Dear Troels,

You deserve a professional answer and I apologize for the delay.

I am unfortunately more busy than I would like running our department
(which means mostly protecting its superb faculty from the stupidity of
senior management) and surviving the weather (which just makes everything
simple hard).

The trip to Purdue was also extraordinary because some of the finest workers
in computational electronics are there (Klimeck and Lundstrom) and that community
of (THOUSANDS of scientists) is the only one I know of that follows the overwhelming
imperative THOU SHALT NEVER VIOLATE MAXWELL'S EQUATIONS AND BOUNDARY
CONDITIONS (i.e., for us Poisson equation and boundary conditions). 

Purdue also has superb chemists (Dor Amotz) who know about the nonideality of ionic
solutions better than I (although they have not said that fact loudly enough), and wonderful
mathematicians who can implement the variational approach I advocate without much trouble.

So you can see why I spent so much energy with them.

Now to your quite correct (in my opinion) interest in the NONIDEAL aspects of pH.

I think this problem should actually be addressed and not just discussed between you
and me.

I urge you to contact the leaders at the Tech Univer of Denmark and MAKE them 
understand the clinical significance of understanding pH and getting it right.

They will (if my past experience is right) be THRILLED to know that (what for them
is a rather dry and somewhat boring part of physical chemistry) is CENTRAL to
medicine and biology, which it is, as I do not have to tell you.

They (the chemical engineers) will provide the expertise WITH COMPLEX IONIC SOLUTIONS
and data describing them that you and I would struggle to ever learn.

They and you should be able to raise money for a 1 week meeting, or a visit by me first
to help organize such a meeting, in which

a) the clinical significance of pH is explained (with enough repetition and pictures of
dead patients preferably cute children and infants that it can never be forgotten)

b) the BIOLOGICAL significance of pH is explained (e.g., 'every' enzyme property
depends on pH, usually quite sensitively), pH of brain is EXQUISITELY regulated etc etc

c) the chemical significance of pH (NOT its meaning, rather its significance in experiment)

d) the OPERATIONAL definition of pH (i.e., what you measure, NOT what you think you
measure)

e) existing theory (which in my opinion is entirely inadequate since it cannot deal in a calibrated way with the properties of mixtures of ions in which pH and biology always occur)

f) the variational approach to ionic solutions and chemical reactions

This will motivate and set the stage for people to use the variational approach or something
equivalent (NO I am not crazy, the variational approach is not the only valid approach. But any
valid approach must be consistent, that is to say, all the variables in the equations must satisfy
all field equations (partial differential equations usually) and boundary conditions.


I fear that without something like this, you and I will not get far enough to make a significant
difference.

As ever
Bob