first of all, we need to define time. in my opinion(feel free to debunk if you can), time is only an concept created by men, measuring how fast something moves in space. in order to go back in time, you would need to move backwards in a space where something that has already happened hasent happened yet. now when it comes to this, we need to look at how space expands. my INTJ friend has a good theory about this, basically photons are always still in space, but space expands, creating an illusion of photons traveling in space, when in fact its the space that expands in the rate of photons. so in order to move back in time, we would need to move faster than photons, which according to laws of physics as we know today is impossible. even if we could move faster than photons(move back in time), it would require us to move in space, away from the place where we want to move in time backwards, sort of escaping from the photons than we previously observed. but then there is another problem, if we move away from earth(lets say we want to move backwards in time of the earth), we would have to go FAAAAAAR away from earth faster than light, just to observe the photons that has been projected by something in earth earlier. but then there is another problem, we can only observe time that has already happened on earth(just like we are observing distant stars and galaxies). in order to overcome this, we would need to move towards earth faster than light again, which would enable us to move back in time. but there are problems in this also(besides it being impossible to move faster than light), when we do move at high speeds in space, we would bump into hydrogen atoms in space(space has around 1 hydrogen atom per square meter), which at high speeds like this would penetrate the what ever we are traveling in and us, causing death.
this has been debunked, just like i suspected when this was released, they didnt take measuring error in electricity slowing down in mass amount of electric circuits into account.
