X-Message-Number: 19785
Date: Mon, 12 Aug 2002 10:50:19 -0700
From: "Ralph C. Merkle" <>
Subject: Re: Probabilities

While the general concept of multiplying probabilities together is useful, 
care must be taken to insure that the probabilities involved are 
independent. For example, P5 in the earlier list (survival of the cryonics 
organization) correlates with P3 (development of nanotech), P4 (survival of 
society), P6 (someone in the future will care to restore you) and P7 
(probability of an acceptable life).

Items which reduce the concern that there might be undesired correlations are:

1) The probability that your memory is intact when suspension begins
2) The probability that your memory survives the suspension process and the 
initial transition to low temperature (currently in LN2).
3) The probability that you remain preserved until technologies that are 
feasible in principle are developed and applied in practice

Item (1) seems likely in most cases (though there are some obvious exceptions).

Item (2) is most often debated -- now that we have vitrification it is much 
more difficult to advance a credible argument that your memory is 
obliterated in the information theoretic sense. I would assign a high 
probability to item (2).

Item (3) (which incorporates the correlated events described by survival of 
the cryonics organization, the development of nanotechnology, the survival 
of society, that someone in the future cares about you, and that the 
technology to restore you is developed and applied in practice and produces 
a satisfactory result) is also debated -- while it is doubtful that general 
agreement will be reached, it does seem clear from the rapid rate of 
technological progress and the rather long survival time of at least some 
cryonics organizations that the probability of (3) is at least reasonable, 
and might be quite good -- particularly if we are active in seeking a 
favorable outcome.

While item (3) includes quite a bit, breaking out the (logically distinct) 
subcategories of item (3) would produce correlated (and often highly 
correlated) items. If the cryonics organization survives, that implies 
society survives.  The survival of society implies (with fairly high 
probability) continued research and ultimate development of 
nanotechnology.  The development of nanotechnology implies the existence of 
a complex research infrastructure and a stable society able to support such 
an infrastructure. Development of methods to restore good health implies 
that the people so restored will find life acceptable -- a method of 
restoring good health presumably results in an acceptable quality of life, 
and anyone applying such a method would presumably only do so if there were 
some reasonable expectation that a continued acceptable quality of life 
would result.  And so on.

Cheers!
    Ralph


At 09:00 AM 8/10/2002 +0000, CryoNet wrote:
>Message #19739
>From: "Steve Harris" <>
>References: <>
>Subject: Re: Shermer and Cryonics
>Date: Fri, 9 Aug 2002 21:54:55 -0600
>


>or not cryonics will work. In fact--- physicist Brian Wowk and I, more than
>a decade ago actually *used* a version of the Drake equation to estimate in
>a Markovian way the chances that cryonics would "work" for somebody signed
>up to do it. It used probabilities like:
>
>P1: Probability that your memories will survive your cardiac arrest until
>the cryonics organization can reach your side and get your brain cool.
>
>P2: Probability that your memories will then survive cryoprotectant solution
>and vitrification in liquid nitrogen.
>
>P3: Probability that eventually molecular repair technology will be invented
>that is capable of restoring humans, memory intact, when damaged this badly
>
>P4: Probability that society will survive development of that technology
>
>P5: Probability that your cryonics organization will survive that long, as
>well as you with it (these can be slip into sub probabilities if you like).
>
>P6: Probability that anybody in the best of futures, will be interested,
>resourceful, and nice enough to use the technology on you.
>
>P7: Probability that you'll then be allowed to live a live that would be
>more acceptable to you than being dead.
>
>Multiply them all together (we presume that the probabilities are
>independent of each other, which is maybe a big assumption) and there you
>are.  Just as with the Drake equation there are many unknowns, and many
>places where you get to extrapolate.

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