Nernst, Walther Hermann

Born June 25, 1864, in Briesen, (present-day Wąbrźezno, Poland); died Nov. 18, 1941, in Ober Zibelle, near Muskau (now in the German Democratic Republic). German physicist and physical chemist; one of the founders of modern physical chemistry.

From 1883 to 1887, Nernst studied at the universities at Zürich, Berlin, Graz, and Würzburg; he specialized in physics under L. Boltzmann and F. Kohlrausch. Under the influence of S. Arrhenius, he decided to devote himself to physical chemistry, and in 1887 he became an assistant to W. Ostwald at the University of Leipzig. He became a privatdocent in 1890 and a professor at the University of Gottingen in 1891, where he founded the Physicochemical Institute in 1896. At the University of Berlin, Nernst was a professor from 1902 to 1933, as well as director of the Institute of Chemistry from 1905 to 1922 and director of the Institute for Experimental Physics from 1924 to 1933.

In his diploma thesis, based on research performed in the laboratory of A. von Ettingshausen, Nernst described an effect that he discovered—the generation of a potential difference in a metallic plate located in a magnetic field when heat flows through the plate (the Nernst-Ettingshausen effect). In 1888–89 he established the relation between the mobility of ions and the diffusion coefficient of electrolytes; this relation became the basis of his theory of electromotive forces in galvanic cells. The Nernst distribution law was discovered in 1890. In 1894, Nernst demonstrated that the dissociative ability of a solvent increases with increasing dielectric constant of the solvent and discovered the phenomenon of electrostriction. While studying thermal processes at low temperatures, he arrived in 1906 at the formulation of a principle (called the Nernst heat theorem) according to which the change in entropy of a body approaches zero as the body’s temperature approaches zero. This principle does not follow from either the first or the second law of thermodynamics and it is frequently called the third law of thermodynamics. After studying the equilibrium N₂ + O₂ ' 2NO, Nernst gave a physicochemical basis for the industrial production of nitric acid starting from atmospheric nitrogen; between 1905 and 1907 he synthesized ammonia from nitrogen and hydrogen at high temperature and high pressure using manganese as a catalyst. Subsequent work in this area by F. Haber led to the industrial synthesis of ammonia. In 1918, Nernst used concepts of chain reactions to explain the mechanism of the chemical reaction between chlorine and hydrogen.

Nernst was the author of a textbook on theoretical chemistry, which went through 15 editions and was translated into Russian and other languages. It served as a model for courses in physical chemistry that were taught during the late 19th century and the early 20th. Nernst also published several papers on general problems of cosmology and the physical description of the universe.

Nernst was a member of many academies of sciences; he was an honorary member of the Academy of Sciences of the USSR (1927). He received a Nobel Prize in 1920.