why time only flows in the one direction.
the universe may not actually be expanding but only appears to be.This article outlines a theory that explains why the universe isn't expanding evenly in all directions, and it relates to the geometry of space-time. Most scientists believe that space is ‘flat', unless it is being ‘curved' by the presence of matter (which results in gravity). The Toroidal Universe Theory proposes that the universe may not actually be expanding but only appears to be because space-time dynamically flows with the geometry of a torus. So the universe may be simultaneously expanding and contracting in a closed loop – stretching at the top where space-time emerges from the centre of the torus, and contracting at the bottom where space-time flows back into the centre. The Toroidal Universe Theory also explains why time only flows in the one direction – forwards