The only way to recohere the system is if there’s a boundary condition
Or if spacetime is compact in any way, or in fact if there is only finitely much negentropy. In any of these cases, your abstraction of a bunch of distinct but potentially interfering branches will break down, and you can pick up all of your old waste heat even if it is “running away” at light speed.
In the other universes, where somehow things can continue expanding at light speed indefinitely, you can recover perfect info by exploring possible physical theories until you find yourself.
But it seems like all of these considerations are far too frail to have much impact in themselves; they just serve to put a lower bound on how weird we can expect the far future to be.
In the other universes, where somehow things can continue expanding at light speed indefinitely, you can recover perfect info by exploring possible physical theories until you find yourself.
I don’t immediately see how this gets around the problem; I’m probably just being stupid, but aren’t you still left with a bunch of possible histories consistent with your current state/decisions only an unknown subset of which are real? (“Real” in the usual sense, i.e. can reliably be used to coordinate with other agents.)
I agree re lower bound on weirdness, I’d add it serves as a lower bound on how competent your decision theory has to be (which shouldn’t be a problem).
(“Real” in the usual sense, i.e. can reliably be used to coordinate with other agents.)
With respect to e.g. bringing back all of the dead at least it doesn’t seem to matter: there are lots of histories consistent with your memories, some of them aren’t consistent with your ‘real’ history, but (at least if we have appropriate philosophical views towards our prior and so on) each of these histories also leads to an agent in your current situation, so if each one of them guesses the same distribution you end up with the same guesses as if each had been informed of their “real” history. With respect to uncomputing the universe I agree that you can’t recover all of the negentropy, but you do seem to recover perfect info in the relevant sense and in such universes you have infinitely much stuff anyway.
Okay, I understand now; I was thinking about the problem of reversing the past. Your arguments make sense if you just want to resurrect folk; it’s possible (as you seem to think?) that there’s no particularly good reason to reverse the past as long you have tons of computing power and all the information about the past that you’d need in practice. It’s definitely true that the latter strategy is applicable in more possible universes.
Or if spacetime is compact in any way, or in fact if there is only finitely much negentropy. In any of these cases, your abstraction of a bunch of distinct but potentially interfering branches will break down, and you can pick up all of your old waste heat even if it is “running away” at light speed.
In the other universes, where somehow things can continue expanding at light speed indefinitely, you can recover perfect info by exploring possible physical theories until you find yourself.
But it seems like all of these considerations are far too frail to have much impact in themselves; they just serve to put a lower bound on how weird we can expect the far future to be.
I don’t immediately see how this gets around the problem; I’m probably just being stupid, but aren’t you still left with a bunch of possible histories consistent with your current state/decisions only an unknown subset of which are real? (“Real” in the usual sense, i.e. can reliably be used to coordinate with other agents.)
I agree re lower bound on weirdness, I’d add it serves as a lower bound on how competent your decision theory has to be (which shouldn’t be a problem).
With respect to e.g. bringing back all of the dead at least it doesn’t seem to matter: there are lots of histories consistent with your memories, some of them aren’t consistent with your ‘real’ history, but (at least if we have appropriate philosophical views towards our prior and so on) each of these histories also leads to an agent in your current situation, so if each one of them guesses the same distribution you end up with the same guesses as if each had been informed of their “real” history. With respect to uncomputing the universe I agree that you can’t recover all of the negentropy, but you do seem to recover perfect info in the relevant sense and in such universes you have infinitely much stuff anyway.
Okay, I understand now; I was thinking about the problem of reversing the past. Your arguments make sense if you just want to resurrect folk; it’s possible (as you seem to think?) that there’s no particularly good reason to reverse the past as long you have tons of computing power and all the information about the past that you’d need in practice. It’s definitely true that the latter strategy is applicable in more possible universes.