Wikipedia:Reference desk/Archives/Science/2022 June 18

= June 18 =

Infinite work from finite energy
Energy can not be destroyed, so is it possible to do infinite work from a finite amount of energy that is repeatedly used, and all the energy used in this system is reused without any extra energy thereafter required? -- Exclusive Editor  Notify Me! 04:07, 18 June 2022 (UTC)


 * No. The work-energy theorem is a sub-set of the law of conservation of energy and states that the amount of work done on a system is (exactly) equal to the change in energy of that system. Dolphin ( t ) 04:45, 18 June 2022 (UTC)
 * One useful article to read is Thermodynamic free energy, . In effect, energy cannot be "repeatedly used" and some scientist think that ultimately we reach the heat death of the universe. Mike Turnbull (talk) 12:25, 18 June 2022 (UTC)


 * If you do some work on some object, then afterwards the energy you used is in the object, somehow. Before you can reuse that energy, the object has to give it back to you. Neglecting friction and other imperfections, you can use the finite gravitational energy of a bucket of water to pump an infinite amount of water, reusing the energy: let water from the bucket flow down a waterwheel, let the waterwheel drive a pump that pumps water into the same bucket. No infinite gains though. You gain nothing. PiusImpavidus (talk) 12:28, 18 June 2022 (UTC)
 * E = mc2 is the equation of mass–energy equivalence. A finite amount of energy may be used to do work once only and in doing so is converted to mass. For example, the spinning Earth has greater mass than if it had not acquired rotational energy such that its one revolution per day corresponds to over 107 kg mass increase - see examples. The OP's conjecture about a reusable inexhaustable energy would amount to proposing Perpetual motion but that is believed to violate the laws of thermodynamics. That opinion is shared by the United States Patent and Trademark Office (USPTO) that refuses to grant patents for perpetual motion machines without a working model but for interest maintains a collection of past  Perpetual Motion Gimmicks. Philvoids (talk) 12:36, 18 June 2022 (UTC)
 * Time crystals have been in the news lately. If a closed system oscillates perpetually, perhaps it can be considered to be doing perpetual work, inside the system? But then, as Time crystal says, they have "motion without energy", so I suppose also without work. Card Zero  (talk) 13:33, 18 June 2022 (UTC)

Attempting reentry?
In this scene from Moonraker, based on the shuttle's stated position in orbit, if Bond and Dr. Goodhead decide to have sex again immediately (as Goodhead wants to do) and take 10 minutes to finish, would they still be in time to land at Cape Canaveral, or would they have to divert to an alternate airfield? If the latter, would they be able to land in friendly territory, or would they have to land at Baikonur (where presumably they would be detained by the KGB until M intercedes for them)? 69.181.91.208 (talk) 11:55, 18 June 2022 (UTC)
 * Christopher Null of Filmcritic.com described the remark "I think he's attempting re-entry!" by "Q" during Bond and Goodhead's orbiting of the Earth as "featuring what might be the best double entendre ever". Philvoids (talk) 12:59, 18 June 2022 (UTC)
 * Assuming their ground track is the thick white line on the map and they got in range of a tracking ship in the Pacific, their position should be somewhere just northeast of New Zealand. I haven't got any specifics for Space Shuttles (and these are fictional Space Shuttles anyway), but normally you do the deorbit burn about half an orbit, maybe a bit less, from the landing site. Shuttles can land some distance to the side of the ground track of their orbit. So they are already a bit late to land at Cape Canaveral, but could land in Europe or the Middle East. If they wait another 10 minutes (4000km) for the deorbit burn, they would end up in the Indian Ocean (but might be able to land at Diego Garcia). Preparing for the deorbit burn takes some time too, so if in a hurry, they could best start preparing for their deorbit burn, execute it over the Indian Ocean and land at Edwards Air Force Base, which was a regular landing site for the Shuttle. Nine hours later, there would be another opportunity to land at Cape Canaveral, this time when the southbound part of their ground track passes over Florida, or they could wait 24 hours. Every 24 hours, every airport between 55 degrees south and 55 degrees north come in range twice. To land a Space Shuttle, you need a runway at least about 3500m long, a bit more if at high elevation, and preferably with a special guidance system, or it may be a bit hard to hit with a supersonic glider. Our list of Space Shuttle landing sites shows both the regular and the emergency (never used) landing sites for the Space Shuttle, equipped with all the facilities for save landings. PiusImpavidus (talk) 13:04, 18 June 2022 (UTC)
 * Thanks! So, they can land at Diego Garcia, Edwards (also Vandenberg, but this is not their first choice because the runway is shorter) or Cape Canaveral if they wait 9 hours (and they're most emphatically not in a hurry to deorbit, as you can see from the video) -- no need for them to land at Baikonur and spend a night in jail (and cause Nasa quite a bit of trouble in terms of getting the shuttle back to America, too), which is pretty much what I wanted to find out! 2601:646:8A81:6070:F5AD:972D:6C45:ADB3 (talk) 22:45, 21 June 2022 (UTC)

