There are two thoughts related to the big bang theory and universe expansion i think.
1. As the universe exspands it will get colder and colder as all the energy gets more and more dispersed until everything reaches absolute zero and the universe as we know it dies.
2. The universe will expand as above except once it expands past a certain point it will collapse on itself and will get smaller and smaller until i tis back were it started, a tiny ball the size of a pin head. Then it will expload and start all over again.
The weird thing about the second theory is that if you think about we could be living an exact repeat of previous universes.
Computers in the future may weigh no more than 1.5 tons."
- Popular Mechanics, 1949