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[POSSIBLE SPAM] Re: How to avoid mis-interpreting
the sec
Folks -- More seriously, we might consider how a valid
thermodynamic system is discovered / constructed. We 'define'
such a system as the smallest grouping of processes which gives us
between them a positive entropy production, dS >0. Thus, all
nonequilibrium systems are of this kind. With the newer 'maximum
entropy production principle', we can sometimes go further and refine
the system to that combination which maximizes its entropy
production.
STAN
This is a fractional
copy, please see my remark after the cut
John M
----- Original Message -----
From: Sungchul Ji
To: complex-science@necsi.org
Sent: Wednesday, August 06, 2008 12:02
AM
Subject: Re: How to avoid mis-interpreting the
second law of thermodynamics
Thermodynamic systems divide into three classes, depending
on whether the
system is exchanging energy and/or matter with its environment:
Table 1. Three classes of thermodynamic systems
_____________________________________________________________________
Thermodynamic Systems
______________________________________________________
Exchange
Isolated
Closed Open
_____________________________________________________________________
Energy
No
Yes Yes
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
Matter
No
No Yes
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
Example
Adiabatic
Refrigerator Biosphere
systems
Thermometer Cells
Universe* Heating
pad Animals
Engines
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-
Alternative Microcanonical
Canonical Grand
canonical
names
ensembles
ensemble
ensemble
______________________________________________________________________
*The Universe by definition doesn't even have any boundary and
hence
cannot exchange any matter or energy with it.
It is important to note that many physicists and other scientists do
not
differentiate between "closed" and "isolated"
thermodynamic systems. When
they say "closed" system, they usually mean "isolated
systems".
Hope this table helps.
Sung
/discuss/discuss.html
===========================
JM:
Isolated (closed?) is a figment, if it is indeed cut off,
we do not know about it at all. When we know about it, it has got to
have connections (we got) so we may miss 'the rest'.
(My mock-definition of the (then) isotherm and reversible
classic thermodynamics (Carnot - Clausius etc.) as a senior
chemist-student: "it is the system showing how things would
proceed if they would not proceed as they do
proceed."
We just don't know about the 'universe': we have a figment
based on many millennia of mis-observation and their mis-explanations
as our epistemy got gradually enriched.
Matter: going down the scale we find empty space and some
'effects' - no matter in matter.
Energy? a good name, assigned what it 'does' and how
to 'measure' it (what?).
They may be "equivalent"<G> figments of
our conventional sciences.
Sorry for being
facetious
John M
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