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November 25[edit]
Wind speed in UK[edit]
Is wind speed in the United Kingdom (in weather forecasts etc.) measured in miles per hour? I have always thought that it is measured in kilometres per hour. --40bus (talk) 19:00, 25 November 2023 (UTC)
- The Met Office forecasts give a choice of units, for example "Manchester (Greater Manchester) weather". Met Office. shows mph, with drop down options for kph, knots, m/s and Beaufort. See also "How we measure wind". Met Office. – "The normal unit of wind speed is the knot (nautical mile per hour = 0.51 m sec-1 = 1.15 mph)." . . . dave souza, talk 20:21, 25 November 2023 (UTC)
- @40bus The BBC uses mph and degrees Celsius. See their FAQ Mike Turnbull (talk) 20:43, 25 November 2023 (UTC)
- The BBC uses Beaufort for the Inshore Waters forecast, the Shipping forecast and the High Seas forecast. Martin of Sheffield (talk) 21:30, 25 November 2023 (UTC)
- The question was about how wind speed was measured, not forecast. The simple answer is in knots, as explained in the link provided by dave souzaabove - [1]. HiLo48 (talk) 02:31, 26 November 2023 (UTC)
- I think the question is which unit of measure is used (in weather forecasts etc.) to report wind speed. When forecast, the wind speed has not yet been measured, so how it is measured (using anemometers) is irrelevant. As made clear by the first link provided by dave souza above, there can be a user-made choice. Apparently, as stated by Martin of Sheffield, part of the answer is that at least for some forecasts it is not reported in units at all but only on the Beaufort scale. --Lambiam 09:54, 26 November 2023 (UTC)
- You're right. I misunderstood the wording of the question. HiLo48 (talk) 22:54, 26 November 2023 (UTC)
- British TV forecasts are always in statute miles per hour, see Gusts up to 80mph hit parts of UK. Alansplodge (talk) 17:25, 28 November 2023 (UTC)
- You're right. I misunderstood the wording of the question. HiLo48 (talk) 22:54, 26 November 2023 (UTC)
- I think the question is which unit of measure is used (in weather forecasts etc.) to report wind speed. When forecast, the wind speed has not yet been measured, so how it is measured (using anemometers) is irrelevant. As made clear by the first link provided by dave souza above, there can be a user-made choice. Apparently, as stated by Martin of Sheffield, part of the answer is that at least for some forecasts it is not reported in units at all but only on the Beaufort scale. --Lambiam 09:54, 26 November 2023 (UTC)
November 26[edit]
Divining rods[edit]
About 10 years ago I wrote a research paper and cited a Wikipedia post that stated, The American military (Wikipedia, ibid.), in search of a means of locating unexploded ordnance (missiles, warheads, mines, and shells), has tested all of the [divining rod] candidates and found that they did no better than pure chance. i am trying to retrieve this original post but have not been successful. Can u help me find it? Thx. 108.53.229.65 (talk) 00:51, 26 November 2023 (UTC)
@Kojavak: Per WP:RD/G, do not give answers that will be useless to the OP. Thank you.--Jasper Deng (talk) 00:59, 26 November 2023 (UTC) |
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The following discussion has been closed. Please do not modify it. |
- User:108.53.229.65, that quote seems confusing, since it calls Wikipedia part of the military. Is it something that was posted on Wikipedia, definitely this text word-for-word? Or is it just a recollected approximation? Or is it something on another site that cited a Wikipedia article? DMacks (talk) 03:39, 26 November 2023 (UTC)
- There is indeed something confusing. The abbreviation ibid. is used for a bibliographic citation to the same source as the previous one, so the parenthesis is presumably an in-text parenthetical list of citations, as in the APA style. Then Wikipedia is also a (rather underspecified) citation, presumably expanded in the bibliography. Does the research paper have a bibliography section? What is the in-line citation preceding (Wikipedia, ibid.).? What makes this confusing is that citations are meant to be supplied for statements, not for a non-truth-bearing noun phrase such as [t]he American military (except in the rare situation that the noun phrase is an unusual appellation whose coiner needs to be credited, but then it would typically be presented in scare quotes). Should the sentence in the research paper have run like, "The American military, in search of a means of locating unexploded ordnance ... found that they did no better than pure chance (Wikipedia, ibid.)."? The wording "Wikipedia post" can also do with some clarification. We do not refer to articles as "posts", but only to discussion page contributions, which (if cited at all) should be cited by the contributor's user name, not generically by Wikipedia. Citing Wikipedia articles should generally be avoided in research papers, but under no circumstances can claims found on discussion page contributions be used in support of statements in a research paper. --Lambiam 09:11, 26 November 2023 (UTC)
- User:108.53.229.65, that quote seems confusing, since it calls Wikipedia part of the military. Is it something that was posted on Wikipedia, definitely this text word-for-word? Or is it just a recollected approximation? Or is it something on another site that cited a Wikipedia article? DMacks (talk) 03:39, 26 November 2023 (UTC)
- Michel Eugène Chevreul debunked divining rods in 1854 in ""De la baguette divinatoire".[1]
- ^ Chevreul, Michel Eugène (1854). De la baguette divinatoire: du pendule dit explorateur et des tables tournantes, au point de vue de l'histoire de la critique et de la méthode expérimentale (in French). Mallet-Bachelier.
