I have my own Big Bang theory
No, it has nothing to do with what you're thinking, SHUT UP.
The universe is a big cone, you see, and all of the matter settled in the point. Matter is always trying to achieve an equilibrium, but it can't, for reasons that are complicated, like relationships.
So the matter all settles in the point of the cone, and then it's all too close together and repels everything from itself, so it starts to "expand", ie migrate away from other matter. It expands and expands, and as it expands, the cone flattens, until it can flatten no more, and the matter all freaks out by how far away it all is from the other matter, and starts to contract, on the other plane of the cone. It contracts and contracts and the cone gets conier and conier, until all the matter is too close together in the tip of the cone, and then...
It's basically the same as the doughnut model, but way more fun.