X-Message-Number: 5752
From: Marshall Rice <>
Newsgroups: uk.legal,sci.cryonics,sci.life-extension
Subject: Re: Death (was Donaldson MR and Miss Hindley)
Date: Sun, 18 Feb 96 10:50:53 GMT
Message-ID: <>

References: <> 
<>

In article <>
            "Marvin Minsky" writes:

>In article <> 
>writes:
>>In article <>
>>            "John de Rivaz" writes:
>>
>>> We would be interested in your evidence for the suggestion that revivals 
>>> will never be possible. (Or if you have no evidence to hand, the basis for 
>>> this belief that you hold.)
>>
>>
>>How about the nature and extent of intercellular disruption occasioned
>>by (a) anoxia immediately prior to death (b) autolysis (c) the freezing 
>>process (d) long-term lysing of DNA by background radiation?
>
>[snip]
>
>>The impossibility (yes) of recovering (effectively duplicating) that 
>>organisation can be demonstrated mathematically, but is obvious to anyone 
>>with any knowledge of neurophysiology.
> 
>It is possible that all one needs to recover are the approximate
>geometries of the previously existing synaptic connections, and some
>coarse characterizations of their propert ies.  


Unfortunately not. 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.


>A few experiments
>might give us an estimate of how difficult it would be to recover that
>data.  Wasn't there a report about just this by Greg Fahy, in regard
>to various forms of preservation?
> 
>As a mathematician, I've often said that something was obvious--but
>not when someone was asking for evidence.
> 
>Perhaps Marshall is not considering the possibility of reconstructing
>the information-structure.  Rebuilding every detail of the autolyzed cells
>could be
>difficult and possibly infeasible--but that does not rule out the
>possibility of providing adequate substitutes, perhaps ones that are
>entirely electronic, for example.

The problem lies in re-establishing the neural pathways, not the neurons 
and synapses themselves. The fact that there are more potential neural 
pathways in a human brain than atoms in the solar system, gives some idea
of the scale of the problem. Those who are about to jump in and cry
"future technology" should think about that for a few seconds.....

I cannot conceive of any way in which neural pathways could be restored 
other than by (1) reconstructing each neuron and synapse down to the 
molecular level or (2) re-accomodating the synapses. 

In the case of the latter (and quite probably the former), 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, just as surely as if they had gone to feed
the worms.

As to experiments, we have a considerable amount of data from victims of
injury and disease.

-- 
Marshall Rice


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