- Could it have been the British military? Dowsing § Studies (5th item - though both the wording and nationality differ from that in the question). catslash (talk) 19:15, 26 November 2023 (UTC)
- Citation 33 in Dowsing might be what you want. NadVolum (talk) 20:06, 26 November 2023 (UTC)
- Citation 33 is about the etymology of one sense of the verb dowse. I suspect you mean a different citation. --Lambiam 21:07, 26 November 2023 (UTC)
- Sorry it is 49- not sure how I got 33:
- "Guide for the Selection of Commercial Explosives Detection Systems for Law Enforcement Applications (NIJ Guide 100-99), Chapter 7. Warning: Do Not Buy Bogus Explosives Detection Equipment" (PDF). September 1999. pp. 71–72. Archived (PDF) from the original on 2022-02-27. Retrieved 2022-02-25.
- NadVolum (talk) 22:20, 26 November 2023 (UTC)
- Sorry it is 49- not sure how I got 33:
- Could this be what you are looking for? page 71 here: https://www.ojp.gov/sites/g/files/xyckuh241/files/media/document/178913-2.pdf Dhrm77 (talk) 21:37, 27 November 2023 (UTC)
- This is a segment from the guide linked to above by NadVolum, with identical pages 71–72. --Lambiam 09:51, 28 November 2023 (UTC)
- Citation 33 is about the etymology of one sense of the verb dowse. I suspect you mean a different citation. --Lambiam 21:07, 26 November 2023 (UTC)
Time period for highest mountain being in the Himalayas.[edit]
Approximately how many million years ago did the collision of the Indian Subcontinental plate with Asia lead to a peak in the Himalayas, *and* where was likely to have been the highest mountain on the planet before that point? And on the other side, when will erosion of the Himalayas/end of collision and additional collisions (Africa into Europe? Australia into the plates of New Guinea/Philippines?) lead to the highest point on the Planet being outside the Himalayas?Naraht (talk) 13:58, 26 November 2023 (UTC)
- To answer your first question, observations from drilling into the Bengal Fan support an Early Miocene age (~23-16 million years ago) for the start of major uplift in the Himalayas, according to this paper from 1990. This is in agreement with much more recent results, see this paper from 2022. Figure 4 from the second paper show an elevation curve for the Himalayas indicating that the mountains rose from about 2 km to in excess of 5 km during that period, although it also suggests that it continues to rise to the present day. Mikenorton (talk) 15:10, 26 November 2023 (UTC)
- The collision of the India Plate with Eurasia, which is what ultimately sustains the elevation of the Himalayas, show no sign of stopping, even after 50 million years, so it would be just speculation to come up with a number for that. If a new subduction zone does develop south of India, as has been proposed, the whole mass of thickened crust of the Himalayas/Tibetan Plateau would be expected to gravitationally collapse, as appears to have happened back in the Devonian along the lines of the Caledonian Orogeny. Assuming that nothing was happening to affect the elevation of the Andes, that's where you would probably look for your highest peaks. Future mountain ranges are even more speculative. Mikenorton (talk) 15:47, 26 November 2023 (UTC)
- It's kind of a sobering thought that the Himalayas didn't even start to exist until several tens of millions of years after the extinction of the dinosaurs. ←Baseball Bugs What's up, Doc? carrots→ 19:01, 26 November 2023 (UTC)
