X-Message-Number: 13352
From: "john grigg" <>
Subject: regarding cryonics feasibility.....
Date: Fri, 03 Mar 2000 01:42:04 PST

The debate over the feasibility of cryonics has come to a continues.  The 
main topics of course, were about the true nature of brain structure damage 
and whether nano will be up to the task due to the possibility of some 
information being irrepairably lost.  These posts are all well worth 
reading.  I look forward to the discussion they may spark.


sincerely,

John Grigg

Date: Wed, 1 Mar 2000 18:22:15 -0800 (PST)
From: "Robert J. Bradbury" <>
Subject: CRYONICS: feasibility studies

I have finally read through most of/browsed the remainder of
the technical articles by Mike Darwin (BPI Tech Briefs #002/#4)
I agree that the articles are seriously written and for the most
part technically accurate (a little dated perhaps).  However the
articles fail to comment in any serious way on the issue of what
can or cannot be repaired by serious nanotech (which is what Ralph
and a number of others argue will inevitably be required to reanimate).

As Mike points out in BPI Tech Brief #4, regarding the injuries
caused by cerebral ischemia, there are a host of problems that
occur when the brain becomes deoxygenated/deglucose-ylated.
The complexity of these problems is very large and you are
unlikely to have single individuals who can "grok" the entire
range of possible damages (and solutions).  Solution: Cryonicists
should establish a network of individuals, each of which is *the*
expert on the state of the art with regard to various pathologies
(calcium influx, free radical damage, mitochondrial swelling,
neutrophil activation, ice crystal deformation, etc.).  Only if
you have individuals who are expert in these areas who are able to
converse regularly will you begin to see progress in pre &
post-suspension methods.

I'll emphasize this point by observing that Mike's concerns about
arachidonic acid and iron might be dealt with by aspirin and
desferoxamine respectively.
However, the only thing I saw in the entire discussion which
raised warning flags for me was the destruction of the lysosomes.
While ice crystals may disrupt molecules and their locations, they
would tend to retain mirror image structures that allow reconstruction.

Everything else discussed (chromosome rearrangements, extracellular
matrix changes, mitochondrial swelling, etc.) can be repaired with
the exception of damage caused by uncontrolled lysosomal enzymes.
Lysosomal enzymes will fundamentally cause information loss.
They dismantle proteins and rearrange structure in such a way
that it may not be possible to reconstruct the original architecture.
To my mind, that implies that the fundamental requirement for
cryonic reanimation is not CPR for oxygenation or cryoprotectats
for reducing freezing damage, but lowering the temperature of the
brain to reduce the activity of lysosomal enzymes and/or adding drugs
to completely inhibit them.

You have to look at it this way -- If I break your mirror into
a zillion "relatively" unique pieces, I will still be able to
reassemble your mirror exactly the way it was orginally.  On the
other hand if I disassemble your mirror into a zillion "identical"
molecules, I will likely never be able to reassemble it the way
it was orginally.  I may be able to produce a functional equivalent
of what was there originally, but it will not be an original.
Of course these approaches beg the issue of exactly what it is
that people undergoing cryonic suspension are trying to preserve.
That is something, I suspect, is less examined than some might
argue would be desirable.


Eugene Leitl ()
Mon, 28 Feb 2000 02:00:34 -0800 (PST)

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[ Next ][ Previous ] In reply to: 
He tells nothing new in this post other than in

http://www.merkle.com/cryo/cryptoCryo.html

I haven't read that before, so I just did.

His description of the state of the neural tissue due to ischaemia/freezing 
is entirely incorrect. I hate to be blunt, but he's moving entirely outside 
of his area of expertise. Even worse, he is making invalid ad hoc 
assumptions in his area of expertise (assuming a nondissipative, 
deterministic physical process despite dramatic evidence to the contrary 
"the laws of physics are reversible"; plus arbitrarily fixing a lower level 
of structure encoding the personality, despite of sound practise (and 
mounting evidence) to assume a worst case).

