I understand that the universe is gathering speed as it explodes into the nothingness it is presumably filling - in other words the Big Bang is still happening. What I don't quite get is where in the universe the big bang took place. It cannot be expanding all in the same direction, in an odd linear way (or can it?) so there must be some central spot or source. No? If so, where is that spot? If not - well: all explanations gratefully received.