Or lack of ability if FTL is completely impossible relativity puts a limit on the size of a civilization.
And the universe can easily out a time limit on it as well because extinction events can happen.
Even if we move onto mars a GRB would cook all of us.
And even if it's something considerably more boring then expanding to other planets or even star systems might not save a civilization from collapsing.
Even if we move onto mars a GRB would cook all of us.
And even if it's something considerably more boring then expanding to other planets or even star systems might not save a civilization from collapsing.