MWI of Quantum Mechanics (continued)
I am skeptical of any time travel story which invokes a single timeline scheme of reality. (That is, how physical events unfolded and will unfold; i.e., “reality.”) The French suffered defeat at Waterloo, and thus Nappy ending his mercurial career growing potatoes on St. Helena Island. If a retrograde Bonapartist zealot were to travel back into time and provide his or her would-be emperor with vital information that would have enabled him to win the battle, what would result would constitute another timeline to the one we now know, a separate and distinct reality.
But if there is just one timeline, one reality, then I do not see how—even in theory—such could be possible due to the “grandfather paradox,” a violation of the ordering of cause-and-effect. It would seem that only the MWI can both explain the double-slit experiment and allow for the possibility of time travel, at least into the past. Thus, if time travel into the past is possible at all, then I believe the MWI must also be correct by implication.
For example, within my scenario my time traveler returns to his past and (deliberately) prevents himself from ever inventing his time travel device. The contradiction should be obvious to all without my spelling it out. That is why I used the MWI within my story. However, I invoked my own personal variation of it, which amounts to rank speculation.
In the conventional MWI, the branching of reality into myriad divergent ones happens constantly as a force of nature. In my variation, it only happens when reality is forced into it by the intervention of a time traveler. Although not stated within the story (due to the length restrictions I referred to previously), as long as my time traveler is careful to travel back and forth through time so that he always arrives at least one second after his last visitation, then he will not force nature into yet another branching of reality, creating yet another “parallel universe” (timeline) to his own. Thus, he is always certain to arrive at the same timeline he last departed from in regrad to the past. In regard to the future, nature cannot accommodate the "same" two people at identical ages in the same timeline. Thus, he defaults into his original timeline when returning, and not the boy's newly created one (which is just as real as his own).
(It is this moral reservation on his part that he is alluding to when he tells the boy, “I’m not even sure it’s right.” In a very real sense, he’s playing God and it haunts him. He’s a bitter man, but he does have a conscience. Still, he just had to try.)
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