Bruno Marchal wrote:
I mainly agree with your remarks. Some ambiguity remains but I would
like to take some time to succeed making them clear. A priori
our approaches differs methodologically.
Concerning your UDA question, could tell me if you were referring
to the UDA presentation in 11 steps, or to the one in 15 steps
(that is to the conversation with Joel
or to the older presentation in one post I made for Russell)?
Ah you mention step 12, so it is the old one OK. But what do you mean by
a reduced universe?
I got the argument at http://www.escribe.com/science/theory/m1726.html
Step 12 is the step when you introduce the UDA.
By reduced universe, I mean a many-world universe where the number of worlds is less than that of the plenitude or even finite. Your example of teleportation between Washington and Moscow describes a reduced universe: The number of options is limited to only two places. Note that even though the example mentions only one world where this experiment occurs, this description is by the 3rd person. The first person experiences two worlds.
Also, could you explain what you mean by "frame of reference" and this
without physicalist assumptions. Remember I try to deduce the whole of physics
(including geometry but not geography) from the "numbers' dreams".
Frame of reference is difficult to define. I have used the analogy with relativity because it is a convenient model for what I want to express. However, I do not restrict frame of reference to spatio-temporal characteristics. At a first level I include quantum measurements: if two experimenters observes the "apparent collapse of the wave functon" in the same way then they occupy the same world in the plenitude. At a higher level I also include logical processes governing consciousness. Two observer sharing the same logical system experiences the same consciousness. Unfortunately I do not know enough about logic to express logic in a relativistic fashion. I have gone as far as recognizing that conditional probabilities can be viewed as a relativization of information.
I found it convenient to view relativity as a road map. One of the first things Einstein did was to recognize the principle of invariance of c (for special relativity) and the equivalence of acceleration with gravity (for general relativity). Other things he did was to express the concept of simultaneity and to derive a spatio-temporal metric.
We could define the invariance of the plenitude as seen by any observer as a starting point. This principle led me to argue in the past on this list that conditional suicide or even more simply "death" does not alter measure.
The analogy to simultaneity can be expresses by the conditional suicide experiments that we have discussed on this list a few years ago in which different observers see different outcomes depending on how many contingencies they share in their survival.
The analogy with the metric can be expressed by thought experiment that I have presented on this list a few years ago in which the probability of achieving a goal such as winning at a lottery can be calculated using conditional probabilities which are contingent on the survival of the player. This topic I believe was of interest to Wei but I don't think I got him interested in my point of view.
I would also like to include logical systems but as I have mentioned above, I do not know enough about logic to relativitize it. I also would like to set up a thought experiment involving relativistic logical systems but I don't know how to proceed.
All this is just scratching the surface. There is a need for establishing strong links with physics and mathematics and to make this theory falsifiable. There is also the need for unifying all these relativities - make them into one single coherent whole: Einstein's Relativity, Everett's Relative Many-World interpretation, and (Relative?) Logic.
Have a good weekend. I will also be busy till Tuesday.
I am rather busy until tuesday.
At 21:42 12/05/04 -0700, George Levy wrote:
Bruno Marchal wrote:
when you say that the first person is all there is I am not sure it fits nicely with
the methodology I am following. I am not sure I understand why you don't need the UD,
given that the UD is just a nice third person description of the comp plenitude.
[That such a thing could exist is a highly non trivial consequence of the closure of
the set of programmable functions for the diagonalization: the existence of a universal
machine. (The Post Turing discovery)]. Cf the diagonalization posts.
These are difficult issues... First it seems that the UD does not have to be a basic assumption from which the plenitude can be derived. I think you agree with that.
Another issue is that if we begin with the basic assumption of first person perspective (from which the third person can be derived when first persons share the same frame of reference) then the plenitude should necessarily be regarded from the first person perspective.
Is it correct to say that the plenitude is invariant when seen from the first person? In other words, are all the future potentialities present in the same amount as seen by any observer (no matter how little or how much his life is compromised by his circumstances)? This may be a basic invariance law in the MWI similar to the invariance of c in relativity.
If this invariance is true, then your statement that the UD is a nice third person description for the plenitude is OK however it would only be a derivation from the plenitude invariance principle The UD would also be invariant to describe or generate the plenitude, for any observer.
Please recall me your feelings about the comp hyp in the cognitive science/philosophy
of mind, if you mind.
This is a hard question to answer, but I'll give it a try. I am very committed to the first person "relativistic" or "relative" perspective. I believe that science has been gradually moving toward it from the days of Galileo and Copernicus. Einstein made the "I" relative in space and time. Everett made it relative in the quantum realm. I want to push that to its ultimate conclusion: that the "I" should be the basic axiom from which everything else derives. In "I", I include consciousness and its logical process.
I reviewed your Universal Dovetailer Argument. at your internet site and I agree very much with it. However, I have some questions. Step 1-11 forces the reader to consider the first person perspective. Step 12 may have been taken too hastily. It presumes that the observer in steps 1-11 exists in a plenitude (for example a closed set of the set of programmable functions). This is not clear. In fact step 1-11 could have been taken in a reduced universe.