Arnold Sommerfeld

Arnold Sommerfeld
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	Coining the term azimuthal quantum number (1915) Introducing the fine-structure constant (1916) Sommerfeld–Kossel displacement law (1919) Developing the free electron model (1927)
Spouse	Johanna Höpfner
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	Atomic physics Quantum physics
Institutions	University of Göttingen (1895–1897) Bergakademie Clausthal (1897–1900) RWTH Aachen (1900–1906) University of Munich (1906–1935)
Thesis	Die willkürlichen functionen in der mathematischen physik (The arbitrary functions in mathematical physics) (1891)
Doctoral advisor	Ferdinand von Lindemann
Other academic advisors	Felix Klein
Doctoral students	See list Peter Debye (1908) Ludwig Hopf (1909) Rudolf Seeliger (1910) Wilhelm Lenz (1911) Paul Peter Ewald (1912) Paul Sophus Epstein (1914) Alfred Landé (1914) Erwin Fues (1920) Adolf Kratzer (1920) Wolfgang Pauli (1921) Gregor Wentzel (1921) Werner Heisenberg (1923) Otto Laporte (1924) Karl Bechert (1925) Edward Condon (1926) Ernst Guillemin (1926) Helmut Hönl (1926) Ernst C. Stückelberg (1927) Hans Bethe (1928) Hermann Brück (1928) Herbert Fröhlich (1930) Werner Romberg (1933) Walter Franz (1934) Heinrich Welker (1936)
Other notable students	See list William Allis Carl Eckart Eugene Feenberg Walter Heitler William V. Houston Edwin C. Kemble Walther Kossel Max von Laue Karl Meissner Philip M. Morse Linus Pauling Rudolf Peierls Howard P. Robertson Walter Rogowski Wojciech Rubinowicz

Arnold Johannes Wilhelm Sommerfeld (German: [ˈaʁnɔlt joˈhanəs ˈvɪlhɛlm ˈzɔmɐˌfɛlt]; 5 December 1868 – 26 April 1951) was a German theoretical 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 advisor and postdoc advisor 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.