The parallel dimensions might explain ghosts and visions of other times. Their might be natural time travel that need not use Deloreans or Time Tunnels. Their might be many thousands of dimensions —in One Hillary won the election, in another Hitler won WW II (what sort of world would he have made?) One theory holds that Out of Body Trips are only going to a close by dimension. BUT your time trip would not effect your timeline—when you got home nothing would have changed.