I saw the remarkably complete list of correspondents that Professor Hake sent to
Antti Savinainen. I am sorry that Savinainen perhaps had to spend his time on
some of them!
For simplicity, I'll invert the conventional email format -- with first, the
Solution/ Answer to his question re teaching entropy, then the Introduction, and
finally, a salute to the ‘Dauntless Dr. Denker’ :-).
Solution/ Answer/ Conclusion:
Some 450,000 US students in first year university chemistry texts have learned
about entropy as a measure of the dispersal, the spreading out in space, of
energy ...the transfer/spreading of heat (from a warm source) to a cold
substance… the spreading of some energy when substances react spontaneously ---
from such reactants to their surroundings. (Professor Leff in his January 2012
article in "The Physics Teacher" has begun a five-part summary of the comparable
approach for physics instructors that he developed and published in 1996. My
first publication attacking the absurdity of associating entropy with shuffled
cards and messy dorm rooms appeared in 1999 in the Journal of Chemical Education
for chemistry instructors.
Subsequent articles by me and others have convinced some 43 authors of 27
chemistry texts to delete any dependence of entropy on “disorder” and present it
as sketched above. (The list of articles and texts is in http://entropysite.oxy.edu).
Details on a collegiate level...only slightly above that of a US high school
(and perhaps lower than those in Finnish high schools).. are in
entropysite.oxy.edu. Their historical background -- including how Boltzmann
erroneously led to thinking that "disorder" was a key idea in entropy increase
-- is on-line as "The Conceptual Meaning of Thermodynamic Entropy in the 21st
Century" at http://www.sciencedomain.org/issue.php?iid=82&id=7 (Click on "Full
Article PDF") [Check reference 1 of that article for the actual statement by
Boltzmann re “disorder” that has rarely been cited in the literature of
thermodynamics.)]
Introduction
The traditional view of entropy as related to "disorder" is a sad error begun by
Boltzmann, but surprisingly accepted for a century. Its dismissal and a proper
modern/scientific view of entropy is not complex. [The details are in the
references above.]
Dauntless Doctor Denker
Dr. Denker has an excellent background (CalTech graduate) and publication record
in research in physics (Bell Laboratories) and more recently concerning networks
including neural networks up to some ten years ago. For the past several years,
his primary interest other than flying airplanes, appears to have been unusually
extensive communications on several physics and chemistry lists. His sole focus
in thermodynamics -- an online site containing ~135 printed pages (!) (including
those he sent you) is totally based on Shannon probability 'entropy'.
Unfortunately, this almost-a-small-textbook-productivity online has not resulted
in a single page of thermodynamics in a refereed scientific journal.
I would think he has tried, but perhaps the reason for rejection would be in
some way related to what I consider one of his most amusing statements in those
many thermodynamic pages:
“Entropy is not knowing. Entropy measures how much is not known about the
situation.”
That is hardly the interpretation that chemists use daily (and physicists
occasionally) -- when they check the standard molar entropy of graphite and find
it to be 7 J/K mol, or the std. molar entropy of water at 298 K to be 69.9 J/K
mol, or the heat dispersed to the surroundings in a spontaneous chemical
reaction!
What is so offensive about his writing is its authoritative tone despite his
lack of knowledge of the modern understanding of entropy in physics and
chemistry. He cites as my present position, articles of 45 years ago when the
only game in town was “entropy is disorder”. (He didn’t find my talk before a
large Los Angeles ACS meeting in that era – probably including two or more
CalTech professors – about thermodynamics and art, a case of disorder vs. order
-- at the end of which I received a standing ovation. A standing ovation after a
thermodynamics lecture?) Just as amusing as his “entropy is not knowing” is
his clinging to “disorder” as entropy in citing several cartoons to Phys-l, the
classic being the “Office of Entropy” with its door hanging from its hinges.
That was my first success in changing chemistry texts – after I chided the
authors of a popular text about the non-scientific relationship of that cartoon
to entropy in their 2000 edition, it was deleted from the 2003 revision.
Perhaps most distressing to Dr. Denker would be a visit with students in the
general chemistry class of 2011-2012 at his alma mater, the California Institute
of Technology. Their text is one that has followed my recommendations and
deleted references to “disorder”. Its first sentence about entropy is “Entropy
will be defined in terms of molecular motions in Section 8.2 and in terms of
macroscopic process variables in Section 8.3.” Disorder? Fgeddaboudit – so far
as thermodynamic entropy is concerned.