Objective and framing: I want to decrease my probability of information-theoretic death, p(ITD), by optimizing my cryonic preservation arrangements (I’m treating ITD as a binary thing for simplicity). I’m going to talk about p(ITD) as if it’s the most efficient probability that could be assigned given our civilization’s current knowledge and understanding (e.g. by a thickly traded prediction market that resolves soon to an oracle’s answer to the question), rather than my current subjective probability, so that I can ask questions of the form “how does X affect p(ITD)?”.
I’m particularly interested in the effects of warm/cold ischemia on p(ITD), which have implications for standby arrangements and what to do in the case of an unexpected death:
How does p(ITD) drop off with warm and cold ischemic time?
For unexpected deaths, are there any advance arrangements that can be made to substantially decrease p(ITD)? (e.g. by reducing warm ischemic time with an ice bath)
For expected deaths, does local standby have significantly lower p(ITD) than remote standby + transport? (e.g. due to reduced cold ischemic time)
I’m also interested in any other considerations that significantly affect p(ITD), if any come to mind.
One problem of ischemia is that cryoprotectant will not reach all parts of the brain. While cryoprotectant is pumped through existing blood vessels, some brain regions will decay, and one cannot know in advance which ones will be affected.
The solution is known: slice the brain into thin sections and place each section in cryoprotectant or chemical fixative. In this case, the preservation chemicals will reach all parts of the brain, and any damage from slicing is predictable.
Interestingly, Lenin’s brain was preserved this way in 1924. It appears this was the best method available, and we haven’t advanced much since then.