Don wrote:
>Classical Thermodynamics deals with equilibria. It has little bearing on far
>from equilibrium situations. This has been written about by hundreds of
>people. I have a book which deals with these issues "Application of Network
>Thermodynamics to Problems in Biomedical Engineering" NYU Press, 1993.
Don't
>be misled by the title. The essence of the ability of non-equilibrium
systems
>to create elaborate structure including life is in the coupling of precesses.
>The second law requires that the OVERALL entropy production be positive.
Thus
>negative terms in any set of coupled non-equilibrium processes' entropy
>production merely need be compensated by larger positive ones.
......
>This is thermodynamics which is true independent of mechanism.
>
This is my understanding of thermo as well, based on my now archaic physics
training, and I guess that it is still valid for most physicists, although
not without some troubling questions. For example, the theory invokes some
cosmic notions by saying that ultimately, universally (in time and space)
entropy must be decreasing, and that reversals are interventions in this
overall trend (like eddies in a stream). But the origins and end of the
universe are hotly debated. Is there not an inconsistency between this view
and the notion of a cyclical (closed) universe where ultimate collabpse
leads to another big-bang? If all events since the big bang (I assume, but
do not know for sure, that the Hawkingesque reconstructioin of events since
the big bang is consistent with thermodynamics) and leading up to the
predicted end of the universe result in an overall increase in entropy, how
does it again decrease for the next cycle? Where is the process that resets
it? I don't think it is fair to say that such questions are out of the
realm of the theory (or at least its foundations), because the theory
itself invokes a notion of cosmic order.
So, my question is: Is there a corresponding universal process (or
supervening theory such as thermo) that operates in the opposite direction
- i.e., to decrease entropy, and do we know which process (or trend) will
ultimately win out (recognizing that classical theormodynamics may be a
limited view built on the study of observable physical systems). I can't
help believing that "life" as a process is inadequately described, and that
somehow it represents such a process at its essence, certainly in the sense
of an intervening process, but I think the jury should still be out on
whether it may also be viewed as a supervening trend, which then connects
it to all the things we scientists find quite problematic to deal with for
fundamental epistemological reasons.
-----------------------------------------------
John J. Kineman, Physical Scientist/Ecologist
National Geophysical Data Center
325 Broadway E/GC1 (3100 Marine St. Rm: A-152)
Boulder, Colorado 80303 USA
(303) 497-6900 (phone)
(303) 497-6513 (fax)
jjk@ngdc.noaa.gov (email)
(303) 497-6513 (fax)