Talk:Introduction to the mathematics of general relativity

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Wikiversity?[edit]

Hmm...I wonder if this should be moved over to Wikiversity instead? --HappyCamper 16:12, 2 September 2006 (UTC)[reply]

I never heard of wikiversity, so I looked it up. It is apparently just two weeks old now. If this article is moved over, then a large number of related articles should be moved over. Since I never heard of wikiversity, probably a lot of people have not heard about it. Is there a way to duplicate articles on wikiversity and the standard wiki until wikiverisyt takes off? Complexica 16:47, 2 September 2006 (UTC)[reply]

Another possibility would be Wikibooks - see [1]. Mike Peel 17:52, 2 September 2006 (UTC)[reply]

Well I tried wikibooks. The problem I have with wikibooks is that typically there are a number of links in an article to the general wiki. I was not able to see how to link to the general wiki without going through an http link. Is there a way?Complexica 18:34, 2 September 2006 (UTC)[reply]
I don't understand your question...do you mean adding inter-wikilinks? For example, w:Apple is the article on the (English) Wikipedia for Apple. wikt:Apple would be the analogous one on Wiktionary. I forget where this list of prefixes is though. --HappyCamper 06:05, 3 September 2006 (UTC)[reply]
Thanks. This is very helpful. Complexica 17:47, 3 September 2006 (UTC)[reply]

Coordinates powers of each other?[edit]

This looks odd. I don't know what it should be changed to, but I know enough of algebra to convert that to . Perhaps it needs some subscripts? --Brilliand 02:57, 13 April 2007 (UTC)[reply]

Nah, no powers at all... it just that coordianted functions have superscript labels instead below--kiddo 03:11, 13 April 2007 (UTC)[reply]

Still far from "non-technical" and being an "introduction"[edit]

This article begins with the headline: This article is intended as a general, non-technical introduction. For the main encyclopedia article, please see mathematics of general relativity.

However, what follows is almost exclusively a list of very tersely annotated formulas in index notation, hardly what one is inclined to call non-technical. With practically no motivation, context or explanation given to the formulas, I'm afraid this article does not provide a real introduction to the relevant mathematics either. In fact, the main article Mathematics of general relativity in its present state appears (based on a quick glance) to provide a more non-technical introduction, motivating the concepts used and explaining their use at least to some extent.

I have to assume that this article is aiming to be something quite different and is currently a work in progress very far from its intended content, which is why I was reluctant to make this comment at all. However, the article has been in this state for quite some time now, and people following wikilinks from other relativity articles are likely to find their way here expecting an illuminating introduction. I would therefore suggest tagging this article as a work in progress until it gets closer to its (presumed) intended content. I would also consider removing the link from the main page until further progress be made.

As a more specific content proposal, I would suggest that most of the formulas be moved into a separate subpage (in itself a potentially useful glossary or list). Stca74 11:22, 24 May 2007 (UTC)[reply]

This article is technical, just not as technical as the other article. So I changed the introductory line to make that clear, I hope. General relativity is an inherently complicated subject. So it is unreasonable to expect any article on it to be non-technical. JRSpriggs 07:59, 25 May 2007 (UTC)[reply]
Thanks, I think the new introductory line is better. However, I'm afraid I still disagree with your comment to a certain extent. Yes, this is inherently advanced mathematics (late undergrad or graduate level). Nevertheless, I think it can be brought to a significantly more approachable level by incorporating expository text and reducing the number of formulas used. While I appreaciate that there are diverging views on whether the coordinates-and-indices definitions of this article are more or less understandable than the coordinate-free "abstract" definitions (as for myself, I'm strongly in the camp that prefers the coordinate-free definitions in differential geometry), I think that the main article in fact manages to be much more approachable regardless of the reader's preferences. Stca74 12:48, 25 May 2007 (UTC)[reply]
I much prefer the indices as I think they are more useful for practical calculation. Unfortunately, I have many other things on my Wikipedia to-be-done list, so I do not have time to fix this article in the near future. JRSpriggs 06:08, 26 May 2007 (UTC)[reply]
Yes, explicit coordinate forms absolutely necessary for calculations (most of the time, although not always!). But this brings us actually to the question of what is the intended audience of this article: a physics undergrad starting to learn relativity and needing a quick introdution into the index notation and formalism, or perhaps a more general reader interested in seeing the conceptual mathematical framework of relativity without necessarily no intention to perform any calculations. In my opinion the latter target audience is more in line with the goals of an encyclopaedia (as opposed to a wikibook on the subject, for example). Unfortunately my own to do list is similarly quite long already. Stca74 06:27, 26 May 2007 (UTC)[reply]


