For many years I have thought about what role quantum mechanics played in the creation of our universe, as many physicist think that quantum fluctuations caused the big bang.
I have the idea that even quantum effects has to have spacetime for it to exist. When physicist say nothing existed before the big bang, they really mean nothing at all. We can't even think or wonder about nothingness because our brains work IN spacetime and we can only think in terms of cause and effect. It seems to me that without spacetime, even quantum physics becomes meaningless to explain the sudden appearance of the universe from a singularity. I don't think we can use quantum physics alone to explain something which came from nothing. Now I know there are alot of other alternative theories like string theory and the many worlds idea of quantum physics, but the idea of true nothingness interests me the most.
Who really knows what the universe is really like. I think the further we explore our universe, the harder it is going to be for us to match or picture it to our experiences. I think we are on but the surface of a BIG ocean.