An uber-fudge made originally to account for discrepancies in the circular motion of certain celestial bodies. But much less of a fudge now, with better observations (eg. WMAP) that appear to confirm dark matter's existence. Essentially, dark matter is matter whose mass exerts an influence, but hard to detect by normal means. Most likely, they are WIMPs. (weakly interacting massive particles)
Makes sense from a certain point of view - why, after all, should most matter in the universe interact in the ways we are used to?
Re: Dark matter??
There are several threads in the Sticky thread "A&C reference library" (at the top of this sub-forum). Marcus feels that this thread to which I contributed a few posts is a good place to start on this topic.
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