Hard to say what the future can/can’t do. I think I’m, like, 80% that a brain that’s simply dumped in LN2 is going to lose so much information that even a superintelligence could not put the person back together in a way that their loved ones think they simply came back from the dead without being fundamentally changed (modulo cheating by “repairing” the cryonaut in a way that is deliberately designed to match the memories of their loved ones). Like, at the far end of what might be the case, the frozen brain tissue might as well have gone into the fire. The superintelligence can build a person that matches the historical record, but they won’t be the same person.
It could also be the case that the relevant information is still there, even when shredded, like papers put through a shredder, and that a sufficiently dedicated agent could figure out a model of how the ice formed, simulate an inverse process, and have things be fine. Even if I get in an accident and I’m at room temp for days, I would still like to be cryopreserved just in case this is true. But I wouldn’t bet on it.
In the common cryo case, it gets even trickier, since some parts of the brain will be well-perfused, and others won’t be, and there’s a quantitative question of how much. If I lost 10% of my cortex I would still be pretty similar, but would also be pretty different. I don’t think we have good measures here.
In short: idk, my guess is that reality is complicated and “invert the shredding” is not as simple as it sounds, even if it’s possible, in some sense.
what makes the historical record any less valid as a storage of brain structure? my impression is that any bit that depends on brain state is potentially a useful source of evidence, yeah? so eg getting a really low quality brain scan is potentially a useful sanity check for cryonic reconstruction, having lots of recordings of yourself muttering to yourself is a useful sanity check, and anything you ever did publicly would be compared to see if the life-trajectory implied by your reconstructed connectome seems to match correctly. perhaps you’d want to use those as a test set in cases where you have enough info from main reconstruction, but it’d still be quite useful, yeah?
My guess is this would be really underconstrained, maybe even if you had a ridiculous amount of data. The output you produce at some moment is a function of all past inputs. Brain state at that moment screens off past inputs, but then you’re trying to infer state at that moment with one piece of data, which is different from states at different moments.
Yeah, totally. I expect historical records and the memories of other people to be useful.
My point is that I don’t know an objective measure for whether the superintelligence rescued the existing person or built a new person, except via whether they match the other memories and records. If the superintelligence optimizes for the “rescued” person matching the memories of those who knew them, they will seem like they were revived successfully, but might not actually be very close to the real deal.
How confident are you the shredding can’t be inverted?
Hard to say what the future can/can’t do. I think I’m, like, 80% that a brain that’s simply dumped in LN2 is going to lose so much information that even a superintelligence could not put the person back together in a way that their loved ones think they simply came back from the dead without being fundamentally changed (modulo cheating by “repairing” the cryonaut in a way that is deliberately designed to match the memories of their loved ones). Like, at the far end of what might be the case, the frozen brain tissue might as well have gone into the fire. The superintelligence can build a person that matches the historical record, but they won’t be the same person.
It could also be the case that the relevant information is still there, even when shredded, like papers put through a shredder, and that a sufficiently dedicated agent could figure out a model of how the ice formed, simulate an inverse process, and have things be fine. Even if I get in an accident and I’m at room temp for days, I would still like to be cryopreserved just in case this is true. But I wouldn’t bet on it.
In the common cryo case, it gets even trickier, since some parts of the brain will be well-perfused, and others won’t be, and there’s a quantitative question of how much. If I lost 10% of my cortex I would still be pretty similar, but would also be pretty different. I don’t think we have good measures here.
In short: idk, my guess is that reality is complicated and “invert the shredding” is not as simple as it sounds, even if it’s possible, in some sense.
what makes the historical record any less valid as a storage of brain structure? my impression is that any bit that depends on brain state is potentially a useful source of evidence, yeah? so eg getting a really low quality brain scan is potentially a useful sanity check for cryonic reconstruction, having lots of recordings of yourself muttering to yourself is a useful sanity check, and anything you ever did publicly would be compared to see if the life-trajectory implied by your reconstructed connectome seems to match correctly. perhaps you’d want to use those as a test set in cases where you have enough info from main reconstruction, but it’d still be quite useful, yeah?
My guess is this would be really underconstrained, maybe even if you had a ridiculous amount of data. The output you produce at some moment is a function of all past inputs. Brain state at that moment screens off past inputs, but then you’re trying to infer state at that moment with one piece of data, which is different from states at different moments.
Yeah, totally. I expect historical records and the memories of other people to be useful.
My point is that I don’t know an objective measure for whether the superintelligence rescued the existing person or built a new person, except via whether they match the other memories and records. If the superintelligence optimizes for the “rescued” person matching the memories of those who knew them, they will seem like they were revived successfully, but might not actually be very close to the real deal.