Wikipedia:Reference desk/Science: Difference between revisions
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I believe JWST would take [https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives/Science/2022_January_11#Why_JWST_take_so_much_time_to_send_images_whereas_Mars_2020_send_images_within_days_after_landing%3F 6 months] to send first images, but it send too early i.e on 3 February 2022 [https://blogs.nasa.gov/webb/2022/02/03/photons-incoming-webb-team-begins-aligning-the-telescope/ Source], why so? [[User:Rizosome|Rizosome]] ([[User talk:Rizosome|talk]]) 07:24, 22 February 2022 (UTC) |
I believe JWST would take [https://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Archives/Science/2022_January_11#Why_JWST_take_so_much_time_to_send_images_whereas_Mars_2020_send_images_within_days_after_landing%3F 6 months] to send first images, but it send too early i.e on 3 February 2022 [https://blogs.nasa.gov/webb/2022/02/03/photons-incoming-webb-team-begins-aligning-the-telescope/ Source], why so? [[User:Rizosome|Rizosome]] ([[User talk:Rizosome|talk]]) 07:24, 22 February 2022 (UTC) |
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:They need the images to align the mirrors and calibrate everything. It takes six months to finish the alignment so that the telescope can send good-quality science images. What is maybe a bit surprising is that they publish calibration images, but that helps keep the public, including yourself, interested. Incidentally, the website you linked only contains simulated images, not real ones. I've put a real one up here (source is [https://blogs.nasa.gov/webb/2022/02/11/photons-received-webb-sees-its-first-star-18-times/]). --[[User:Wrongfilter|Wrongfilter]] ([[User talk:Wrongfilter|talk]]) 07:34, 22 February 2022 (UTC) |
:They need the images to align the mirrors and calibrate everything. It takes six months to finish the alignment so that the telescope can send good-quality science images. What is maybe a bit surprising is that they publish calibration images, but that helps keep the public, including yourself, interested. Incidentally, the website you linked only contains simulated images, not real ones. I've put a real one up here (source is [https://blogs.nasa.gov/webb/2022/02/11/photons-received-webb-sees-its-first-star-18-times/]). --[[User:Wrongfilter|Wrongfilter]] ([[User talk:Wrongfilter|talk]]) 07:34, 22 February 2022 (UTC) |
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I got the answer from this line: '''They need the images''' to align the mirrors and calibrate everything. [[User:Rizosome|Rizosome]] ([[User talk:Rizosome|talk]]) 04:55, 24 February 2022 (UTC) |
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= February 23 = |
= February 23 = |
Revision as of 04:55, 24 February 2022
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February 16
Minor biology question
In Columnella, why are some of the discoverers(?) in brackets and some not? Clarityfiend (talk) 23:10, 16 February 2022 (UTC)
- The reason was entirely an accident of formatting, and entirely unrelated to anything scientific. I have amended the article to insert brackets in all places where they were missing. Dolphin (t) 23:48, 16 February 2022 (UTC)
- Thanks. So nothing juicy like being a member of the Illuminati or the Cabal? Clarityfiend (talk) 09:49, 17 February 2022 (UTC)
- Not as far as you should know ;) --Jayron32 13:16, 17 February 2022 (UTC)
- Thanks. So nothing juicy like being a member of the Illuminati or the Cabal? Clarityfiend (talk) 09:49, 17 February 2022 (UTC)
- The name and date after a binomial name is a reference to the authorship and date of the publication that first formally described the species. The official convention is to put these in brackets if the species was first described in a different genus. See International Code of Zoological Nomenclature Article 51.3. I have reverted User:Dolphin51's change, so that the brackets now again match those in World Register of Marine Species. Jmchutchinson (talk) 10:10, 18 February 2022 (UTC)
![](http://upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/20px-Yes_check.svg.png)
Clarityfiend (talk) 12:46, 19 February 2022 (UTC)
February 17
Did anytime NASA or any space agency save Earth from major calamity?
