Talk:Gullstrand–Painlevé coordinates

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Rain observer

Unless I misunderstand completely, the section "A rain observer's view...." actually covers the views of both observers. So the word "rain" should be deleted from the title. Fairandbalanced (talk) 01:53, 26 November 2009 (UTC)[reply]

Issues

This article has parts which are good, and parts that are really pretty bad. 1)The history section needs references-- eg the story about the Paris seminar. What is a reference for that? 2)The section on "Free Float" coordinates is just wrong as is the shell coordinates section. 3)The derivation of the rain coordinates from the shell coordinates is also wrong, both for reason 2 and because the transformation is not a valid coordinate transformation 4)It is not clear to me that the section on the rain observer's view should not be in an article of its own. It really does not have anything to do with the Gullstrand-Painleve coordinates. (Why is Gullstrand's name first since his paper was published later?). This section also needs a reference since Wikipedia is not supposed to be original research. 24.84.125.240 (talk) 10:24, 23 November 2013 (UTC)[reply]

Shell observer

"Shell observer" is not (or no longer?) defined, and should be. Moo (talk) 21:50, 7 August 2017 (UTC)[reply]

River model

I'd like to see a section in this article, or perhaps a new article, that recapitulates the river model of black holes, Andrew J. S. Hamilton and Jason P. Lisle (2004) https://arxiv.org/abs/gr-qc/0411060 A section in this article would be appropriate, since, to a large degree, the river model is just about frame fields. But also, a brand new article devoted only to the river model would be even better. 67.198.37.16 (talk) 06:06, 11 November 2023 (UTC)[reply]