X-Message-Number: 9573
From: Ettinger <>
Date: Thu, 30 Apr 1998 18:55:22 EDT
Subject: Thresholds etc.

THRESHOLDS ETC.

Paul Wakfer (Cryonet #9566) shows misunderstanding of the meaning of
probability.

I had said that even crude biostasis would leave the patient's brain with less
loss of information than would be experienced in the grave, and therefore with
a better chance of eventual rescue. He responded that "There is a[n unknown]
'threshold' of damage above which recovery of .'identity' is impossible by
any means."

In the second place, that "impossible by any means" is just Paul's feeling,
not a fact. Frank Tipler, who is smarter and better informed than both of us
put together, thinks otherwise. Personally, I think there are good reasons to
believe that information is conserved, but that is another long story, which I
will relate in due course.

In the first place, even if that impossibility threshold did exist, it would
not affect the argument. Something can be impossible (factually, from a cosmic
perspective) without having a zero probability (as correctly calculated by a
particular observer). 

For example, suppose you want to estimate your life expectancy. You look it up
in an actuarial table, and find (say) that someone fitting your profile has a
50% probability of living another 20 years. But suppose, further, that you
have an undiscovered fatal malignancy that is sure to kill you within one
year. Now, is your chance of living another 20 years 50% or is it 0? It is
50%, based on what you know. If you don't understand that, then you don't
understand the meaning of probability.

You unquestionably have a better chance of rescue in crude biostasis than in
the grave. Open and shut.

Finally, a brief word on numbers and intimidation. Wakfer said that, in
comparing brain repair to a jigsaw puzzle with enormous complications, I
displayed incomprehension of the humongous size of the problem. He offered no
calculations to support his implicit claim that the job is forever beyond
feasibility, or his implicit claim that computer simulation of freeze (and
other) damage will never be feasible or useful. Merkle and others have done
some of the relevant calculations, and are not intimidated. 

Wakfer's position reminds me of THE NEXT MILLION YEARS, a book by Darwin (I
forget his first name, a descendant of the famous naturalist) whose thesis was
that Malthusian cycles of overpopulation and starvation would dominate that
vast period. Of course he gave lip service to "incredible flowerings" of
technology during some epochs to come--but he was sure those wonders would
never extend to synthetic foods or widespread birth control, let alone space
emigration etc.!  

Yes, Virginia, there will be a future, and its limits will not be those of the
imaginations of the pessimists.

Robert Ettinger
Cryonics Institute
Immortalist Society
http://www.cryonics.org

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