“closed,” and does not require reference beyond itself for its being or its meaning. On the other hand, however, as Hegel pointed out in a different context, one cannot define a limit unless one is already beyond it.2 Indeed, a limit cannot exist except within the context of what exceeds it. This is, of course, what represents the great enigma of cosmology: Is the universe a limited whole? If so, what lies on the other side of its borders such that it makes sense to speak of a border? What, in other