Did anytime NASA or any space agency save Earth from major calamity? Like diverting mountain-sized comet etc. Rizosome (talk) 16:17, 17 February 2022 (UTC)
- Only in movies. --T*U (talk) 18:09, 17 February 2022 (UTC)
- No, they have not, but they may be very likely in the process of causing one. --Jayron32 19:43, 17 February 2022 (UTC)
- That particular Internet meme calamity was not caused by NASA. That meme is caused by the Internet echo chamber of know-it-alls learning their physics from Sandra Bullock in that thing. 85.76.97.34 (talk) 16:08, 18 February 2022 (UTC)
- Or from Ken MacLeod in The Sky Road, or … —Tamfang (talk) 01:25, 22 February 2022 (UTC)
- That particular Internet meme calamity was not caused by NASA. That meme is caused by the Internet echo chamber of know-it-alls learning their physics from Sandra Bullock in that thing. 85.76.97.34 (talk) 16:08, 18 February 2022 (UTC)
- No Janes were ever harmed by NASA. Clarityfiend (talk) 00:11, 18 February 2022 (UTC)
- I'd argue their work on climate change is helping to moderate, if not avert one. Fgf10 (talk) 00:14, 18 February 2022 (UTC)
I got the answer from this line: Only in movies. Rizosome (talk) 15:02, 20 February 2022 (UTC)
- NASA's Nimbus 7 satellite discovered the ozone hole. That discovery led to action which prevented major calamity. --OuroborosCobra (talk) 21:42, 20 February 2022 (UTC)
- The USGS and the Philippine Institute of Volcanology and Seismology (PHIVOLCS) predicted the 1991 eruption of Mount Pinatubo in the Philippines, which helped to convince 60,000 people to evacuate to safer ground. The volcanologists were likely aided by many working professionals in the space science community as there is some overlap in the space and Earth sciences, particularly when it comes to remote sensing. Viriditas (talk) 22:20, 20 February 2022 (UTC)
human detecting when mobile phone is about to ring
Please ignore any hypothetical medical aspects to this question (I know about that policy, and will ask a Dr if it becomes an issue). The question is intended as purely about detecting electromagnetism biologically.
Yesterday evening I was resting in bed, not really asleep, when I had a sudden feeling of panic (something like an electric shock in my chest) that lasted about 1 second, enough to bolt awake. A second or two later, my cell phone rang. I'm aware of LED gizmos that flash when your phone is about to ring, due to some kind of change in the electromagnetic environment when the tower connects to the phone (I guess the phone's transmitter powers up). So I'm wondering whether I did a similar detection biophysically somehow.
Any thoughts about this? A quick web search didn't find anything. I don't remember noticing this effect if my phone rings while I'm awake. Thanks. 2602:24A:DE47:B8E0:1B43:29FD:A863:33CA (talk) 23:11, 17 February 2022 (UTC)
- Certain birds and fishes can perceive electric / magnetic fields: see bioelectromagnetics, perception and behavioral effects of electromagnetic fields, and electroperception. While evidence in humans is scarce, especially in air medium and at radio frequencies, it is conceivable that perhaps something rare and undiscovered may be present in some individuals. Another explanation could be happenstance. How often do you feel panic or something similar during evenings? How often do you get phone calls during that time? Perhaps they simply happened together. GeorgiaDC (talk) 04:00, 18 February 2022 (UTC)
- Evidence in humans is scarce, but not non-existent. For example, it appears that humans are sensitive enough to sense changes in Earth's magnetic field. Sensing when a phone is going to ring is very different of course and very susceptible to confirmation bias. Matt Deres (talk) 13:56, 18 February 2022 (UTC)
- Beyond GeorgiaDC's explanation that this might be something you are regularly experiencing that you happened to attach to the phone ringing, another far more mundane (and therefore IMO likely) explanation is that your phone was already doing something before you detected it ringing. Many smart phones will turn on the screen maybe a second or two before they have an audible ring, if your phone was within your line of sight, you might have noticed this. Phones can of course also affect other things notably speakers so if your phone was near a speaker that was playing music, you might have heard this. Alternatively it's possible it had an audible ring before you became aware of it. Either way in your sleepy state you misinterpreted the surprise from whatever your phone did or cause as a physical sensation, and probably also misinterpreted the time between the surprise and your phone ringing. Edit: line of sight may be indirect especially in a darkened room since the brightness of the phone may light up the ceiling or whatever even if the phone is completely out of even your peripheral vision.) Nil Einne (talk) 10:26, 18 February 2022 (UTC) 11:55, 18 February 2022 (UTC)
- A third possibility is that you had been dreaming, and the phone woke you up, and that in the fraction of a second that this happened, your brain concocted a story to explain this, involving an apparent electric shock apparently happening before the phone rang. Note that sense of time in dreams is screwy: I've had "long" dreams, that seamlessly incorporated the event that woke me from that dream, in a way that is unlikely to be possible unless the whole dream actually occurred and was triggered by the thing that woke me. Also note that its possible to start dreaming before you fall asleep, and to continue dreaming after you wake up: see Hypnagogia and Hypnopompic. Iapetus (talk) 10:39, 18 February 2022 (UTC)
- I am surprised nobody linked yet to our article about electromagnetic hypersensitivity.
