X-Message-Number: 19760
Date: Sun, 11 Aug 2002 10:37:52 -0400
From: Thomas Donaldson <>
Subject: CryoNet #19741 - #19757

A bit more on the probability question:

The difficulty with working out the probability of an event which
so far has never happened comes exactly from that fact: it's never 
happened, at least not yet.

The original Drake equation, for instance, tries to find a 
"probability" of extraterrestrial intelligent life. That's fine,
but we have no case but our own (by definition, not extraterrestrial)
to go on. And after only a few decades, some of the major original
assumptions turn out to be flat wrong. (I refer to what we know 
about probability of "earthlike" planets).

The same may be said of any probability calculations for the
success of cryonics, either in a particular case or in general.
Once we have some successes under our belt, we can THEN start
working out probabilities. If Steve Harris or others know of 
any cryonics successes on which to base their calculations, then
by all means they should tell us of them. For cryonics, to be short
about it, the problem is even worse than for extraterrestrial 
civilizations. The time allowed for a successful cryonics revival
runs into the thousands of years, at a minimum. Even if some
event destroys ALL existing patients, that does not prevent
future patients (depending on what happens and where), so that
history isn't ended even if we all fail for "extraneous" reasons.
Already, in a single normal human lifetime, we've seen the 
ability of revival of "dead" people pass from giving up on a
patient when they weren't breathing, to heart and lung methods
sometimes able to revive someone after 5 minutes, to (now)
the latest techniques capable of reviving after 10 minutes. Or
more. So what do you say about the probability of revival
when its 1950, and what do you say now? WE DON'T EVEN UNDERSTAND
HOW LONG TERM MEMORY WORKS. It may work by a means that makes
revivals difficult or impossible, or it may work by some other
means. We'll someday find out, but even that won't completely
solve the problem. It may just tell us what we can do with
our "present" (as of the time we find out) technology. And
so we start to revive people, but what about those we don't
know how to revive (just then)? If you want to claim that their
probability has become ZERO, no one will hit you but you're
likely to be quite wrong.

It is one thing to work out probabilities in card games, or
in gambling, or simply on throwing (unweighted) dice. It is
quite another to work out the probability of an event which
so far has never happened. Basically you are trying to find
a probability with no information about incidence of the event
at all. Sure, you can dress it up with impressive language,
like "Markovian" etc, but that's just a way to fool yourself
and others.

And as for probability of extraterrestrial life, we'll get
an idea of that after we look at some section of the Galaxy
which contains all the various possible star systems we know
of. And we MAY get a better idea of the success of cryonics
if we look at its success for (say) the next 500 years.
Yes, neither one of these are things we can do now. Sorry,
but that's the what the world gave us, and we must make the
best of it.

		Best wishes and long long life for all,

			Thomas Donaldson

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