Time is a tool invented by animals to keep a pace with change. It has been perpetuated by societies in many different ways along much of the now counted change. Time has been seen as a real, existing thing outside of being a way of counting the change of everything, when it is in fact not. Time travel is only possible if done in small increments, as making time travel of everything would mean having to take every particle of everything everywhere and moving them back into a collective, previous position. This puts future time travel into an even more impossible feat, as it also requires the decision of where to put everything everywhere. Time is an illusion set up by society, not just any old illusion.