Walter Gerlach

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Walther Gerlach
Walther Gerlach.jpg
Born(1889-08-01)1 August 1889
Died10 August 1979(1979-08-10) (aged 90)
NationalityGerman
Alma mater Eberhard Karls University of Tübingen
Known for Stern–Gerlach experiment
Space quantization
Scientific career
Fields Physics
Institutions Johann Wolfgang Goethe University of Frankfurt am Main
Eberhard Karls University of Tübingen
Doctoral students Gertrude Scharff Goldhaber [1]
Heinz Billing [2]

Walther Gerlach (1 August 1889 – 10 August 1979) was a German physicist who co-discovered spin quantization in a magnetic field, the Stern–Gerlach effect.

Physicist scientist who does research in physics

A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate causes of phenomena, and usually frame their understanding in mathematical terms. Physicists work across a wide range of research fields, spanning all length scales: from sub-atomic and particle physics, through biological physics, to cosmological length scales encompassing the universe as a whole. The field generally includes two types of physicists: experimental physicists who specialize in the observation of physical phenomena and the analysis of experiments, and theoretical physicists who specialize in mathematical modeling of physical systems to rationalize, explain and predict natural phenomena. Physicists can apply their knowledge towards solving practical problems or to developing new technologies.

Stern–Gerlach experiment Physical experiment that demonstrated the quantization of angular momentum

The Stern–Gerlach experiment demonstrated that the spatial orientation of angular momentum is quantized. Thus an atomic-scale system was shown to have intrinsically quantum properties. In the original experiment, silver atoms were sent through a spatially varying magnetic field, which deflected them before they struck a detector screen, such as a glass slide. Particles with non-zero magnetic moment are deflected, due to the magnetic field gradient, from a straight path. The screen reveals discrete points of accumulation, rather than a continuous distribution, owing to their quantized spin. Historically, this experiment was decisive in convincing physicists of the reality of angular-momentum quantization in all atomic-scale systems.

Contents

Education

Gerlach was born in Biebrich, Hessen-Nassau, German Empire, as son of Dr. med. Valentin Gerlach and his wife Marie Niederhaeuser.

Biebrich, Rhineland Palatinate Place in Rhineland-Palatinate, Germany

Biebrich is a municipality in the district of Rhein-Lahn, in Rhineland-Palatinate, in western Germany.

He studied at the University of Tübingen from 1908, and received his doctorate in 1912, under Friedrich Paschen. The subject of his dissertation was on the measurement of radiation. After obtaining his doctorate, he continued on as an assistant to Paschen, which he had been since 1911. Gerlach completed his Habilitation at Tübingen in 1916, while serving during World War I. [3]

University of Tübingen public research university located in the city of Tübingen, Baden-Württemberg, Germany

The University of Tübingen, officially the Eberhard Karls University of Tübingen, is a public research university located in the city of Tübingen, Baden-Württemberg, Germany.

Friedrich Paschen German physicist

Louis Carl Heinrich Friedrich Paschen, was a German physicist, known for his work on electrical discharges. He is also known for the Paschen series, a series of hydrogen spectral lines in the infrared region that he first observed in 1908. He established the now widely used Paschen curve in his article "Über die zum Funkenübergang in Luft, Wasserstoff und Kohlensäure bei verschiedenen Drücken erforderliche Potentialdifferenz". He is known for the Paschen-Back effect, which is the Zeeman effect's becoming non-linear at high magnetic field. He helped explain the hollow cathode effect in 1916.

Habilitation defines the qualification to conduct self-contained university teaching and is the key for access to a professorship in many European countries. Despite all changes implemented in the European higher education systems during the Bologna Process, it is the highest qualification level issued through the process of a university examination and remains a core concept of scientific careers in these countries.

Career

From 1915 to 1918, during the war, Gerlach did service with the German Army. He worked on wireless telegraphy at Jena under Max Wien. He also served in the Artillerie-Prüfungskommission under Rudolf Ladenburg. [4] [5]

German Army (German Empire) 1871-1919 land warfare branch of the German military

The Imperial German Army was the unified ground and air force of the German Empire. The term Deutsches Heer is also used for the modern German Army, the land component of the Bundeswehr. The German Army was formed after the unification of Germany under Prussian leadership in 1871 and dissolved in 1919, after the defeat of the German Empire in World War I.

Jena Place in Thuringia, Germany

Jena is a German university city and the second largest city in Thuringia. Together with the nearby cities of Erfurt and Weimar, it forms the central metropolitan area of Thuringia with approximately 500,000 inhabitants, while the city itself has a population of about 110,000. Jena is a centre of education and research; the Friedrich Schiller University was founded in 1558 and had 18,000 students in 2017 and the Ernst-Abbe-Fachhochschule Jena counts another 5,000 students. Furthermore, there are many institutes of the leading German research societies.

Max Karl Werner Wien was a German physicist and the director of the Institute of Physics at the University of Jena. He was born in Königsberg, Prussia. He was a cousin of Nobel laureate Wilhelm Wien.

