Re: Entropy question


Hi, Andy,


> > What have you got against the Blake theory?
> I am unfamiliar with the Blake theory- do you have a reference?


Blake, T. D. et al.,J. Colloid Interface Sci. 30, (1969) 421.
Blake, T. D. In Wettability; Berg, J. C., Ed.; Marcel Dekker: New York
(1993) Chapter 5, pp 251-309.
Blake, T. D et al., Langmuir 13 (1997) 2164.
Blake, T. D. et al., Phys. Fluids 11 (1999) 1995.
Sharpe M. R. et al., Langmuir 18 (2002) 3549.
Petrov, J. G.; et al., . Colloid Polym. Sci. 259 (1981) 753.
Schneemilch, M. et al., Langmuir 14 (1998) 7047.


> The
> only work I have seen is by E.B. Dussan V. and her collaborators. In
> Slattery's book "Interfacial Transport Phenomena", he clearly and
> plainly states that no complete solutions exist for moving and deforming
> phase interfaces (p. 923).


I am unfamiliar with E.B. Dussan V. I see she did some work thirty
years ago. My contact with the field is more recent.


> Ok, let me back up. Maybe I misunderstand what you mean by 'mechanics'.


I think we're probably just arguing over definitions of words. However
I still think that statistical mechanics is contained within mechanics
as an approximation valid under situations which may be called
'thermodynamic equilibrium', just as Newtonian mechanics is contained
within QM as an approximation valid under situations where h may be
approximated by zero.


> I may be able to write down a potential energy U which has
> contributions from gravity, electromagnetism, chemical potentials,
> enthalpy, etc. etc., and from that write down a force [-grad(U)], but
> this 'force' is qualitatively different from a Newtonian 'force': at
> what spacetime point does the force resulting from an unbalanced
> chemical reaction act?.


Statistical mechanics is consistent with the microscopic picture, but
only predicts probability distributions, rather than detailed
space-time histories of particles.


> So we say we are dealing with "generalized"
> forces: it looks like a force, but it isn't a *force*.... maybe it acts
> in some abstract phase space or something. That's fine and ok, but it's
> no longer properly mechanics.


It's an approximation method.


> I wonder if we are getting off track here: my thesis is that
> "statistical mechanics" contains concepts not derivable from mechanics-
> concepts that cannot be considered as an approximation to the dynamics
> of mass-points. Or of the deformation of continous media. Or of quantum
> fields. Also, I'm not claiming that statistical mechanics is in some
> way more fundamental than mechanics.


OK, I think we will have to agree to disagree. I don't think we are
disagreeing about the facts, just about ways of looking at the facts.
Vive la différence!

Cheers,

Zigoteau.

.