Re: Turing vs math

From: Marchal <marchal.domain.name.hidden>
Date: Thu Nov 4 01:17:19 1999

Jacques M. Mallah wrote:

>On 2 Mar -1, Marchal wrote:
>> Take the self-duplication experiment as a simple illustration, where
>> after having been read I am reconstitued at two different places.
>> Nobody (not even God) can compute where I will find myself after the
>> duplication.
>
> That has nothing to do with computability! The fact is, depending
>on how 'you' is defined, you are either at BOTH places, or at NEITHER
>place!

That has nothing to do with computability, but that has a lot to do
with the computationalist hypothesis: the hypothesis that there is a
level of description such that I survive a (finitely describable)
digital functional substitution at that level.

Now you are partially right. But you should have said: ``The fact is,
depending on how 'you' is defined, you are either at BOTH places, or
at NEITHER place ... OR at one or the other place".

Precisely: if you survive classical teleportation, you survive classical
duplication. OK ? (this need a minimal amount of folk-psychology).
Now if you define ``you" by the 3-person description of your body at
the correct level of description then indeed you will be at BOTH places.
If you define ``you" by an owner of your personal historical-memories
(such as those you would put in a diary), i.e. what I call the 1-person,
then after the duplication one of such ``you" will write in (each)
diary book either ``I am in Washington" (let us say), and the other
``you" will write ``I am in Moscow".
No 1-person will write ``I am simultaneously" at Moscow and Washington.
It is easy to show that before the duplication the result of the 1-self
localisation experience after the duplication is totaly undetermined.
That is what I call the comp-indeterminism.
And that is a major step in my argument that IF we are digitalisable,
then the physical sciences are reducible to the psychology of
digital machines. In particular quantum indeterminism will be
explained by the comp-indeterminism.

With an ad hoc definition of ``you", you can be at NEITHER place. But
with comp this amount to say that ``I" totaly disappear at each instant.
It means that my expected life duration is O second.
In that case I would prefer to abandon comp, for I take it for sure
that I have been living for at least 2 seconds.

Bruno
Received on Thu Nov 04 1999 - 01:17:19 PST