what about the grandfather paradox? if you go back in time and kill your grandfather, would you cease to exist?
Einstein believed that if we could surpass the speed of light, we would become infinitely large and could thus travel time. Which is a great point because, if you look at a light shining from a flashlight, it takes TIME for that light to travel to your eye. Thus, if you could travel out far and FAST enough, you could see light projecting from Earth that was from thousands of years ago. And thus , you'd be surpassing time because you'd be surpassing light.
If you could actually go back in time, you will disrupt a realm which will distort the entire universe. We can go back in time from the world of forms and not from the materialistic world.
You might go back in time and prolly kill your grandfather, your dad won't be born, then you won't be born, if you are not born how can you then travel back in time to kill your grandfather?