Hello. I think I don't understand very well the Paul Steinhardt's cyclic model of Universe(s). According to Paul Steinhardt, 2 universes get closer. Then, there's the big bounce, which products effects like a big bang. If 2 universes get closer, they have a (relative) speed ( speed is the derivative of the position with respect to time). So, for having a speed (for example in meters per second), we need a time dimension. However, we have a time dimension, but INSIDE our universe (a space-time universe). So, have we got ANOTHER time dimension OUTSIDE our universe ? Or have we a time dimension which is shared by several universes ?