>>936212510 (OP)Because the geometry of spacetime isn't like that.
It's composed of various particles with spins that adhere to probabilistic fields that play out in a tensor field.
The symmetries between the spin of these particles is what shapes the forces of the universe (except gravity).
If we apply M-theory, then the particles themselves are in the 11th dimension and this does account for gravity and the theory of general relativity.
The reason you can't go back in time is because you're too big, not fast enough, and adhere to the function of quantum mechanics.