Also, if all matter prior to the Big bang was collected within a singularity at the center of the universe, what possibly could have caused it to explode?

The gravity would be so crushing that nothing would ever escape, since even a black hole lets not even light out, so clearly an explosion is out of the question.

Furthermore, it could not have been an outside force in physical space, since all energy and matter was in the singularity.

According to science, the Big Bang is impossible.