Thanks to all who pointed out that the Joule-Thompson gedanken is a case
in which the volume changes but no work is done, at least in the case
where one has a perfect vacuum on one side...I'm not so sure about the
real case where there is no perfect vacuum.
This is a good example of how our private vision informs our
communication...the issue behind many of my comments about what does or
does not happen in a classroom. I had been thinking entirely in terms of
a chamber with a movable piston, so that things stay in equilibrium.
cheers,
joe
Joseph J. Bellina, Jr. 574-284-4662
Associate Professor of Physics
Saint Mary's College
Notre Dame, IN 46556