By the way, that sort of time-travel gives rise to Newcomb-like problems:
Suppose you have access to a time-machine and want to cheat on a really important exam (or make a fortune on the stock marked or save the world or whatever. The cheating example is the simplest). You decide to send yourself at a particular time a list with the questions after taking the exam. If you don’t find the list at the time you decided you know that somehow your attempt at sending the list failed (you changed your mind, the machine exploded in a spectacular fashion, you were caught attempting to send the list …).
But if you now change your mind and don’t try to send the list there never was any possibility of receiving the list in the first place! The only way to get the list if for you to try to send the list even if you already know you will fail, so that’s what you have to do if you really want to cheat. And if you really would do that, and only then, you will probably get the list at the specified time and never have to do it without knowing you succeed, but only if your pre-commitment is strong enough to even do it in the face of failure.
And if you would send yourself back useful information at other times even without having either received the information yourself or pre-commited to sending that particular information you will probably receive that sort of information.
Why was this post voted back down to 0 after having been at 2?
Newcomb-like problems are on-topic for this site and I would think having examples of such problems in a scenario not specifically constructed for them is a good thing? If it was because time travel is off topic wouldn’t the more prudent thing have been voting down the parent? The same if the time travel mechanics are considered incoherent (though I’d be really interested in learning why?) . If you think this post doesn’t actually describe anything Newcomb-like I would like to know why. Maybe I misunderstood the point of earlier examples here, or maybe I didn’t explain things sufficiently? Or is it just that the post was written badly? I’m not really happy with it, but I don’t see how I could have made it much clearer.
It’s an interesting point. It actually came up in the most recent Artemis Fowl novel, when he managed to ‘precommit’ himself out of a locked trunk in a car. :)
By the way, that sort of time-travel gives rise to Newcomb-like problems:
Suppose you have access to a time-machine and want to cheat on a really important exam (or make a fortune on the stock marked or save the world or whatever. The cheating example is the simplest). You decide to send yourself at a particular time a list with the questions after taking the exam. If you don’t find the list at the time you decided you know that somehow your attempt at sending the list failed (you changed your mind, the machine exploded in a spectacular fashion, you were caught attempting to send the list …). But if you now change your mind and don’t try to send the list there never was any possibility of receiving the list in the first place! The only way to get the list if for you to try to send the list even if you already know you will fail, so that’s what you have to do if you really want to cheat. And if you really would do that, and only then, you will probably get the list at the specified time and never have to do it without knowing you succeed, but only if your pre-commitment is strong enough to even do it in the face of failure.
And if you would send yourself back useful information at other times even without having either received the information yourself or pre-commited to sending that particular information you will probably receive that sort of information.
Why was this post voted back down to 0 after having been at 2? Newcomb-like problems are on-topic for this site and I would think having examples of such problems in a scenario not specifically constructed for them is a good thing? If it was because time travel is off topic wouldn’t the more prudent thing have been voting down the parent? The same if the time travel mechanics are considered incoherent (though I’d be really interested in learning why?) . If you think this post doesn’t actually describe anything Newcomb-like I would like to know why. Maybe I misunderstood the point of earlier examples here, or maybe I didn’t explain things sufficiently? Or is it just that the post was written badly? I’m not really happy with it, but I don’t see how I could have made it much clearer.
It’s an interesting point. It actually came up in the most recent Artemis Fowl novel, when he managed to ‘precommit’ himself out of a locked trunk in a car. :)