- Short version: some people complain of headaches (and other symptoms) which they attribute to the presence of electromagnetic fields nearby. A considerable number of scientific studies have been done on the subject (along the lines of: turn on and off a transmitter at random, ask the subjects if the transmitter is on or off, see if they do better than random chance). The conclusion of those studies is pretty clear: the symptoms are due to the nocebo effect rather than actual physiological sensitivity.
- Presumably, if a patient in those studies could reliably feel an "electric shock through the chest" whenever the transmitter was turned on, they would have scored very high on detection ability, and we would have heard of them by now. Maybe OP is just much better at detecting EM fields than all of the participants in electrosensitivity studies, but the explanations above seem more plausible. TigraanClick here for my talk page ("private" contact) 14:36, 18 February 2022 (UTC)
- See also coincidence. Alansplodge (talk) 11:03, 19 February 2022 (UTC)
- And also Synchronicity. {The poster formerly known as 87.81.230.195} 90.193.130.191 (talk) 11:55, 19 February 2022 (UTC)
- This phenomenon of predicting an event before it occurs may also be a neurological phenomenon where the brain interprets the sequence of events out of order. I remember reading a paper about it a long time ago. Similarly, we know the brain experiences natural distortion of perception due to trauma, most notably during a car accident, where many people will report time slowing down. This is also related to perceptual distortions such as flow and peak experiences, as well as non-dualism. It may also be the case that the perception of cause and effect may seem reversed due to the brain getting confused, similar to something like synesthesia. Viriditas (talk) 22:39, 20 February 2022 (UTC)
- An acquaintance of mine is very sensitive to electrical appliances. When she turns on eg the kettle, toaster, bedside lamp, the fuse in the plug or circuit breaker sometimes blows. Subjectively, this happens much more frequently than might be expected. More specifically, she gets an uncomfortable "buzzing feeling" in her head when she walks directly under a failed coil-type energy-saving lightbulb when the switch is turned on. MinorProphet (talk) 20:03, 23 February 2022 (UTC)
February 18
Has anyone ever tabulated element yields in the r-process
The r-process produces heavy as well as light elements and I've seen many papers graphically displaying the expected element yields for a given mass number and electron fraction, but none displaying them in tabular format. Anyone know one that does? Jo-Jo Eumerus (talk) 16:31, 18 February 2022 (UTC)
- How about this one? Pritychenko, Boris (2020). "Determination of Solar System R-Process Abundances using ENDF/B-VIII.0 and TENDL-2015 libraries". arXiv:2012.06728 [astro-ph.SR]. --Amble (talk) 22:18, 18 February 2022 (UTC)
February 20
Where do birds go in a bad storm?
We just had one in England, so it got me thinking. I live by the sea, so I know what the gulls do. They either go far out to sea and ride out the storm on the water, or try to fly above the storm. Or they go inland and find an open space (less risk of flying objects), such as a field and hunker down until it's over. I think it depends on the strength and type of storm.
