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Denker's Thermodynamics essay



John in one of his postings kindly provided a link to a monograph of his on
many of the thermodynamics questions that perennially plague this forum.

http://www.monmouth.com/~jsd/physics/thermo-laws.htm

I want to make a few comments on a few items in hopes that John will expand
on some of this thoughts and to initiate some discussion: not hard to do at
phys-L.

A lot of the document is a plea to eliminate the usual mathematical
representation of the 1st Law that is rather ubiquitously found in most
texts. Denker's equation 3.

(3) Delta E = W+Q

1) In the discussion John provides four bulleted items for the four possible
ways energy can leave system A and arrive at system B. I simply don't see
that the structure of this equation doesn't allow for the 3rd and 4th
possibilities; it strikes me that the structure either allows all four ways
or none.

E.g. 3 units of energy are transfered from system A in thermal form and
arrive at B in nonthermal form.

Then Delta E = +3 and W = 0 and Q =+3, the structure allowed it. I admit
the structure doesn't allow me to retain the information that the energy
arrived at B in non-thermal form; but the structure still allows the
situation and can be incorporated the equation.

2) In Section 3, I quote:

"It [entropy] depends not only on the state of the system, but also on how
much of a description I've been given."
This implies that entropy is not a state variable of a system (function of
state). Many people like to insist that it is a state variable. Comments?

3) From section 4,
". . .thermal energy is just a special type of kinetic energy."
This may be true of an ideal gas consisting of infinitesimally sized hard
spheres, but what of a gas consisting of vibrating mass dipoles? Do not
conventional discussions of thermal energy admit potential energy degrees of
freedom as well in the thermal energy count?

That's all for now.
Joel Rauber