The concept about the whole universe is usually defined in terms of a parameter Omega, where Omega = 1 means the mass of the universe is at the boundary between open and closed. According to inflation theory, Omega should be 1, and much of the current discusion in the cosmology community is where is the missing matter, since observed matter is only about .01, while dark matter (observed by studying the rotation of stars in the outer edges of galaxies) raises Omega to be about .1. No one yet has any idea where the remaining (missing matter) .9 is, or even if the current model of inflation is correct.