The seagulls are physically strong, thick plumaged birds and powerful flyers, however. What do the rest of them, do? I'm thinking of the ubiquitous urban pigeons, sparrows, crows, starlings and such. --Iloveparrots (talk) 00:37, 20 February 2022 (UTC)
- Some can perch in thick trees with claws that grasp automatically when muscles are relaxed. Others may gather on the leeward side of structures, vegetations, or forests. See 1 2 3 4. Most still need to feed and drink, however, especially to maintain body temperature against the weather. Sometimes they find insects hiding in the same places as they are from the storm. Sometimes they're unlucky and starve or exhaust themselves, even for seabirds who can fly with the storm or shelter within its eye as long as they keep pace with its movements. On a personal note, it's not uncommon to find birds under/inside people's domiciles around here during a major storm. GeorgiaDC (talk) 07:01, 20 February 2022 (UTC)
- The gulls come inland. When I lived in Whitley Bay, Tyneside we could always tell when there was bad weather out at sea, the school playing fields (about a mile inland) were covered in gulls. What's more, even if disturbed they walked, hopped or if they had to made a short flight. They certainly did not want to be up in the air. Martin of Sheffield (talk) 08:26, 20 February 2022 (UTC)
- There are always lots of gulls in Birmingham and we're about as far from the sea as you can get. --TrogWoolley (talk) 13:13, 21 February 2022 (UTC)
- Some original research: at the height of the storm at midday on Friday in Hertfordshire (about 45 miles from the Essex coast), there were blue tits, great tits, nut hatches, a robin and a lesser spotted woodpecker at my birdfeeder which was swinging around violently. So I think the answer must be that they keep calm and carry on. Many garden birds are territorial, [1] so they won't stray far from home. Alansplodge (talk) 11:43, 20 February 2022 (UTC)
- The robin sits in a barn to keep himself warm. DuncanHill (talk) 12:16, 20 February 2022 (UTC)
- Addressed by xkcd. CodeTalker (talk) 19:49, 20 February 2022 (UTC)
- The gulls come inland. When I lived in Whitley Bay, Tyneside we could always tell when there was bad weather out at sea, the school playing fields (about a mile inland) were covered in gulls. What's more, even if disturbed they walked, hopped or if they had to made a short flight. They certainly did not want to be up in the air. Martin of Sheffield (talk) 08:26, 20 February 2022 (UTC)
Lots of storms move in from the seas. Bad idea to try to ride them out out there. And storm systems can extend far up in the atmosphere. Think how many planes have crashed because they fly into instrument conditions up there. 74.64.73.24 (talk) 01:52, 21 February 2022 (UTC)
- Err, since GB is an island, ALL storms move in from the sea! :-) Martin of Sheffield (talk) 08:20, 21 February 2022 (UTC)
- Not at all. Many types of storm form directly over land. ----
- Our little island is a bit too small for any of that. Nearly all of our storms are second-hand from the Atlantic. On the rare occasions that they come from Continental Europe, watch out!. Alansplodge (talk) 23:24, 21 February 2022 (UTC)
- Not at all. Many types of storm form directly over land. ----
Clockwork Orange, the Ludovico technique - would it actually have worked?
For anyone who didn't see the film or read the book, it involved aversion therapy. The government, in the story was experimenting with curing criminal behaviour by exposing people to graphic images of violence, rape, war, genocide and such while simultaneously pumping them full of drugs which brought upon a feeling of sickness and a "death like, paralysis state". The idea being that long term mental associations would be formed that would cause even the thought of doing such things to make it physically impossible to act upon such impulses because of permanent changes to the psyche. Like a an aggressive thought would cause the sickness and paralysis to return until the person purposefully rejected that thought, the idea being that it was now physically impossible for the subject of the experiment to commit an aggressive act.
The story was obviously a warning against such things. That it was better to be a bad man than to be compelled to "goodness" against one's will.
