How analogy helped create the new science of thermodynamics

Sadi Carnot’s 1824 Reflections on the Motive Power of Fire created new science thermodynamics. It succeeded in its audacious goal finding a very general theory efficiency heat engines, by introducing and exploiting strange unexpected notion thermodynamically reversible process. The is internally contradictory. requires states these processes to be both unchanging equilibrium, with perfect balance driving forces, while also changing. work Sadi’s father, Lazare Carnot, ordinary machines provided template machines; characterization most efficient them as those that minimize differences forces can run reverse. Lazare’s could provide resources because choice dissipative ontology inelastic collisions among hard bodies. This historically ill-fated meant were analogous engines their key aspects: they are built from essentially processes. strategies for controlling dissipation optimizing his transferrable problems found engines. unanswerable historical question whether would have sought at all or theoretical devices without analogy prior Lazare.