Re: [Phys-L] work versus mechanical transfer of energy

[John Denker <jsd@av8n.com>]

On 01/06/2016 07:05 PM, Diego Saravia wrote:

> So you have a total system with two temperatures.
>
> This is not in equilibrium, that was one of mi conditions.

Well, if you exclude the possibility of subsystems with
different temperatures, then you're not talking about
thermodynamics.  I don't know what to call it, maybe
thermostatics or something.

Every discussion of thermodynamics since (and including)
Carnot has dealt with multiple subsystems, each with its
own temperature.  Loosely speaking, one requirement is 
that each subsystem /unto itself/ should be sufficiently
well-behaved that we can assign a temperature to it.
(Hence the weakness of the couplings in the experiments
I suggested earlier.)  If you require all the subsystems
to be permanently in equilibrium with each other, you 
have thrown out the baby and kept only the bathwater.