Backward Time Travel, possable or not?

[RIP-Felix]

After careful over thinking I have decided backward time travel is impossible.

If multiverses doesn't exist:

It's not possible to travel into (or communicate with) the past without being seen or heard by someone, which would alter the past. That's not allowed because paradoxes requiring alternate realities would ensue. The butterfly effect and grandfather paradoxes would mean that no matter how careful you are, you would inadvertently change something requiring multiverse to explain. It's disallowed in this thought experiment, so that's the end of non-multiverse. You cannot travel into, or communicate with the past without multiverse.

If multiverse exists:

Any change you make would create a pardox that can't be explained in your reality. You must split timelines into an alternate reality - just another in an infinite sea of multiverse realities where every permutation has been done at nauseum and beyond. Sending messages into the past just splits the timeline and it can't change your reality. If you could travel into your past, you couldn't return to your own reality because the trip itself puts you into an alternate - the butterfly effect and gradfather paradoxes prohibit your timeiline from being achievable anymore. Your mere presence in your own past timeline obliterates it. Everything you do changes an outcome. Therefore, in a multiverse there is no reason to communicate with the past and no point traveling into it unless you're bored and never want to return to your own reality. You could have a life in an past era, but never return to your own timeline. But that creates the possibility of "time settlers" and "time criminals".

Going deeper, if backward time travel/communication were possible, we'd meet/correspond with "time settlers/criminals" all the time. We'd be inundated with them from an infinite number of multiverses in which someone figured out how to do it. In fact, their "mass" (bodies/information) would reach critical concentrations causing Big bangs that sterilize that universe. And thanks to infinity being infinite, universes would be "massed to death" over and over again. In fact all of them but the ones not visited be sterilized. Inevitably, any living observer must be in one of the surviving universe's. And all multiverses must never achieve backward time travel, or they'd be "massed to death" by infinite "time suicides" (those wishing to visit the big bang of their own universe) causing big bangs in in others, reseting one after another until they sterilize the multiverse again. Isn't infinity great? And if multiverse is not true, then backward time travel is impossible anyway.

Either way, no backward time travel is one metaphysical traffic law.

[Draco1962]

Thanks, Ass, for nullifying the "Back to the Future", "Terminator',  "The Final Countdown" and any number of iterations of H.G. Wells "The Time Machine" movies.  For your insensitivity, I think I will "CHER" with you a video on the subject:

 

[RIP-Felix]

Well played sir!