When I imagine the big bang, I first imagine a tiny ball surrounded by black void. Then the ball explodes and the universe begins. I assume most physicists have the same basic idea.
But how do we know nothing was around that tiny ball when it exploded? It seems like any existing energy/matter at the time of the big bang would have become mixed up with the energy/matter from the singularity, thus rendering it indistinguishable. That means something else could have existed at the time of the big bang, but we can't say for sure.
Has this been ruled out? If so, why? If not, how is it taken into account?
