On Fri, Jul 2, 2021 at 9:09 AM Lawrence Crowell < goldenfieldquaterni...@gmail.com> wrote:
*> The problem is not so much with preserving brain states, though that is > a possible consideration, it is phase change.* > I'm not sure what you mean here. If information on where bits of the brain are supposed to go, or can be easily deduced, then then Information Theoretic-Death has been avoided; and at this point that's all I'm interested in, I leave the problem of actually extracting that information and using it to construct a body or a machine or a virtual existence of some sort to future technology. I just want to do my best to preserve the information. Information-Theoretic Death <https://www.merkle.com/definitions/infodeath.html> * > Phase changes occur in a way that breaks symmetry. In freezing there is > a breaking of scale size for water in the solid form. Beyond a certain > large scale crystals are disconnected.* > I guess you're talking about cracking, and it's true that when biological tissue is cooled two less than -135C cracking occurs, and all the brains that ALCOR stores are cooled to liquid nitrogen temperature of -196C, so all of them have cracks in them. Sure, any damage is undesirable but the sad fact is even if a patient is cryopreserved using the best methods available today a huge amount of damage will be caused and a massive amount of repairing (or replacing) will be needed to bring the person back to consciousness. But cracks are by far the least serious form of damage because they are the easiest to fix or replace; if 2 areas are displaced along a well-defined line by a few hundred nanometers it doesn't take much brain power to figure out how things looked before the crack developed. If you can't even fix a simple crack then you have no hope of fixing the far more serious forms of damage. I don't think any Cryonics patient will be revived until we have Drexler style Nanotechnology and can control matter at the atomic level. That's why I say cryonics will remain an unproven technology until the day it becomes obsolete. The key question is has Information Theoretic Death occurred? If the information on what makes you be you is lost then you're dead. That's why I think Alcor should switch from the vitrification process it uses now to ASC (Aldehyde Stabilized Cryopreservation). In ASC in addition to a cryoprotectant a brain is also infused with the chemical Glutaraldehyde, it's the stuff in wart removing lotion you can get over the counter in any drugstore. Glutaraldehyde kills cells because it cross-links proteins, but that very cross-linking holds things in place even when they're cooled down to liquid nitrogen temperatures, and so Information Theoretic Death is avoided. ASC has been used on an entire pig's brain which was then cooled down to near liquid nitrogen temperatures and then warmed back up to room temperature and sliced into thin sections and sent to an electron microscope. The result was beautiful pictures of synapses and other brain structures that are superior to the pictures Alcor's current vitrification process can produce, and there is no reason to think molecular-level information wouldn't be preserved too. It's even more impressive when you consider that *THE PICTURES WERE MADE AFTER REWARMING*, because most of the damage happens at the warming stage not the cooling stage. The pictures were so good I would have been delighted even if they were made while the brain was still frozen because I'd be willing to let future technology worry about warming, but this is even better. Nevertheless Alcor has resisted changing over to ASC, I suspect the reason for their hesitation is that if they did so they would implicitly be saying "*we're not even trying to bring that frozen body back to life, we're just trying to preserve the information in it because information on how the atoms are arranged in my brain are different from the way they are arranged in your brain is the only difference between you and me*". I happen to think that's exactly what Alcor should be saying, but the ghost of the discredited 19th century theory of Vitalism is still haunting the 21th century and many still think that despite all the scientific evidence to the contrary the atoms in our bodies must somehow have our name scratched on them. I suspect Alcor is reluctant to change because they believe ASC would be bad public relations. But I think reality is more important than PR and the Vitalism superstition could get people killed. *> With ordinary temperature induced phase changes it would require some > mechanism to localize atoms or molecules so the water in the body is in the > same crystalline state. If you do not do that the cellular structures are > torn up into mush.* > Now Lawrence, you must know that's just silly. Multicellular creatures and even human embryos have been frozen in liquid nitrogen for decades and brought back to life with no damage. Yes, things as large as a human brain do have freezing damage, but electron microscopic pictures clearly show structure that is very far away from just mush. The Large Mammal Brain Preservation Prize has been won <https://turingchurch.net/cryonics-for-uploaders-the-brain-preservation-prize-has-been-won-cebbe98c241a> > *Unfreezing is also probably critical as well so the ice does not enter > into different crystalline phases while thawing.* > I don't worry about unfreezing very much, nobody will have to worry about it for decades and perhaps never. My hunch is that if I am lucky enough to be revived my brain will never be unfrozen, my hunch is my brain will be slowly dismantled while it is still in the frozen state with the nanomachines keeping track of where all the parts were. The information could then be used to make a replacement, probably a virtual one. *> These people in bottles of liquid nitrogen are simply dead.* > Maybe. Maybe not. John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis> igt4 > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAJPayv22QS2y8DhY-un4hO_PepLzQ-0NAXbw7KhfHTSx%2B3xv6w%40mail.gmail.com.