In short, the argumentation as presented makes only a very weak case.

Eugene
"In theory, there is difference between theory and practice. In practice, 
there is."

 writes:
>Coincidentally(?), Ralph Merkle has posted an article today to sci.crypt
>about the analogy between cryonics and cryptanalysis. You can read it
>at http://www.deja.com/[ST_rn=ps]/getdoc.xp?AN=590357353. Click on
>"thread" to find any follow-ups. I see that at least one reply has
>mentioned the issue of possible information loss.
>
>Hal


Eugene Leitl ()
Mon, 28 Feb 2000 18:18:38 -0800 (PST)

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[ Next ][ Previous ] In reply to: Jim Hart
Jim Hart writes:

>"What we have here is a failure to communicate".


"Some men, you just can't reach".

> >(assuming a
> >nondissipative, deterministic physical process despite dramatic
> >evidence to the contrary
>
>Freezing is largely nondissipative. Cracked and displaced


No. Disagree strongly here. Though not having to bear burden of proof, 
provided things go as expected I will nevertheless document this 
extensively. You can't improve a process if you don't have a quality metric.

>surfaces, furthermore, leave around a large amount of information
>on matching surfaces, like a jigsaw puzzle. Thus for freezing


I do not regard the cracks a problem at all. Nor do I share this peculiar 
specialist blindness.

>damage Merkle's analysis may be too *pessimistic*: we can often use


                                   ^^^^^^^^^^^^^^^^

This is a joke, no?
>pattern matching rather than the computationally more expensive
>cryptanalysis/machine learing techniques. Ischemic damage


The cryptoanalysis analogy is btw perfectly valid if you attempt to 
reconstruct the real thing by monitoring operation (say, using 10^9 
nanoprobes in vivo), especially if including manipulative measures (exciting 
subsystems and analyzing their activity dynamics).

It's just that a lot of people will die, perhaps all of us here present, if 
we wait for the advent of this technology (if it indeed arrives, which is 
far from being guaranteed). Nor is sustainability of patient storage 
guaranteed. As in every small market, customer (your) attitude matters.

>is another matter. It involves quite dissipative chemical
>reactions. There is good reason to believe that freezing
>damaging will be vastly easier to correct than ischemic damage.


Disagree here also. Ischaemic damage is synergistic, however, because it 
inhibits or prevents altogether the loading of tissue with cryoprotectants. 
Such a small issue, eh?

If you thought that typical cryonics patients look bad, don't even try to 
look at straight freeze. Ugh.

>The good news is that hypothermic conditions, for example
>hypothermic surgery, have been observed to prevent ischemia
>for hours at a time. Unfortuneately good hypothermic


Yes, there are magic drugs, and there are advanced methods (partial liquid 
ventilation with fluorocarbons, which uses the lung as efficient heat 
exchanger allowing cooling rates better than invasive measures like 
peritoneal lavage).

Such new drugs and novel methods are not widely deployed in medical 
practice, and will not be used on patients considered hopeless or already 
dead. Suspensions under controlled conditions are _not_ the norm. Your 
stainless steel bracelet does not guarantee salvation.

>conditions are often absent. Prevention of ischemic damage
>needs much further study and higher priority in cryonics procedures.


No, ischaemia is being adequately addressed, also (especially, considering 
the resources) by the mainstream. Brain vitrification is not.

>Another piece of good news (for cryonics!) is that ischemic damage
>is a very common event, for example stroke, that the brain
>has to some extent evolved to protect against, for example
>through redundant storage of long term memories. Brain
>damage from stroke is usually the result of loss of function
>of parts of the brain the function of which is to retrieve
>and process long term memories, rather than loss of the long
>term memories themselves. So after even a major stroke
>lasting for days the information is usually still there.


