Hello everyone, can someone clear up these Big Bang problems for me? As far as I know quantum physics is a set of physical laws and rules describing our universe. If so, how can we say the Big Bang sprang from a quantum fluctuation if there was no Universe (and hence no laws of quantum physics) "before" then? Also, the quantum theories about the Big Bang and inflation all rely on the fact that the Universe was very small (pointlike) at the Big Bang. Well this is true for the observable universe and a closed universe, but if the universe is flat (which it seems to be) or open then it will be infinite in extent, even at the Bang itself? So how can we use quantum physics to describe it? The Universe wouldn't make any special distinction between any small part of it and the whole, so how can we use quantum physics to describe an infinite universe? Can someone give me a simple explanation of inflation and the mechanisms that are believed to have triggered and stopped it (particularly scalar fields?) I can't seem to find anything I can understand on the web. Can someone clear this up for me?