As an introduction to GR mathematical ideas, this article totally useless. The idea that anyone who did not know this stuff already could use it as an introduction is laughable. It would be better to call it reminder notes on GR maths. —Preceding unsigned comment added by 79.70.197.119 (talk) 06:51, 18 March 2010 (UTC)[reply]

Content Review Sought[edit]

I would like to get in touch with the curator of this article. GeMiJa 01:35, 31 May 2007 (UTC)[reply]

There are no curators at Wikipedia. People work on the articles if and when it suits them. JRSpriggs 10:56, 31 May 2007 (UTC)[reply]

Perhaps "moderator" is the preferred term? Poignantly, my pursuit is for a professional in quantum mechanics. GeMiJa 11:19, 1 June 2007 (UTC)[reply]

Perhaps I was not clear. There is NO PERSON assigned to care for this article, by any title. If you or I or anyone else wants to make a change, he can. If not, nothing happens. Everyone is equal in that respect.
I understand that there is a process by which you can ask experts to review an article. I have never used it, so I do not know how it works. You could ask WillowW (talk · contribs) who has done that. If you have a general comment or complaint about physics articles, you could express it at Wikipedia talk:WikiProject Physics. JRSpriggs 04:06, 2 June 2007 (UTC)[reply]

Typo?[edit]

I have limited understanding of the topic, but this (from the page) looks suspicious to me:

If one defines a new coordinate system xμ' such that

   x^{\mu'} = x^{\mu'}\left ( x^{\mu} \right )

—Preceding unsigned comment added by EJR (talkcontribs)

That is in the sub-sub-sub-section Introduction to mathematics of general relativity#Transformation of dx. It is just saying that the coordinates of an event in a new coordinate system (indicated by a prime) are a function of the old coordinates (indicated by the lack of a prime) of that same event. OK? JRSpriggs 08:07, 4 June 2007 (UTC)[reply]
It reflects that physicists often make no difference between entity and field of entity (or functions and their values). 193.179.29.210 15:36, 17 August 2007 (UTC)[reply]
It is so annoying...

The header[edit]

JRRSprigs, you have replaced the standard template for introduction to articles with a custom message. This practice is not encouraged except in special situations, and I believe this is a general rather than special case. Because this article and the main article are closely tied, it is automatically implied that this is a non-technical introduction relative to the original article. There is no such thing as absolutely non-technical. The article title claims to be an introduction to the mathematics used in General relativity, and in that case the standard template is the proper thing to use. If you believe this article serves a different purpose, then it should be move to reflect that fact. Loom91 08:22, 16 July 2007 (UTC)[reply]

See the discussion above. I'm inclined to agree that this is a different case to the other introduction articles. My solution was to agree to the manually written hatnote, and to manually add the category. Incidentially, the template category categorises everything under "I", when ideally they would be categorised under 'G', 'E' etc. DEFAULTSORT can fix that, but maybe the template can as well? The other solution is to make the introductory template have an option for a hatnote where the wording doesn't say "non-technical", which seems to be the sticking point here. Carcharoth 10:00, 16 July 2007 (UTC)[reply]
I changed the texts of the templates to clarify that the difference between the main article and the trampoline is relative. An introduction to evolution will necessarily be more accessible than an introduction to quantum chromodynamics. Loom91 11:42, 16 July 2007 (UTC)[reply]
That is an improvement, but this here article is not "generally accessible". To me it reads like a set of notes written by a physicist to remind themselves of the equations and mathematics involved. But that is a problem with the article, so either the article or the title needs to change (as you said before). Carcharoth 15:00, 16 July 2007 (UTC)[reply]
I agree that it does not fit the goals of an Introduction to article. JRRSprigs has now reverted me, so I assume he agrees also. What should it be renamed to? In fact, I susoect the usefulness of the article. After it is renamed, perhaps it should be nominated for merging with the original? Loom91 20:57, 18 July 2007 (UTC)[reply]
This article is neither "basic" nor an "introduction" to GR mathematics. I would nominate it for merge with the "Mathematic of GR", but I suggest moving it to WikiBooks or Wikiversity instead. Madcoverboy 14:22, 20 July 2007 (UTC)[reply]
I agree. This is not an often-visite article, no point in waiting further. Will you do the merge and turn this into a redirect? I'm not knowledgable enough to do it. Loom91 14:51, 20 July 2007 (UTC)[reply]

Editor Assistance[edit]

This article is currently under discussion at Wikipedia:Editor assistance/Requests#Math of General Relativity and page swap D O N D E groovily Talk to me 16:30, 25 September 2010 (UTC)[reply]

Transcript[edit]

This is a copy of the discussion that took place as described above. It has been posted here so it does not get lost in the editor assistance archives

We have an odd situation here. Introduction to mathematics of general relativity is supposed to be a non-technical page for those not familiar with relativity, while mathematics of general relativity is supposed to be technical for those that are familiar with the topic. What we have is an intro article that is almost purely equations and an other article that has lots of explanatory prose that ordinary people can understand. What seems to be needed is not a move or a redirect, but a page swap. I've never heard of this happening on Wiki, so as far as I know, this is the place to post this. D O N D E groovily Talk to me 05:31, 25 September 2010 (UTC)[reply]

I see that there is a stalled merge discussion on these two articles. The existence of both is an example of content forking which should be avoided. Mathematics articles, as with all other content on Wikipedia, should be accessible to the general reader and should not be written as a textbook. Jezhotwells (talk) 13:55, 25 September 2010 (UTC)[reply]
I don't see this as content forking. "Introduction to" articles are explicitly part of wikipedia policy for topics that are very complex and technical to provide the basics for new readers, while the main article goes into the complex details. Mathematics of General Relativity is definitely one of those topics. You do, however have a point about textbook style. Based on that, sounds like the "intro to" article in this case should be deleted and directed to the main article. D O N D E groovily Talk to me 15:34, 25 September 2010 (UTC)[reply]

Complete rewrite[edit]

This article needs a complete rewrite. I will tag the page accordingly, and I will work on creating a non-technical explanation of really really really complicated math. D O N D E groovily Talk to me 14:02, 28 September 2010 (UTC)[reply]

Wikiversity[edit]

Jwoodger nominated this page to move to Wikiversity. I looked at Wikiversity's intro page, but I'm not really clear what the difference is. Jwoodger, could you clear up for me what exactly Wikiversity is and why you feel that article qualifies? D O N D E groovily Talk to me 05:03, 22 October 2010 (UTC)[reply]

The difference lies in the style of prose, more than anything else. For example, Wikipedia articles don't normally refer to themselves, such as "All the mathematics discussed in this article..." There is also a lot of inappropriate point of view in the text - I.e. "we use", "This allows us to write", "Suppose we have a point", etc - makes it sound like a class textbook, or a teacher leading a class. This point of view is what is encouraged at Wikiversity to help students and researchers, but not at Wikipedia.
For example, "The curvature K of a surface is simply the angle through which a vector is turned as we take it around an infinitesimal closed path" should ideally be converted to use less of an instructional tone (apologies if I mess up the logic of what the sentence should be saying) - "The curvature K of a surface is the angle through which a vector is turned as it travels around an infinitesimal closed path". Jwoodger (talk) 05:58, 22 October 2010 (UTC)[reply]
I think the article should be wikified rather than removed from Wikipedia. The discussion has gone nowhere for over a year, so I have removed the tag from the article. The Transhumanist 20:46, 4 January 2012 (UTC)[reply]

An introduction to the introduction[edit]

This introduction is a nice once until we hit Parallel transport. From that point forward, my head explodes and I need an introduction to the introduction. Any kind soul care to dumb it down further? I'd offer to help, but if I knew how, I wouldn't be reading this introduction in the first place. Thanks! Wknight94 talk 23:12, 24 January 2011 (UTC)[reply]

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Diagram of spacetime dilation of star[edit]

The gravity well is shown as falling away like some black hole, the slope getting steeper even within the star. This is wrong. The slope will be greatest at the surface and diminish inside the star because the remaining mass below it at any point is lessened as one goes deeper. At the center of gravity, spacetime will be flat and though tremendously dense, the matter will be weightless.

Ideally, the degree of dilation (stretch) of spacetime (space radially stretched about the center of gravity) would be directly proportional to the change in gravitational potential energy between the observed point and the observer (perhaps Schwarzschild's observer at infinity). Spacetime will be flat at infinity and flat in the center of gravity of any mass that is in free fall, like the star. — Preceding unsigned comment added by McGinnis (talkcontribs) 03:15, 22 August 2018 (UTC)[reply]

Thanks![edit]

I like the effort put in this article! It tells me there is at least one person in the world of Wikipedia who tries to explain things in a somewhat less rigorous way. Many articles are written by persons with only their own ego in mind. — Preceding unsigned comment added by Koitus~nlwiki (talkcontribs) 23:56, 18 December 2019 (UTC)[reply]

GRT transformations[edit]

where do You have such transformations https://de.wikibooks.org/wiki/Formelsammlung_Physik:_Relativitätstheorie#Geschwindigkeit 79.202.43.228 (talk) 09:37, 6 February 2023 (UTC)[reply]