Alfred Landé

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Alfred Landé in the USA (1940)

Alfred Landé (born December 13, 1888 in Elberfeld (today a district of Wuppertal ), † October 30, 1976 in Columbus , Ohio , USA ) was a German physicist . He worked, among other things, in the field of quantum physics and spectroscopy and in 1921 described the Landé factor named after him . In addition, half of the Born-Landé equation is named after him.

life and work

Youth, Family and Education

Landé came from a liberal, open-minded bourgeois family of Jewish origin who was influenced by socialism and who was primarily interested in literature, science and politics. In addition to his work, his father took time to help with homework and read books with the children. Each family member mastered an instrument.

His younger sister Charlotte (1890–1977) began studying human medicine as an external student at the Remscheid Realgymnasium in the summer semester of 1909 after graduating from high school. His younger brother Franz (1893–1942) initially law and economics. In Berlin, he also attended courses in music theory and finally decided to focus on music. The youngest sister Eva (1901–1977) also did her Abitur as an external student at the Odenwald School and became a teacher, first at the reform pedagogical New School Hellerau in Dresden-Hellerau , later at an elementary school in Chemnitz . Since 1933 she lived in exile with her family.

His father Hugo (1859–1936) was the district president in Düsseldorf , leader of the SPD parliamentary group in the Elberfeld city council, lawyer and judiciary. His mother Thekla (1864-1932) became a city councilor in 1919. As one of the first female MPs in the Rhineland, she focused on the welfare system and the education of girls and women. From the age of five, Alfred received piano lessons, and his training in music theory and composition continued until he was 18. During his school days he was initially particularly interested in cosmology, then in crystals and minerals, finally in chemistry and later in electricity. In high school, he proved to be clearly superior to his classmates in mathematics and physics, and his teachers viewed him as a child prodigy .

In the end he gave preference to the natural sciences. In 1908 he began studying mathematics and physics in Marburg , and later in Munich and Göttingen . As he put it in an online interview on March 5, 1962, he discovered in the course of his studies that there were many other child prodigies, so that he found it difficult to keep up with them. Even after the third year of study, no particular specialization or orientation of his studies had emerged, nor had a personal relationship with one of the professors.

In Göttingen, he initially dealt with experimental physics on cathode rays, but finally switched to theoretical physics and determined his personal inclination to this area. As one of only five students, he heard Max Born's inaugural lecture . After moving to Munich, Arnold Sommerfeld was impressed, who he described as "the greatest teacher of theoretical physics east of the Rhine". In Munich, Landé met other talented students who later became prominent scientists, such as Peter Debye , Paul Sophus Epstein , Paul Peter Ewald , Max von Laue . In 1912 von Laue made the discovery of X-ray diffraction, a scientific sensation at the time. The young scientists met after lunch in Munich's Hofgarten and discussed there. In winter they went on weekly ski trips.

While Sommerfeld and other physicists on the wing, who were considered progressive, viewed quantum theory as an absolutely new fundamental theory, Landé tried to understand the quantum puzzle as a gap in classical statistical mechanics . This different approach subsequently led to differences between Sommerfeld and Landé.

In 1913 Landé became the assistant to David Hilbert and successor to Paul Peter Ewald in Göttingen. It was his job to keep the great mathematician Hilbert up to date on current specialist physics literature. This task led to close contact between Landé and Max Born. It was the time when Bohr's atomic model and the specific heat at low temperatures (Born, Debye, von Kármán ) were discussed. In addition to Hilbert, Landé met scientists in Göttingen such as Paul Bernays , Niels Bohr , Richard Courant , Vladimir Fock , Erwin Freundlich , Paul Hertz , Felix Klein , Edmund Landau , Hendrik Antoon Lorentz , Erwin Madelung , George Pólya , Ludwig Prandtl (founder of aerodynamics ) , Eduard Riecke , Carl Runge , Otto Toeplitz , Woldemar Voigt , Hermann Weyl . Landé translated Lorentz's work "Theory of Electrons" into German for his own training, which later became an important prerequisite for his own work on radiation theory.

