I've always been curious about about the big bang because (from what I've read) it's a point we're not able predict before. Is there a possibility that our view of an expanding universe just means we can't see beyond the big bang? Or is there a reason that is ruled out and that everything outside of our view is expanding as well? On that note, I am also unclear on whether the big bang theory is supposed to be a theory of how our universe started, or how our "known" universe started? I am assuming the latter.