Talk:Weyl's postulate

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To-do list for Weyl's postulate:	edit · history · watch · refresh
tasks for expert: write and link to articles on ADM formalism, explain hyperslices and evolving geometry therein, write and link to articles giving explicit examples of congruences with zero and nonzero vorticity in flat and curved spacetimes, explain therein the relation to locally non-rotating and to fluid dynamics, write articles on Bianchi dusts, Wainwright solutions, etc.

[edit] Fundamental assumption of big-bang theory?

Nonsense! The hypothesis just says that the world lines of the dust particles (model galaxies or whatever) are vorticity-free. This is indeed true for the FRW dusts, FRW fluids, and many closely related models such as the Bianchi dusts. But there are plenty of cosmological models which do not satisfy this hypothesis but which can be described as big bang models! There are even models close to the familiar FRW models which exhibit nonzero vorticity. ---CH 04:03, 2 February 2006 (UTC)

I have rewritten the article and added a todo list for further work.---CH 04:30, 2 February 2006 (UTC)

[edit] Fundamental assumptions, etc.

It's not complete nonsense, because the requirement of the orthogonality of the base sets in any coordinate system is a simple axiom of all physical vector spaces. It is a foundational tool of quantum mechanics, and of electromagnetism as well, and it is thus independent of a cosmological model. This article states that it is in need of an expert - and this is true for as it stands it is terse at best and only through my math and physics background can I make heads or tails of it. I will be glad to put it on my watchlist and to improve it, and if there are any other astrophysicists or applied mathematicians who can help make this article readable, let's discuss the improvements we can make. If you do not have a strong background in math and physics, please discuss proposed changes here on the talk page before making them, or otherwise cite your changes with supporting peer-reviewed literature or a revert is more likely on the changes. Let's make this article a good one! Cheers, Astrobayes 20:49, 23 June 2006 (UTC)