Wikipedia:Reference desk/Archives/Science/2023 August 10

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August 10

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Do chemical reactions occur via electron displacement Newton’s first law of motion should prevent instantaneous electron displacement during a chemical reaction and electron acceleration during the photoelectric effect. Chemical reactions can occur within attosecond, as indicated by attosecond chemistry. Light travels 0.3 angstroms during an attosecond. The average distance a hydrogen atom’s electron travels between the ground state and the first excited state Is 1.587 angstroms (simplified Bohr model). Therefore, attosecond electron displacement to the first excited state can require an electron to travel 5.3 times the speed of light. Exceeding the speed of light would require infinite energy. Time dilation would be infinite. Vze2wgsm1 (talk) 18:54, 10 August 2023 (UTC)Vze2wgsm1 (talk) 18:54, 10 August 2023 (UTC) Could you point out where in attosecond physics you see that chemical reactions can occur within an attosecond? I'm finding reference to timescales of multiple attoseconds, but not less than an attosecond. --Amble (talk) 19:23, 10 August 2023 (UTC) Multiple attoseconds can elapse between chemical reactions. That is a limit on duration of a single chemical reaction, not the duration of a single chemical reaction. All chemical reactions are too brief for physical measurement. Vze2wgsm1 (talk) 20:58, 10 August 2023 (UTC) A heads up to other editors before responding, we have dealt with the OP before, and these discussions get terribly bogged down by the OP both not understanding the topics being discussed at all (or is it refusing to understand?) and applying scientific principles to areas that they have nothing to do with. They seem to be waging a personal war against modern quantum mechanics in favor of their own erroneous, mathematically and physically flawed, and untested personal beliefs. Normally, I wouldn't leave a comment here like this, but conversations with this editor are tedious and an absolute waste of everyone's time, including the time of the OP (which would be far better spent examining and understanding actual theory before trying to toss it out). I highly suggest that this discussion be closed fairly quickly if it heads in that direction. --OuroborosCobra (talk) 19:26, 10 August 2023 (UTC) Attosecond pulses can be generated via a high-intensity laser beam is focused onto a gas target (usually a noble gas like argon). The intense laser field ionizes the gas atoms, causing their electrons to be driven away and then recaptured by the parent ion. This recapture causes emission of high-energy, high-frequency XUV photons that collectively form an attosecond pulse. Free electrons do not directly interact with photons. Therefore, ionization can be a chemical reaction, recapture of the electron can be a chemical reaction, and then emission of an XUV photon can be a third chemical reaction. Vze2wgsm1 (talk) 19:56, 10 August 2023 (UTC) Are you speaking for Wikipedia or yourself? Did you find anything unproven, a misunderstanding, or anything false within this post? I challenge you to prove that a chemical reaction can last longer than an attosecond. All chemical reactions are too brief to directly measure. Vze2wgsm1 (talk) 20:56, 10 August 2023 (UTC) References

Is it true to say that any planet will have cold poles?

The northen pole and the southern pole of Planet Earth are much colder than the non polar areas of the planet.
Should this be correct with every planet?

I'd guess that if a planet is between four suns (northern sun, eastern sun, southern sun, western sun) than it may be hot anywhere, but I don't have enough knowledge in physics to determine if such a scenario is even possible in our universe. 2A10:8012:21:8C9A:C1B4:3F6B:B6E3:4842 (talk) 10:08, 10 August 2023 (UTC)

I think you'll find that polar ice caps are most prominent on Earth and Mars. The other planets have different configurations and your observations don't really apply. ←Baseball Bugs ^{What's up, Doc?} carrots→ 10:29, 10 August 2023 (UTC)

The axis of Uranus is on the same plane almost as its orbit round the sun, sosometimes they will be warmest or coldest parts of the planet. As to cold a friend was recently on a cruise to the Arctic circle and they had people in bathing suits sunning themselves on the sun deck. NadVolum (talk) 11:11, 10 August 2023 (UTC)

Uranus is also far enough from the sun that it receives very little in the way of what we might call "warmth" in the way that Earth does. Uranus's atmosphere is at a temperature of around 49K:[1], for comparison room temperature is about 300K. Uranus is cold. And I think most of that heat is generated internally; very little of the heat on Uranus is attributable to light from the sun. Since Uranus is 20 AU away from the sun (20x the distance as earth is) it only receives 1/400th of the sunlight (by the inverse square law) as Earth does. --Jayron32 13:07, 10 August 2023 (UTC)

