In some of the shows I see about time travel (and there aren’t that many), the claim is made that if you travel faster than light, you will go back in time.
I don’t see why this would happen.
If you read the laws of special relativity, you will find the formulas relating time and space. One of them (Lorentz contraction) tells you the rate at which you travel through time is sqrt(1 - (v/c)2), where v is the rate at which you travel through space. The quicker you go through space, the slower you go through time. But what happens when v > c? You get the square root of a negative number. You do not get a negative number; you get an imaginary number.
Alternatively, you can think of it as the Pythagorean theorem, where one leg of the triangle is speed through space, one leg is speed through time, and the hypotenuse is the speed of light. (Is this Minkowski space?) In this model, it makes no sense to go faster than light. You can’t have a triangle where one leg is longer than the hypotenuse.
So it’s not at all obvious to me how going faster than light makes you go backwards in time.
Another thing that bothers me is the talk of wormholes. Oh sure, if you could bend the entire universe in half, you might be able to go back in time. Bending the universe seems like a harder problem than time travel.
I do think backwards time travel could be possible. However, I think the only reasonable way to make it would be to travel from one universe to another. You have to believe in the many-worlds theory first. I don’t believe backwards time travel into the same universe can work.