lew@ihuxr.UUCP (Lew Mammel, Jr.) (04/20/84)
I think Troy Shinbrot's comments on thermoSTATICS were misleading. He seemed to imply that thermodynamics is incapable of dealing with cycles involving irreversible processes. This is not true. Thermodynamic variables such as temperature and entropy are "state variables". This means that they are defined for a system in equilibrium, no matter how it got there. One often calculates the change in (say) entropy by integrating along a reversible path between two states. The calculated result is valid no matter what the path of transition was, and even if the transition was irreversible. Sometimes, irreversible transitions are indicated on state diagrams by fuzzy paths. Incidentally, I believe the term "thermodynamics" derives from its dealing with thermal and mechanical (dynamical) processes in a unified way. It does not indicate that its subject is "the dynamics of heat". Lew Mammel, Jr. ihnp4!ihuxr!lew