Answer to Question #184644 in Mechanics | Relativity for Nina

Question

How could you travel far into the future without aging significantly? Could this method also allow you to travel into the past?

Answer 1

You can exploit time dilation to travel in such a way that you return to your start after many years have passed for everyone who remained.

You are only a few years or days in to your own future, but many years into everyone elses.

At all times, you are in the present… not the future. However, this is what people usually mean by time travel into the future.

In principle, the same thing could be used to travel into the past. This requires faster than light speeds or some sort of exotic matter. Physicists call this, “causality violation” because of paradoxes that crop up. If this sort of thing is possible, then Nature has some way to resolve the paradox we don’t know about. Right now the best evidence is that this is not allowed.