Ludwig Boltzmann

Ludwig Boltzmann , 1844-1906, Austrian physicist, b. Vienna, educated at Univ. of Vienna. He began teaching (1869) at Graz Univ. In 1873 he became mathematics professor at Vienna and then physics professor at Graz (1876), Munich (1890), Vienna (1895), and Leipzig (1900). Boltzmann made important contributions to the kinetic theory of gases and to statistical mechanics—the Boltzmann constant, which relates the mean total energy of a molecule to its absolute temperature, is used widely in statistics and is named for him. Working independently, he demonstrated a law on black body radiation that had been stated by the Austrian physicist Josef Stefan; hence the law is sometimes known as the Stefan-Boltzmann law.

Boltzmann, Ludwig (1844–1906) Austrian physicist, acclaimed for his contribution to statistical mechanics and to the kinetic theory of gases. His research extended the ideas of James Maxwell. Boltzmann's general law asserts that a system will approach a state of thermodynamic equilibrium because that is the most probable state. He introduced the ‘Boltzmann equation’ (1877) relating the kinetic energy of a gas atom or molecule to temperature. Symbol K in the formula, the gas constant per molecule, is called the ‘Boltzmann constant’. In 1884 he derived a law, often termed the ‘Stefan-Boltzmann law’, for black body radiation discovered by his teacher, Josef Stefan (1835–93). Attacked for his belief in the atomic theory of matter, Boltzmann committed suicide.