Such considerations have led to the speculation that our universe is a black hole within a larger universe. It is true that a closed universe has no boundary, while a black hole has an event horizon, but this is not a good argument against the idea… If one is going to assume that our universe is a black hole within a larger universe, then there is no good reason for rejecting the idea that the latter may be a black hole within a still larger universe. Such a progression could go on forever – one could have an infinite number of universes nested within one another like Chinese boxes…1
- Morris, Richard. The Fate of the Universe. Camden House, 1982. 107 [↩]