- Back 66 million years ago, in North America, only the Laramide mountains existed and there were still remnants of the Western Interior Seaway. Greenland was still connected to Eurasia, there being no northern North Atlantic. In Eurasia, most of the Tethys ocean crust had yet to be subducted, with no Pyrenees, Alps, Alborz and Zagros mountains, Tibetan Plateau or Anatolian Plate.In Africa, there was no Arabian Plate, Red Sea or East African Rift. The Sea of Japan had yet to open. Australia had yet to collide with Eurasia and Zealandia was still rifting away to the east and was almost entirely under water. Mikenorton (talk) 12:36, 27 November 2023 (UTC)
- It's kind of a sobering thought that the Himalayas didn't even start to exist until several tens of millions of years after the extinction of the dinosaurs. ←Baseball Bugs What's up, Doc? carrots→ 19:01, 26 November 2023 (UTC)
November 27[edit]
Mycoplasma vs mushrooms[edit]
Is there some connection between mycoplasma (a class of bacteria) and mycology (the study of mushrooms)? Or is the name resemblance coincidental, or what? The mycoplasma article didn't say anything about this. Thanks. 2601:644:8501:AAF0:0:0:0:6375 (talk) 04:36, 27 November 2023 (UTC)
- You can look up Wiktionary wikt:mycoplasma says the word means "fungus shaped". wikt:mycology can be checked out too. Graeme Bartlett (talk) 07:04, 27 November 2023 (UTC)
- Thanks! I didn't think of looking there. 2601:644:8501:AAF0:0:0:0:6375 (talk) 23:13, 27 November 2023 (UTC)
Ozone-like smell after carbon dioxide buildup[edit]
I used to cover myself entirely with a blanket (up to the head) while sleeping and noticed that after unbearable CO2 buildup there and pulling the blanket down to breathe openly I sense ozone-like smell for a few seconds which rapidly disappears. Is it because of ground-level ozone, oxygen itself or something else? 212.180.235.46 (talk) 13:39, 27 November 2023 (UTC)
- what on earth does ozone smell like im curious mushi( ? ) 14:52, 27 November 2023 (UTC)
- See ozone, second paragraph. Or stick your nose near a photocopier. Bazza (talk) 14:55, 27 November 2023 (UTC)
- One can readily generate small amounts of ozone from static discharges (see Static_electricity#Ozone_cracking) caused by blankets, especially nylon ones in a dry atmosphere. Mike Turnbull (talk) 17:13, 27 November 2023 (UTC)
- It maybe just due to bad breath, when you breathe deeply, perhaps you get to smell it. Graeme Bartlett (talk) 10:24, 28 November 2023 (UTC)
- I do not have a reference, but I have assumed it is temperature change. I get the same ozone-smell sensation when I walk out of a warm house into the cold outside, just for a few seconds. The change from breathing warm air to cold air appears to be the trigger more than anything else... at least for me. 12.116.29.106 (talk) 13:15, 28 November 2023 (UTC)
- Thanks. Indeed, it appears to happen to me in cold weather rather than in warm weather. 212.180.235.46 (talk) 13:22, 28 November 2023 (UTC)
Interaction picture transformable into Heisenberg picture[edit]
Since matrices can basically be treated as a type of vector and vice versa, could the Heisenberg picture transformed into the Dirac Picture? 2A02:8071:60A0:92E0:9D32:9360:2436:9F78 (talk) 16:41, 27 November 2023 (UTC)
- The Heisenberg picture can be transformed into the Schrödinger picture, and (in a non-relativistic setting) the latter can be transformed into the Dirac picture, so by taking the product of the two operators you should be able to skip the middle man. --Lambiam 09:44, 28 November 2023 (UTC)
November 28[edit]
Airplanes with 2 pilots.[edit]
Afaik airlines for same-country typically have 2 pilots, with none sitting in "the center." How do they split the work? Like 80/20, or 50/50? Is 1 more of an assistant pilot? I suspect now, the airline company can also control the plane, on some auto-pilot, like if there was a solo pilot who went to the bathroom, the airline company can control the plane via some remote auto-pilot? Thanks. 131.193.14.154 (talk) 20:46, 28 November 2023 (UTC).
