Everything and nothing. We've barely scratched the surface since our visible universe can only go so far and it's only a small corner of the theoretical size of the universe itself.
↑View previous replies…
Because all fusion eventually causes atoms to become iron. Heavier elements are made in supernova explosions. It is the fate of all stars that move past the brown dwarf stage long after they've gone nova.
Just means the universe will eventually be a cold, dark, and rusty place.