Objects can move forward and backward in space, and physical laws have no preferred space direction. Objects cannot move forward and backward in time, though physical laws have no preferred time direction. In space-time, can objects move forward and backward in time {time travel}|?
If time travel is possible, people can deduce what has happened from knowledge of the future. Past-time observation affects past. Because contradictions violate causation, nothing can communicate or transport backward through time. The meaning of space and movement prevents moving forward and backward in time. Relative velocity is moving through space over time. Movement is always in space-time spatial dimension. Moving forward and backward in time cannot separate from moving forward and backward in space.
Physical Sciences>Physics>Relativity>General Relativity>Time
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Date Modified: 2022.0224