Arnold Sommerfeld

Arnold Johannes Wilhelm Sommerfeld ( born December 5, 1868 in Königsberg, East Prussia, † April 26, 1951 in Munich) was a German mathematician and theoretical physicist.

Life

Sommerfeld, son of a scientifically interested general practitioner, after graduating from high school in 1886 Altstädtischer began studying mathematics at the Albertina in Königsberg, one of the first universities to which the Theoretical Physics was set up as a separate subject. Among his academic teachers were so important scholars such as David Hilbert, Ferdinand von Lindemann and Adolf Hurwitz. During his studies, he played as a member of the fraternity Germania Königsberg ( Entry: 1887) numerous duels. From one of these sword fights he wore them a distinctive scar on his forehead. He received his Ph.D. in Königsberg 1891 The arbitrary functions in mathematical physics. In its early days Sommerfeld was decisively influenced by Emil Wiechert. Later there was a good friendship between Sommerfeld and Wiechert. The early correspondence between Sommerfeld and Wiechert was by Wilfried Schröder (Arch. Hist. Ex. Sci, 1984) published.

1893 Sommerfeld went after military service to the University of Göttingen, then the center of mathematical science in Germany. He was there first assistant at the mineralogical institute, but his main interest remained mathematics and mathematical physics. In 1894 he became assistant to the mathematician Felix Klein, who became his scientific model. He wrote under him in 1895 his habilitation thesis Mathematical Theory of Diffraction and initially was then a lecturer of Mathematics. With Klein, he also wrote a book about the theory of the gyroscope and was commissioned by this to write different sections on physics in the Encyclopedia of Mathematical Sciences.

Sommerfeld married in 1897 Johanna Hopfner ( 1874-1955 ), the daughter of the literary historian and curator Ernst Hoepfner ( 1836-1915 ). He was appointed to a full professorship of mathematics at the Mining Academy, 1900 saw the Department of Engineering Mechanics at the RWTH Aachen. In 1906 he was then a professor of theoretical physics at the Ludwig- Maximilians- University of Munich, where he built a major center for theoretical physics. Here he spent, although he received offers to other prestigious professorships, the rest of his career, interrupted by a visiting professor in the United States ( University of Wisconsin, 1922/23 ) and through a journey as an academic teacher that took him to Asia (India, China, Japan), and led to the United States (1928 /29).. , 1935, he was given emeritus status, but was still teaching until 1940 cause of this long transition was the question of succession: Sommerfeld favored Werner Heisenberg as his successor, but met with opposition by representatives of the "German physics " that ultimately her - according to Sommerfeld's view worst of all to choose from standing - candidates won: Wilhelm Müller. After the end of the Nazi dictatorship Sommerfeld sought after 1945 again by a successor who would continue the tradition of his school, and suggested, among others, Werner Heisenberg, Karl Bechert, Hans Bethe and Carl Friedrich von Weizsäcker, but refused.

Sommerfeld died in 1951 following a traffic accident.

Services

Sommerfeld counts along with Max Planck, Albert Einstein and Niels Bohr to researchers, the modern theoretical physics created at the beginning of the 20th century with its pillars of quantum physics and relativity and made ​​it the foundation of physics. It was important both as a researcher and as an academic teacher. His contribution to science was less in the formulation of new, cataclysmic physical theories but rather in the application of advanced mathematical methods for physical and technical problems. An important contribution to the early quantum physics was the extension of the Bohr model of the atom, so that could be explained with this also the fine structure of the spectral lines of hydrogen ( Bohr-Sommerfeld cal model of the atom ). He led the fine structure constant α a. Furthermore, he developed a theory of X-ray radiation, improved the Drude theory of electrons in metals by application of quantum mechanics ( Drude -Sommerfeld theory ) and collaborated with Felix Klein from a comprehensive theory of the gyroscope. Sommerfeld was also one of the first physicists who accept Albert Einstein's Special Theory of Relativity, application Deten and enforce so that helped. Furthermore Sommerfeld dealt with hydrodynamic bearings and developed the eponymous Sommerfeld number as a measure of the loading of a warehouse.

