posted 20. November 2002 11:32                   

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I do not find the distinction between near-equilibrium and far-equilibrium to be useful. For instance, how far is far? And also equilibrium is a relative state, depending on what system and what aspects of it we are looking at (if you include nuclear processes, entropy is maximised by fusion/fission to iron, and most systems are a long way from this equilibrium).
SLOT is universal, both near-equilibrium and far-equilibrium systems are affected by it. Look at this paper, which comments on Prigogine's work (and others too), especially p32-33.

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One has to be careful using terms like equilibrium when discussing thermodynamic equilibrium or quasi-equilibrium. These assumptions are often made to simplify the calculations of processes which are for all practical purposes in equilibrium.
As Prigogine and others have argued far equilibrium thermodynamics.

Equilibrium thermodynamics is what we learn in school, PV=nRT
Non equilibrium theromodynamics looks at processes which maintain themselves against a gradient. Life processes are infamous for instance. And while equilibrium processes can be quite 'boring', far equilibrium processes can be far more exciting. In the end of course all use the same basic laws of physics but the various approximations used lead to very different behaviors

Of course equilibium processes are not truely equilibrium or nothing too interesting would happen. But often one can approximate their path through time as being in (quaisi) equilibrium, that it they change 'slowly enough' that they can be approximated and modeled by equilibrium thermodynamics.
The Carnot cycle is a classical example of equilibrium thermodynamics and indeed is somewhat idealized.

posted 22. November 2002 10:11                   

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One has to be careful using terms like equilibrium when discussing thermodynamic equilibrium or quasi-equilibrium. These assumptions are often made to simplify the calculations of processes which are for all practical purposes in equilibrium.
As Prigogine and others have argued far equilibrium thermodynamics.

Equilibrium thermodynamics is what we learn in school, PV=nRT
Non equilibrium theromodynamics looks at processes which maintain themselves against a gradient. Life processes are infamous for instance. And while equilibrium processes can be quite 'boring', far equilibrium processes can be far more exciting. In the end of course all use the same basic laws of physics but the various approximations used lead to very different behaviors

Of course equilibium processes are not truely equilibrium or nothing too interesting would happen. But often one can approximate their path through time as being in (quaisi) equilibrium, that it they change 'slowly enough' that they can be approximated and modeled by equilibrium thermodynamics.
The Carnot cycle is a classical example of equilibrium thermodynamics and indeed is somewhat idealized.

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Prigogine's work reconciled the Second Law with the obvious facts of life. He realized that in certain systems - self-catalytic chemical reactions, for example - perturbations that get far enough away from thermal equilibrium will no longer subside but will continue to grow. Such a system eventually can reach a new, stable configuration far from equilibrium; it will then maintain itself against thermal disruption by a continuous throughput of matter and energy, which carry off internally generated entropy to the outside.

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they change 'slowly enough' that they can be approximated and modeled by equilibrium thermodynamics

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posted 25. November 2002 07:34                   

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If one thinks ONLY in the CLASSICAL PHYSICS sense then there really is NO LAW here since entropy increase is NOT an exceptionless principle and the H-Theorem is a dead horse/redundant (the probabilities work both ways and an asymmetry is assumed or snuck in to get the effect).

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Boltzmann realized this in his later more mature thinking as he addressed critics like Culverwell and the "reversibility-objection," moving him and others to mature statistical mechanics.

Entropy increase is existential not universal and is due to a low entopy past (boundary condition) since there is no asymmetry in the underlying physical laws. To make it universal, or law-like, or exceptionless requires an asymmetric law.

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The question then arises if an additional anomaly is needed since the phenomena can be accounted for by the ONE HUGE ANOMALY that we already have, which was discovered in the latter half of the 20th century. One reason would be that we just want it exceptionless because of psychological need, another would be that we really had independent evidence for an asymmetric law in physics.

Classically there is none but in the Quantum domain the "measurement problem" or "projection postulate" may provide one. MAYBE?

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posted 27. November 2002 07:35                   

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The explanation and justification ...our section of the universe.

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But this means that things could have been different and can become different in the evolution of the universe. Even though the probabilities are hugh for entopy increase, there is no asymmetric physical principle that we accept as a law that underlies this and would make it exceptionless, all the explanatory work is done based on a boundary condition.

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Now for the BIG ANOMALY...the discovery of the required initial condition. It's that the matter in the universe is distributed extremely evenly, immediately after the Big Bang. This is the puzzling hugh source of low entropy for the evolving universe. In a system dominated by a universal attractive force, a uniform distribution of matter is highly unstable. The thing you would expect it to do is clump together. With no objective reason for a difference, the Big Bang can also be regarded as the end point of gravitational collapse and for such a collapse to produce a very smooth distribution of matter is very surprising.

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