Talk:Celestial mechanics

message: Should this page be merged with Astrodynamics? ❝Sverdrup❞ 10:06, 12 Sep 2004 (UTC)
thread_title:  Merging 

message: The categorization shows that astrodynamics is a sub-cat of celestial mechanics; astrodynamics uses the principles of celestial mechanics, as its article states. This suggests that the notice be taken down. Ancheta Wis 09:56, 20 Apr 2005 (UTC)
replies: text: I agree entirely. This article is very poor, and there's too much spacecraft stuff in it which should be at astrodynamics. Also, is it really necessary for both articles to duplicate material on Kepler's equation? -- 80.168.226.10 15:27, 20 May 2005 (UTC)

text: I agree that those three belong in astrodynamics Dpu2002 15:02, 16 June 2006 (UTC)
thread_title:  Category consensus 

message: Some unidentified person has put in a section on "open problems" (if you hit her/his talk page it is a group page). I thought that it was proven a long time ago that you can't get an analytic solution for even the three body problem (except very restricted cases like Lagrange points). So I suggest this be deleted or rephrased.  Anyway, it does not say "analytic" so it is ambiguous, too. Computer solutions exist for very many orbits but may fail long-term, although recently "symplectic methods" seem to handle that (e.g. for the life of the solar system so far). Pdn 01:34, 15 Jun 2005 (UTC)
thread_title:  Open Problems 

message: Um, I'm a bit confused about the talk above regarding "taking down the notice." I'm assuming that the discussion is concerning a merge/catagory notice, and not the expansion notice that was at the top of this page. I personally think the article should be expanded -- right now it's mostly history. With that, I'm moving the expansion request to the article itself. MFago 03:26, 18 March 2006 (UTC)
replies: text: I just compounded the problem by tidying up the history section.  I agree that there is a need for someone who really knows modern celestial mechanics to provide a good readable introduction to its fundamental concepts, principles, and methods.  The examples of problems section is too rapid a jump without a good grounding in the nature of the discipline.  --SteveMcCluskey 18:57, 22 January 2007 (UTC)
thread_title:  Expansion 

message: The section in the article describing the circular orbit assumption seems misleading. When I read it, I get the idea that circular orbits are assumed very often, when this is far from the case. Maybe its just me sucking at reading today, does anyone else think that? Dpu2002 15:01, 16 June 2006 (UTC)
thread_title:  Circular Orbit Assumption 

message: This is something about orbits I read a little while back, that might be appropriate in this article:
In order to slow down, you speed up; to speed up, you slow down.
Slowing down puts you into a lower orbit, which is faster in relation to a point on the surface of the body you are orbiting around. Speeding up puts you into a higher orbit, which is slower in relation to the aforementioned point.
Can anyone think of a place to put this?
Phædrus 00:05, 20 March 2007 (UTC)
replies: text: On a little post-it note above the controls of a space capsule? 2A01:CB0C:CD:D800:6D25:E588:EE7:8EE3 (talk) 17:52, 19 December 2021 (UTC)
thread_title:  Neat little law: 

message: I have temporarily reverted an edit by User:William M. Connolley, concerning the usage of the verb "emit".  I checked Wiktionary, where it is defined as "To send out or give off", which reflection of light would seem to satisfy, especially at the atomic level.  While the modern usage in physics does favor reflection as being distinct from emission (our article List of light sources, to which Light emission redirects, does not mention reflection), in the context of medieval understanding this was probably a hazy point, possibly confused in the translation from Arabic.  In any case, the paragraph needs to be reworked a bit (which I cannot do immediately) before changing it, as emits is used more than once. Wwheaton (talk) 03:13, 13 February 2011 (UTC)
replies: text: Looking at it now again, we cannot change "emit" without mangling the quotations.  The translator might better have chosen a different word, but our modern usage in physics would perhaps have been lost on Ibn al-Haytham, who had no way of knowing if the light was reflection or florescence, or what — just that it was sent out or given off (in all directions) wherever sunlight struck the spherical Moon.  Another possibility would be to truncate the quotation before emit & emitted appear, and replace them by "diffusely reflect" or some such, but that carries his meaning forward to our era in a way that seems dubious.  Or just substitute "send out or give off" before the truncated quotation.  Personally, I think it best just to leave it as-is, as the central celestial mechanical point seems clear enough. Wwheaton (talk) 07:10, 13 February 2011 (UTC)
replies: text:  florescence really is a very different thing from what you probably mean here 2A01:CB0C:CD:D800:6D25:E588:EE7:8EE3 (talk) 17:51, 19 December 2021 (UTC)
thread_title:  "Emits"? 

message: Isaac Newton says: a century later, Pierre-Simon Laplace's work "Celestial Mechanics" had a natural explanation for why the planet orbits don't require periodic divine intervention. - that sounds like he had some significant contribution to the field. If that's the case, maybe he deserves a section in this article? —  Ark25  (talk) 18:10, 1 July 2014 (UTC)
thread_title:  A section for Laplace 

message: a word is missing here, possibly the word of but it is an odd sentence anyway so I cannot be sure  2A01:CB0C:CD:D800:6D25:E588:EE7:8EE3 (talk) 17:46, 19 December 2021 (UTC)
thread_title:  "Two solutions, called VSOP82 and VSOP87 are versions one mathematical theory" 

message: It's totally understandable that astronomers use celestial mechanics to generate ephemerides. The article could be improved by providing a more inclusive lede sentence, defining celestial mechanics as useful for both astronomy observations and spaceflight engineering applications. (— 𝐬𝐝𝐒𝐝𝐬 — - talk) 23:23, 3 March 2024 (UTC)
thread_title:  Astronomers and ephemerides