On 30 Aug 2005, at 18:55, kurtleegod.domain.name.hidden (GK, Godfrey) wrote:
> [BM]
> As Russell point out to Godfrey, it is important to distinguish
> sort of constructive physicalism a-la-Schmidhuber, where the
> physical universe is a computational object and comp where there is
> no physical universe at all. from this I can conclude you are not
> reading the posts (still less my papers), and you are fighting an
> idea you have build from comp.
>
> [GK]
> Since you referred me to John Preskill's delightful lectures on
> quantum computation I figured I may quote you a little jewel
> I found in there which, though obviously mistaken in terminology,
> is quite relevant to this point and others you have raised.
>
> About the Measurement Problem (chapt3, pg.50) Preskill points out
> that "There are at least two schools of thought:
>
> "Platonic": Physics describes reality. In quantum theory "the wave
> function of the universe" is a complete description
> of physical reality"
>
> "Positivist": Physics describes our perceptions. The wave function
> encodes our state of knowledge, and the task of
> quantum theory is to make the best possible predictions about the
> future, given our current state of knowledge. "
>
> The he goes on to defend his choice of the first school:
> "I believe in reality. My reason, I think, is a pragmatic one. As
> a physicist I seek the most economical model that
> explains what I perceive. etc..." (you can read the rest...)
>
> Platonists and positivists would certainly scream at this
> description of their views but I think
> it shows is that even the staunchest defenders of the Everett
> interpretation think that by embracing it they
> are embracing "reality" by which they mean the Physical Reality
> that, you claim, does not exist ! To me this
> suggests again that you have a very crooked view of MWI if you
> think it supports you in any way...
>
Of course, Everett still postulates EQM, and interpret it in a
physicalist way. I have clear that I don't follow him in the sense
that, once comp is assumed, my theorem shows that SWE is either
redundant or false.
Now I am a realist. reality is independent of me, but with comp it
just cannot be "physical", unless you redefined "physical" by
"observable", but then you need a theory of observation, which is
what comp provides freely (with and without YD); and then the
physical emerges "logically" from the number theoretical true relations.
Bruno
http://iridia.ulb.ac.be/~marchal/
Received on Wed Aug 31 2005 - 09:52:03 PDT