Question I have here, is would this have actually worked in real life? I know that attempts at aversion therapy WRT things like homosexually didn't work, so I'm curious. I'm suspecting that various governments probably tried such things over the years. Just watched the movie on DVD... — Preceding unsigned comment added by Iloveparrots (talk • contribs) 02:19, 20 February 2022 (UTC)
- The reports on the effectiveness of aversion therapy are a mixed bunch, and controlled experiments described in sufficient detail to make them repeatable are rare. When reasonably effective at all, this appears to depend on the condition being treated. There is no body of established psychological theory that would allow one to predict the effectiveness of operant conditioning by torture for what seems to be sociopathy. --Lambiam 10:18, 20 February 2022 (UTC)
- You may be interested in Classical Conditioning in “A Clockwork Orange” from Psychology Today. Alansplodge (talk) 11:50, 20 February 2022 (UTC)
February 21
Onion in sock
Is it true that sleeping with a onion in your sock is a good remedy for the common cold? Thanks. 205.239.40.3 (talk) 11:03, 21 February 2022 (UTC)
- No. Surprisingly, I can even cite a source to support my answer.
there have not been any scientific studies that have looked at this specifically
is code for "that hypothesis would violate so many rules of physics and biology that no serious researcher would devote time to testing it, no serious funding agency would give money to study it, and no serious journal would publish results about it". - @OP: since you asked here, presumably you thought it was possible the answer was "yes". I would encourage you to examine why you believe so. I suspect the answer is that someone told you, and possibly that someone added that they did it and it worked. Citing from Anecdotal_evidence#Scientific_context:
A common way anecdotal evidence becomes unscientific is through fallacious reasoning such as the post hoc ergo propter hoc fallacy, the human tendency to assume that if one event happens after another, then the first must be the cause of the second. (...) For example, here is anecdotal evidence presented as proof of a desired conclusion:
There's abundant proof that drinking water cures cancer. Just last week I read about a girl who was dying of cancer. After drinking water she was cured.
Anecdotes like this do not prove anything. In any case where some factor affects the probability of an outcome, rather than uniquely determining it, selected individual cases prove nothing. (...) In medicine, anecdotal evidence is also subject to placebo effects: it is well-established that a patient's (or doctor's) expectation can genuinely change the outcome of treatment. Only double-blind randomized placebo-controlled clinical trials can confirm a hypothesis about the effectiveness of a treatment independently of expectations.
- Synchronicity is "a person's subjective experience that coincidences between events in their mind and the outside world may be causally unrelated to each other yet have some other unknown connection." Alansplodge (talk) 14:49, 21 February 2022 (UTC)
- See randomized controlled trial for the actual method to know if something works. TigraanClick here for my talk page ("private" contact) 12:01, 21 February 2022 (UTC)
- At least some scientists thought it worth their time and effort to conduct a double-blinded, placebo-controlled trial of garlic as a mosquito repellant, and a peer-reviewed journal published by a highly respected learned society thought this merited publication.[2] I doubt there are a priori reasons to rule out the effectiveness of sulfur compounds exuded by onions as providing relief for the common cold, any more than there are reasons to rule out a role for zinc supplements. --Lambiam 18:16, 21 February 2022 (UTC)
- Eating onion or smelling or onion vapors can very plausibly produce a biological effect. The "put it in a sock" part, less so. TigraanClick here for my talk page ("private" contact) 13:34, 22 February 2022 (UTC)
- At least some scientists thought it worth their time and effort to conduct a double-blinded, placebo-controlled trial of garlic as a mosquito repellant, and a peer-reviewed journal published by a highly respected learned society thought this merited publication.[2] I doubt there are a priori reasons to rule out the effectiveness of sulfur compounds exuded by onions as providing relief for the common cold, any more than there are reasons to rule out a role for zinc supplements. --Lambiam 18:16, 21 February 2022 (UTC)
- Apparently, according to National Onion Association, the claim that raw onion can treat the flu is "a theory that dates back to the 1500s" and "In recent years, many articles online have claimed that this folk remedy is effective." One assumes those national onions are American ones. Maybe it's something that would be used by Novak Djokovic who, in 2020, spoke of his knowledge of "some people" using "prayer" and "gratitude" to "turn the most toxic food, or maybe most polluted water into the most healing water."?? Martinevans123 (talk) 12:24, 21 February 2022 (UTC) p.s. onions can be quite large, so presumably you'd need and extra large sock to accommodate one?
