A Question About Parallel Universes....

[BadgerBadger92]

Keep in mind this is completely a theoretical question... In the end I know nothing about physics. I just have a question.

If parallel universes exist, and two or more of them had the ability to travel time (If that were even possible at all. Doubtful.) could someone technically travel to this parallel universe and travel back to their universe at a past time and completely change things? What about the grandfather paradox? If you did go to a parallel universe, would it be possible to travel back to your universe? I know very little about this subject but I would like any input.

 

[mfb]

Without a plausible theory for both parallel universes and time travel, this is pure speculation instead of actual physics, and we don't accept threads with pure speculation here.

 

[Nugatory]

If parallel universes exist, and two or more of them had the ability to travel time (If that were even possible at all. Doubtful.)

They don't, which kind of takes the fun out of the rest of the question

This sort of question is essentially equivalent to asking "What do the laws of physics as we understand them say would happen in a situation where the laws of physics cannot be applied?" There cannot be any sensible answer, so this thread us closed.