Wednesday, May 13, 2015

Prayer, prophecy, and time travel

This post isn't really about time travel. It simply uses time travel as a theological illustration. An analogy for prophecy and prayer. 

i) Time travel is a popular scifi convention. Indeed, time travel accounts for some of scifi's popularity. 

ii) There are variations on time travel. Traveling into the future or into the past.

There's also the question of changing the past. The familiar scenario of a time-traveler who goes back in time, and either intentionally or inadvertently changes the past–which, in turn–changes the future. 

That can generate antinomies, like the grandfather paradox. 

One question is whether it's possible to make discrete, self-contained changes to the future. If so, retrocausation might not be incoherent in those cases. If, however, even one change has a ripple effect, then his action destroys the future he came from–which is incoherent.

iii) However, the principle can operate in reverse. Suppose a man travels into the future. He may do so out of sheer curiosity. Or he may do so to escape the present.

Suppose he's appalled by what he discovers. In-between, there was a global catastrophe. He therefore returns to the present, forearmed with his knowledge of the future, and attempts to avert the dire outcome. 

This isn't prima facie incoherent in the same way that retrocausation is. He didn't originate in the future he changes. And present events cause the future. So his action doesn't necessarily disrupt the linear direction of cause and effect.

Of course, on this scenario, we're dealing with two different futures. The future which will eventuate if he doesn't act on his foreknowledge, and an alternate future which will eventuate if he does. The alternate timeline that replaces the future he initially visited is subsequent to the former. So that's still consistent with the linearity of time and causality. 

It's possible that this is subtly incoherent, but, if so, that has to be teased out.

iv) There is, however, another possibility. A more fatalistic scenario (on one definition of fatalism). Perhaps he doesn't change the future he visited the first time around. Perhaps his efforts to change the future unwittingly contribute to the very outcome he was endeavoring to avoid. 

He knows something about the present, and something about the future (that he encountered). But he didn't witness the intervening events. He doesn't know the chain of events linking the present to the future. Hence, his efforts to change the catastrophic future might be a necessary condition for that to happen. Due to his ignorance of the intervening events, he ends up precipitating the very disaster he was laboring to preempt or prevent. 

v) Apropos (iv), some freewill theists consider predestined prayer to be otiose. If the future is etched in stone, then nothing we say or do in the present can change the future.

However, prayer could be like the time traveler in (iv). What he does in the present has results. He contributes to the future he prays for, not by changing the future, but by acting at present in ways that, unforeseen to him, fascinate the outcome he prayed for. Prayer needn't change the future to be instrumental in realizing the future object of prayer. 

vi) Some time travel scenarios focus on a different dilemma. The traveler has seen the future. He's aghast. He returns to the present to warn his contemporaries. He desperately exhorts them to take necessary countermeasures, before it's too late, to avert disaster.

But he confronts a conundrum: how does he convince anyone that he knows what he's talking about? Although he has seen the future, they have not, and they have no reason to believe him. Indeed, they think he's a raving mad man. 

Out of frustration, he takes matters into his own hands. He attempts to sabotage the source of the impending catastrophe. 

As a result, the authorities view him as a crazed domestic terrorist, and lock him up in a secure facility. Indeed, he might have been involuntarily committed just for crazy talk, but his subversive activities seal the deal. 

In theory, this, too, could precipitate the catastrophe. Due to his actions, they tighten security measures, thereby ensuring the disastrous outcome.

Confined to his padded cell, his prevision becomes a curse. He can't make anyone take him seriously. The harder he tries, the worse it gets. 

Depending on the story, the character may know enough about the near future to make a few short-term predictions that indicate he really does have advance knowledge. That may persuade a key person. 

However, that may confirm the suspicion of authorities that he's a domestic terrorist who's privy to terrorist plots. He only succeed in persuading them that he's dangerous!

This is much like the situation of OT prophets. Having previewed the future, they warn their contemporaries to repent before it's too late avoid judgment. But like the hapless time traveler, his contemporaries dismiss him as a crackpot. A cranky lunatic. They find out the hard way that he was right all along. 


  1. Steve said: "It's possible that this is subtly incoherent, but, if so, that has to be teased out."

    Challenge accepted! :-D

    Suppose a man goes into the future. He sees a horrific event, and returns to his own time to correct it. His correct results in the horrific event never occurring. But this means when he went to the future he would not have seen the horrific event. His seeing that horrific event is necessary in order for him to enact the changes to avoid the horrific event, so not having seen the horrific event he fails to change the future and the horrific event returns.

    Thus, I see the same logic as the grandfather paradox works toward the future too.

    Incidentally, what you describe in iv) works in reverse too. That is, anyone who goes into the past must have *always* gone into the past, even before the future existed. This view of time seems to fit the most with modern physics, given the fact that relative velocities alter the concept of "now" and "simultaneous events". Of course, it also seems to necessitate a B theory of time.

  2. "Suppose a man goes into the future. He sees a horrific event, and returns to his own time to correct it. His correction results in the horrific event never occurring. But this means when he went to the future he would not have seen the horrific event."

    Does it mean that event never occurred, or does it meant that event never occurred in that alternate timeline, which replaced the former timeline he entered during his first trip into the future?

    When he went into the future on the first occasion, he went into the uncorrected future. If he were to go back, after the correction, he'd experience a different future. The former future which he encountered on the first trip was replaced by an alternative future, as the result of his correction in the present.

    1. Put another way, is the notion of staggered alternate futures, where one replaces another, incoherent?

      Keep in mind that my fallback proposal: even though he tries to change the future, his counterproductive actions bring about the horrific outcome which he witnessed during his initial foray into the future. It was that future all along. His evasive maneuvers make it happen!

    2. Gotcha. Yes, if he comes back to a point that is *after* his initial travel forward in time, then that would resolve the tension.

    3. That's the answer I needed to put the finishing touches on my time machine.

    4. It needs to be red, candy apple red, with deep glossy clear coat, and must have some sequence of randomly flashing lights. The lights needn't perform any actual function, we're going for style here, fashion before function.

      Some vintage E.L.O. or Boston should emanate softly when it's fired up, also. My work here is done.

    5. Well, my time machine totally works since they named a giant mountain after me (evidence that you can invest now on a sure thing). For decorative purposes, I made mine look like a stone box. Went back sometime to the 1800s. I accidentally miscalculated where I would land and it ended up being buried in a hillside near Manchester, New York. Thankfully, there was a weird guy there practicing with his dowsing rod so I told him, "I'm such a moron! Can you help me dig my machine out of this hillside?" He did a good job, but I didn't really have anything of value to give him for his help (I hadn't gotten any 19 century money yet). But he found the art I drew on some gold plates intriguing. I didn't want to mess up the timeline, so I told him it was hieroglyphics in reformed Egyptian. Then went on my way. Dodged a bullet for sure on that one.