A theory on time travel based on practical experiments:
It is an established fact that clocks run slower on board airplanes. This is why clocks also run slower on satellites.
If it were possible to fly an airplane high enough and fast enough, would time evetually slow down enough to stop, and then start to go backwards?
I’m thinking of that scene in the Superman movie, where Superman flies around the Earth so quickly that time actually goes backwards. Is this pure science fiction, or is there any basis for it in reality?
A time travel paradox:
Suppose I was transported back in time, by whatever method, one year into the past. By interacting with the environment, I would cause a ripple effect which would change the future. This would mean that I may never be in the position to go back in time in the first place. This means that I cannot possibly exist in the past or the present, and I negate my own existence. Would this cause all of existence to be out of whack, by virtue of said ripple effect?
Another time travel paradox:
If time travel is ever invented at any point in the future, why hasn’t someone come back from the future to tell us about it? Or maybe they did, and they caused a paradox to occur, negating their existence?
My first point will probably be dismissed with an explanation of how all time is relative, but please do not use too much advanced physics in your replies, as this will probably whoosh me.
My other two points, while having no basis in science (as we currently know it), intrigue me, and I would like to know what other’s thoughts are on these points.
In any case, I find the subject fascinating, and would like to here what the thoughts and theories of the straight dopers are.