From: Paul Grant (shade999@optonline.net)
Date: Fri Jul 11 2003 - 00:06:01 MDT
Just as a side note; even if you could scan the brain in the method you
describe,
you would be no closer to remotely understanding it; the brain is more
than just
synaptic electro-chemical processing; alot of the processing occurs is
not intracellular,
its inter-cellular... ergo identical neurotransmitters can instigate
different cellular
responses based on a cell-specific (sub-cellular) response.. if you
included direct
replication of your structure (your atomic scan), of the entire body,
and not just the
brain, then of course, the point is moot :) But as I said, IF you
decide to include
direct replication of the brain...
and if thats the case, why bother freezing the meat, if you can freeze
the signal...
in any event, that level of technology is so distant, I wouldn't even
begin to hazard
a timeline :)
And to directly address your question (heisenberg uncertainty as it
relates
to a nondestructive, atomic-level scan), not to my knowledge....
although I
heard rumors 5 years or so ago about a passive (rather than active) scan
which would allow you to technically sidestep heisenbergs principle...
sadly (for you and me both), I have absolutely no references on this;
and given the importance associated with such an event, coupled with the
complete lack of fanfair, doubt that it even exists, except perhaps as
a theoretical construct or an exception that proves the rule...
of course, all this is from an educated lay-mans perspective, discussing
various prospects with experts :) I have yet to track down a physicist
though and engage in a discussion on quantum dynamics/mechanics since
I would be at best, woefully unprepared for such a discussion...
maybe in a couple of years when I read up a bit on subatomic stuff :)
I did have an interesting discussion with somebody on a tangential
topic;
its my firm belief (note, belief), that it would be more beneficial to
work
on the brain in a sub-cellular viewpoint, rather than an organization of
differentiated cell-neurons and the like... of course the latter
viewpoint
is the more predominantly pursued of the two...
omard-out
-----Original Message-----
From: owner-extropians@extropy.org [mailto:owner-extropians@extropy.org]
On Behalf Of Brett Paatsch
Sent: Monday, July 07, 2003 5:15 AM
To: extropians@extropy.org
Subject: Re: Cryonics and information theory
Eliezer S. Yudkowsky wrote:
> Harvey Newstrom wrote:
> >
> > We have a lot better imaging technology now, and pictures of
> > patients' brains who have been frozen. The damage is a lot worse
> > than we thought. The cells shrank and pulled apart from each other
> > with gaps between them. Where the cells stayed put, they are
> > disconnected from other cells. Where the cells stayed connected,
> > they are all pulled together leaving huge gaps. The structure and
> > positional relationship between the cells may or may not be
> > recoverable. Some people have likened this result to "hamburger",
> > under the analogy that resurrecting a brain in that condition would
> > be like resurrecting a cow from hamburger.
> >
> ...it still looks to me like it would be
> better to just chop off the head and drop it into a bucket
> of liquid nitrogen as fast as possible. *Large*-scale freezing damage
> is irrelevant; you can still connect the dots easily enough. What you
> want to ensure is that the information, the Shannon information, is
> still there. I would not be surprised to find even the earliest
> cryonics patients are resurrectable in toto; it is not necessary that
> the cells be reparable but that their physical state, when scanned
> down to the atomic level, contain enough information to extrapolate
> back the original brain and its relevant high-level information. The
> critical parameters here are a matter of information theory, not just
> medicine, and not at all obvious (i.e., how many initial states
> map to the same post-freezing state, whether critical
> information is in global patterns or local patterns, whether
> information makes a distinction in the final molecular state
> even if the apparent functional characteristics of the neuron
> have been destroyed).
What it the state of the art currently in scanning? Its been my
impression that the atomic level granularity of a scan that I
imagine to be necessary can only be done by destroying each layer in
reading it. Is this the case currently?
Obviously if each layer could be read in slices of a few Angstrom
without destroying the brain tissue itself you could run mulitple parses
from multiple directions.
It would seem to be a relatively simple exercise to drop a sheeps brain
(comparable in size to the human brain into liquid
nitrogen) and then see what sort of freezing damage arises givin an
indication as to whether the information can be
extracted once we have something approaching the scanning technology
required. Obviously the data storage requirements are going to be a
challenge could we now scan non destructively say any 5 millimetre cube
within a frozen sheep brain and
store the data?
- Brett Paatsch
This archive was generated by hypermail 2.1.5 : Fri Jul 11 2003 - 00:16:40 MDT