Re: Cryonics sources [was: Nature defines transhumanist]

From: Robert Bradbury (
Date: Mon Jun 19 2000 - 16:55:26 MDT

On Sun, 18 Jun 2000 wrote:

> but I think I know enough to make a relatively firm decision on the point,
> even with my layman's understanding of the science and technology.

Greg, I'll take the "layman's understanding" and chew on it a bit
(because all those people believing in the resurection are "laypersons"
as well... :-)).

> 1. The mind is a function of the material operation of the brain.

Yep, though you have to jump up and down on Penrose with spiked heels
to get that through to people.

> 2. Identity persists through highly varied states of brain functioning
> (although identity may be effected significantly by those changes in brain
> states).

Yes, and given that many people wake up beside people who clearly have
a different identity (or mental state) than the person they went to sleep
beside the night before, this begs the issue of what cryonics reanimations
will "wake up" as.

> 3. Freezing with good cryoprotectants can preserve at least some of the
> informational content of a dead or dying brain. Information preservation
> will get better as cryopreservation techniques improve.
I'm coming more and more to believe that the cryoprotectant issue is a noop.
Fundamentally it comes down to the computer power you have to put the pieces
back together and whether the pieces *largely* have the information content
of the brain before freezing. Freeze a piece of meat (w/o cryoprotectants)
and you still get back a piece of meat when you thaw it out.

> 4. Technology is advancing on a broad front such that "reading" the
> information content of a cryopreserved brain will be more and more complete
> and precise.

Yep. But there is clearly a threshold of "readability" that must be reached.
Below that and cryonics is useless. Above that and the marginal benefits
are probably small.

> 5. Not cryopreserving your brain will result in a near-complete loss of its
> information content in a relatively short period of time.

"near-complete"?? Unless you are a Tiplerian, the loss is so close to complete
that it *is* complete. However, there may be leftovers unrelated to your brain
(e.g. Sasha's memoirs) that allow the reconstitution of a relative approximation
of individuals. Now, there are going to be a lot of people with raised eyebrows
if a combination of genetic backtracking, historic pattern matching and
simulation integration with known outcomes allows you to by and large recreate
an individual without any frozen wet-matter at all! How much of the "Greg" personality
could I get knowing the time and place of years of the crystallization of your

IMO, you can throw away the rest of the arguments and simply stick with #5.
Even a 0.000001 % chance of survival is better than the 10^-??? chance
allowed by dependence on "faith" or "belief". The cost is minimal relative
to the potential benefit.


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