**Lancelot Fletcher** (*lance.fletcher@freelance-academy.org*)

*Wed, 29 Sep 1999 02:09:40 -0500*

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Stephen,

*> -----Original Message-----
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*> From: owner-time@kitada.com [mailto:owner-time@kitada.com]On Behalf Of
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*> Stephen Paul King
*

*> Sent: Tuesday, September 28, 1999 9:28 PM
*

*> To: time@kitada.com
*

*> Subject: [time 830] Re: Does a fundamental time exist in GR and QM? The
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*> thinking of others...
*

I was a little puzzled about why you re-posted that message by John Baez

which was originally posted on Aug. 12 on the sci.physics.research

newsgroup as message 112 in a thread containing 119 messages. Out of

curiosity I tracked down the first message in that thread, from Paul

Stewart Snyder on Aug. 6, and I have copied it below. It seems to me that

some of this, especially the second paragraph, resembles Hitoshi's approach

in ways that might be worth exploring.

Lance

===================================

From: "Paul Stewart Snyder" <ps@ws5.com>

Subject: Does a fundamental time exist in GR and QM?

Date: 06 Aug 1999 00:00:00 GMT

Message-ID: <rqe8crihq1tcq6@corp.supernews.com>

Approved: mmcirvin@world.std.com (sci.physics.research)

Sender: mmcirvin@world.std.com (Matthew J McIrvin)

Organization: Posted via Supernews, http://www.supernews.com

Newsgroups: sci.physics.research

I have tried to digest the basic information in the recent threads about

spacetime in GR. To me the most interesting ideas follow from what Carlo

Rovelli suggested in 1991 (Physical Review D43, 442), that in GR time

should

be treated as a derived and not a fundamental quantity. In extending this

to

the quantum world, he argues that "in the absence of a fundamental time and

of an exact Schrodinger equation, there are gauge invariant observables,

that commute with the hamiltonian constraint, which describe evolution with

respect to physical clocks. The observables are self-adjoint operators on

the space of the solutions of the Wheeler-DeWitt equation.. Evolution with

respect to physical clocks is described by self-adjoint operators

corresponding to the observables.. This extension is well-defined both in

terms of the coherence of the formalism, and from the point of view of the

viability of the standard probabilistic interpretation."

It seems to me that rethinking the answers to the questions about what is

"here and now" and what is "casuality", in terms of spatial contiguity in

an

atemporal universe, might resolve some of the apparent paradoxes of GR/QM?

Indeed, the idea of hamiltonian mechanics in a presymplectic space seems

"elegant" and, if this actually models nature, might provide a useful way

of

viewing phenomena that seem to lack temporal constraints. Are there any

clear objections or impediments in pursuing this approach?

**Next message:**Ben Goertzel: "[time 834] RE: [time 832] RE: [time 825] Chu spaces, causality, local systems... quantum laws of form? ..."**Previous message:**Lancelot Fletcher: "[time 832] RE: [time 825] Chu spaces, causality, local systems... quantum laws of form? ..."**In reply to:**Ben Goertzel: "[time 825] Chu spaces, causality, local systems... quantum laws of form? ..."

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