End of the Univers. What happens to matter?

[pokervintage]

Recently I watched a Discovery program concerning the end of the Universe. The latest theory from what I gather is that the univers will continue to expand to a point, some 50 billion years in the future, where it will just disappear. Physical forces will cause it to collapse or explode. The physicists explaining this result used a balloon to simulate the results. They blew it up to a point and then punctured it to show kind of what is expected.

My question is, what happens to the matter after the expansion - explosion - collapse? Does the matter evaporate and disappear? Is anyone familiar with this prediction?

pokervintage