shawn77

But what are these membranes? How many are there? How many types are there? How many dimensions do they occupy? Why do these collisions produce universes?

Membranes are universes in this sence.

Well, in infinite amount i assume. That is because the 11th dimension is infinitly big.

We dont know.

How ever that they do. some branes can hold more than others.

think of it as a product type thing. when you hit two rocks together, you get energy right? well imagine two huge branes colliding. the branes come together and the energy given off creates a new brane.