- Between 1946 and 1989, the British Government funded the Common Cold Unit, where volunteers could have an all-expenses-paid holiday on Salisbury Plain, provided that they were willing to be infected with one of the many cold viruses, in the hope that a cure or effective treatment could be found. The unit eventually closed with the conclusion that there was none. Whether they experimented with onions-in-socks seems unlikely. Alansplodge (talk) 13:36, 21 February 2022 (UTC)
- Onions are mentioned here but only as "In ancient Egypt, cold sufferers were told to treat it by reciting a magical spell, while the ancient Romans recommended wolf's liver in mulled wine. Other “treatments” have included eating mustard or milk-soaked onions, wearing nutmeg around your neck, or inhaling chlorine gas." I guess they never thought of putting their feet in the milk-soaked onions. Martinevans123 (talk) 13:50, 21 February 2022 (UTC)
- Onions might help open up your breathing passageway, although putting them in socks doesn't seem like the best placement. --←Baseball Bugs What's up, Doc? carrots→ 15:56, 21 February 2022 (UTC)
- If you don't put on clean socks (and wash your feet), you may smell sufficiently strongly as to make people keep their distance, which will actually lessen your chances of catching a cold, etc., from them.
- Actually, I believe the original idea was to hang the onion-bearing sock around your neck, and it may be that this traditional belief has persisted orally from a couple or more centuries ago, when (for poor people at any rate), washing bodies and clothes was a luxury (geddit?) of cost and time that could less often be afforded. {The poster formerly known as 87.81.230.195} 90.193.130.191 (talk) 22:32, 21 February 2022 (UTC)
- No wonder it didn't work! Everyone knows you need to wear the onion on your belt, which was the style at the time. --47.155.96.47 (talk) 22:48, 21 February 2022 (UTC)
- I think the question was about a possible remedy, not a prophylactic. [3]. Martinevans123 (talk) 22:54, 21 February 2022 (UTC)
- Onions might help open up your breathing passageway, although putting them in socks doesn't seem like the best placement. --←Baseball Bugs What's up, Doc? carrots→ 15:56, 21 February 2022 (UTC)
- Onions are mentioned here but only as "In ancient Egypt, cold sufferers were told to treat it by reciting a magical spell, while the ancient Romans recommended wolf's liver in mulled wine. Other “treatments” have included eating mustard or milk-soaked onions, wearing nutmeg around your neck, or inhaling chlorine gas." I guess they never thought of putting their feet in the milk-soaked onions. Martinevans123 (talk) 13:50, 21 February 2022 (UTC)
- Whoever told you this doesn't know their onions about cures. Clarityfiend (talk) 23:00, 21 February 2022 (UTC)
- They should get on their bike. Martinevans123 (talk) 23:05, 21 February 2022 (UTC)
- Brings to mind the old saying: An apple a day keeps the doctor away. An onion a day keeps everybody away. --←Baseball Bugs What's up, Doc? carrots→ 23:27, 21 February 2022 (UTC)
Onions (and garlic, peppers and a few other vegetables) have significant amounts of sulfur, which makes your breath smell bad but is supposedly good for your health,[4] or maybe bad for it.[5] Dunno about putting them in your socks though. Back in my day, we wore them on our belts, which was the style at the time. 2602:24A:DE47:B8E0:1B43:29FD:A863:33CA (talk) 01:57, 24 February 2022 (UTC)
February 22
Why did JWST send first images too early?
![](http://upload.wikimedia.org/wikipedia/commons/thumb/8/84/JWST_-_First_images_of_HD_84406.jpg/220px-JWST_-_First_images_of_HD_84406.jpg)
I believe JWST would take 6 months to send first images, but it send too early i.e on 3 February 2022 Source, why so? Rizosome (talk) 07:24, 22 February 2022 (UTC)
- They need the images to align the mirrors and calibrate everything. It takes six months to finish the alignment so that the telescope can send good-quality science images. What is maybe a bit surprising is that they publish calibration images, but that helps keep the public, including yourself, interested. Incidentally, the website you linked only contains simulated images, not real ones. I've put a real one up here (source is [6]). --Wrongfilter (talk) 07:34, 22 February 2022 (UTC)
I got the answer from this line: They need the images to align the mirrors and calibrate everything. Rizosome (talk) 04:55, 24 February 2022 (UTC)
February 23
Are there any animals that have knees that bend the opposite way to ours?