Uranus' internal heat is actually very low. The total power radiated is 1.06 times that received from the Sun, i.e. internal heat only contributes about 6 per cent. One question would be where to measure the temperature in question, given that Uranus has no solid surface. They do define a troposphere, though, so the bottom of that seems like a reasonable place. I haven't found anything regarding the latitudinal dependence of that temperature, maybe due to a lack of data (or because I haven't looked hard enough). --Wrongfilter (talk) 13:40, 10 August 2023 (UTC)

They often use the 1 bar level as nominal surface. Sagittarian Milky Way (talk) 14:19, 10 August 2023 (UTC)

The surface temperature on Venus is fairly homogeneous due to its thick atmosphere and strong greenhouse effect which mitigates the effect of varying mean insolation. That four-sun scenario — not possible. --Wrongfilter (talk) 12:14, 10 August 2023 (UTC)

I don't think that 4 suns could exist in the configuration that you imagined. You might want to start by looking at planets around binary stars, first. Regardless, The one other case you should consider is when a planet is tidally locked to its star. For instance Trappist 1d or Trappist 1e which are thought of as habitable and tidally locked. In this case, it's not 2 poles that are colder, it's the dark side of the planet that is much colder than the rest, a ring (the terminator zone) that is temperate, and the center of that face that is facing the star that is likely the hottest. Dhrm77 (talk) 16:21, 10 August 2023 (UTC)

That's quite true. 4 suns and 1 planet is a 5-body problem, and we don't even have any way to solve a 4-body problem; it's essentially a chaotic system where such gravitationally bound objects will behave in wildly erratic ways; it is likely not even stable over moderate time periods, and any number of the bodies would likely be ejected on non-returning (hyperbolic or parabolic) paths. See n-body problem for more information. --Jayron32 17:30, 10 August 2023 (UTC)

[EDIT. See responses below.] Are we not missing the point of the original question, which was whether a planet's poles will always be cooler than the equatorial region? Yes, insolation varies as the above answers explain but I believe a more relevant answer has to do with the axial tilt - the angle between the rotational axis (between the poles) and the orbital axis (perpendicular to the plane of the earth's orbit around, neccissarily intersecting the sun). The earth's axial tilt is about 23 degrees, which means the poles never get heated as much as the equator, although being greater than zero, we do get seasons. Venus has an axial tilt of 97 degrees (by convention it is 97 degrees and not 83 degrees because of the direction of rotation) and so its south pole is never ever heated by the sun. So no, it is not inevitable. Ignoring all the clever stuff about the realities of Venus, it would have one hot pole and one cold pole and a temperate equator. A good thought experiment might be the detailed nature of a planet with exactly 45 degrees of axial tilt. Hayttom (talk) 00:20, 11 August 2023 (UTC)

Wrong. Venus is 177 degrees, Uranus is 97 degrees (or 98?), its south pole has summer once an orbit just like Earth. It's orbiting, not attached with a rigid rod. Sagittarian Milky Way (talk) 02:31, 11 August 2023 (UTC)

Ach, yes, I see where I was wrong. The tilt is of course essentially constant against the stars (such as our pole star) regardless of where we are in our orbit of the sun. Hayttom (talk) 19:07, 11 August 2023 (UTC)

Or like if you threw a ball with spin axis vertical, if you could throw it hard enough to orbit and there was no air or hills in the way it would do a full orbit and there'd be no force to act on it to make it turn to keep down pole down. Things near the solar system plane (especially Sun and Moon) are attracted to the rotational bulge changing the pole star by c. 47° but that takes 26,000 years (luckily it can't change the tilt from 0 to 47° too cause even the much smaller tilt changes this does cause have caused ice ages or effects similar to fossil fuels). The Moon's orbit is tilted 5° from Earth's and wobbles in only 18.6 years but duration of wobble seems to be inversely correlated with duration of orbit. Sagittarian Milky Way (talk) 20:22, 11 August 2023 (UTC)

The number for Venus shows that the direction is retrograde. It's just been confirmed that Mars had seasons millions of years ago. 2A02:C7B:107:2600:5859:C4A3:C5CD:E12B (talk) 09:56, 11 August 2023 (UTC)