It seems that god (or the gods) did not say "let there be light" and there was a time before beginning. So what happened is the god(s) brought two hands together and when the membranes collided, this universe was created. Those membranes or "branes" are undulating x + y dimensional strings which are probably bubbles floating in space like soap bubbles in the air. Here is an intro.
screw the math, here are some soap bubbles: