Talk:Gravity well

message: 3D?
In the terms of Physics everything in our universe experiances time, and time being the fourth dimension means that everything in the universe is fourth dimensional. So, shouldn't the article say 4 dimensional? --Science Lord 13:40, 23 March 2006 (UTC)
thread_title: 3D? In the terms of Physics everything in our universe experiances time

message: This article is very poorly written with regards to scientific and mathematic exactness: "an extrusion of an otherwise 2-dimensional sheet", "time slows down to the point where it is not noticeably moving" are not phrases that belong in an encyclopedia without qualification (and even as an analogy these phrases are more misleading than helpful). The entire last paragraph sounds like it's lifted from a cheap SF novel.
I would urge a complete rewrite, or rather a deletion and redirection of the term to some existing article (e.g. Gravity).
Thomas 19:51, 6 July 2007 (UTC)
thread_title:  Poor style and content 

message: well, at the 3d-center of any spherical mass with radius R, gravity is zero, everyone knows.
and it sure stays differentiable around and at R.
so what does a gravity well cross-section really look like?
--Tobyvoss (talk) 17:23, 14 February 2008 (UTC)
replies: text: I don't understand the question. The cross section shown in the article is differentiable everywhere, and the derivative (acceleration vector) at the center is zero. -- BenRG (talk) 00:28, 15 February 2008 (UTC)

text: ah thanks for the explanation with the acceleration vector, i wasn't thinking... --Tobyvoss (talk) 10:52, 15 February 2008 (UTC)
thread_title:  external/internal gravitational potential 

message: Would I be correct in thinking that the diagram is a representation of gravity acting in two dimensions and would actually be more complicated if there were a 3rd dimension? Theshibboleth (talk) 11:47, 13 June 2008 (UTC)
thread_title:  Interpreting diagram 

message: Pardon if I seem ignorant of some of the terms used here - it's been over twenty years since I was last in a Physics class.
I get that M in the function given is the mass of the object creating the gravitational well, and that x is the distance from that gravity source, but is G the Universal Gravitational Constant here, or merely indicative of the force of gravity acting at radius x?
{Geez.  Some elementary algebra just solved part of this for me.  If Φ is potential energy in Joules (kg*m2/s2, M is given in kilograms, and x is given in meters, solving for G yields units of m3/kg*s2, hence G is, indeed, the Universal Gravitational Constant.  The product GM is explained well here:  }
I'm also making the presumption here that y = Φ(x), and that the upper "plane" of the well is an asymptotic approach to the x-axis?  Is that correct?
My interest is somewhat specific:  I would like to be able to plot gravitational wells for hypothetical stars of given masses.  It would be convenient for my purposes for x to be expressed in AU, M in solar masses, and that leaves me in a quandary as to what units G would be in (so I get to do some more algebra, or unit analysis, to derive a conversion constant). A more complete identification of all the parameters in this equation, along with the usual units used, would go a great distance to making this a more understandable and useful article.
Note:  I managed to accomplish some prelminary plots (first-order approximations which will be useful for my purposes).  
Horusfalcon (talk) 14:39, 7 January 2009 (UTC)
thread_title:  Some questions 

message: Instead of reverting and undoing reverts and arguing in the edit comments, I suggest we talk about linking to the comic here on the talk page.
* I personally don't think the page should be linked to, and if it should be, then it definitely doesn't belong in the introduction.  There are much better graphical examples of gravity wells than some guy's drawing, and those should be linked to for reference (probably in their own section) before some comic. Gamer 2k4 (talk) 16:35, 30 December 2009 (UTC)
thread_title:  Linking to xkcd #681 

message: Is it possible to refer to the "size" of an object's gravity well, or some related terminology? By size I mean the radius from the center of the (primary) object such that a small (secondary) object will or will not fall to the primary object depending on whether the distance of the secondary from the primary is less than or greater than that critical radius. (Obviously this would be relative to surrounding environment, such as the proximity and mass of the primary's star.) Duoduoduo (talk) 16:05, 30 December 2012 (UTC)
thread_title:  "Size" of an object's gravity well? 

message: "this does not depict the Sun's gravity well": Is this a pun or ambiguous?  Is gravity an adjective and well a noun, i.e. it is referring to a gravity well, or is gravity a noun and well an adverb, i.e. the analogy does not depict well what it is supposed to depict?  — Preceding unsigned comment added by 193.29.76.37 (talk) 18:52, 11 September 2015 (UTC)
thread_title:  pun or ambiguity 

message: And by merge, I mean make this a redirect to General relativity. The point about space being curved is there in the lead paragraph. Everything else seems to be unsourced original research. UpdateNerd (talk) 06:35, 30 October 2019 (UTC)
thread_title:  Merge proposal