In a message dated 05/21/2000 9:52:54 PM Pacific Daylight Time,
R.Standish.domain.name.hidden writes:
> GSLevy.domain.name.hidden wrote:
> >
> > In a message dated 05/21/2000 7:59:35 PM Pacific Daylight Time,
> > R.Standish.domain.name.hidden writes:
> >
> > > http://parallel.hpc.unsw.edu.au/rks/pubs.html
> >
> > >The necessity comes from the requirements of the anthropic principle,
> > however >when a particular aspect of the universe is not constrained by
> the
> > AP, its value >must be decided by chance (according to the SSA) the
first
> > time it is ``measured'' >by self-aware beings.
> >
> > I may have misunderstood you Russell, but the above statement from your
> paper
> > reminded me a lot of Wheeler's participatory universe with which I
> strongly
> > disagree. You are saying here that a parameter not constrained by the AP
> will
> > take a value as soon as it is observed by observers. Your use of plural
in
>
> > "Self Aware Beings" is confusing. Does it take observations from several
> > beings to collapse that parameter? What do beings observe, who have not
> been
> > instrumental in this collapse?
>
> OK, I'll try to chase up a ref about Wheeler's ideas to see what
> relationship, if any there might be. I hate being misunderstood :)
>
> As for your second question, perhaps I can clarify it with a simple
> example of two observers, looking at a binary observable:
>
> Observer A and Observer B share a common history up until time t0, at
> which point A examines the binary variable x. This implies that if A
> talks to B, they will agree on all values of observations in their
> environment. After time t0, there are two distinct histories for
> observer A, which we call A0 and A1, depending on whether x is 0 or
> 1. To observer A0, B should agree the value of x=0, but doesn't know
> it yet. Conversely, A1 thinks that B should agree the value is x=1. At
> time t1, B makes an observation of x. There will now be two histories
> - one in which A0 agrees with B0 that x=0, and another one where A1
> and B1 agree that x=1. The history where A0 discusses the measurement
> with B1 is ruled out. (Assuming, for the sake of argument, that the
> measurements were perfectly reliable). There will also be a history
> where B measures a totally different variable y at t1.
>
> So the answer to your question is that there may well be more than 1
> observer involved in setting a particular history (all observer need
> to agree consistently on all aspects of the history in order to
> communicate - ie a "Don't know" is consistent with any particular
> value, but when I later go to measure the value, it should be the same
> as what you told me). However, it is not necessary for there to be
> multiple observers. Many aspects of my observational history will
> remain private and unknown to any other observer.
>
I think that now we agree. A0 and B0 measure the same value for variable x
because they share the same history. Another interpretation on "same history"
is that there must be a logical/rational/computational link between A0 and B0
which forces them to perceive the world as rational. A disagreement between
A0 and B0 on the value of x could certainly not sustain the scrutiny of
scientific inquiry. Same goes for A1 and B1.
Received on Mon May 22 2000 - 10:13:00 PDT