We're very likely NOT alone in the universe, but we might as well be alone, for all practical purposes. If the next civilisation is more than (say) 200 light y

We're very likely NOT alone in the universe, but we might as well be alone, for all practical purposes. If the next civilisation is more than (say) 200 light years away, they can have no interaction with us and none for us with them, so they might as well not exist at all.