Dear Russell,
Don Page explored a similar idea to mine in: quant-ph/9506010
Kindest regards,
Stephen
----- Original Message -----
From: "Stephen Paul King" <stephenk1.domain.name.hidden>
To: "Russell Standish" <R.Standish.domain.name.hidden>
Cc: <everything-list.domain.name.hidden>; <issues.domain.name.hidden.org>
Sent: Sunday, February 22, 2004 11:45 PM
Subject: [issues] Re: Is the universe computable?
> Dear Russell,
>
> Let me add that I do not think that it is sufficient to embed
space-time
> in Hilbert space, we also need some way of explaining how space-time
> phenomena acts on the Hilbert space's vectors. The infamous
"back-action"...
> I have an idea but it is pure vapor at this point ...
>
>
> Kindest regards,
>
> Stephen
>
> ----- Original Message -----
> From: "Stephen Paul King" <stephenk1.domain.name.hidden>
> To: "Russell Standish" <R.Standish.domain.name.hidden>
> Cc: <everything-list.domain.name.hidden>; <issues.domain.name.hidden.org>
> Sent: Sunday, February 22, 2004 11:39 PM
> Subject: Re: Is the universe computable?
>
>
> > Dear Russel,
> >
> > Does this "quantum theorist " have anything published on this that i
> can
> > find online? I do need to do better than "can"! I need a "must"! ;-)
> >
> > Stephen
> >
> > ----- Original Message -----
> > From: "Russell Standish" <R.Standish.domain.name.hidden>
> > To: "Stephen Paul King" <stephenk1.domain.name.hidden>
> > Cc: "Russell Standish" <R.Standish.domain.name.hidden>;
> > <everything-list.domain.name.hidden>; <issues.domain.name.hidden.org>
> > Sent: Sunday, February 22, 2004 11:22 PM
> > Subject: Re: Is the universe computable?
> >
> > On Sun, Feb 22, 2004 at 10:33:37PM -0500, Stephen Paul King wrote:
> > > Dear Russel,
> > >
> > > The reference page is about the necessary resources for quantum
> > > computation in general. The "result" that "our space-time structure
can
> > > emerge from a computation on a Hilbert space" is not complicated, we
> just
> > > prove that the class of all possible evolutions of QM systems includes
> QM
> > > computations.
> > > Then we take Deutsch's work showing how classical systems can be
> > > simulated by quantum computations and identify the subset(class) of
> > > simulations with the subset(class) of our experiences of "our world"
> and
> > > figure out how to switch from a 3rd person to a 1st person
> representation
> > > (something like what Bruno Marchal proposes) .
> >
> > Ahh, that little word "can". I was taking your previous statement as
> > stating something much more profound - that 4D space-time must emerge
> > from a Hilbert space computation. Still - perhaps it is possible. I
> > was at dinner a couple of weeks ago with a quantum theorist who
> > claimed exactly that, starting from a standard QED formulation, and
> > taking the h->0 limit. Alas, they tend not to teach QED at
> > undergraduate level, so my ability to evaluate this claim is
> > impoverished.
> >
> > > The hard part is taking the idea that Hilbert space is a
> > representation
> > > of something that has ontological reality - not just a mental
construct.
> > >
> >
> > Its not so hard. If we accept ensembles of descriptions as having the
> > ultimate ontological reality (similar, if not equivalent, to Bruno's
> > arithmetic realism), then Hilbert spaces emerge as the highest measure
> > structure under fairly mild assumptions about the nature of
> > consciousness. (detailed in my "Why Occam's Razor paper).
> >
> > > Kindest regards,
> > >
> > >
> > > Stephen
> > >
> > > ----- Original Message -----
> > > From: "Russell Standish" <R.Standish.domain.name.hidden>
> > > To: "Stephen Paul King" <stephenk1.domain.name.hidden>
> > > Cc: <everything-list.domain.name.hidden>; <issues.domain.name.hidden.org>
> > > Sent: Sunday, February 22, 2004 6:04 PM
> > > Subject: Re: Is the universe computable?
> > >
> > > On Wed, Jan 21, 2004 at 11:46:17AM -0500, Stephen Paul King wrote:
> > > >
> > > > Again, that does not work because we can not take space-time
(ala
> > GR)
> > > to
> > > > be "big enough" to allow us to fit QM into it. On the other hand, it
> has
> > > > been shown that a QM system, considered as a quantum computational
> > system,
> > > > can simulate, with arbitrary accurasy, any classical system, given
> > > > sufficient "Hilbert space" dimensions - which play the role of
> "physical
> > > > resources" for QM systems.
> > > >
> > > > See: http://arxiv.org/abs/quant-ph/0204157
> > > >
> > > >
> > > >
> > > > This leads me to the idea that maybe space-time itself is
> something
> > > that
> > > > is secondary. It and all of its contents (including our physical
> bodies)
> > > > might just be a simulation being generated in some sufficiently
large
> > > > Hilbert space. This idea, of course, requires us to give Hilbert
space
> > > (and
> > > > L^2 spaces in general?) the same ontological status that we usually
> only
> > > > confer to space-time. ;-)
> > > >
> > > >
> > >
> > > Interesting speculation. I'm not sure that it follows from the ref you
> > > give above, however if indeed our space-time structure can emerge from
> > > a computation on a Hilbert space as you suggest, then this would be a
> > > powerful result. I have already shown (viz my Occam's Razor paper)
> > > that the Hilbert space stucture follows from Anthropic arguments on
> > > ensemble theories. Getting the space time structure is the next big
> > > task to be solved.
> > >
> > > Cheers
> > >
> >
>
> --------------------------------------------------------------------------
> > --
> > > A/Prof Russell Standish Director
> > > High Performance Computing Support Unit, Phone 9385 6967, 8308 3119
> > (mobile)
> > > UNSW SYDNEY 2052 Fax 9385 6965, 0425 253119
(")
> > > Australia R.Standish.domain.name.hidden
> > > Room 2075, Red Centre
> > http://parallel.hpc.unsw.edu.au/rks
> > > International prefix +612, Interstate prefix 02
> >
>
> --------------------------------------------------------------------------
>
>
>
Received on Sun Feb 22 2004 - 23:56:47 PST