In 1914, two weeks before the outbreak of the First World War , Landé did his doctorate in Munich under Arnold Sommerfeld with the subject: On the method of natural oscillations in quantum theory . He himself later described his dissertation as "rather insignificant Ph. D. thesis" and commented self-critically on the oral examination: "almost flunked my orals with Röntgen because of a spectacular blunder in optics - did not know of phase shift upon reflection".

period of service

In the first two years of World War I he served as a Red Cross helper on the Eastern Front . Then he came to one of the few scientific sections of the military , the Artillery Examination Commission in Berlin , which was headed by Rudolf Ladenburg . Landé became Max Born's assistant. In addition to measuring sound, his tasks included investigating the cohesive forces and compressibility of crystals. In the course of this work it came to the unexpected result that electron orbits in atoms do not all run like planetary orbits in one plane, as assumed until then as a reliable basic knowledge. This research result fell on the period between November 5th and 8th, 1918, the phase between the Kiel sailors' uprising and the proclamation of the republic in Berlin. For Alfred Landé this was the first experience of a scientific innovation, of overcoming generally accepted doctrines, of a progress in which he participated. His work on cubic and tetrahedral electron orbits, so-called cube atoms, received great attention from Bohr, Debye and Sommerfeld.

Professional and personal development

In December 1918, Landé left Berlin and began working as a music teacher at the Odenwald School , a private school on Bergstrasse between Frankfurt am Main and Heidelberg. In his memoirs he described this time as follows: "In the morning I had free time for theoretical physics, in the afternoon I earned my living by taking music lessons in a spiritually stimulating atmosphere among educators, artists, nature lovers, etc."

From 1919 Landé turned increasingly to spectroscopy , although at that time the spatial orientation of atoms was viewed as the most interesting problem in physics. The reason for this was Max's change from Laues to Berlin and from Max Born to Frankfurt am Main to von Laue's former chair. Max Born was supposed to support Landé's habilitation in Frankfurt. In October 1920, Landé visited his colleague Niels Bohr in Copenhagen and from December of the same year began to investigate the problem of the anomalous Zeeman effect .

From 1919 on as a private lecturer in Frankfurt am Main , he only moved there from the Odenwald in December 1920 or January 1921. Until then, he traveled to Frankfurt every week for his lectures. After moving, he sublet a room from Privy Councilor Freund's wife, the widow of a chemistry professor at the university. His life in this city is now considered the most important phase of his scientific work, largely determined by the Landé's g-formula or the Landé factor - a major breakthrough in quantum mechanics - and the explanation he provided of the Zeeman- Effect. Historian Paul Forman later devoted a lengthy study to this period, which was very interesting from a human, historical and physical point of view, in which he published the correspondence between Landé, Ernst Back , Friedrich Paschen and Arnold Sommerfeld.

Landé married Elisabeth Grunewald in 1922, with whom he had two sons, Arnold Landé , later a surgeon in Minneapolis, and Carl Landé (1924-2005), later professor of political science.

In autumn 1922 Alfred Landé was appointed professor at Tübingen at the urging of Friedrich Paschen .

From 1925/1926 he began to deal with the quantum theory of radiation , light coherence and spontaneous and induced emission . In the fall semester of 1929, Landé was invited to Ohio State University in Columbus to give a series of lectures.

After a second stay in 1930/1931 he decided to settle in the USA and from then on devoted himself primarily to teaching and the writing and publishing of textbooks.

Landé's sister Charlotte was appointed Frankfurt city doctor for life from October 1931, but was later removed from this position by the National Socialists . In 1936, Landé's father Hugo committed suicide in Switzerland, where he fled from the Nazis. In the same year Charlotte visited her brother Alfred in the USA. Alfred Landé took on an affidavit of support for her emigration, but not for her considerably younger husband Herbert Czempin , whom she married on March 2, 1934 in Frankfurt am Main. Alfred's sister emigrated to the United States in February 1937 and met her husband in June 1937. In August 1941, Eva Landé and her daughter were also able to travel to the USA with Alfred's support. Alfred's younger brother Franz was deported to Auschwitz in 1942 and murdered there.

After 1954, Alfred Landé intensively took up the problem of the justification and interpretation of quantum theory, the prevailing interpretation of which he repeatedly questioned until his death. He later referred to this period as his second productive phase of life.

Through his careful scientific work in the development of quantum theory and spectroscopy, through his ideas in the theory of radiation and elementary particles as well as his courage to dare a new justification of quantum theory even against the generally prevailing doctrine, Alfred Landé has a permanent place in the Physics of the 20th century secured. He died on October 30, 1976 in Columbus / Ohio, USA.

