The Boltzmann definition of entropy is S = klnW, where k= Boltzmann's const and W is the number of degrees of freedom of the system. More degrees of freedom equals more disorder.Originally posted by Zero
I don't think this is technically true, is it? My understanding was that entropy has to do with heat and efficiency, not with order specifically.
Entropy itself has nothing to do with heat and efficiency. But since the entropy change during a thermodynamic process, must increase or stay the same (2nd law of thermo), there is the familiar consequences that engine efficiencies must be < 1, heat flows from hotter to colder objects, etc.