French physicist, who first worked as a military engineer. He then turned to scientific research and in 1824 published his analysis of the efficiency of heat engines. The key to this analysis is the thermodynamic carnot cycle and the eventual introduction of the idea of entropy in thermodynamics.

Technically, he is the world's first thermodynamicist and often called the "Father of thermodynamics", being responsible for such concepts as Carnot efficiency, Carnot theorem, Carnot heat engine and others.