On Thu, Jul 1, 2021 at 9:13 AM Lawrence Crowell < [email protected]> wrote:
> *> I think this is a modern version of entombment with ideas of > resurrection. We might think of it as similar to what the Egyptians > thought.* In a way yes, but the Egyptian's relied on magic for the process to work and the basic difference between magic and science is one of them works and the other one doesn't. And the Egyptian's carefully preserved every part of the body as best they could EXCEPT for the brain, they didn't even try to preserve the brain, they just yanked it out of the skull with an iron hook pushed up the nose and threw the brain away. I think we can do a little better than that these days. *> **Cryogenic preservation works best with small organisms. * > Yes. *> This is in part because ice crystallization occurs at a lower ratio to > body mass. Single cells, sperm, ovum or even fetuses at very early stages > can be preserved. This low rate of differential crystallization reflect how > the freezing occurs very quickly. * > Absolutely true. There are advantages in being a tardigrade, or a fetus. The most impressive demonstration of this that I know of is a report of nematode worms being frozen for two weeks at -80 degrees centigrade, and the worms not only survived they retained a memory too. Persistence of Long-Term Memory in Vitrified and Revived Caenorhabditis elegans <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4620520/> > > If there is any way to make this scheme work it will require some field > effect or something that is able to localize the thermal motion of every > atom and molecule almost instantly at once and the thermal energy rapidly > extracted. > First of all it's almost certain that the brain information would not need to be preserved with atomic precision, even molecular precision would probably be overkill, cellular precision would probably be sufficient, and we already know single cells can be frozen with little or no damage. The difference between being alive and being dead is putting cells in the right place. And actually rewarming is a greater problem than freezing because during freezing if a piece of a cell breaks off it won't be able to diffuse very far away because the liquid environment will soon freeze, so you can figure out where it came from, but with rewarming the environment will turn from solid to liquid so that piece could end up anywhere. With freezing the damage automatically stops when things become solid, and there are no time constraints so we can leave the problem of rewarming and repairing the damage that has occurred to future technology. Or at least we can provided the brain information has not been so scrambled that even Nanotechnology can't unscramble it, and that could happen if turbulence sets in. So the key question is "will the micro-currents in my brain be in a turbulent state when it is in the process of being frozen or will the flow be laminar?". If it's turbulent then very small changes in initial conditions will result in large changes in outcome and I'm dead meat, even nanotechnology couldn't put Humpty Dumpty back together again; but if the flow is laminar figuring out what things were like before they were frozen would be pretty straightforward. Fluid flow stops being smoothly Laminar and starts to become chaotically turbulent when a system has a Reynolds number between 2300 and 4000, although you might get some non chaotic vortices if it is bigger than 30. When chaotic turbulence starts a very small change in initial conditions will result in a huge difference in outcome and that is exactly what we want to avoid because we want to be able to figure out what the brain was like before it was frozen. We can find the approximate Reynolds number by using the formula LDV/N. L is the characteristic size we're interested in, we're interested in cells so L is about 10^-6 meter. D is the density of water, 10^3 kilograms/cubic meter. V is the velocity of the flow, during freezing it's probably less than 10^-3 meters per second but let's be conservative, I'll give you 3 orders of magnitude and call V 1 meter per second. N is the viscosity of water and at room temperature N is 0.001 newton-second/meter^2, it would be less than that when things get cold and even less when water is mixed with glycerol as it is in cryonics but let's be conservative again and ignore those factors. If you plug these numbers into the formula you get a Reynolds number of about 1. 1 is a lot less than 2300 so it looks like any mixing caused by freezing would probably be laminar not turbulent, so you can still deduce the position where things are were from the position of where things are now, you can figure out how the parts of the puzzle are supposed to fit together. > > These people in liquid nitrogen bottles are not much more than > high-tech mummies that are completely dead. > Maybe. Maybe not. Cryonics is an unproven technology and it will remain unproven until the day it becomes obsolete, the day when Drexler's style nano machinery becomes available. I would say the chances those people frozen in nitrogen have are greater than zero and less than 100%. But even if it doesn't work, being frozen won't make me any deader, so since I could easily afford it I couldn't think of a good reason not to give it a try. Actually scientific and technological considerations are only number 4 on my list of reasons why I think cryonics might not work, my first three reasons are: 1) I might not get frozen quickly after I am declared legally dead. 2) I might not be retained at liquid nitrogen temperatures until the age of Drexler style nanomachines arrives. 3) Mr. Jupiter brain, or whoever's around at the time, might not think I'm worth reviving; I am realistic enough to know that my value to it will be almost zero, my hope is that it will not be exactly Zero. I do have one thing going for me, in the age of Nanotechnology everything could be put into one of two categories, impossible to obtain at any price, or dirt cheap, nothing will be expensive. John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis> nrz6 > -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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