Hi everyone, I'm new here.
I've read, that asking what the universe was before the big bang was like asking for a direction north of a north pole. However some developments in theoretical physics suggest and I quote "time did not have a beginning and will not have an end...it might have even gone through a cycle of death and rebirth."
The big bang may not have been the origin but simply a result of the preexisting state, a violent transition from acceleration to deceleration. The bang took place but the universe predated it. The universe has existed and will exist forever, the forces strengthened and matter began to clump until eventually matter became so dense that in some of this regions, black holes were formed until matter inside it were cut off from the outside, matter fell toward the center of the black hole, quantum effects caused it to rebound into a big bang. From that Universe, distinct universes were created. Our "universe" is part of a multiverse. If the question is what was there before the "multiverse" began or how the multiverse came to be, no one knows(I think)
PS: anyway, for those who consider String Theory rubbish then they will also find that explanation rubbish.