RE: Reversible computing

From: David Barrett-Lennard <dbl.domain.name.hidden>
Date: Thu, 13 Nov 2003 11:09:10 +0800

I haven’t read much about invertible systems.

Curiously though, earlier this year I was working on a difficult problem
related to optimistic concurrency control in a distributed object
oriented database I’m developing, and found that I only solved it when
I decomposed it as an invertible problem into parts that were
invertible. The decomposition always involved invertible functions with
two inputs and two outputs. All state changes (to a local database) are
applied as invertible operations, and the problem is to transform
operations so they can be applied in different orders at different sites
and yet achieve convergence. I guess it’s unlikely that this has
relevance to physics.

- David


-----Original Message-----
From: Stephen Paul King [mailto:stephenk1.domain.name.hidden]
Sent: Thursday, 13 November 2003 10:14 AM
To: everything-list.domain.name.hidden
Subject: Re: Reversible computing

Dear David,
 
    Have you read any of the books by Michael C. Mackey on the
implications of reversible (invertible) and non-invertible systems?
Some, notably Oliver Penrose, have attacked his reasoning, but I find
his work to be both insightful and novel and that his detractors are
mostly driven by their own inabilities to take statistical dynamics and
thermodynamics forward.
 
    Mackey shows that invertible dynamical system will be at equilibrium
perpetually and that only non-invertible system will exhibit an "arrow
of time". I am very interested in the subject of reversible computation,
as it relates to my study of Hitoshi Kitada's theory of Time, and would
like to learn about what you have found about them.
 
Kindest regards,
 
Stephen
----- Original Message -----
From: David Barrett-Lennard
To: everything-list.domain.name.hidden
Sent: Wednesday, November 12, 2003 8:36 PM
Subject: Reversible computing

I have been wondering whether there is something significant in the fact
that our laws of physics are mostly time symmetric, and we have a law of
conservation of mass/energy. Does this suggest that our universe is
associated with a reversible (and information preserving) computation?

- David
Received on Wed Nov 12 2003 - 22:11:23 PST