I know it's a common misconception that birds have backwards knees. What looks like a knee is actually the ankle and what looks like the lower leg is actually the foot and what looks like the foot is just the toes.
Are there any animals that do have knees that bend backwards, compared to our knees? --Iloveparrots (talk) 01:43, 23 February 2022 (UTC)
- Insects? --←Baseball Bugs What's up, Doc? carrots→ 06:01, 23 February 2022 (UTC)
- Stricly speaking, only primates have knees. See Knee#Other_animals.--Shantavira|feed me 09:20, 23 February 2022 (UTC)
Gravity Question (I couldn’t come up with a better title)
Is there a name for the point between any two celestial bodies A and B, that any object C placed at that point will be equally affected by the gravity of both celestial bodies (feel the same amount of newtons of gravitational force from both celestial bodies)? Also, is there an equation to calculate how far said point is from the two celestial bodies, provided that they’re M meters apart, Body A has a mass of K kilograms, and Body B has a mass of H kilograms? Primal Groudon (talk) 04:22, 23 February 2022 (UTC)
- I've come across "gravitational midpoint" used with this meaning -- either in reference to a point on the straight line between A and B, or to a point on the orbit that object C is following that brings it near both bodies (such as a spacecraft from the Earth to the Moon).
- Newton's law of universal gravitation tells us that if object C is at the gravitational midpoint on the straight line between A and B, and is at distance X from body A, then K/X² = H/(M-X)². This simplifies to give a quadratic equation that can be solved for X. --184.144.97.125 (talk) 05:51, 23 February 2022 (UTC)
- Lagrange point? --←Baseball Bugs What's up, Doc? carrots→ 05:59, 23 February 2022 (UTC)
- Wrong, that's a different concept. --184.144.97.125 (talk) 21:01, 23 February 2022 (UTC)
- I'm not aware of any name of this gravitational equilibrium point between two stationary masses. Yes, there an equilibrium point, and 184.144... has given the equation for it, but it's usually not a very interesting point. It's an unstable equilibrium and it only remains there when the the masses are kept stationary, despite the gravity they exert on each other. In space there's no way to keep these masses at fixed positions. They can be kept at a fixed separation if they orbit each other. In that case there's a new unstable equilibrium point, called the L1 Lagrange point, where the test mass can orbit with the other masses, but this is displaced from the point of no force towards the heavier mass. PiusImpavidus (talk) 09:23, 23 February 2022 (UTC)
- Two stationary masses will not remain stationary for long. If there is no relative motion between them, they begin to will move towards each other along a straight line with a relative acceleration proportional to their masses, until they crash into each other. That's how gravity works. --Jayron32 13:43, 23 February 2022 (UTC)
- I'd have thought that it gets a bit more complicated that that. Bodies A and B will be in orbit around their combined centre of mass. In the case of the Earth-Moon system the barycentre is just over 1,000 miles below the Earth's surface. In such a case as this an object at the gravitational neutral point would be in orbit around the Earth and the circular path would contribute its own forces to add to the simple linear equation above. I beg to differ slightly with PiusImpavidus; in the media it was a very interesting point when the Apollo spacecraft started to accelerate towards the Moon (or the Earth on the return journey). IIRC it was a headline over the lead story for Apollos 8 and 11. Martin of Sheffield (talk) 16:10, 23 February 2022 (UTC)
- If they have existing motion, then yes you are correct. I was making the point about stationariness (and the lack thereof ion the real world) that PiusImpavidus stated when he said "gravitational equilibrium point between two stationary masses". There is no equilibrium between two stationary masses that are not in contact; they will move towards each other. Such equilibrium (whether stable or meta-stable) will only exist if the bodies are in relative motion, at which point the most common stable set up is some kind of elliptical orbit. That orbit has lagrange points. If you were to place two bodies in space stationary to each other, they would start moving towards each other instantly (well, speed-of-light instantly, but you know). --Jayron32 17:04, 23 February 2022 (UTC)
- The Apollos entered the Moon's Hill sphere at that point (in time!). This is delimited by a surface, not defined by a point (in space). --Wrongfilter (talk) 16:23, 23 February 2022 (UTC)
- The intersection of a surface and a line (the trajectory) is a point though! Martin of Sheffield (talk) 17:47, 23 February 2022 (UTC)
- I'd have thought that it gets a bit more complicated that that. Bodies A and B will be in orbit around their combined centre of mass. In the case of the Earth-Moon system the barycentre is just over 1,000 miles below the Earth's surface. In such a case as this an object at the gravitational neutral point would be in orbit around the Earth and the circular path would contribute its own forces to add to the simple linear equation above. I beg to differ slightly with PiusImpavidus; in the media it was a very interesting point when the Apollo spacecraft started to accelerate towards the Moon (or the Earth on the return journey). IIRC it was a headline over the lead story for Apollos 8 and 11. Martin of Sheffield (talk) 16:10, 23 February 2022 (UTC)
is the Huisheng (Kengan Ashura) have a basis on reality?
