Re: entropy - motivation for definition

[Bob LaMontagne <rlamont@POSTOFFICE.PROVIDENCE.EDU>]

A minor protest here!
Teaching thermodynamics to engineers (vs. physicists)
solely by using statistical mechanics may be an interesting
exercise, but I'm not sure it helps them understand the
thermodynamics of ductwork. If you're teaching a service
course to engineers or chemists you have to respect the
needs of your audience.

Bob at PC

*********** REPLY SEPARATOR  ***********

On 4/5/2004 at 11:11 AM Edmiston, Mike wrote:

> I don't disagree with what John Denker has said.  But I
also think we
> have to realize how entrenched classical thermodynamics
is/was in
> chemistry academia.  There are still chemists teaching
classical
> thermodynamics (delta-S =3D Q/T).  I teach physcial
chemistry at Bluf=
> fton
> College and I did not stop teaching it that way until
about 1990.  Wh=
> y,
> because we knew that standardized tests such as the GRE
were going to
> expect chemistry graduates to know the old approach.
>
> The physicists were much quicker to move toward the
statistical
> thermodynamics approach than the chemists.  I had the
unpleasant
> situation of trying to teach statistical thermodynamics to
physics
> students and teaching classical thermodynamics to
chemistry students.
> Finally, about 1990, I merged the two courses into one
course and
> abandoned the classical approach altogether.  For a while
this meant =
> I
> could not use a physical chemistry text and had to use a
thermal phys=
> ics
> text.  This made the chemists angry.  Recently I have been
using the
> text Thermal Physics by Daniel Schroeder because he
includes more
> chemistry than most thermal physics authors.
>
> Also, while Denker is correct that we should define
temperature in te=
> rms
> of entropy, we need to remember that classical
thermodynamicist reall=
> y
> did do it the other way.  The early guys all "knew" what
temperature
> was, but did not know statistical thermodynamics.
Therefore, when
> trying to make sense out of why something happened the way
it did, th=
> ey
> eventually came up with this Q/T idea that worked.  Once
that became
> established it might be that the "if it works, don't' fix
it" attitud=
> e
> became pretty strong.
>
> Whatever the reason, the idea that delta-S is Q/T is still
way more
> prevalent in chemistry than it should be.
>
> Michael D. Edmiston, Ph.D.
> Professor of Chemistry and Physics
> Bluffton College
> Bluffton, OH 45817
> (419)-358-3270
> edmiston@bluffton.edu