Remember that it takes a lot more radiation to erase someone than to merely kill them.
To information-theoretically erase a person would seem to require that at least 40% of the molecules in their brains are altered, which would seem to imply at least 10^24 or so radioactive particles. This is extremely high.
I’m curious where you are getting the 40% number. I’m not completely sure what we mean by erasing a person since the mind isn’t a binary presence that is there or not. Damage can result in loss of some aspects of personality or some memories without complete erasure. Presumably, most people would like to minimize that issue.
Given your 40% claim I tentatively agree with your 10^24 number. There’s a minor issue of cascading particles but that shouldn’t be a problem since most of the radiation is going to be low energy beta particles. I am however concerned slightly that radiation could result in additional free radicals which are able to jump around and do unpleasant chemical stuff even at the temperatures of liquid nitrogen. I suspect that this would not be a major issue either but I don’t think I have anywhere near enough biochem knowledge to make a strong conclusion about this.
Additionally, as STL pointed out, we don’t want to make things more difficult for the people reviving them. This combines badly with the first-in-last-out nature of cryonics- the bodies which have been around longer will have more radiation damage and will already be much more technically difficult to revive. Moreover, some people will strongly prefer being reanimated in their own bodies rather than as simulations on computers. The chance that that can occur is lower if the bodies have serious problems due to radiation damage.
Say you randomly alter 1% of the molecules in the brain. Then almost every neuron would still recognizably be a neuron, and still have synapses that connected to the right things, and any concentration of neurotransmitter X would still recognizably be type X (rather than Y). There is no way I see for 1% random destruction to erase the person information-theoretically.
The difference between 1% and 40% is not actually so much… 10^22 vs 10^24. Still huge.
Say you randomly alter 1% of the molecules in the brain. Then almost every neuron would still recognizably be a neuron, and still have synapses that connected to the right things, and any concentration of neurotransmitter X would still recognizably be type X (rather than Y). There is no way I see for 1% random destruction to erase the person information-theoretically.
Would this be enough to keep thresholds for action potentials correct? I’m more familiar with neural nets for computational purposes than with actual neural architecture, but for neural nets this matters a lot. You can have wildly different behavior even with the same neurons connected to each other just by changing the potential levels. Learning behavior consists not just in constructing or removing connections but also in strengthening and weakening existing connections.
I don’t know why you mention the concentrations of neurotransmitters since that’s a fairly temporary thing which (as far as I’m aware) doesn’t contain much in the way of actual data except about neurons which have fired very recently.
Would this be enough to keep thresholds for action potentials correct
What determines the threshold for an action potential? If it’s something bigger than a few dozen molecules, it seems that a random 1% destruction can’t erase it.
There is no way I see for 1% random destruction to erase the person information-theoretically.
I suspect you are right. Since the important structures involved are significantly larger than one molecule, most of the single molecule alterations will be rather obvious and easy to reverse (for a given kind of ‘easy’).
Remember that it takes a lot more radiation to erase someone than to merely kill them.
To information-theoretically erase a person would seem to require that at least 40% of the molecules in their brains are altered, which would seem to imply at least 10^24 or so radioactive particles. This is extremely high.
I’m curious where you are getting the 40% number. I’m not completely sure what we mean by erasing a person since the mind isn’t a binary presence that is there or not. Damage can result in loss of some aspects of personality or some memories without complete erasure. Presumably, most people would like to minimize that issue.
Given your 40% claim I tentatively agree with your 10^24 number. There’s a minor issue of cascading particles but that shouldn’t be a problem since most of the radiation is going to be low energy beta particles. I am however concerned slightly that radiation could result in additional free radicals which are able to jump around and do unpleasant chemical stuff even at the temperatures of liquid nitrogen. I suspect that this would not be a major issue either but I don’t think I have anywhere near enough biochem knowledge to make a strong conclusion about this.
Additionally, as STL pointed out, we don’t want to make things more difficult for the people reviving them. This combines badly with the first-in-last-out nature of cryonics- the bodies which have been around longer will have more radiation damage and will already be much more technically difficult to revive. Moreover, some people will strongly prefer being reanimated in their own bodies rather than as simulations on computers. The chance that that can occur is lower if the bodies have serious problems due to radiation damage.
Say you randomly alter 1% of the molecules in the brain. Then almost every neuron would still recognizably be a neuron, and still have synapses that connected to the right things, and any concentration of neurotransmitter X would still recognizably be type X (rather than Y). There is no way I see for 1% random destruction to erase the person information-theoretically.
The difference between 1% and 40% is not actually so much… 10^22 vs 10^24. Still huge.
Would this be enough to keep thresholds for action potentials correct? I’m more familiar with neural nets for computational purposes than with actual neural architecture, but for neural nets this matters a lot. You can have wildly different behavior even with the same neurons connected to each other just by changing the potential levels. Learning behavior consists not just in constructing or removing connections but also in strengthening and weakening existing connections.
I don’t know why you mention the concentrations of neurotransmitters since that’s a fairly temporary thing which (as far as I’m aware) doesn’t contain much in the way of actual data except about neurons which have fired very recently.
What determines the threshold for an action potential? If it’s something bigger than a few dozen molecules, it seems that a random 1% destruction can’t erase it.
I don’t know enough about the mechanisms to to comment. Do we have any more biologically inclined individuals here who can?
I suspect you are right. Since the important structures involved are significantly larger than one molecule, most of the single molecule alterations will be rather obvious and easy to reverse (for a given kind of ‘easy’).