Arnold Sommerfeld (Sommerfeld Arnold)

(1868-1951)
Born December 5, 1868 in KцІnigsberg (now Kaliningrad). He graduated from the University of KцІnigsberg (1891). In 1891-1897 he worked at the University of GцІttingen. Professor of Mathematics, Mining Academy in Clausthal (1897-1900), the Higher Technical School in Aachen (1900-1906), University of Munich (1906-1938).
The main focus of the Sommerfeld quantum theory of atomic spectroscopy, mathematical physics. In 1895, based on Maxwell's theory, he created a rigorous mathematical theory of diffraction, in 1909 solved the problem of radiation of a vertical dipole located on the border of two media. Improve the model Bohr atom, creating a quantum theory of elliptic orbits (1915-1916). He has introduced a radical and azimuthal quantum number, explained the fine structure of the spectra of hydrogen atoms, entering the fine structure constant (1916). Together with P. Debye construct a quantum theory of the Zeeman effect (1916) and introduced the magnetic quantum number. Gave the selection rules for the doublet and triplet spectra. Assuming that the free electrons in metals behave like a rarefied gas, obey the Fermi - Dirac explained the effects such as Joule heat, thermoelectric effect (1928).

Zommerfedl - author of several books on various branches of physics and monographs devoted to fundamental problems of physics. Many of his books have been translated into Russian. Among students Sommerfeld - Heisenberg, Pauli, P. Debye, H. Bethe, W. Heitler and many. Died Sommerfeld in Munich, April 26, 1951.