Talk:Friedmann-Lemaître-Robertson-Walker metric

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I think this article should be renamed FRW model. One reason is that I need to refer to it a lot and can never remember this crazy name. Another reason (probably a much better one) is that noone would ever type in this phrase to search for information on FRW models. Comments? ---CH (talk) 23:46, 17 September 2005 (UTC)

I agree; this seems to be the most common usage. I've never heard it referred to as the FLRW model. Maybe it's better to spell it out (as in Friedmann-Robertson-Walker model) for the actual title though. Either is fine with me. -- Fropuff 02:15, 18 September 2005 (UTC)
I agree. The word 'model' in the title is more informative as to the nature of the article than four hyphenated names. --Eddie | Talk 07:53, 19 September 2005 (UTC)
I'm confused; I would have expected this to be the FRW metric, or maybe the FLRW metric - it's talking purely about the metric, which while it does represent a model it is not the entire model, more a subset of the GR model. The current name ('Robertson-Walker coordinates') makes no sense to me. As such, I would propose a name change to FRW metric. The names don't need to be spelled out, methinks. When any name change is made, remember to change the links from other pages (especially the cosmology template). Mike Peel 17:01, 25 February 2006 (UTC)
I do not agree. I am a physicist, I have taken many courses on Relativity and FRW is a metric, not a model. it's a mathematical object, not a model of behavior for a system. Astrobayes 23:56, 3 June 2006 (UTC)
Based on the above comments, I think that Friedmann-Robertson-Walker metric is probably the best candidate for a name change - reasons: (1) clearly, 'coordinates' should not be in the title, as it's a reference to the metric (2) I think it's the most common reference to the metric ('FRW model', as Astrobayes suggests, is not technically correct, even though many people refer to the metric as the model). MP (talk) 18:32, 17 June 2006 (UTC)
This is not supposed to be a USA-UK-centric encyclopedia, nor an EU-Russian-centric encyclopedia. Friedmann was Russian, Lemaitre was Belgian, Robertson was from the US, Walker was from the UK. Check out French authors e.g. Lachieze-Rey & Luminet 1995 http://arxiv.org/abs/gr-qc/9605010 who use only Friedmann and Lemaitre. For FLRW, just a few examples of usage by practising scientists are e.g.
NPOV surely favours FLRW. So i'm shifting back to FLRW. FLRW metric is fine rather than FLRW model. Boud 00:33, 31 December 2006 (UTC)

Contents

[edit] Derivation

I was wondering whether a derivation of the FRW metric might be handy? I've got a fairly nice (read 'hand waving') derivation from a Part II Experimental and Theoretical Physics course at Cambridge (3rd year Astrophysics) that does it without the need for tensor calc... I can have a look at whacking it up if people think it is worthy? MikeMorley 18:48, 11 June 2006 (UTC)

Fear not, when I get to it I plan a complete revision/reorganization of all articles pertaining to coordinate charts in gtr or exact solutions in gtr (this article fits into both categories, obviously), which will include derivations of such things. ---CH 01:20, 12 June 2006 (UTC)
Well, scratch that; see next section. ---CH 03:42, 1 July 2006 (UTC)
I'd like to have a look at it too if you come by it. Has Friedmann's paper ever been translated from German? JDoolin 02:41, 5 September 2006 (UTC)

I want to add, that the metric is not a SOLUTION to the einstein equations. It is a metric imposed by the symmetries homogenities etc...

In my opinion putting derivations in an encyclopedia is a Bad Idea. Wikipedia is, above all and foremost an encyclopedia, not a collection of student coursebooks where derivations are appropriate. In an encyclopedia you publish results, not intermediaries, unless it has an explicit bearing upon the subject. And that is not the case here. Instead I would focus more on interpretation of the result. 82.72.112.188 23:00, 15 December 2006 (UTC)

[edit] Students beware

I edited the July 2005 version of this article, planned to greatly improve it, and had been monitoring it for bad edits, but I am leaving the WP and am now abandoning this article to its fate.

Just wanted to provide notice that I am only responsible (in part) for the last version I edited; see User:Hillman/Archive. I emphatically do not vouch for anything you might see in more recent versions. I hope for the best, but gtr attracts many cranks, and cosmology has been "hijacked" by political action groups (creation science (sic) and all that) to further their adjenda of supressing scientific belief which they feel somewhow threatens their particular religious dogmas, so the reader should beware; it seems likely that at least some future versions of this article will contain slanted information, misinformation, or disinformation.

Good luck to all students in your search for information, regardless!---CH 03:42, 1 July 2006 (UTC)

[edit] Friedmann-Lemaître-Robertson-Walker metric

(Comments moved here from the newly-created talk page, which will be deleted shortly as I attempt to fix the mangled move. Mike Peel 11:10, 7 January 2007 (UTC))

Depending on geographical/historical preferences, this may be referred to under the names of a preferred subset of the four scientists Alexander Friedmann, Georges Lemaître, Howard Percy Robertson and Arthur Geoffrey Walker, e.g. Friedmann-Robertson-Walker (FRW) or Robertson-Walker (RW) or Friedmann-Lemaître (FL).

Boud 00:42, 31 December 2006 (UTC)

While most US/UK based cosmologists tend to choose the US-UK scientists and write RW or FRW (the latter including the Russian), European cosmologists e.g. Lachieze-Rey & Luminet 1995 http://arxiv.org/abs/gr-qc/9605010 sometimes use only Friedmann and Lemaitre.

A few examples of NPOV usage - FLRW - among practising scientists are e.g.

Boud 00:48, 31 December 2006 (UTC)

You may want to mention that in writing the Friedmann equations, you are setting various constants (h, G, c, 8pi) equal to 1. These are common units for cosmologists, but not to incoming students. 76.23.174.125 23:54, 3 February 2007 (UTC)A. D.

[edit] Merge with Einstein's radius of the universe?

There's been a merge tag on Einstein's radius of the universe to merge it here. They don't seem related but I'm not a physicist. Does anyone know if they should be merged, or should the tag be removed? Tocharianne 16:23, 14 July 2007 (UTC)

[edit] Some possible merges

It looks to me as though Lemaitre metric and Lemaitre-Tolman metric ought to be merged here. Or if it's not appropriate to merge them, then at least those two articles should discuss the relationship between the various models, along the lines of the discussion in section 4 of this article. Gdr 14:39, 28 November 2007 (UTC)

[edit] Two Naviagtion templates

Aren't two Naviagational templates too much in an article ? I propose to remove the GR template, as I did already one month ago !(Sheliak (talk) 15:35, 7 February 2008 (UTC))

[edit] Criticisms

Why is there no criticisms section in this article? That seems horribly peculiar. 66.69.194.16 (talk) 15:18, 3 June 2008 (UTC)