Sommerfeld was proposed total of 81 times for the Nobel Prize ( proposal are entitled only very selected people, such as former Nobel Prize winner ) - more than any other physicists before or after him. Even as a high school teacher had more future Nobel laureate to his assistants, graduate students or listeners than any other recent Nobel laureate in physics. The so-called Sommerfeld school of theoretical physics, the development of their science (especially quantum theory and its dissemination ) heavily influenced, both because of the quality of their work as well as by many chairs that were occupied in Germany and the United States through their representatives in the subsequent period. With Werner Heisenberg and Wolfgang Pauli two of the key in the formulation of quantum mechanics researchers have a PhD in the summer field. Other graduate students of Sommerfeld were, inter alia, Peter Debye, Hans Bethe, Paul Sophus Epstein, Walter Heitler, Walter Franz, Ludwig Hopf, Herbert Fröhlich, Paul Peter Ewald, Adolf Kratzer, Alfred Landé, Wilhelm Lenz, Otto Laporte, Josef Meixner, Albrecht Unsold, Gregor Wentzel, Ernst A. Guillemin, Rudolf Seeliger, Helmut Honl, Fritz Bopp and Heinrich Welker. Foreign postdocs as Isidor Isaac Rabi and Linus Carl Pauling was at his institute.

Not everyone got along with Sommerfeld's personality. Heisenberg said ( quite respectfully ) about him:

"He was a Privy Councillor in the old style with very definite ideas about morality, politics, behavior and so on. Pauli used to say of him: " He looks like an old hussar colonel ". He had the mustache, the personality and determined views. "

Was further told Known and smile with an anecdote that was peddled by Edward Teller: The Young Americans (and later Nobel Prize winner ) John Hasbrouck Van Vleck studied at the Munich Institute of Physics. One day, Van Vleck was sitting in the library and Sommerfeld entered the room, followed by Van Vleck rose from the square and polite Good morning Mr. Sommerfeld! said, was welcomed by Sommerfeld but only with an unwilling hum. The next morning, repeated the scene, Van Vleck jumped up and said: Good morning sir, after Sommerfeld smiled slightly, but said nothing! . On the third day, the two met again and Van Vleck welcomed summer field with Good Morning Doctor!. Sommerfeld also replied with Good Morning! . On the fourth day finally Sommerfeld again entered the library and was developed by Van Vleck with Good Morning Privy! welcomed. Thereupon Sommerfeld bent amazed to his students and said, praising: But your German is better every day!.

Even as the author of books took Sommerfeld influence on science. His 1919 book Atomic structure and spectral lines publicized for the first time appeared in the following years in ever-expanding requirements that reflect the rapid development of atomic physics at that time. It has long been one of the most important publications, the theoretical insights of quantum mechanics made ​​the young experimenters accessible and also in the training of students played a prominent role.

Sommerfeld was a member of the Bavarian Academy of Sciences and since 1926 Fellow of the Royal Society London since 1908. He was 1917 1931 awarded by the Prussian Academy of Sciences, the Helmholtz Medal of the German Physical Society and the Max Planck Medal. In 1949 he was awarded the Oersted Medal of the AAPT.

Were named after him, the Arnold Sommerfeld Center, Research Center for Theoretical Physics at the Ludwig- Maximilians- University of Munich and the Arnold -Sommerfeld price of Mathematics and Natural Sciences of the Bavarian Academy of Sciences.

The asteroid ( 32809 ) Sommerfeld bears his name since 2002.

Quotes

Albert Einstein on Arnold Sommerfeld:

• " What I particularly admire about you that you have a large number of young talents such as built from the ground. That is very strange. You must have a gift, to ennoble the spirits of your handset and activate. "- Albert Einstein in a letter of 14 January 1922, Arnold Sommerfeld

Works

• Theory of the gyro. 4 volumes (together with Felix Klein ), Leipzig 1897-1910
• Atomic structure and spectral lines. Brunswick 1919, Harri German 1978, ISBN 3-87144-484-7.
• Lectures on theoretical physics. reissued in publishing Harri German, Frankfurt: Volume 1: Mechanics. Leipzig in 1943, Harri German 1994, ISBN 3-87144-374-3.
• Volume 2: Mechanics of deformable media. Leipzig in 1945, Harri German 1992, ISBN 3-87144-375-1.
• Volume 3: electrodynamics. Wiesbaden 1948, Harri German 2005, ISBN 3-87144-376- X.
• Volume 4: optics. Wiesbaden in 1950, Harri German, 1988, ISBN 3-87144-377-8.
• Volume 5: Thermodynamics and statistics. Wiesbaden 1952, Harri German, 1988, ISBN 3-87144-378-6.
• Volume 6: Partial differential equations of physics. Leipzig in 1945, Harri German 1992, ISBN 3-87144-379-4.