Werner Heisenberg (5 December 1901 – 1 February 1976) was a German theoretical physicist who made foundational contributions to quantum mechanics and is best known for asserting the uncertainty principle of quantum theory. In addition, he also made important contributions to nuclear physics, quantum field theory, and particle physics. Heisenberg, along with Max Born and Pascual Jordan, set forth the matrix formulation of quantum mechanics in 1925. Heisenberg was awarded the 1932 Nobel Prize in Physics.
After Adolf Hitler ascended to power in 1933, Heisenberg was attacked in the press by elements of the deutsche Physik (German Physics) movement, and he came under investigation by the SS.
This was embroiled with the attempt to appoint Heisenberg as successor to Arnold Sommerfeld at the University of Munich; it became known as the Heisenberg Affair. The issue was resolved by Heinrich Himmler, the head of the SS, in 1938. While Heisenberg was not selected as Sommerfeld’s successor, he was completely rehabilitated to the physics community relative to the Third Reich.
The German nuclear energy project, also known informally as the Uranium Club, began in 1939 under the auspices of the German Ordnance Office.
In 1942, control of the project was relinquished to the Reich Research Council. Throughout the project, Heisenberg was one of the nine principals heading up research and development for the program. In 1942, Heisenberg was appointed as director-in-residence of the Kaiser Wilhelm Institute for Physics. Heisenberg was one of 10 German scientists arrested near the end of World War II under the American Operation Alsos.
He was detained in England from May 1945 to January 1946. Upon Heisenberg’s return to Germany, he settled in Gottingen in the British occupation zone, where he was appointed director of the Kaiser Wilhelm Institute for Physics, which was soon thereafter renamed the Max Planck Institute for Physics. He was director of the institute until it was moved to Munich in 1958, when it was expanded and renamed the Max Planck Institute for Physics and Astrophysics. For two years, he was co-director with the astrophysicist Ludwig Biermann.
Heisenberg was director of the institute from 1960 to 1970. Heisenberg was also president of the German Research Council, chairman of the Commission for Atomic Physics, chairman of the Nuclear Physics Working Group, and president of the Alexander von Humboldt Foundation. In 1957, Heisenberg was a signatory of the Gottingen Manifesto, a declaration of 18 leading nuclear scientists of West Germany against arming the West German army with tactical nuclear weapons.  Biography  Early years Heisenberg was born in Wurzburg, Germany.
He studied physics and mathematics from 1920 to 1923 at the Ludwig-Maximilians-Universitat Munchen and the Georg-August-Universitat Gottingen. At Munich, he studied under Arnold Sommerfeld and Wilhelm Wien. At Gottingen, he studied physics with Max Born and James Franck, and he studied mathematics with David Hilbert. He received his doctorate in 1923, at Munich under Sommerfeld. He completed his Habilitation in 1924, at Gottingen under Born.  In his youth he was a member and Scoutleader of the Neupfadfinder, a German Scout association and part of the German Youth Movement.
 In August 1923 Robert Honsell and Heisenberg organized a trip (Gro? fahrt) to Finland with a Scout group of this association from Munich.  Because Sommerfeld had a sincere interest in his students and knew of Heisenberg’s interest in Niels Bohr’s theories on atomic physics, Sommerfeld took Heisenberg to Gottingen to the Bohr-Festspiele (Bohr Festival) in June 1922. At the event, Bohr was a guest lecturer and gave a series of comprehensive lectures on quantum atomic physics. There, Heisenberg met Bohr for the first time, and it had a significant and continuing effect on him.
 Heisenberg’s doctoral thesis, the topic of which was suggested by Sommerfeld, was on turbulence; the thesis discussed both the stability of laminar flow and the nature of turbulent flow. The problem of stability was investigated by the use of the Orr–Sommerfeld equation, a fourth order linear differential equation for small disturbances from laminar flow. He would briefly return to this topic after World War II.  Heisenberg’s paper on the anomalous Zeeman effect was accepted as his Habilitationsschrift under Max Born at Gottingen.
