Talk:Angular size redshift relation
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Something unusual is going on with this article. The equation is described as a relation between angular size and redshift (hence the name), but redshift z does not occur in the equation. The graph looks nice, but unless the units are explained, the graph is unrelated to the algebra. Are the units of angular size "arc-seconds" or "kiloparsecs per arc-second" or what? As a non-astronomer, it's unclear to me what's going on here. Flying Jazz 13:08, 21 May 2006 (UTC)
The distance and the redshift are related to each other - but in a non trivial way that depends on the geometry of the universe and how you define distance. I included links to redshift and angular diameter distance to try and make this clear. Redshift is often used as a unit of distance in Cosmology. The units of angular size are kiloparsecs per arc-second - it is written on the graph but is rather small - and requires the knowledge that " is an abbreviation for arcseconds. It is explained in the summary of the graph. The graph is related to the algebra in the case of small distances/redshifts only. Hopefully someone can add the maths which explains the full shape of the graph. Hjb26
[edit] Notation
The notation in the formula is not fully explained. What is Qo? --Booberfish 18:42, 8 August 2007 (UTC)
