Arnold Sommerfeld

Arnold Sommerfeld ForMemRS
Sommerfeld, 1920s
Born	Arnold Johannes Wilhelm Sommerfeld (1868-12-05)5 December 1868 Königsberg, Province of Prussia, Kingdom of Prussia, North German Confederation
Died	26 April 1951(1951-04-26) (aged 82) Munich, Bavaria, West Germany
Alma mater	University of Königsberg (PhD, 1891) University of Göttingen (Dr. habil., 1895)
Known for	Introducing the fine-structure constant (1916) Proposing the free electron model (1928)
Awards	Matteucci Medal (1924) ForMemRS (1926)[1] Max Planck Medal (1931) James Scott Prize Lectureship (1933) Lorentz Medal (1939) Oersted Medal (1949)
Scientific career
Fields	Physics Atomic physics Quantum mechanics
Institutions	University of Göttingen (1895–1897) Clausthal University of Technology (1897–1900) University of Aachen (1900–1906) University of Munich (1906–1935)
Thesis	The arbitrary functions in mathematical physics  (1891)
Doctoral advisor	Ferdinand von Lindemann
Doctoral students	See list Karl Bechert Hans Bethe Hermann Brück Peter Debye Paul Sophus Epstein Paul Peter Ewald Eugene Feenberg Walter Franz Herbert Fröhlich Erwin Fues Ernst Guillemin Werner Heisenberg Karl Herzfeld Helmut Hönl Ludwig Hopf Walther Kossel Adolf Kratzer Alfred Landé Otto Laporte Wilhelm Lenz Karl Meissner Wolfgang Pauli Rudolf Peierls Walter Rogowski Rudolf Seeliger Ernst C. Stückelberg Heinrich Welker Gregor Wentzel
Other notable students	See list Herbert Kroemer Linus Pauling Isidor I. Rabi Walter Heitler Werner Romberg Max von Laue William Allis Carl Eckart Edwin C. Kemble William V. Houston Edward Condon Philip M. Morse Howard Robertson Wojciech Rubinowicz

Arnold Johannes Wilhelm Sommerfeld (German: [ˈaʁnɔlt ˈzɔmɐˌfɛlt]; 5 December 1868 – 26 April 1951) was a German physicist who pioneered developments in atomic and quantum physics, and also educated and mentored many students for the new era of theoretical physics. He served as doctoral supervisor and postdoc supervisor to seven Nobel Prize winners and supervised at least 30 other famous physicists and chemists. Only J. J. Thomson's record of mentorship offers a comparable list of high-achieving students.

He introduced the second quantum number, azimuthal quantum number, and the third quantum number, magnetic quantum number.^[2] He also introduced the fine-structure constant and pioneered X-ray wave theory.