Originally posted by dragonrider
This could lead to the first concrete evidence of dark matter, which may make up 30% of the universe.
Originally posted by SeaBass
Another (more boring) theory about dark matter is that this "missing mass" is present in nertrinos. Nertrinos are so abundant that a tiny neutrino rest order on the order of 20 eV would furnish this missing mass and therefore "close" the universe.
A lot of research is going on in this area. Pretty interesting stuff.