On Fri, 16 Apr 1999, Gilles HENRI wrote:
> A computer has a number of physical degrees of freedom
> (physical entropy) enormously greater than the number of its computational
> degrees of freedom (memory and processor size); that allows to reproduce
> the same computational complexity with many different material structures.
> So it is clear that if you want to simulate a physical system (down to
> detailed molecular structure) with a computer, you will need a computer
> huger than this system. But then this computer cannot behave PHYSICALLY
> like this system. The only possibility is to built a "molecular" computer
> that has exactly the same PHYSICAL behaviour than your system, that is in
> fact an exact PHYSICAL copy of you (usually what SF authors assume!).

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It's not necessary to simulate exactly 'your' behavior for all
time. The point is that a human brain implements some digital
computations. An analog system is perfectly capable of implementing
digital computations; usually only for a certain set of initial
conditions. The basic unit which is associated with consciousness
is one time step of such a computation. To reproduce a particular
observation - which you can call 'you' - you only need to implement the
given computation by any means.
If a computer 'fails' due to thermal coupling to the environment,
then it + the environment did not implement the given computation. It +
the environment implemented a different computation. (Of course in the
MWI we don't expect to be able to observe the final state of such a
system, which is given by its full wavefunction; presumably it will
have many implementations of the same computation; see my web page for
more details.)
- - - - - - -
Jacques Mallah ([EMAIL PROTECTED])
Graduate Student / Many Worlder / Devil's Advocate
"I know what no one else knows" - 'Runaway Train', Soul Asylum
My URL: http://pages.nyu.edu/~jqm1584/