> None of this matters, because the limiting factor for civs is collective intelligence, not energy. Is this really the limiting factor? I've always assumed th

> None of this matters, because the limiting factor for civs is collective intelligence, not energy. Is this really the limiting factor? I've always assumed the limiting factor was distance. I can envision a species that is more intelligent or more altruistic. But what I can't envision is how collective action is coordinated over interstellar distances. It would seem to me that the extreme communication delay would cause any interstellar civilization to inevitably break apart into a bunch of separate "local" civilizations.