Precis of time travel to the past

 To summarize: objectors to time-travel-to-the-past say that the traveler would change the past, and that would contradict the past and the present through the chain of causality. Therefore time-travel-to-the-past cannot be.

But I show that their conclusion is not necessary because they have ignored a hidden assumption that is itself incoherent (part of their view). I show that the revived past need not have any causal relation to already experienced pasts or the present. The going-back view of time-travel-to-the-past is incoherent — it creates dual worlds which are simultaneously the same world, thereby contradicting themselves — but it’s only one notion of time-travel-to-the-past, and a mistaken one.

If you assume that time is always forward, and time travel to the past occurs in the future, then there’s only one world, only one causal chain, no logical problems at all. Time travel to the past is logically possible.

Now that leads to a question: how could the past appear in the future? In my opinion, it’s factually impossible for the same reason that it’s logically possible: time moves only in one direction (we call it ‘forward’, but it’s really just change), just as motion only moves forward. No matter which direction you choose, you walk forward. Even in reverse, your car moves forward, just with the back end leading the forward motion. Same with time. (Someone will object, if you could move backward in time, then you’d be moving backward in space too. That’s true, but my objection is a factual speculation, not a logical point.)

The past doesn’t actually exist except as a fiction of memory and in its causal consequences in the present. And that’s why you can’t go backward. Time is not really on a time-line. It’s just change. The time-line is a convenient analogy for representation. So if you encountered the past, it wouldn’t affect your present, because there’s only one world of changing ‘forward.’ But you’d never encounter the past because it isn’t there anymore, unless perhaps it could be recreated. And that happens all the time — at Disney World.

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