Don't you know what are http://motls.blogspot.com/2005/03/melting-crystals-and-quantum-foam.html" [Broken]? Horse-radish,:grumpy: you will understand that. What I imagine. At the beginning there was space-time and it was a solid, a crystal. Then there was the Big Bang, there came a Brane and knocked space-time, as a result space-time heated and started to melt. Now the space-time is a liquid or a gas, right? Oh, idea! Just have thought up, that space-time when it is solid or liquid must evaporate too, and there must be space-time steam. This steam may come even from other brane.