  Career  Gottingen, Copenhagen, and Leipzig From 1924 to 1927, Heisenberg was a Privatdozent at Gottingen. From 17 September 1924 to 1 May 1925, under an International Education Board Rockefeller Foundation fellowship, Heisenberg went to do research with Niels Bohr, director of the Institute of Theoretical Physics at the University of Copenhagen. He returned to Gottingen and with Max Born and Pascual Jordan, over a period of about six months, developed the matrix mechanics formulation of quantum mechanics.
On 1 May 1926, Heisenberg began his appointment as a university lecturer and assistant to Bohr in Copenhagen. It was in Copenhagen, in 1927, that Heisenberg developed his uncertainty principle, while working on the mathematical foundations of quantum mechanics. In his paper on the uncertainty principle, Heisenberg used the word “Ungenauigkeit” (imprecision).  In 1927, Heisenberg was appointed ordentlicher Professor (ordinarius professor) of theoretical physics and head of the department of physics at the Universitat Leipzig; he gave his inaugural lecture on 1 February 1928.
In his first paper published from Leipzig, Heisenberg used the Pauli exclusion principle to solve the mystery of ferromagnetism.  In Heisenberg’s tenure at Leipzig, the quality of doctoral students, post-graduate and research associates who studied and worked with Heisenberg there is attested to by the acclaim later earned by these personnel. At various times, these personnel included: Erich Bagge, Felix Bloch, Ugo Fano, Siegfried Flugge, William Vermillion Houston, Friedrich Hund, Robert S. Mulliken, Rudolf Peierls, George Placzek, Isidor Isaac Rabi, Fritz Sauter, John C.
Slater, Edward Teller, John Hasbrouck van Vleck, Victor Frederick Weisskopf, Carl Friedrich von Weizsacker, Gregor Wentzel, and Clarence Zener.  In early 1929, Heisenberg and Wolfgang Pauli submitted the first of two papers laying the foundation for relativistic quantum field theory. Also in 1929, Heisenberg went on a lecture tour in the United States, Japan, China, and India.  Shortly after the discovery of the neutron by James Chadwick in 1932, Heisenberg submitted the first of three papers on his neutron-proton model of the nucleus.
He was awarded the 1932 Nobel Prize in Physics.  In 1928, the British mathematical physicist P. A. M. Dirac had derived the relativistic wave equation of quantum mechanics, which implied the existence of positive electrons, later to be named positrons. In 1932, from a cloud chamber photograph of cosmic rays, the American physicist Carl David Anderson identified a track as having been made by a positron. In mid-1933, Heisenberg presented his theory of the positron.
His thinking on Dirac’s theory and further development of the theory were set forth in two papers. The first, Bemerkungen zur Diracschen Theorie des Positrons (Remarks on Dirac’s theory of the positron) was published in 1934, and the second, Folgerungen aus der Diracschen Theorie des Positrons (Consequences of Dirac’s Theory of the Positron), was published in 1936.  In the early 1930s in Germany, the deutsche Physik movement was anti-Semitic and anti-theoretical physics, especially including quantum mechanics and the theory of relativity.
As applied in the university environment, political factors took priority over the historically applied concept of scholarly ability, even though its two most prominent supporters were the Nobel Laureates in Physics Philipp Lenard and Johannes Stark.  When Adolf Hitler became Chancellor of Germany on January 30, 1933, the concept and movement took on more favour and more fervor. Supporters of deutsche Physik launched vicious attacks against leading theoretical physicists, including Arnold Sommerfeld and Heisenberg.
On June 29, 1936, a National Socialist Party newspaper published an article attacking Heisenberg. On July 15, 1937, he was attacked in a periodical of the Schutzstaffel (SS). This was the beginning of what is called the Heisenberg Affair.  In mid-1936, Heisenberg presented his theory of cosmic-ray showers in two papers.  Four more papers appeared in the next two years.  In June 1939, Heisenberg bought a summer home for his family in Urfeld, in southern Germany, to be used as a retreat.
Also in 1939, Heisenberg traveled to the United States in June and July. There, he visited Samuel Abraham Goudsmit, at the University of Michigan in Ann Arbor. Heisenberg refused an invitation to emigrate to the United States. Heisenberg would not see Goudsmit again until six years later, when Goudsmit was the chief scientific advisor to the American Operation Alsos at the close of World War II. Heisenberg would be arrested under Operation Alsos and detained in England under Operation Epsilon.