Talk:Escape velocity

message: Black holes are objects from General Relativity, and the fact that their escape velocity at the event horizon is c is merely a coincidence. Light can't escape from it, but it's not because of the escape velocity. See the History section of [Black holes]: "Modern relativity factually dispels Michell's (this) notion of a light ray shooting directly from the surface of a supermassive star, being slowed down by the star's gravity, stopping, and then free-falling back to the star's surface."
I thought about plainly deleting that, but we might want to delete the link to black holes altogether. Opinions? LucasFehlau (talk) 11:43, 30 May 2018 (UTC)
replies: text: This has since been cleaned up. -- Beland (talk) 09:03, 26 January 2024 (UTC)
thread_title:  Black hole 

message: It would be nice to get some references in this section so that readers interested in the derivation of this expression, and how the assumptions play into this result, have some leads.
207.38.134.235 (talk) 22:19, 16 January 2021 (UTC)
replies: text: Yes, that would be nice. And necessary. I have tagged the section for sources. I will remove it per wp:NOR in a month or so. Thanks for having noticed. - DVdm (talk) 22:32, 16 January 2021 (UTC)
replies: text:  A month has gone by. I have removed the unsourced section. - DVdm (talk) 14:45, 16 February 2021 (UTC)

text:  The section should be restored as this formula trivially follows from the previous section, namely the hyperbolic excess speed formula. Moreover, the next section uses the currently deleted formula for the system escape speed column. One can find full derivation from scratch in Italian, Russian, and Ukranian Wikipedias. The formula can also be found in Hendel, A. Z. Solar escape. The only difference is using the escape speed for the second body instead of the orbital speed; however, it is well-known and mentioned in this English article that they are proportional with the coefficient {\sqrt2}. Anton Lapounov (talk) 19:26, 8 December 2021 (UTC)
thread_title:  Multiple bodies section 

message: "Luna 1, launched in 1959, was the first man-made object to attain escape velocity from Earth (see below table)."
Sputnik was 2 years earlier, why is this not listed? The source number 5 seems to not make such a claim as the image caption does.  HolmKønøman (talk) 22:26, 5 May 2022 (UTC)
replies: text: Sputnik never achieved escape velocity. It only ever orbited Earth before burning up in the atmosphere. I added a link to List of solar system probes for verification. -- Beland (talk) 09:21, 26 January 2024 (UTC)
thread_title:  Possible correction about first manmade object to reach escape velocity 

message: Has anyone ever been to the economic order quantity Wikipedia article and noticed how that formula is remarkably similar to the Escape Velocity formula?  Would it be justified to add that observation into the article or not?
Theboombody (talk) 22:20, 24 May 2022 (UTC)
replies: text: I don't think so; they have nothing to do with each other, and the fact they both use the denominator in a square root is a coincidence. -- Beland (talk) 09:05, 26 January 2024 (UTC)
thread_title:  Comparison to Economic Order Quantity Formula 

message: In the lede:
For example, the escape speed from Earth's surface is about 11.186 km/s (40,270 km/h; 25,020 mph; 36,700 ft/s) and the surface gravity is 9.8 m/s (35 km/h; 22 mph; 32 ft/s).
The units of gravity are those of acceleration (m.s-2), but those given in this sentence are velocity. Or am I missing something? Wocky (talk) 23:32, 26 September 2022 (UTC)
replies: text: Good catch; that's since been fixed to m/s2. -- Beland (talk) 09:24, 26 January 2024 (UTC)
thread_title:  Surface gravity units 

message: Q:How much velocity is needed to go out the range of gravitational field and who we named it? 103.200.197.234 (talk) 10:11, 13 February 2023 (UTC)
thread_title:  Physics 

message: This article might be improved by an early link to Parabolic trajectory, which covers the celestial mechanics fairly well. Is it appropriate to do that in the lede section? (sdsds - talk) 00:30, 1 February 2024 (UTC)
replies: text: Oh there it was, with the target parabola rather than parabolic trajectory. (— 𝐬𝐝𝐒𝐝𝐬 — - talk) 09:44, 27 February 2024 (UTC)
thread_title:  Link to Parabolic trajectory article? 

message: Currently the article uses speed (and velocity) without mention of a particular frame of reference. There's the implicit assumption the primary body is fixed and all the motion pertains to the secondary body (with mass m << M). The article would be improved either by making that explicit, or by discussing the relative velocity of the two bodies. The second alternative has much less practical application, and is well covered in the Two-body problem article. (— 𝐬𝐝𝐒𝐝𝐬 — - talk) 10:10, 27 February 2024 (UTC)
thread_title:  Frame of reference