THEODORE DREWLO
May 26, 2015
WERNER HEISENBERG
FISSION AND FUSION NEUCLEAR REACTIONS
MR. SAIYAN

Werner Heisenberg was a German born in 1907 that was a theoretical physicist who made foundational contributions to quantum theory. He is best known for the development of the matrix mechanics formulation of quantum mechanics in 1925 and for asserting the uncertainty principle in 1926, although he also made important contributions to nuclear physics, quantum field theory and particle physics. He was awarded the Nobel Prize in Physics in 1932 “for the creation of quantum mechanics". From 1924 to 1927, Heisenberg lectured at the University of Göttingen, and conducted research with Niels Bohr at the University of Copenhagen. It was during this time that the young Heisenberg developed the “matrix mechanics” formulation of quantum mechanics (in collaboration with Max Born and Pascual Jordan). Matrix mechanics was the first complete and correct definition of quantum mechanics, and it extended the Bohr model of atoms by describing how the quantum jumps occur and by interpreting the physical properties of particles as matrices that evolve over time.
In 1939, Heisenberg travelled to the United States to visit Samuel Abraham Goudsmit at the University of Michigan, but refused an invitation to emigrate to the United States. Back in Germany, in 1939, shortly after the discovery of nuclear fission, Heisenberg became one of the principal scientists leading research and development in the German nuclear energy project, known as the “Uranium Club”, and he travelled to German-occupied Copenhagen in 1941 to lecture and discuss nuclear research and theoretical physics with Niels Bohr. In 1942, he was asked by the Nazi administration to direct the Uranium Club's research more toward developing nuclear weapons and, when Heisenberg prevaricated, the authority and regulation of the project was changed. In 1943, Heisenberg was appointed to the Chair for Theoretical Physics at Humboldt University in Berlin, and was elected to the Prussian Academy of Sciences. But, as Allied bombing increased in Berlin, he moved his family to their rural retreat in Urfeld, and later joined them there. In May 1945, at the end of the War, Heisenberg was picked up by Operation Alsos (along with nine other prominent German scientists working in the nuclear field) and was incarcerated for a time in England under Operation Epsilon.
On his release in 1946, he settled in Göttingen where he worked as director of the Max Planck Institute for Physics until 1958, and then of the expanded Max Planck Institute for Physics and Astrophysics in Berlin until 1970. Throughout this period, he continued to lecture across the world and to publish papers, including works on superconductivity, turbulence and cosmic-ray showers, as well as being appointed to various councils, commissions and associations, and receiving numerous honours and awards. Heisenberg died of cancer of the kidneys and gall bladder at his Munich home on 1 February 1976, aged 74.

FUSION AND FISSION NUCLEAR REACTIONS Nuclear fusion and nuclear fission are different types of reactions that release energy due to the presence of high-powered atomic bonds between particles found within a nucleus. In fission, an atom is split into two or more smaller, lighter atoms. Fusion, in contrast, occurs when two or more smaller atoms fuse together, creating a larger, heavier atom.