Monday 21 February 2022

Discontinuities III

Time travel in a single immutable timeline is logically odd. A time traveler learns that, if he tries to change the past, then something prevents him. Therefore, he stops trying. So then, in many cases, the fact that he did not even try to prevent an event is a sufficient reason why it occurred. Read Audrey Niffenegger's The Time Traveler's Wife.

And there is another factor, which Niffeneger also addresses. A time traveler can never be certain that he does inhabit a single immutable timeline. Maybe, if he tries to change another past event, then this time he will succeed and will therefore be unable to return to his preferred present. If he does not want to run any risk of this outcome, then he had better avoid meddling with the past: a one-man Time Patrol. However odd this sounds, none of it is logically inconsistent, which is all that should concern a philosopher.

 We have wandered away from Poul Anderson's texts but that is the nature of sf. We follow ideas through several authors' works and will soon return to Anderson.

3 comments:

Sean M. Brooks said...

Kaor, Paul!

It does seem logical to think that if someone succeeds in killing Lenin, he would not return to the "present" he departed from. The period the assassin departed from would no longer be the same as it would have been if Lenin had not been killed.

Or would this simply have been a splitting off of one alternate universe from another? Alternate Universe 1: Lenin was not killed. Alternate Universe 2: Lenin was killed.

Ad astra! Sean

paulshackley2017@gmail.com said...

Sean,

In the Time Patrol universe, time criminals who change the past travel forward into a changed present and future but the British sf author, Bob Shaw, argued that, having changed the past, a time traveler would revert to his original timeline. I see no reason for this.

If universes split off from each other, then an entire other universe is created every time someone changes the past! I think it makes more sense to say that, just as the 3D universe changes in successive moments of the first temporal dimension, so the 4D continuum changes in successive moments of a second temporal dimension.

Paul.

Sean M. Brooks said...

Kaor, Paul!

I agree with your criticism of Bob Shaw's suggestion. It doesn't make sense to me.

My impression is, it you could ask Anderson, he would lean to the idea that historical events turning out differently in different timelines means they did become alternate universes. That seems to fit in with what you suggested in your second paragraph.

Ad astra! Sean