Perhaps. But I guess what I was saying was that, given that the expansion of the universe is accelerating, it may be physically impossible to propagate outside

Perhaps. But I guess what I was saying was that, given that the expansion of the universe is accelerating, it may be physically impossible to propagate outside a local area, given a universal speed limit. An event horizon outside of which no information can escape, and where attempting to do so merely increases the dispersion of energy. Ie, a localized acceleration towards heat death. The universe can be totally full, and noticing it can also be outside our possibility of observing it, ever.