Puppeteer bird
A bird I heard this morning says, "Puppeteer" or perhaps "Booker T". You'd think by now I had heard all the bird calls.— Vchimpanzee  •  talk  •  contributions  •  18:07, 18 June 2022 (UTC)
 * A Big Bird, perhaps? nagualdesign 19:36, 18 June 2022 (UTC)
 * Was it like "drink your tea"? Card Zero  (talk) 19:36, 18 June 2022 (UTC)
 * I've heard that bird in this area but I don't think so.— Vchimpanzee  •  talk  •  contributions  •  21:14, 18 June 2022 (UTC)

Astronomy
Should the word "astronomy" have a capital A within a sentence? — Preceding unsigned comment added by Nopzilla (talk • contribs) 23:14, 18 June 2022 (UTC)
 * It's a common noun, so generally it should be lowercase. ComplexRational (talk) 23:39, 18 June 2022 (UTC)
 * I agree with ComplexRational, but note the "generally." There are some circumstances where a capital would be appropriate, such as if the sentence involves consideration of Astronomy as a scientific discipline or refers to a faculty or department in an academic institution. In short, it may depend on the sentence and the wider text that contains it.
 * In the case of your recent edits (from 'A' to 'a') in the article Astronomical Society of New South Wales, I would have preferred 'A' since the references were to Astronomy as a discipline, but (despite being an erstwhile astronomer) I don't feel so strongly about it that I'd revert you. {The poster formerly known as 87.81.230.195 90.201.73.64 (talk) 00:20, 19 June 2022 (UTC)
 * I just took a look at these edits, and I agree with the change to lowercase. In this context, astronomy is being used as a common noun, whereas in the name Astronomical Society of New South Wales it should definitely be uppercase. By the same reasoning, I would also argue that standalone instances of society should be lowercase, though context is key. ComplexRational (talk) 00:48, 19 June 2022 (UTC)


 * That surprises me. When is astronomy not a scientific discipline? Even so, in defence the possibility that it might take a capital letter, I went looking for inconsistency about what is or isn't a proper noun, and found a lot examples. (I concentrated on -ism words.)
 * The followers of most religions, and religious doctrines, are proper nouns, even when the name of the religion is not derived from a proper noun: Spiritists, Ranters. Some seem more flexible: universalism, spiritualism. The vaguely religious ietsists rarely get a capital letter.
 * Members of some art movements are proper nouns: Stuckists, Viennese Actionists, Romantics. (That last is probably a special case, since "a romantic" can mean something else.) Others may or may not be: surrealists, suprematists.
 * In philosophy, Cynics (named after a word for dog) sometimes are, but utilitarians aren't. (It's the members of the ancient Greek Cynic school of philosophy who get the capital letter, of course, and modern day grouches are just lower case cynics.)
 * In politics, Chartists are, but bimetallism isn't. Somehow gerrymandering isn't, despite being named after Elbridge Gerry.
 * Plutonism, named after a Greek god, yes, but vulcanism, named after a Roman god, no.
 * The rule seems to be that a set of ideas doesn't get a capital letter, but the approximately coherent and singular cultural group holding those ideas, if there is one, does get the capital letter. Does that include astronomy, is it a unified and coherent group, like Walmart (or at least like Aldi)? I think it isn't really. Card Zero  (talk) 03:26, 19 June 2022 (UTC)
 * In a designation such as "Department of Astronomy", one expects the scientific discipline to be written with a capital letter, but not in general, at least not in modern texts. ("Herschel studied astronomy in all its aspects." – "Hassel took an interest in astronomy while in his final years at the school for the deaf." – "Latvia is one of the few countries where astronomy is taught as a separate discipline.") --Lambiam 07:01, 19 June 2022 (UTC)
 * Names of faculties or departments (or journals), yes, but I've never seen "scientific disciplines" get capitalised. Except perhaps in more archaic texts (e.g. 18th/19th century) or those imitating them, where all sorts of Important Concepts would be capitalised.  Iapetus (talk) 09:08, 21 June 2022 (UTC)
 * Sigh, this is hardly a science question now, but what about biology, chemistry, physics? Should they also be capitalized too? 67.165.185.178 (talk) 13:25, 19 June 2022 (UTC).
 * Exactly the same answer. --jpgordon&#x1d122;&#x1d106;&#x1D110;&#x1d107; 19:31, 19 June 2022 (UTC)
 * Which is not that they should "also" be capitalized. All (astronomy, biology, chemistry, ..., zoology) should generally be written in sentence case – with some obvious exceptions, such as when they form part of a proper noun. --Lambiam 21:44, 19 June 2022 (UTC)