>>12439714Big rip, big crunch, or heat death of the universe.
Assuming no expansion, like a Newtonian universe, all the suns eventually burn out, all the black holes evaporate, and all remaining power sources exhaust. No work can be performed as entropy has consumed all.
Big crunch. If the expansion of space reverses, all the stuff comes back together in an opposite big-bang.
Big rip. The expansion of space accelerates forever, eventually isolating and then ripping apart all atoms.
So far the heat-death of the universe is looking like the most likely with the expansion of space approaching a stable state (no expansion).
