Newsgroups: sci.math
From: Ken Quirici <kquir...@yahoo.com>
Date: Tue, 3 Nov 2009 19:05:29 -0800 (PST)
Local: Wed, Nov 4 2009 3:05 am
Subject: Wikipedia contradiction in re: hyperbolic geometry; and in general, the geometries
First, Wikipedia's article on non-euclidean geometry contradicts the
article on hyperbolic geometry in that the former says that, in a hyperbolic geometry, given a line l and a point P, there are *infinitely* many distinct lines passing thru P and parallel to l. On the other hand, the article on hyperbolic geometry says that for such a geometry *at least two* distinct lines pass thru P and are parallel to l. (BTW the Mathworld article on hyperbolic geometry makes the So which is hyperbolic - infinitely many, or > 2, or 'many', and Secondly, the three types of geometry define the case for all lines l, There is now I discover 'absolute' geometry which does not Am I correct in assuming that an absolute geometry allows for BTW I can find no way to make sense of the notion of You must Sign in before you can post messages.
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