up/down to change speed the scratch cat feels like they are going at a certain speed but you (the viewer see that scratch is jumping forward and not at a steady speed) thats dilation. i guess
i think if speed goes too high or too low you could time travel this is a heavily modified example (dilation is not this noticeable) also until you hit the speed of light you are still visibly the same speed to others (idk im not a genius, just a programmer)
