R. (Rudolf) Clausius

Born in Köslin, Prussia, in 1822, Rudolf Clausius became one of the key scientists behind the modern science of thermodynamics. He studied in Berlin and went on to teach at several universities, including Zürich, Würzburg, and Bonn.

Clausius is best known for clarifying the laws of thermodynamics and for introducing the term entropy. By reworking earlier ideas about heat engines and energy, he helped turn the study of heat into a rigorous mathematical science.

His influence reached far beyond his own century: the principles he developed remain central to physics, chemistry, and engineering. Clausius died in 1888, but his name is still closely tied to some of the most important ideas in physical science.