Well, I don't know. It is just a common topic in fiction that great civilizations just fade out, and it seems reasonable to me. I do not believe the average in

Well, I don't know. It is just a common topic in fiction that great civilizations just fade out, and it seems reasonable to me. I do not believe the average individual would want to live forever, and at some point I feel the same would apply to civilizations. But for the sake of fun, I can recall some ideas from literature :) Maybe they evolve into higher states of being and leave our plane of existence. Maybe they stop reproducing and slowly die out. Maybe they reach a level of self-introspection where they believe continuing existing is pointless. Maybe they migrate to a more reliable virtual world in a sub-space computer. Maybe each individual gets its own universe. Maybe the society splinters over some trivial concepts and the old knowledge is lost when the machines start to fail. There's a lot of interesting things that can happen, let's hope we'll find out late enough :)