According to Membrane Theory the big bang possibly happened when two universes collided in the multiverse. The multiverse, being infinite in every way, sort of postpones the question "how did it start". Postpones it indefinitely, in fact.
That's why some people just don't like Membrane Theory. Religious people tend to go running to god when they can't explain something. Theorists go running for infinity (they even have their own dogma: sub-quantum theory. The answer's in the strings and the foam, but we can never reach it!). The difference is rather hard to tell apart in praxis. Science ends when there is no longer any way to prove theory by analysis.
