Re: Why does electrostatic attraction in water decrease?

[Bob Sciamanda <trebor@VELOCITY.NET>]

I quit.

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor
----- Original Message -----
From: "Pentcho Valev" <pvalev@BAS.BG>
To: <PHYS-L@lists.nau.edu>
Sent: Friday, April 26, 2002 1:15 PM
Subject: Re: Why does electrostatic attraction in water decrease?


"Thermalizing" involves the action of a non-conservative force. For
instance, consider a (non-charged) gas between two oppositely charged
pistons. As the pistons move towards each other, their Coulombic energy is
"thermalized" and, isothermally, some heat is released, but also WORK is
done against the gas pressure. This work should be added to the Coulombic
work in a correct analysis.

Pentcho

Bob Sciamanda wrote:

> What do you mean by "no heating must occur"?  Surely, some Coulombic
> energy introduced simply by applying an E field could then become
> "thermalized" and effect a temperature change - would your "no heating
> must occur" exclude this possibility?
>
> Bob Sciamanda (W3NLV)
> Physics, Edinboro Univ of PA (em)
> trebor@velocity.net
> http://www.velocity.net/~trebor
> ----- Original Message -----
> From: "Pentcho Valev" <pvalev@BAS.BG>
> To: <PHYS-L@lists.nau.edu>
> Sent: Friday, April 26, 2002 12:53 PM
> Subject: Re: Why does electrostatic attraction in water decrease?
>
> Bob Sciamanda wrote:
>
> > Panofsky is here adding the caveat that he has calculated the
> > electrostatic energy changes on the assumption that the dielectric
> > constant k is fixed in time. Since k may be a function of temerature,
> and
> > applying the E field may heat the material,
>
> Just a remark (I have to think more). If only conservative (Coulomb)
> forces
> are involved, as Panofsky stresses, no heating must occur. In my view,
> heating
> can only result from the action of a non-conservative force akin to gas
> pressure. Some prefer to call such forces "entropic".
>
> Pentcho