Does string theory merge space and time into spacetime? GR combines space and time as spacetime, I've heard that in string theory there is 9+1 or 10+1 spatial dimensions, with 3 large, 6 curled, 1 time dimension. Is there a spacetime in string theory? Are Yau-Calibi manifolds part of this spacetime? How does string theory deal with the different conception of space and time in GR and QM? Is the spacetime in string theory 4D or 11D?