Gerlach became a Privatdozent at the University of Tübingen in 1916. A year later, he became a Privatdozent at the Georg-August University of Göttingen. From 1919 to 1920, he was the head of a physics laboratory of Farbenfabriken Elberfeld, formerly Bayer-Werke. [3] [4]

Privatdozent or Privatdozentin, abbreviated PD, P.D. or Priv.-Doz., is an academic title similar to Adjunct professor in North America conferred at some European universities, especially in German-speaking countries, to someone who holds certain formal qualifications that denote an ability to teach a designated subject at university level. In its current usage, the title indicates that the holder has permission to teach and examine independently without having a position. The title is not necessarily connected to a salaried position, but may entail a nominal obligation to teach.

In 1920, he became a teaching assistant and lecturer at the Johann Wolfgang Goethe University of Frankfurt am Main. The next year, he took a position as extraordinarius professor at Frankfurt. It was in November 1921/1922 that he and Otto Stern discovered spin quantization in a magnetic field, known as the Stern–Gerlach effect. [3] [6] [7] Otto Stern (compare his article) was among the nominees for the physics Nobel Prize in 1943 and was awarded the prize on 9 November 1944. The citation did not mention the highly important Stern-Gerlach experiment which Walther Gerlach finally carried out successfully early in 1922 during the Weimar Republic in the absence of Otto Stern who had already moved on to Rostock, thus withholding the honour from Gerlach in view of his continued activity in "Nazi-led" Germany (oral information from Prof. Dr. Horst Schmidt-Böcking, Institute for nuclear physics, Johann-Wolfgang-Goethe-Universität Frankfurt/Main in 2015, who conserves the unpublished documentation concerning the differing opinions within the Nobel-Committee on the subject of Walther Gerlach. Schmidt-Böcking is also engaged in the physical reassembling of Gerlach's experiment within the planned new Senckenberg-Museum at Frankfurt).

Otto Stern German physicist

Otto Stern was a German-American physicist and Nobel laureate in physics. He was the second most nominated person for a Nobel Prize with 82 nominations in the years 1925–1945, ultimately winning in 1943.

In 1925, Gerlach took a call and became an ordinarius professor at the University of Tübingen, successor to Friedrich Paschen. In 1929, he took a call and became ordinarius professor at the Ludwig Maximilians University of Munich, successor to Wilhelm Wien. He held this position until May 1945, when he was arrested by the American and British Armed Forces. [3] [5]

From 1937 until 1945, Gerlach was a member of the supervisory board of the Kaiser-Wilhelm-Gesellschaft (KWG). After 1946, he continued to be an influential official in its successor organization after World War II, the Max-Planck-Gesellschaft (MPG). [3]

On 1 January 1944, Gerlach officially became head of the physics section of the Reichsforschungsrat (RFR, Reich Research Council) and Bevollmächtigter (plenipotentiary) of nuclear physics, replacing Abraham Esau. In April of that year, he founded the Reichsberichte für Physik, which were official reports appearing as supplements to the Physikalische Zeitschrift. [3]

From May 1945, Gerlach was interned in France and Belgium by British and American Armed Forces under Operation Alsos. From July of that year to January 1946, he was interned in England at Farm Hall under Operation Epsilon, which interned 10 German scientists who were thought to have participated in the development of atomic weapons. [3] [5] [8]

Upon Gerlach's return to Germany in 1946, he became a visiting professor at the University of Bonn. From 1948, he became an ordinarius professor of experimental physics and director of the physics department at the University of Munich, a position he held until 1957. He was also rector of the university from 1948 to 1951. [3]

From 1949 to 1951, Gerlach was the founding president of the Fraunhofer-Gesellschaft, which promotes applied sciences. From 1949 to 1961, he was the vice-president of the Deutsche Gemeinschaft zur Erhaltung und Förderung der Forschung (German Association for the Support and Advancement of Scientific Research); also known in short as the Deutsche Forschungs-Gemeinschaft (DFG), previously the Notgemeinschaft der Deutschen Wissenschaft. [3]

In 1957, Gerlach was a co-signer of the Göttingen Manifesto, which was against rearming the Federal Republic of Germany with atomic weapons. [3]

He died in Munich in 1979.

Other positions / Decorations / Honours

Books

Articles

See also

Notes

  1. Bond, Peter D.; Henley, Ernest (1999), Gertrude Scharff Goldhaber 1911–1998: A Biographical Memoir, Biographical Memoirs, 77, Washington, D.C.: The National Academy Press, p. 4
  2. J. A. N. Lee (1995). "Heinz Billing". Computer pioneers. IEEE Computer Society. ISBN   978-0-8186-6357-4 . Retrieved 21 February 2016.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Hentschel, 1996, Appendix F; see the entry for Walter Gerlach.
  4. 1 2 Mehra and Rechenberg, Vol. 1, Part 2, 2001, 436.
  5. 1 2 3 Bernstein, 2001, 364.
  6. Breitislav, 2003, 53-59.
  7. Walther Gerlach and Otto Stern Das magnetische Moment des Silberatoms, Zeitschrift für Physik Volume 9, Number 1, 353-355 (1922).
  8. The nine other scientists interned at Farm Hall with Gerlach were: Erich Bagge, Kurt Diebner, Otto Hahn, Paul Harteck, Werner Heisenberg, Horst Korsching, Max von Laue, Carl Friedrich von Weizsäcker, and Karl Wirtz.

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