Imagine this: You are able to record the position and velocity of every atom on Earth and then after a decade you can somehow magically revert every particle back to where it was a decade ago.
This isn't possible because Heisenberg's uncertainty principle prevents physicists from knowing the position and the velocity of a particle. The act of measuring the position changes the velocity.
Anyways in order to really go back in time a decade you'd have to record the position and the velocity of every atom in the universe and revert it back somehow. If the neurons in your brain are arranged in such a way so as to remember traveling back in time, you didn't actually travel back in time. You are a part of the universe and in order to travel back in time would require the atoms in your body to revert back to where they were at the time you want to travel back to.
This poses a problem if you were somehow able to travel back to a time before humans existed. You don't know where your atoms would end up. 65 million years ago your atoms might have been dino dick. If you revert everything back except the atoms in your body you didn't actually travel back in time.
Submitted June 13, 2018 at 12:12PM by 43242343242353423523 https://ift.tt/2l5767m
