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Re: [Phys-l] T dS versus dQ

But I'll leave it as a question to the group: Is
there anything you can do with "dQ" that you can't
do just as well (or better!) with T dS?

For a reversible process, I hope everyone would agree the answer is no.

But for an irreversible process, I think there can still be questions. Bob's example of paint stirring for instance:

We know the energy and the entropy and the temperature.

I agree we know the energy from Fdx. But it seems to me that the entropy and temperature are time dependent, as the stirred paint thermalizes from bulk rotation to mesoscopic turbulence to microscopic KE.

I know we've been over this before and you have addressed it in your own writing. But I think part of the rationale for heat/work divisions is simply an attempt to categorize how the energy is initially input (as opposed to how it eventually becomes distributed over the internal modes). It might be a weak rationale but there it is. -Carl
Carl E Mungan, Assoc Prof of Physics 410-293-6680 (O) -3729 (F)
Naval Academy Stop 9c, 572C Holloway Rd, Annapolis MD 21402-1363