There was nothing before the Big Bang considering time is a result of the expansion of the universe itself. But when the universe has finished expanding, movement will be reversed.
If string theory is correct, the universe has nine spatial dimensions and one temporal dimension. Before the Big Bang, these were all combined, but once it occurred then three dimensions, height, width, and depth, and one temporal dimension we know as time, were deployed. The other six remained minuscule.
Which brings me to this
If we are in a world of wound dimensions how can we tell between illusion and reality?
From Mr. Nobody, a great film