- From what I've learned by watching Mayday and general reading on the subject, it's typically 50/50 between the two pilots. The "pilot flying" is responsible for operating the controls and the "pilot not flying" is responsible for radio communications, consulting written reference material, and so on; and they each do each job about half the time, with the captain in overall command. As to the autopilot and related devices, they can do things like keep the plane flying straight and level, turn to a specific heading, climb to a specific altitude, and so on. But airliners cannot be controlled remotely. --142.112.220.31 (talk) 23:14, 28 November 2023 (UTC)
- (edit conflict) One of the two pilots is the "pilot flying", which means they operate the flight controls of the aircraft (possibly those of the autopilot), while other tasks, such as contact with air traffic control, can be delegated to the second pilot. There is no fixed formula, but one of the pilots is the pilot in command, and they can make the decision who will be the pilot flying, taking all aspects into consideration. For more challenging parts of a flight, the more experienced pilot will often (but not necessarily) be in control. Another factor is that pilots need to reach a certain amount of flying hours to obtain or keep certain flying licenses. --Lambiam 23:20, 28 November 2023 (UTC)
- That last sentence suggests that hours in the air as Pilot Not Flying do not count as 'flying hours' in maintaining currency for licenses, even though there are monitoring and communication responsibilities. Is this correct? And if so, what is the mechanism by which 'hours as PF' are distinguished from 'hours aloft'? -- Verbarson talkedits 13:59, 29 November 2023 (UTC)
- Some unmanned aerial vehicles can be controlled remotely by a human operator, but airline aircraft and other passenger aircraft are never controlled remotely. These aircraft can be flown by an auto-pilot but turning the auto-pilot ON and OFF, and setting the target parameters such as altitude and heading, is normally carried out by the pilot flying. Dolphin (t) 00:01, 29 November 2023 (UTC)
- Company in-flight control would require installing a lot more equipment to get a grasp of the situation. Also, imagine someone hacking into the system and either holding the passengers for ransom or going 9/11. Clarityfiend (talk) 07:47, 29 November 2023 (UTC)
- Remote Control Airlines has to be implemented very carefully to keep things safe and secure, but a limited way for ATC to send instructions to the flight management system (proceed past holding point X of your flight plan, execute standard terminal arrival Y, change altitude to the minimum published for this holding stack, execute instrument approach procedure Z with autoland) could have saved Helios Airways Flight 522. PiusImpavidus (talk) 18:57, 29 November 2023 (UTC)
- There has to be a pilot in the cockpit at all times; if not flying, then at least to monitor the autopilot or take action when something unexpected happens. On flights with a single pilot, the pilot can't go to the bathroom. Flights with only a single pilot are normally short hops in small aircraft that don't even have a bathroom. PiusImpavidus (talk) 19:04, 29 November 2023 (UTC)
From what the 1st responder said, does not sound like 50/50 work to me. Can both pilots drive the plane from their spots, even though 1 at a time? 170.76.231.162 (talk) 19:08, 29 November 2023 (UTC).