Fonts

  • Alfred Landé: Advances in quantum theory . Steinkopff. Dresden and Leipzig 1922
  • Ernst Back, Alfred Landé: Zeeman effect and multiplet structure of the spectral lines . Springer 1925
  • Alfred Landé: Newer Development of Quantum Theory . 1926
  • Alfred Landé: Principles of quantum mechanics . Macmillan / Cambridge 1937
  • Alfred Landé: Physics of flight . 1945
  • Alfred Landé: Quantum mechanics . Cambridge University Press / Sir Isaac Pitman et al. Sons 1951
  • Alfred Landé: Foundations of quantum theory; a study in continuity and symmetry . Yale University Press 1955. ISBN 1-1241-6338-7
  • Alfred Landé: From dualism to unity in quantum physics . Cambridge University Press 1960. ISBN 1-1241-0191-8
  • Alfred Landé: New foundations of quantum mechanics . Cambridge University Press 1965. ISBN 1-1148-2854-8
  • Alfred Landé: Quantum mechanics in a new key . Exposition Press 1973. ISBN 0-6824-7667-6

literature

  • Paul Forman : Alfred Landé and the anomalous Zeeman Effect, 1919-1921 . Historical Studies in the Physical Sciences, Vol. 2, 1970, pp. 153-261.
  • Wolfgang Yourgrau, Alwyn van der Merwe: Perspectives in quantum theory; essays in honor of Alfred Landé . MIT Press 1971 / Dover Publications 1979. ISBN 0-2622-4014-9 ; ISBN 0-486-63778-6
  • Helmut Rechenberg:  Alfred Landé. In: New German Biography (NDB). Volume 13, Duncker & Humblot, Berlin 1982, ISBN 3-428-00194-X , pp. 494-496 ( digitized version ).
  • Jagdish Mehra, Helmut Rechenberg: The Historical Development of Quantum Theory 1-6: The Quantum Theory of Planck, Einstein, Bohr and Sommerfeld: Its Foundation and the Rise of Its Difficulties 1900-1925 . Springer US 1982. ISBN 0-3879-5175-X
  • Asim O. Barut , Alwyn van der Merwe: Selected scientific papers of Alfred Landé . Springer Netherlands 1988. ISBN 9-0277-2594-2
  • Elke Brychta, Anna-Maria Reinhold, Arno Mersmann (eds.): Courageous, contentious, reformist: The Landés - six biographies . Klartext-Verlag. Essen 2004. ISBN 3-8986-1273-2

Web links

Individual evidence

  1. ^ Asim O. Barut: Alfred Landé 1888-1976. In: uni-frankfurt.de. Archived from the original on November 13, 2012 ; accessed on January 17, 2018 .
  2. ↑ For Eva Landé see: Known members of the Association of German Teacher Emigrants: Eva Landé and Erich Stedeli
  3. ^ Elke Brychta, Anna-Maria Reinhold, Arno Mersmann (ed.): Courageous, arguable, reformist: The Landés - six biographies . Klartext-Verlag. Essen 2004. ISBN 3-8986-1273-2
  4. ↑ Interview with Dr. Alfred Landé on March 5, 1962 in Berkeley, California, USA at: aip.org
  5. ↑ Constance Reid: Hilbert , Springer 1996. P. 133. ISBN 0-3879-4674-8
  6. ^ Inaugural dissertation on the method of natural oscillations in the quantum theory by Alfred Landé, 1914
  7. ^ Paul Forman, Alfred Landé and the anomalous Zeeman Effect, 1919-1921 , Historical Studies in the Physical Sciences, Vol. 2, 1970, 153-261.
  8. ^ Helmut Rechenberg: Landé, Alfred . In: New German Biography . tape 13 , 1982, pp. 494-496 ( deutsche-biographie.de ).
  9. ↑ Jagdish Mehra, Helmut Rechenberg: The Historical Development of Quantum Theory 1-6: The Quantum Theory of Planck, Einstein, Bohr and Sommerfeld: Its Foundation and the Rise of Its Difficulties 1900–1925 Springer US 1982. ISBN 0-3879-5175 -X
personal data
SURNAME Landé, Alfred
BRIEF DESCRIPTION German physicist
DATE OF BIRTH December 13, 1888
PLACE OF BIRTH Elberfeld (today a district of Wuppertal )
DATE OF DEATH October 30, 1976
Place of death Columbus , Ohio , USA