[treed]

I think "dark matter" is just a term used in place of "we haven't a clue what's out there". I think it's supposed to be all of the things we can't see because of the missing light. Some guess it is sub-atomic particles (hot), and others guess it is large masses (cold). Everything in the universe that is detectable by us so far equals between 5-10% of closure density (this is not something I understand mathematically, and depends upon the theory of inflation)--since we have no clue what makes up the other 90-95%, we have dubbed it "dark matter."