- Sure. It has to be possible for either one to take over without getting up. The 50/50 division is time spent as pilot flying vs. pilot not flying. "You fly from here to Boston and I'll fly coming back", that sort of thing. --142.112.220.31 (talk) 03:06, 30 November 2023 (UTC)
- I recall seeing that for one of the Airbus models, the aircraft could be flown from either seat, but while taxiing the plane could only be controlled from the left seat. Jc3s5h (talk) 20:18, 29 November 2023 (UTC)
- The Airbus flight controls are on side sticks, which can (somewhat unbelievably) be operated independently by both pilots while being mounted in such a way that one pilot cannot see what the other pilot is doing. This played a role in the fate of Air France Flight 447. This document, dated years before the crash, describes a fix that should have prevented the accident, but was apparently insufficient. --Lambiam 21:29, 29 November 2023 (UTC)
- Jc3s5h: In transport category aircraft (large aircraft of the kind that are used by major airlines and freight carriers) it is universal as far as I know that only the pilot in the left seat has a tiller for steering the nosewheel. It isn't just Airbus. Consequently taxying is performed by the pilot in the left seat, but in flight the aircraft can be flown from either seat. When the pilot in the right seat is performing the take-off, the other pilot will use the nosewheel tiller to keep the aircraft on the center-line until the aircraft reaches about 60 knots when the rudder pedals become adequate for directional control. Dolphin (t) 12:26, 1 December 2023 (UTC)
November 30[edit]
Little experiment to determine whether it's worth having blinds/curtains open in the day in winter[edit]
I'm interested in whether the heat from the sun on cold, overcast days in northern England is worth having the blinds open for during the winter. I reckon it is but my mother reckons it isn't. My plan to determine this experimentally is to use an Arduino or similar to record the temperature on the windowsill every five minutes and store it on an SD card. I thought it could also be interesting to record the light intensity (I would probably measure that every 15-30 seconds and store an average alongside the temperature). My question is what should I use to measure the light intensity? I know that LEDs will generate a small voltage but I also have some photodiodes (if I can find them) or maybe just a CdS light-dependent resistor, assuming that it doesn't max out too easily. Or would something else entirely be much better? The heating would not be on for the duration of the experiment. --05:58, 30 November 2023 (UTC) 92.7.46.126 (talk) 05:58, 30 November 2023 (UTC)
- The outcome will be dependent on the insulation value of the windows. Undoubtably direct sunlight coming in will contribute some heat (this is a commonplace observation I often make at my partially glazed front door), but this may or may not be negated by more heat radiating or conducting out (I will charitably assume no actual draughts). Any light-intensity measuring instruments you use need to be able to capture infrared as well as visible light – specifically photographic instruments may not. {The poster formerly known as 87.81.230.195} 51.194.245.32 (talk) 08:21, 30 November 2023 (UTC)
- I'm pretty sure that on a typical Western European overcast winter day (I'm in the Netherlands), the thermal radiation from the clouds exceeds the sunlight by a comfortable margin, but the outgoing thermal radiation is even more. When sitting at a north facing window, clear days feel a lot colder than overcast days at the same temperature. Of course, good, modern windows are supposed to be fairly reflective in the infrared, but taking infrared into account may be useful. It will vary with the height (and therefore temperature) of the cloud base, but not by a huge amount. Semiconductor-based light sensors have some cut-off; above the wavelength corresponding to the band gap of the semiconductor they can't detect light.
- FYI: I would take two rooms, one with the blinds/curtains open, the other closed, and record temperature during the day. Next day with identical weather, swap the roles of the rooms to compensate for differences in window size and room heat capacity. PiusImpavidus (talk) 10:16, 30 November 2023 (UTC)
- To obtain data that can be properly used to draw a conclusion, the experiment should also be repeated on several days, preferably under varying weather conditions (outside temperature, precipitation, wind factor, sky coverage). There should be some effect; see also Greenhouse § Theory of operation. Before you engage in performing this non-trivial experiment, you should decide for which size of the effect you will consider it "worth" having the blinds/curtains open. --Lambiam 12:20, 30 November 2023 (UTC)
December 1[edit]
AC vs refrigerator[edit]
Hi. I was told by my HVAC installers that AC units need regular re-fills of refrigerants. I have followed their advice and have refilled my AC units regularly.
But then I realized that my refrigerator has never had a refill of refrigerants. Nor have I ever heard of any non-commercial user refill their refrigerator with new refrigerants. These three sources seem to confirm my understanding [2][3][4].
How come ACs need refills when refrigerators don't?
Are they not both closed systems? (Assuming no system damage or leaks) Liberté2 (talk) 03:46, 1 December 2023 (UTC)
- According to this,[5] refrigerators can leak, and then you have to deal with adding more freon. And according to this,[6] air conditioners shouldn't need new freon unless - guess what - they leak! ←Baseball Bugs What's up, Doc? carrots→ 07:36, 1 December 2023 (UTC)
- Both are closed systems, but the piping in refrigerators is created in the factory under controlled conditions. The piping for AC is installed on site. Combine that with the larger size and length of piping and it becomes probable that the AC systems will leak more. Rmvandijk (talk) 09:18, 1 December 2023 (UTC)
Blueshift[edit]
Is there any theoretical limit, on the blueshifting effect (whether caused by gravitation or by the Doppler effect)?
i.e. a limit on how much a given object's color can be blueshifted.
I guess there is no such limit, but I want to be sure.