Stroke=focal damage. Ichaemia is global stroke. But again, ischaemia itself 
is not a primary source of damage, if patient in optimal settings, including 
premedication. Even postmedication stretches the window a lot, and we're not 
talking merely structural preservation but viability. I am not concerned 
about viability, the usual gold standard, but structural conservation only.

>These are all testable claims and it would be great to
>discuss studies on hypothermia, stroke, etc. rather than
>continue to speculate. There also needs to be more


I have to tried minimizing speculation on my part. However, I've seen that a 
lot of my arguments are being either ignored, dismissed or misunderstood. I 
am beginning to see the origins of that often voiced source of irritation.

>cross-disciplinary learning between computer scientists and
>cryobiologists.


Alas, so far information flow has been negligeable.


RE: Charles Platt responds to Billy Brown on CryoNet Message #13281
Eugene Leitl ()
Mon, 28 Feb 2000 23:20:59 -0800 (PST)

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[ Next ][ Previous ] In reply to: Billy Brown Next in thread: Billy Brown
I don't have much time for this, so I have to be selective/brief. Also this 
is starting to get past the point of diminishing returns.

Billy Brown writes:
[...]
>Now, I think that the case of cryopreservation is a lot closer to my 
>example
>than yours. Typical slides of preserved tissue show a bewildering jumble of
>mixed-up parts, not a homogeneous sludge. In this kind of situation the


You'll never see a homogenous sludge because the system has not been 
perfectly homogenized (I don't know why you did expect that), and also 
because there is autoassembly. You can be looking at pure artefacts, yet 
thinking you're looking at native structure. This can be very deceptful. As 
I said, things look just great on vanilla light micrographs.

>I'm a software engineer - and yes, that is a very different thing than 
>being
>a programmer. But that's another thread.


I urge you to accept my word for it that software people believe in an 
orderly world. Too orderly world. Way too orderly world. It is both because 
of the self selected personality style and because of the training. Heck, 
I've been noticing some of it myself. You need to take that intrinsic bias 
into account when you look at things.

> > If I use a true random generator (or a pseudorandom generator unknown
> > to you) to scramble the picture, information is lost. Period.
>
>No kidding. I've said that several times myself. There's no need to keep
>beating a dead horse.


I think it just moved a bit. There! It's just pretending.

> > You are surely aware that the position you question are held by the
> > only specialists in the matter there are? There are no better ones
> > yet. What are your credentials in the matter? Programmer, aren't you?
>
>Ah, the argument from authority. Does this mean you don't have actual data
>on hand?


If you ask me whether I'll believe Merkle or Fahy when it comes to 
interpreting electron micrographs, I will hesitate about 250 ms. (About as 
long as it takes me to understand the question). Call it blind belief in 
authority, if you must.

Also, I think I have a pretty good intuition for physical processes. I can 
think on my own. I think.

>There are no specialists on brain reconstruction. Neurobiology,
>conventional medicine and cryopreservation are all only tangentially
>related. Asking a specialist in one of these fields about reconstruction
>techniques is like asking a paint-and-canvas artist about digital image
>processing. Heck, most 'experts' still seem to think that clinical death
>and the capacity for spontaneous recovery are meaningful yardsticks here.


I am usually not known for being conservative
on this list I arguably know more about the matter than anybody else
I also intend to find out a lot more in the years to come.

>The only group that even tries to understand the real situation are the few
>pioneers who do cryopreservation research for the cryonics organizations,
>and they haven't had the time, funding or manpower to create the kind of
>well-supported body of experience that would allow them to become a real
>specialty. Besides, the last I heard they were cautiously optimistic except
>when they're asking for money.


They wouldn't be asking for money if they didn't want to find out more about 
what is going on. Otherwise I'm not sure about the optimism bit, with the 
exception of the kidney cryopreservation (that one might actually work, 
albeit probably not economical by the time it is perfected).

