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They don't! If someone could freeze at least a small insect brain after it "learned something", unfreeze it and prove that it retained what it learned, I might

by nnq 14y ago

They don't! If someone could freeze at least a small insect brain after it "learned something", unfreeze it and prove that it retained what it learned, I might have at least a grain of faith in this. Even getting an insect ganglia out on a feeder plate with electrodes, training it to respond in a way to a certain sequence of input electrical impulses and proving that after thawing and reanimation it still preserves that memory would light a spark of faith, but we don't even have this! Understanding "biology 101" means understanding that biology is about experiments, everyth is empirical (and will be for quite some time I guess), nothing can be said that "it works" in biology or medicine until you experimentally prove it does. Maybe in a few centuries we'll have cool equations describing life and have something like "theoretical biology" that will be like theoretical physics is to physics (no, what we call "theoretical biology" nowadays is not that!). Show me some equations (derived from experiments, of course, and that can predict other experiments of course) describing the amount of information relevant to a human's personality that can be recovered from a frozen brain! If you can't, prove it experimentally. If you can't... bad luck! With the kinds of probabilities involved in biology, "good things" (like being lucky to be able to revive a frozen human brain) don't happen by chance! "Nature"/"The universe"/"God" is NOT on our side on this path, so there's no room for optimistic thinking, we can only rely on cold (literally) hard science and math!

nawitus 14y ago
So your argument is that until it's "proven" that we can cryopreserve and then restore brains, the probability of success is zero? If you agree that the probability is non-zero, then you agree with the cryopreservation advocates. In addition, if you agree that it's non-zero, you must agree that it's better than doing nothing (which clearly has a zero chance of revival). Cryopreservation advocates do not claim that the process is proven to be work, they claim that the chance may be small, but it's non-zero. >"Nature"/"The universe"/"God" is NOT on our side on this path, so there's no room for optimistic thinking, we can only rely on cold (literally) hard science and math! I don't even know where you're going with this discourse. If you're a utilitarian rationalist you can estimate the chance of success for cryopreservation and revival. It's quite easy to show that if the probability is non-zero, then it's beneficial to make such a bet, as the possible positive utility can be huge if the cryopreservation is succesful. If you think that probability estimates are "not science" and therefore "irrational", you don't know what you're talking about. If you think that current scientific evidence shows that the chance of revival is zero, then you're clearly wrong (and that would contradict your own claims, as zero chance would mean there's no need to make any new experiments).
- mikeash 14y ago
  "Cryopreservation advocates do not claim that the process is proven to be work, they claim that the chance may be small, but it's non-zero." They implicitly claim that not only is the chance non-zero, but that it's large enough to be worth the opportunity cost of actually freezing people. I agree that a non-zero chance seems obvious, but this claim definitely does not, and needs a lot more substantiation than there actually is.
  - nawitus 14y ago
    That's a good point. You can look it this way: life after rewarming can last for hundreds of years, easily a thousand as medical technology will have advanced at that point. People are currently willing to pay $100k in medical bills to extend their life by about one year with 50% chance, which means that the cost is $200k per year. Cryopreservation also costs about $100k (slightly more in real life I guess, I'm rounding numbers for simplicity). If cryopreservation has a 1% of success to extend life by 1000 years for $100k, then they will "buy" 1 year for $10k. Of course, you can change the numbers (in any direction), e.g. 100 years of life would come out to $100k per year, still cheaper than what most people are willing to pay today to live slightly longer. The 1% success rate is rather pessimistic, too. If you take quality of life into consideration, the argument starts to favour cryonics quite heavily (we can assume that life is a lot better in the future thanks to advancement of technology).
    - mikeash 14y ago
      > The 1% success rate is rather pessimistic, too. Where do you get that? From what little I understand, 1% seems highly optimistic, given how destructive the freezing process is at the moment.
      - nawitus 14y ago
        It's my own estimation based on the evidence I've seen. There's plenty of detail when you look at neural tissue using a microscope: http://www.alcor.org/Library/html/braincryopreservation1.html http://www.alcor.org/Library/html/braincryopreservation1.htm...
lsparrish 14y ago
> Understanding "biology 101" means understanding that biology is about experiments, everyth is empirical (and will be for quite some time I guess), nothing can be said that "it works" in biology or medicine until you experimentally prove it does. Part of this isn't really biology (as we know it) though, so I'm not sure that biologists who criticize are seeing the whole picture. Look at it like a cryptographer: Is putting a brain in liquid nitrogen a secure erasure method against all future attacks from a determined opponent with lots of resources? Would you trust your financial data to such a method of data erasure? > "Nature"/"The universe"/"God" is NOT on our side on this path, so there's no room for optimistic thinking, we can only rely on cold (literally) hard science and math! I like this sentiment, I wish more cryonics people took it to heart, but at the same time I don't believe that "The Force" is actually against us. There is some reasonable burden of proof on the assertion that the data is is utterly gone and out of reach of all realistic future technology.

