If the many worlds of the Many Worlds Interpretation of quantum mechanics are real, there's at least a good chance that Quantum Immortality is real as well: All conscious beings should expect to experience the next moment in at least one Everett branch even if they stop existing in all other branches, and the moment after that in at least one other branch, and so on forever.
However, the transition from life to death isn't usually a binary change. For most people it happens slowly as your brain and the rest of your body deteriorates, often painfully.
Doesn't it follow that each of us should expect to keep living in this state of constant degradation and suffering for a very, very long time, perhaps forever?
I don't know much about quantum mechanics, so I don't have anything to contribute to this discussion. I'm just terrified, and I'd like, not to be reassured by well-meaning lies, but to know the truth. How likely is it that Quantum Torment is real?
I'm signed up for cryonics. I'm a bit worried about what happens to everyone else.
Going on the basic anthropic assumption that we're trying to do a sum over conditional probabilities while eliminating Death events to get your anticipated future, then depending on to what degree causal continuity is required for personal identity, once someone's measure gets small enough, you might be able to simulate them and then insert a rescue experience for almost all of their subjective conditional probability. The trouble is if you die via a route that degrades the detail and complexity of your subjective experience before it gets small enough to be rescued, in which case you merge into a lot of other people with dying experiences indistinguishable from yours and only get rescued as a group. Furthermore, anyone with computing power can try to grab a share of your soul and not all of them may be what we would consider "nice", just like if we kindly rescued a Babyeater we wouldn't go on letting them eat babies. As the Doctor observes of this proposition in the Finale of the Ultimate Meta Mega Crossover, "Hell of a scary afterlife you got here, missy."
The only actual recommendations that emerge from this set of assumptions seem to amount to:
1) Sign up for cryonics. All of your subjective future will continue into quantum worlds that care enough to revive you, without regard for worlds where the cryonics organization went bankrupt or there was a nuclear war.
2) If you can't be suspended, try to die only by routes that kill you very quickly with certainty, or (this is possibly better) kill almost all of your measure over a continuous period without degrading your processing power. In other words, the ideal disease has a quantum 50% probability of killing you while you sleep, but has no visible effects when you wake up, and finally kills you with certainty after a couple of months. Your soul's measure will be so small that almost all of its subjective quantity will at this point be in worlds simulated by whatever Tegmark Level IV parties have an interest in your soul, if you believe that's a good thing. If you don't think that's a good thing, try to die only by routes that kill you very quickly with certainty, so that it requires a violation of physical law rather than a quantum improbability to save you.
3) In other words, sign up for cryonics.
! ! !
Be honest. Are you prescient? And are you using your eldritch powers to troll us?