>Meanwhile, the people whose opinions I most respect in this regard
>unanimously hold the same position I do. The only difference between my
>claim and the comments that Drexler, Merkle et. al. make is that I left out
>the minimal qualifiers that scientists habitually attach to any statement 
>of
>fact.


Fine, you have your authorities, I have mine.

> > So we assume a best case as default. No further research needs to be
> > done, because the information Is Still In There, Somehow.
>
>No, we take past experience as our guide. Finding ways to computationally
>unscramble mangled structures is so common that we should expect it to
>happen as a matter of course whenever someone decides to devote some real
>effort to any given problem. If you don't think it can be done in this
>particular case, you need to actually show that the necessary information
>does not exist.


Once again, in the topsy-turvy world of cryonics the bringer of bad news 
bears the burden of proof. Don't expect me to waste a lot of my time on it.

>Which brings me back to the point you've been ignoring. The fact that a
>structure 'appears' scrambled says nothing about its actual information
>content. The fact that cremation and long-term decomposition cause


Nothing indeed. It's all just a PRNG, deep down below. Once you know the 
algorithm, you can reverse it. In a vision, St. Margolus told me that, while 
cherubs Fredkin and Toffioli sang a sweet duet above.

>irreversible damage is easy to demonstrate, but the same is not true of 
>less
>severe insults that leave substantial amounts of structure intact. So, do
>you have any actual experimental evidence regarding the degree of
>information loss caused by various forms of trauma? Failing that, do you
>have a good logical argument for believing that the information loss is
>catastrophic?


You'll have your evidence, hopefully in form of a few publications. Once 
again, don't expect me to waste significant amounts of my time pounding the 
message home. I do not care enough to try to change your mind.

>You need to calm down and start actually reading me before you reply. Look
>at Drexler's scenario in Engines of Creation for a typical example of what
>I'm talking about. You've got a bazillion MIPS of computing power being
>used to run something that sounds like a mating between a molecular CAD
>program and an expert system. I understand why he didn't want to spend
>another 50 pages getting the reader fully up to speed on what is really
>possible, but his brief references to engineering AI go right past most
>people without ever making an impression.


I have been telling you all the time that for the purposes of argumentation 
you can assume to have access to perfect technology. Behold, yon dead horse, 
in a perfect illustration of reversiblity, just rose and is galloping away 
as briskly as ever. D e s t r u c t i o n o f i n f o r m a t i o n. N o O m 
e g a. No other constraints. This are the assumptions I'm operating on.

Did I already mention I was a big pessimist?

>Certainly, there are people around who know better. Drexler is one of them,
>and so are most of the other big names in nanotech. But most people (even a
>lot of extropian and transhumanist types) are still thinking in terms of a
>program that shuffles atoms using algorithms that any good programmer could
>implement.


Not this transhumanist type.

>That is not even remotely realistic. What they should be imagining is
>something more like the FBI working over an especially important crime
>scene, only with even more layers of specialized knowledge and processing.
>The degree of expertise that can be applied to solving each particular
>sub-problem (membrane reassembly, oxidation reversal, etc.) will grow
>steadily over time, and it is difficult to say exactly where it will reach
>its limits.


It will be reaching their limits asymptotically when the amount of 
extractable information about the original structure still contained in the 
artefact has been extracted. I hope this was clear enough.

>What on Earth does an argument about the quality of current suspensions 
>have
>to do with the long-term stability of cryonics organizations?


Nothing. However, an argument about attitudes about the quality of current 
suspensions on long-term stability of cryonics organizations does quite a 
lot.

>Actually, if you look back on this thread, you'll find that my original
>remarks were directed against a post that argued this very point -
> was claiming that the odds of not getting suspended at
>all were high enough to constitute a valid reason for not bothering to sign
>up.


That's his personal calculus. If there was a 5-10% chance of being 
successfully suspended and ~100% chance of cryonics to work in principle I 
would have mailed my signup paperwork long time ago.



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