by nnq 14y ago

nawitus 14y ago

So your argument is that until it's "proven" that we can cryopreserve and then restore brains, the probability of success is zero? If you agree that the probability is non-zero, then you agree with the cryopreservation advocates. In addition, if you agree that it's non-zero, you must agree that it's better than doing nothing (which clearly has a zero chance of revival). Cryopreservation advocates do not claim that the process is proven to be work, they claim that the chance may be small, but it's non-zero. >"Nature"/"The universe"/"God" is NOT on our side on this path, so there's no room for optimistic thinking, we can only rely on cold (literally) hard science and math! I don't even know where you're going with this discourse. If you're a utilitarian rationalist you can estimate the chance of success for cryopreservation and revival. It's quite easy to show that if the probability is non-zero, then it's beneficial to make such a bet, as the possible positive utility can be huge if the cryopreservation is succesful. If you think that probability estimates are "not science" and therefore "irrational", you don't know what you're talking about. If you think that current scientific evidence shows that the chance of revival is zero, then you're clearly wrong (and that would contradict your own claims, as zero chance would mean there's no need to make any new experiments).

mikeash 14y ago
"Cryopreservation advocates do not claim that the process is proven to be work, they claim that the chance may be small, but it's non-zero." They implicitly claim that not only is the chance non-zero, but that it's large enough to be worth the opportunity cost of actually freezing people. I agree that a non-zero chance seems obvious, but this claim definitely does not, and needs a lot more substantiation than there actually is.
- nawitus 14y ago
  That's a good point. You can look it this way: life after rewarming can last for hundreds of years, easily a thousand as medical technology will have advanced at that point. People are currently willing to pay $100k in medical bills to extend their life by about one year with 50% chance, which means that the cost is $200k per year. Cryopreservation also costs about $100k (slightly more in real life I guess, I'm rounding numbers for simplicity). If cryopreservation has a 1% of success to extend life by 1000 years for $100k, then they will "buy" 1 year for $10k. Of course, you can change the numbers (in any direction), e.g. 100 years of life would come out to $100k per year, still cheaper than what most people are willing to pay today to live slightly longer. The 1% success rate is rather pessimistic, too. If you take quality of life into consideration, the argument starts to favour cryonics quite heavily (we can assume that life is a lot better in the future thanks to advancement of technology).
  - mikeash 14y ago
    > The 1% success rate is rather pessimistic, too. Where do you get that? From what little I understand, 1% seems highly optimistic, given how destructive the freezing process is at the moment.
    - nawitus 14y ago
      It's my own estimation based on the evidence I've seen. There's plenty of detail when you look at neural tissue using a microscope: http://www.alcor.org/Library/html/braincryopreservation1.html http://www.alcor.org/Library/html/braincryopreservation1.htm...

lsparrish 14y ago

> Understanding "biology 101" means understanding that biology is about experiments, everyth is empirical (and will be for quite some time I guess), nothing can be said that "it works" in biology or medicine until you experimentally prove it does. Part of this isn't really biology (as we know it) though, so I'm not sure that biologists who criticize are seeing the whole picture. Look at it like a cryptographer: Is putting a brain in liquid nitrogen a secure erasure method against all future attacks from a determined opponent with lots of resources? Would you trust your financial data to such a method of data erasure? > "Nature"/"The universe"/"God" is NOT on our side on this path, so there's no room for optimistic thinking, we can only rely on cold (literally) hard science and math! I like this sentiment, I wish more cryonics people took it to heart, but at the same time I don't believe that "The Force" is actually against us. There is some reasonable burden of proof on the assertion that the data is is utterly gone and out of reach of all realistic future technology.