Re: Measure of the prisoner

From: Saibal Mitra <>
Date: Thu, 14 Sep 2000 17:57:18 +0200

Bruno wrote:

----- Oorspronkelijk bericht -----
Van: "Marchal" <>
Aan: <>
Verzonden: woensdag 29 maart 2000 11:40
Onderwerp: Re: Measure of the prisoner

> >Suppose that the simulated prisoner is a ``digital copy of a real
> Saibal Mitra wrote:
> >[...] If the simulated time also corresponds exactly to real time then
> >the probability of the prisoner finding himself in the simulated world is
> >almost exactly 1/2.
> Why ?

> Even if the simulated time does not correspond to the real time the
> probability of the prisoner finding himself in the simulated world is 1/2.
> Unless you solve Jacques Mallah's desperate implementation problem
> (see the archive or Mallah's URL) you will not be able to use "time"
> to define the measure on the prisoner's experiences.
> >From the point of view of the
> prisonner, if COMP is correct, he cannot make any difference
> between real or un-real-time. Time (like
> space) is a construction of the observer's mind and is defined only in a
> relative way. What you need to do is to defined a notion of first person
> (or subjective) time *from* the measure on the possible computationnal
> continuation of the prisoner's mind.
> Note also that there is no "real" time in any many-world view of
> relativistic quantum mechanics (even without COMP).
> With COMP (which you are using here) there is no real time nor is there
> any need for such a thing.
> More on this in the archive at
> Bruno

I now think Bruno is right. The measure doesn't depend on t'/t. But, in any
case, consistency with other thougth experiments (e.g. simulations within a
simulation with another relative time-dilatation factor t''/t') limits how
the ratio of the measures can behave as a function of t'/t :

m2/m1 = (t'/t) ^ x

(m2 is the measure of the simulated prisoner m1 that of the real prisoner,
and it takes t seconds to simulate t' seconds of the life of the prisoner).

A nonzero value for x can still arise in certain cases. E.g. if one
simulates one day of the life of the prisoner with periodic boundary
conditions, one has x = 1. To see this, suppose the prisoner is simulated on
two different
computers, one with t'/t = 1 and the other with t'/t = 1/2. Only one day of
the life of the
prisoner is simulated. After a simulated time of 24 hours the simulation
starts all over again. Then clearly in a time interval of 2 T days, the life
of the
prisoner is simulated 2 T times on the fast computer and T times on the slow

Received on Thu Sep 14 2000 - 09:09:01 PDT

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