Time travel would be in a certain direction on the spiral time stream(note the spiral turning of spiral galaxies), forward on the time stream, away from the dark energy at the center of the galaxy or backward on the time stream, toward the dark energy at the center of the galaxy. Stopping time would be non movement on the time stream, and everything except your mind(which is a different reality) is motionless. The old Superman comics covered all the angles, I believe. Somebody there really had an imagination.