Last night David Letterman had physicist Brian Greene as a guest. The topics were the origins of the universe, inflation, and even a little about string theory. At one point in the conversation they talked about what might have existed "prior" to the big bang. A short excerpt: Letterman: But even in nothingness, nothingness in and of itself is something. Greene: Yes, it does wind up taxing language to describe these ideas using common words, but the notion would be that the familiar things we know about like space and time and matter really would not have existed. It would have been either a different realm, or a realm literally not composed of anything we know of or could describe. Letterman: Like Trenton.