So in the Kengan Ashura manga, there's a technique called Huisheng. (more details in the wikia article here.
TLDR version of the technique is that a person tells a child all about himself (memories, likes, dislikes etc.) several times in his lifetime until he dies. In turn that child, now a grown up, will pass it to the younger generation. Of course you can also use audio recordings and earphones for more convenience. The point of the technique is that the personality is passed down orally through the generations, making it some sort of pseudo immortality for the original personality.
Does a similar technique exists IRL? --Lenticel (talk) 06:28, 23 February 2022 (UTC)
- If audio recordings are used, one can skip a few generations. And why tie this to spoken text? One can also write it down. This technique exists IRL and is known as "autobiography". --Lambiam 10:48, 23 February 2022 (UTC)
- Oral tradition is the term, and is known in some form in just about every culture throughout history. --Jayron32 13:40, 23 February 2022 (UTC)
- Thanks, just with a little brainwashing thrown in I guess. --Lenticel (talk) 01:17, 24 February 2022 (UTC)
Is there any equation for tidal heating in a subsurface ocean?
I've been looking for an approximative tidal heating equation akin to the one presented at Tidal heating for bodies with a subsurface ocean, but I can't find one. Publications about Enceladus, Europa and the like don't provide one, either, only solutions specific for these bodies and these aren't general enough. Jo-Jo Eumerus (talk) 10:05, 23 February 2022 (UTC)
- There are a bunch of results from Google Scholar. Have you gone through them and not found what you're looking for? GeorgiaDC (talk) 04:54, 24 February 2022 (UTC)
Academic Union Oxford; What's it?
Is this organisation an academic body of any academic standing? https://oau.ebaoxford.co.uk/ Recently they seem to have conferred some honorary position on one Sabu Thomas who blows his own trumpet rather too loud, if his fancy website http://www.sabuthomas.com/ is any indication. (The article on the scientist could be autobiographical. Most of the contributions come from the IP of the institution the subject works at. Then there is a contributor named Iiucnn who seems to have made no contribution to any other article.) — Preceding unsigned comment added by Narrativist (talk • contribs) 15:23, 23 February 2022 (UTC)
- See this press release. It does not read like a rejoinder by a respectable organization. Not only is the style that of a scam artist who is exposed, but the content is demonstrably dishonest. As reported, journalist Prega Govender of the (South African) Sunday Times was indeed rebuked, but not for an article about this Academic Union Oxford. The rebuke was for an article about a new sex-ed textbook rolled out in South Africa. Govender did write an article under the title "Oxford scam artists turn Bloemfontein principal into a fake prof";[7] the "scam artists" are the AUO. It is behind a paywall, but the basic facts revealed in the article can be found here. --Lambiam 16:57, 23 February 2022 (UTC)
- Thanks a lot, Lambiam. Guess that unmasks the organisation enough.--Narrativist (talk) 17:25, 23 February 2022 (UTC)