) 16:13, 28 August 2017 (UTC)


 * Here's one relevant study: Infant Perception of Non-Native Consonant Contrasts that Adults Assimilate in Different Ways and here are a bunch of other studies on even newborns. μηδείς (talk) 02:34, 26 August 2017 (UTC)


 * It's an interesting Q as to why adults don't have the same aptitude for learning new languages. Part of it seems to be that all knowledge becomes somewhat "cemented" at some point, which has the advantage of making us less likely to forget it, but also makes us less flexible.  The proverbial "riding a bicycle" is a case where this serves us well.  StuRat (talk) 21:14, 26 August 2017 (UTC)