Arnold Sommerfeld

Arnold Sommerfeld
Arnold Johannes Wilhelm Sommerfeld (1868–1951)
Born	Arnold Johannes Wilhelm Sommerfeld (1868-12-05)5 December 1868 Königsberg, Kingdom of Prussia
Died	26 April 1951(1951-04-26) (aged 82) Munich, West Germany
Residence	Germany
Nationality	German
Fields	Physics
Institutions	University of Göttingen Technische Universität Clausthal University of Aachen University of Munich
Alma mater	University of Königsberg
Doctoral advisor	Ferdinand von Lindemann
Doctoral students	Werner Heisenberg Wolfgang Pauli Peter Debye Paul Sophus Epstein Hans Bethe Ernst Guillemin Karl Bechert Paul Peter Ewald Herbert Fröhlich Erwin Fues Helmut Hönl Ludwig Hopf Walther Kossel Adolf Kratzer Alfred Landé Otto Laporte Wilhelm Lenz Rudolf Peierls Walter Rogowski Rudolf Seeliger Heinrich Welker Gregor Wentzel
Other notable students	Herbert Kroemer Linus Pauling Walter Heitler Werner Romberg
Known for	Drude–Sommerfeld model Fine-structure constant Sommerfeld identity Sommerfeld–Kossel displacement Sommerfeld–Wilson quantization Sommerfeld–Bohr theory
Influenced	John Bardeen Léon Brillouin Karl Herzfeld
Notable awards	Matteucci Medal (1924) Max-Planck Medal (1931) Lorentz Medal (1939) Oersted Medal (1949) Fellow of the Royal Society

Arnold Johannes Wilhelm Sommerfeld, ForMemRS (5 December 1868 – 26 April 1951) was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and mentored a large number of students for the new era of theoretical physics. He served as PhD supervisor for many Nobel Prize winners in physics and chemistry (only J. J. Thomson's record of mentorship is comparable to his).

He introduced the 2nd quantum number (azimuthal quantum number) and the 4th quantum number (spin quantum number). He also introduced the fine-structure constant and pioneered X-ray wave theory.

Sommerfeld studied mathematics and physical sciences at the Albertina University of his native city, Königsberg, East Prussia. His dissertation advisor was the mathematician Ferdinand von Lindemann, and he also benefited from classes with mathematicians Adolf Hurwitz and David Hilbert and physicist Emil Wiechert. His participation in the student fraternity Deutsche Burschenschaft resulted in a fencing scar on his face. He received his Ph.D. on October 24, 1891 (age 22).

After receiving his doctorate, Sommerfeld remained at Königsberg to work on his teaching diploma. He passed the national exam in 1892 and then began a year of military service, which was done with the reserve regiment in Königsberg. He completed his obligatory military service in September 1893, and for the next eight years continued voluntary eight-week military service. With his turned up moustache, his physical build, his Prussian bearing, and the fencing scar on his face, he gave the impression of being a colonel in the hussars.