Rudolf Clausius

Overview

Rudolf Clausius taught in Berlin, Zurich, Würzburg, and Bonn, and turned Carnot's engineering result into general physics. In 1850 he showed that Carnot's conclusion survives once heat is treated as a form of energy rather than a conserved fluid, which resolved the contradiction between Carnot's argument and the newly established conservation of energy. In 1865 he introduced the quantity he called entropy and stated the two laws in the compact form still quoted: the energy of the universe is constant, and its entropy tends to a maximum. He also did early work on the kinetic theory of gases, introducing the mean free path, which fed directly into Maxwell's and Boltzmann's statistical work. His papers are technical; most readers should approach him through an account of the second law rather than through the originals.

Where to start reading

• On the Moving Force of Heat 1850

  The paper that reconciled Carnot's efficiency limit with the conservation of energy, and set out what became the first and second laws of thermodynamics.

• The Mechanical Theory of Heat 1867

  A collected presentation of his thermodynamic papers, including the introduction of entropy as a measurable state quantity.

Part of

• Thermodynamics
• Statistical mechanics

Sources

1. Rudolf Clausius English Wikipedia
2. Rudolf Clausius Britannica
3. Second law of thermodynamics English Wikipedia