Re: Time/Life/Science

["Tim Gwinn" <***>]

Hi Jeff,

The idea the 2nd law is a unique instance of irreversibility in physics is
closely tied to the reversibility inherent in the Newtonian formalism.
Within the confines of Newtonian-type physics, irreversible processes ought
not to exist since they cannot even be formulated within that formalism.
This makes the 2nd law seem to have a special status in physics.

However, as Rosen (and probably others, too) has shown, reversibility of
processes in physics is not generic. Generically, dynamics are not described
by fixed functions, but by networks of partial differential equations. [EL
ch. 11 & 22] In my view, the former will demonstrate path-independence
(reversibility), the latter will demonstrate path-dependence
(irreversibility).

My feeling is that this elevates all of physics to be generically
irreversible and removes any special status for the 2nd law. If so, the 2nd
law is but one of many examples of the "arrow of time". Further, the 2nd law
applies only to a small class of degenerate systems; namely,
thermodynamically closed systems. If the 2nd law had some fundamental
importance to time, then it would seem time would not exist for open
systems.

I wonder if Caratheodory's formulation of the 2nd law ("Arbitrarily near to
any given state there exist states which cannot be reached by means of
adiabatic processes") could also be taken as saying that "paths between
states are generically unique"? Which is what Rosen's generalized
formulation of dynamics seems to say.

Regards,
Tim


> -----Original Message-----
> From: ROSEN Forum [mailto:*** Behalf Of Jeff
> Pridaux
> Sent: Tuesday, October 07, 2003 2:09 PM
> To: ***
> Subject: Re: Time/Life/Science
>
>
> I view time as being related to the second law of thermodynamics.  This
> gives time a direction (a progression).  Time advances as entropy
> increases.  Since macroscopically, we live in an entropy-increasing world,
> time advances for us.
>
> By this logic, time wouldn't necessarily advance at the same rate
> everywhere... (assuming the increase of entropy isn't the same
> everywhere).
>
> Perhaps there exists conditions in certain parts of the world (probably
> only microscopically) where time runs the other way if entropy is
> decreasing...
>
> If only I could figure out what the next lottery drawing would be... ;)
>
> regards,
>
> Jeff