As described in movie Interstellar, Dr. Romilly stayed in the spaceship for 23 years but Cooper and Amelia just went to Planet Millar for about 3 hours. The scenario clearly demonstrates that time travels relatively slower on the Planet than in the spaceship since the planet is closer to the black hole. The short distance between the planet and black hole make the planet has such a high speed of rotation and revolution. According to restricted relativity, the faster one move the slower time goes compare to those moves at lower speed. And hypothetically when the moving speed achieves c, aka light speed, the time stops just as hypothesized in absolute zero.

Since we can “stop” the time at the speed of light, why don’t we imagine a little further. What if the speed surpasses the speed of light? Although real number cannot be calculated out when there are negative number under spare roots, it seems reasonable that we assume time can reverse at Superluminal speed. When travelling back through time truly become possible, future human beings will be able to find distinct answers to all archaeological problems.
Now the ship for travelling backward is prepared; how can we travel forward to see how the future is like? This is even easier than traveling to histories. Light-speed travel makes the individual experiencing it feels no time change, so no matter how long the outer world has changed through time, for the individual in our visit ship to the future, it’s still the same moment when his ship achieved/s light speed. Slow the ship down after appropriate time has achieved, and welcome to the future!

Medias from Google Image