Right, so even with near-c von Neumann probes in all directions, vacuum collapse or some other galactic x-risk moving at c would only allow civilization to survive as a thin spherical shell of space on a perpetually migrating wave front around the extinction zone that would quickly eat up the center of the colonized volume.
Such a civilization could still contain many planets and stars if they can get a decent head start before a galactic x-risk occurs + travel at near c without getting slowed down much by having to make stops to produce and accelerate more von Neumann probes. Yeah, that’s a lot of if’s.
20 billion ly estimate seems accurate, so cosmic expansion only protects against galactic x-risks on very long timescales. And without very robust governance it’s doubtful we might not get to that point.
Right, so even with near-c von Neumann probes in all directions, vacuum collapse or some other galactic x-risk moving at c would only allow civilization to survive as a thin spherical shell of space on a perpetually migrating wave front around the extinction zone that would quickly eat up the center of the colonized volume.
Such a civilization could still contain many planets and stars if they can get a decent head start before a galactic x-risk occurs + travel at near c without getting slowed down much by having to make stops to produce and accelerate more von Neumann probes. Yeah, that’s a lot of if’s.
20 billion ly estimate seems accurate, so cosmic expansion only protects against galactic x-risks on very long timescales. And without very robust governance it’s doubtful we might not get to that point.