Rudolf Clausius

Rudolf Julius Emanuel Clausius was born in Prussia on 2 January 1822, trained as a physicist and mathematician, and spent his career rewriting the theory of heat from principle up. In 1850 he published "On the Moving Force of Heat," which first articulated the basic ideas of what became the second law of thermodynamics, rescuing and refining Sadi Carnot's earlier work on the Carnot cycle. Fifteen years later, in 1865, he coined the term entropy to describe the measure of disorder that can never decrease in a closed system. In 1870 he introduced the virial theorem, extending his methods to the behavior of heat in dynamic systems. He died on 24 August 1888, having laid the conceptual foundation for much of modern physics.