Re: [Phys-L] thermodynamics of open systems

["Bob Sciamanda" <treborsci@verizon.net>]

IMHO the point of Carl's paper was that associating dS with only Q/T does 
not account for the additional change in S that can result from an increment 
in mole number.

-----Original Message----- 
From: John Denker
Sent: Tuesday, July 17, 2012 5:26 PM
To: Phys-L@Phys-L.org
Subject: Re: [Phys-L] thermodynamics of open systems

On 07/17/2012 01:51 PM, Bob Sciamanda wrote:
> But John, the whole point of Carl's paper is that TdS is NOT ALWAYS equal 
> to Q (or dQ).

I'll let Carl speak for himself ... but if that was the point, it
would have sufficed to write a far shorter and simpler paper.

On 07/15/2012 02:37 PM, Carl Mungan wrote:> (Try hard not to get hung up on
> > terminology, unless that *really* impedes understanding in your opinion.)

Maybe we are (despite our best efforts) getting hung up on terminology.

AFAICT when people write "dQ" there are only two things it could mean:
 a) dQ = the derivative of Q
 b) dQ = abusive shorthand for T dS

If there are additional possibilities, I have no idea what meaning was
intended.

In case (a), please explain why you think Q exists (except in trivial
cases).

In case (b), please explain why it would not be better in every way
to write T dS instead of dQ.

If there are other possibilities, I have no clue what they might be, so
please explain.
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Bob Sciamanda
Physics, Edinboro Univ of PA (Em)
treborsci@verizon.net
http://mysite.verizon.net/res12merh/