[extropy-chat] Cryonics without comprehensive brain disassembly? - No
Robert J. Bradbury
bradbury at aeiveos.com
Tue Apr 20 11:28:20 UTC 2004
Ok Brett, I'll tackle some of this now. Perhaps more later.
On Tue, 20 Apr 2004, Brett Paatsch (responding to my comments
on cryonics and to a lesser extent preservation of identity)
> > I would like to correct a misperception -- cryonics does *not*
> > strictly require the disassembly of the brain.
> I think you are making a distinction without an important difference.
> Its of course trivially true that cryonics - a purported potential
> procedure does require anything. Its not a person.
> But go ahead and show me if you can, how Robert Bradbury's
> superior perception of cryonics can do both an end-run around
> entropy and extract sufficient information on personal neuronal
> structures to produce even a very good *copy* of the original self.
I don't have to show you. Its documented in Ralph Merkle's paper
on the "The molecular repair of the brain"  (which is about 10 years
old now). Freezing doesn't damage *most* of the cellular structures
we know that because we can freeze bacteria, yeast, sperm, eggs, etc.
and revive them and they function perfectly well. The problem with
freezing (as it is now done) vs. vitrification is that one gets
fractures at the macroscale and that disrupts things like blood
vessels, axon structure, etc. Ralph goes into how nanorobots
could repair these. I suspect you have never done much rock
collecting. If you had you would know that when you fracture
a solid object you get pieces that go back together very precisely.
So long as you can map the fractures and you have nanotech that
can put things back together properly the fractures are not
So I would assert that in a significant fraction of cryonics patients
you can put a "humpty dumpty" brain back together again (so long
as you are dealing with solid material where there is little
Now, there *are* some secondary effects due to external and internal
radiation. Robert Freitas has looked at part of this , though I'm
not at liberty to release it. It looks like this isn't a significant
problem for individuals who are frozen for at least hundreds of
years (longer time scales -- such as interstellar travel times
might start to present problems).
> No one isn't. No one has. Or do you have evidence that brains have
> been reanimated after undergoing a cryonics "preservation"
> procedure that I don't? If so please share.
No direct evidence. I am extending the idea that if many types
of cells can be frozen and reanimated and function properly that
the cells of the brain can be as well. Eugen or Anders might
know if people have actually frozen and reanimated neurons.
One could argue that one might lose some fraction of the cells
in the process -- *but* you are losing cells every day .
I'm working on the basis of personal experience -- I've actually
ordered Deinococcus radiodurans that were freeze dried at the
ATCC and grown them in the lab. You can't assert (to me) that
one cannot recover frozen cells to a fully functional state.
> > Sooo... using my original analogy you may (*or may not*) get
> > back your original atoms in their original structural form.
> I'm saying you can't. No way. No chance. But please show me if
> you can, if you really think you can.
Ok, first let me assert that you do not from day to day retain
unchanging structural forms -- not at the molecular level.
Ribosomes, neurotransmitters, neuroreceptors, etc. are all
being recycled (broken down and rebuilt) at some rate (so the
atoms and many molecules that were in one place yesterday are
not the same atoms and molecules that may be in those places today).
So this isn't a strict requirement.
But this goes back to my discussion of the disassembly of Mars.
If you have the computer resources to compress and someplace
to store the compressed information it is perfectly reasonable
to disassemble things atom-by-atom and record the information
(there are multiple experiments with AFMs and STMs doing this
kind of thing now even without nanotech). Now if you add an
extra step of sorting and storing the atoms as you perform the
disassembly process, *and* you have robust nanotech, then
reassembly using the original atoms seems reasonable. Now
with biological systems since there is so much redundancy
(in the genomes and proteins) would could adopt a policy of
not storing information that may be defective or damaged
in some way and perform the reassembly using the "best case"
(for an individual) or the "best case" (as determined by
the state-of-the-art biological knowledge base). So one
might perform a reanimation of an individual in the best
health of their life or perhaps in the best health science
and engineering is currently capable of. This is entirely
distinct from standard "uploading" methods where one replicates
the intelligence on entirely different hardware (such as an
equivalent mind within a computer).
Whether one views the original brain that is restored back into
an operational state by nanorobots or a completely disassembled
and reassembled brain as oneself or a copy gets into philisophical
issues. One could ask similar questions about people brought back
to life after drowning or a heart attack.
This leads to one of the problems I think stem cells may need
to address in the long term -- How do you find the stem cell(s)
that are in the best condition? So in cases where one is attempting
to restore a damaged brain (from disease, death, cryonics, etc.)
how does one decide what stem cells to use?
And yes, I've enjoyed recent comments by both Harvey and Chris
and I will probably need to wade through them further to see
what responses might be useful.
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