Physics Discussion

So we're moving in all 4 dimensions. In the 3 dimensions, we change our speed, directions, we stop, do whatever we want. But why not in time? Herbert George Wells said that just like we cannot move upwards in a gravity bound space, we cannot move backward in time. Although he did argue that it is possible just like we can jump or fly upward in space. If gravity is the energy that provides the force to keep us from moving upwards, its possible that there exists some energy that is exhibiting force to keep us from moving backwards in time or to keep us in a state of continuous motion in time.