X-Message-Number: 5771
Date: Mon, 19 Feb 1996 21:24:18 -0800
From: John K Clark <>
Subject: SCI.CRYONICS Death

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Marshall Rice <> On Sun, 18 Feb 96 Wrote:
                    


                >What I object to is the taking of money to freeze dead meat,
                
                >on the pretence that it may  somehow, some day, some way,
                                >become 'you' again.

Why do you object to how people spend their own money? You're
free to spend your money as you see fit, let us do the same.
Everybody in cryonics knows it's a very long shot, but not as
long as rotting in a box.
                   


                >it is and always will be impossible to reverse cellular
                                >death. 

I don't believe in a soul or a vital force or in devil demons
from Pango Pango. The difference between life and death is only
in the arrangement of atoms and you could change one into the
other if you had the proper  information. "Impossible" is a very
strong word and "always" is a very long  time, both words should
be used with care.
                 


                >We would need to duplicate the precise properties of each
                
                >synapse, i.e. at what level of stimulation it was triggered
                                >and for how  long.

                  
That is almost certainly untrue. The  most important memory
storage mechanism in the brain is thought by most to be Long
Term  Potentiation ( LTP). It theorizes that memory is encoded
by varying the  strength of the 10^14 synapses that connect the
10^11 neurons in the human  brain. It had been thought that LTP
could be specified to a single synapse so  each synapse was
equivalent to one computer bit, perhaps several bits, but  now
it looks like that is a vast overstatement.

In the January 28 1994 issue of Science Dan Madison and Erin
Schuman  report that LTP spreads out ( the LTP signal is
probably sent by  the diffusion of nitric oxide) to a large
number of synapses on  many different neurons. The individual
synapse cannot be the computer bit  of the brain. Neural Net
expert Terrence Sejnowski commented on these new  findings "
Instead of thinking of a synapse as representing a piece of 
information you can now begin thinking of a population of
potentiated  synapses acting together".

All this severely reduces the storage capacity of the brain but 
increases it's redundancy. This is good news if we want to
repair a badly damaged frozen brain. Also, although it may hurt
our pride to think that our essence can be defined with less
information than we thought, it also means that uploading will
be easier ; there's less you need to upload. 

It's not obvious to me that we must need an astronomical amount
of long term  memory in order to function. I've heard that some
medical specialists were  distressed to find that AI programs of
just a few megabytes could make pretty good diagnoses in their
field.  Considering the years it took them to acquire this knowledge,  
they expected that a much larger program would be needed.       
                         
                      

                >although you may be able to duplicate the personality,
                
                >emotions and memories of an individual, in no sense would
                
                >they be the same person. The consciousness of the original
                                >individual would have been lost                  


Why? If somebody has the same personality, emotions and memories
as you then  it is you. The fact that the atoms may be different
is of no importance,  we constantly change our atoms, you are
quite literally not the man you were  a year ago. Science can
find no difference between one hydrogen atom and  another so I
can't see how it could make the slightest difference.

The only way you could be right is if we possessed some innate
quality that could not be duplicated by Nanotechnology or even
detected by the scientific method, in other words if we had a
soul. If I believed that I would be much more interested in the
mumbo jumbo of conventional religion than in Science.
                                        


                >Let me draw an analogy. Imagine a shelf of books. Imagine
                
                >that you began tearing out the pages and throwing them on
                
                >the floor, then tearing the pages into individual sentences,
                
                >then the sentences into words and finally the words into
                                >letters. At the same time, imagine that someone was   

                >recombining fragments in different order to the original,
                
                >which you again tore up.  At what point could you say that
                                >the information in the books could never be recovered? 
                                        

In your example I would say that things would become pretty
hopeless as soon as your book tearing process became chaotic.
For Cryonics I would say that things would be hopeless if the
freezing process brought on turbulence. It would mean that tiny
changes in initial conditions would lead to huge changes  in the
outcome, it would mean loss of information making recovery
virtually  impossible, it would mean the end of the ball game as
far as the feasibility  of cryonics was concerned. Fortunately
this probably doesn't happen. 

Chaotic turbulent flow sets in when a system has a Reynolds
number that is  larger than 2000, although you might get some
non chaotic vortices if it is  bigger than 30. We can find the
approximate Reynolds number by using the formula RDV/N. R is the
characteristic size of the volume we're interested in, we're
interested in cells so R is about 10^-6 meter. D is the density 
of water 10^3 kilograms/cubic meter. V is the velocity of the
flow, it's  probably less that 10^-3 meters per second but let's
be conservative, I'll  give you 3 orders of magnitude and call V
1 meter per second. N is the  viscosity of water,  at room
temperature N is 0.001 newton-second/meter^2 it would be less
than that when thing get cold and even less when water is mixed
with glycerol as it is in cryonics but let's be conservative
again and ignore those factors. If you plug these numbers into
the formula you get a Reynolds number of about 1. 

It looks like any mixing caused by freezing would be laminar not
turbulent.  Of course you would still have severe cell damage
and to repair it you would need a technology that could control
the position of individual atoms,  Nanotechnology, but it looks
like you could figure out where things were suppose to go,
especially when you consider that you would have the  computing
power of one of today's super computers to repair each cell in
the brain.


                                          John K Clark       

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