( I ignore the issue, of limits caused - if at all - by the Planck units, which is a controversial issue brought up by another user some days ago. As far as my question is concerned, I'm asking about a process, i.e. about changing the color).
HOTmag (talk) 09:58, 1 December 2023 (UTC)
- The wavelength of a spectral line can be blueshifted to arbitrarily small (but always positive) values — or equivalently, the frequency to arbitrarily large values. This is not different to the redshifting effect(s). However, the usual quantification in terms of is limited to values , but that's a numerical limit, not a physical one. --Wrongfilter (talk) 10:22, 1 December 2023 (UTC)
- Thanks. So, I understand there's no theoretical limit on the very process of blueshifting, when it's caused by the Doppler effect. I guess the same is true for a blueshifting effect caused by gravitation, right? HOTmag (talk) 10:35, 1 December 2023 (UTC)
- The largest increase in energy should be observed in a photon approaching a massive black hole. While gravitational time dilation will have the effect of decreasing its frequency, the blueshift can only be observed by an observer near the black hole. (Sending the photon back with a mirror makes it travel out of the gravitational well and get redshifted back to normal.) The observer undergoes the same time dilation, so (I think) this effect can be ignored. A limit on the mass of black holes (such as the mass of the observable universe) should then give a limit on the gravitational blueshift. --Lambiam 12:11, 1 December 2023 (UTC)
- Here's a thought on this type of question and the types of answers that we are giving. What is meant by a "theoretical limit"? Purely within a theory, such as special or general relativity, there may not be a limit on, say gravitation or Doppler redshifts. In special relativity, there is no limit on the energy that a particle can have as we can always transform to an inertial system where the particle's energy is Lorentz boosted to any value you'd like. This is the type of answer that I tend to give, because I don't feel particularly at ease in the real world. There are however limits that are tied to the particular realisation of our universe, these are contingent limits. For instance, we do not expect to observe cosmic rays of arbitrarily high energy, even ignoring the GZK limit, because in our universe there are no processes that create particles of arbitrarily high energy and no relative velocities that would Lorentz boost to arbitrarily high energies. Lambiam's limit would be of the second type. Does that make sense? I'm not sure what you mean by "The observer undergoes the same time dilation" — observers always carry their proper time with them, which I would understand as "observers do not undergo time dilation". But maybe you meant something else. --Wrongfilter (talk) 12:46, 1 December 2023 (UTC)
- From the point of view of an outside observer, clocks slow down near a black hole, and the frequency of incoming photons decreases accordingly. However, an outside observer cannot measure this frequency; this has to be an inside job. But the clocks of "inside" observers also slow down – still from the point of view of an outside observer. --Lambiam 07:58, 2 December 2023 (UTC)
- Here's a thought on this type of question and the types of answers that we are giving. What is meant by a "theoretical limit"? Purely within a theory, such as special or general relativity, there may not be a limit on, say gravitation or Doppler redshifts. In special relativity, there is no limit on the energy that a particle can have as we can always transform to an inertial system where the particle's energy is Lorentz boosted to any value you'd like. This is the type of answer that I tend to give, because I don't feel particularly at ease in the real world. There are however limits that are tied to the particular realisation of our universe, these are contingent limits. For instance, we do not expect to observe cosmic rays of arbitrarily high energy, even ignoring the GZK limit, because in our universe there are no processes that create particles of arbitrarily high energy and no relative velocities that would Lorentz boost to arbitrarily high energies. Lambiam's limit would be of the second type. Does that make sense? I'm not sure what you mean by "The observer undergoes the same time dilation" — observers always carry their proper time with them, which I would understand as "observers do not undergo time dilation". But maybe you meant something else. --Wrongfilter (talk) 12:46, 1 December 2023 (UTC)
