Color enhanced portrait of Rudolf Julius Emanuel Clausius (1822-1888) a German mathematical physicist who, through his study of the mechanical theory of heat, made thermodynamics a science. His most important paper, "Uber die bewegende Kraft der Warme" ("On the Moving Force of Heat and the Laws of Heat which may be Deduced Therefrom"), was published in 1850 and first stated the basic ideas of the second law of thermodynamics, which notes the tendency towards disorder within closed systems as potential energy is dispersed.