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 ha...
This post may be interesting to some LWers.
In summary: it looks like our universe can support reversible computers which don't create entropy. Reversible computers can simulate irreversible computers, with pretty mild time and space blowup. So if moral value comes from computation, negentropy probably won't be such an important resource for distant future folks, and if the universe lasts a long time we may be able to simulate astronomically long-lived civilizations (easily 10^(10^25) clock cycles, using current estimates and neglecting other obstructions).
Has this been discussed before, and/or is there some reason that it doesn't work or isn't relevant? I suspect that this consideration won't matter in the long run, but it is at least interesting and seems to significantly deflate (long-run) concerns about entropy.