- The largest increase in energy should be observed in a photon approaching a massive black hole. While gravitational time dilation will have the effect of decreasing its frequency, the blueshift can only be observed by an observer near the black hole. (Sending the photon back with a mirror makes it travel out of the gravitational well and get redshifted back to normal.) The observer undergoes the same time dilation, so (I think) this effect can be ignored. A limit on the mass of black holes (such as the mass of the observable universe) should then give a limit on the gravitational blueshift. --Lambiam 12:11, 1 December 2023 (UTC)
- Thanks. So, I understand there's no theoretical limit on the very process of blueshifting, when it's caused by the Doppler effect. I guess the same is true for a blueshifting effect caused by gravitation, right? HOTmag (talk) 10:35, 1 December 2023 (UTC)
- There's no theoretical limit that I know of but there are practical limits as explained in Greisen–Zatsepin–Kuzmin limit and the higher the energy the less far they can go. I guess in the limit the source has to be enormous and the distance they can go gets very small . But that's in astronomical terms ;-) NadVolum (talk) 13:51, 2 December 2023 (UTC)
Longest earthquake?[edit]
I keep thinking of a question of the longest earthquake ever recorded, by duration. Can anyone answer what it is? Thank you. Brennan1234567890 (talk) 13:27, 1 December 2023 (UTC)
- Multiple sources claim that the longest earthquake was 32 years. It was a "slow slip event" that occurred in Sumatra. The event was undetected by the people who lived through it. It ended with an 8.5 magnitude earthquake in 1861. 97.82.165.112 (talk) 15:36, 1 December 2023 (UTC)
- Source:National Geographic (provided by 1861 Sumatra earthquake)-gadfium 19:54, 1 December 2023 (UTC)
December 2[edit]
Lucky charm in cockpit[edit]
Is there any way to bring a talisman into the cockpit of a fighter jet such that it does not become a hazard during a dogfight (keeping in mind that the plane and everything in it may be subjected to a force of up to 12 G's)? (I know that this is against regulations regardless, but this is for a work of fiction and is important for symbolic reasons, so I just want to know how much creative license I can take with this!) 2601:646:8080:FC40:DDBC:A58:C6C:6D97 (talk) 06:07, 2 December 2023 (UTC)
- It depends on the nature of the object. If it is a relatively thin and light medaillon-shaped object that can be worn under the clothing, put in a back pocket or be stitched-on like a button, it shouldn't pose a problem. --Lambiam 07:47, 2 December 2023 (UTC)
- See The adorable story of Scoff, the plushy ducky who flies in an F-15. Alansplodge (talk) 11:58, 2 December 2023 (UTC)
- Also Cockpit photo exposes North Korean pilot using a ridiculous lace-trimmed ejection seat headrest cover (probably made by his wife). Alansplodge (talk) 12:02, 2 December 2023 (UTC)
- And several more examples here: These stuffed animals have way more flight hours than you. Alansplodge (talk) 12:09, 2 December 2023 (UTC)
- Also Cockpit photo exposes North Korean pilot using a ridiculous lace-trimmed ejection seat headrest cover (probably made by his wife). Alansplodge (talk) 12:02, 2 December 2023 (UTC)
- See The adorable story of Scoff, the plushy ducky who flies in an F-15. Alansplodge (talk) 11:58, 2 December 2023 (UTC)
Carl Sagan and Stephen Hawking[edit]
Nowadays I see many videos about Carl Sagan in social media. In the past, all media used to cover Stephen Hawking as the most celebrated scientist.
I have seen they did not win any science Nobel Prize.
Why do they get more media coverage than Nobel Prize winning scientists and inventors? 2409:40E1:107C:3400:F11D:AA8C:2EA6:A965 (talk) 10:07, 2 December 2023 (UTC)
- Both Sagan and Hawking have done a lot for the popularisation of science, Sagan notably through his TV series Cosmos, Hawking through his book A Brief History of Time. While both were eminent scientists, they lacked that one discovery that might have been deemed worthy of a Nobel prize — this doesn't make them any less important. Nobel prizes are awarded for particular discoveries, which are oftentimes somewhat too technical for the general public to appreciate, and so the laureates tend not to remain so much in the public eye except maybe for a brief moment after the announcement of the prize. --Wrongfilter (talk) 11:02, 2 December 2023 (UTC)
- Didn't you think about the case of A. Einstein, who was both a Nobel laureate and a highly celebrated scientist (and still to some extent today)? When Einstein was alive and resided in US, there were moments when the media reporters couldn't stop from interviewing and asking him about "that theory" (the general relativity) =)). But ironically, A. Einstein was awarded the Nobel prize for his works on photoelectric effect instead of "that theory", which must be in some ways more prominent. 2402:800:63AD:9E45:652D:5A64:8F07:FE00 (talk) 14:14, 2 December 2023 (UTC)