Pascual Jordan

From Hanover to Göttingen

Ernst Pascual Jordan was born on 18 October 1902 in Hanover, Germany. He began his university studies at the Technical University of Hanover in 1921 before moving to the University of Göttingen in 1922, where he studied physics, mathematics and zoology.

Göttingen was one of the great centres of physics in the 1920s, led by Max Born. Jordan received his doctorate there in 1924 and remained as Born's assistant.

Matrix Mechanics

In 1925, Werner Heisenberg, working at Göttingen, introduced a new mathematical approach to atomic physics. Max Born recognised that Heisenberg's arrays of numbers were matrices — objects from linear algebra.

Born and Jordan then developed the matrix formalism further, and the three physicists — Born, Heisenberg and Jordan — produced their famous three-author paper giving a comprehensive formulation of what became known as matrix mechanics. Jordan's contribution to this work was substantial.

Matrix mechanics was one of the first complete formulations of quantum mechanics. It gave correct predictions for atomic phenomena using mathematics that was unfamiliar to many physicists at the time.

Quantum Field Theory and Later Work

Jordan later made important contributions to quantum field theory, including work on second quantisation. His name also survives mathematically in Jordan algebras.

In 1927, Jordan spent several months at Niels Bohr's institute in Copenhagen as a Rockefeller fellow. He became associate professor at the University of Rostock in 1929 and full professor there in 1935.

In later decades Jordan's work extended into gravitation and cosmology. He joined the Nazi Party in May 1933 and remained a member until 1945 — historical context that is part of his biography, though it does not diminish his scientific contributions.

Hamburg and Legacy

From 1947 Jordan worked at the University of Hamburg, becoming full professor there in 1953. He retired in 1970.

From 1957 to 1961, Jordan served as a member of the West German Bundestag for the CDU, combining his scientific career with a period in politics.

Jordan's contribution to matrix mechanics has sometimes received less public attention than those of Born and Heisenberg, but his role in establishing one of the foundational formulations of quantum mechanics was significant. He worked with several major quantum theorists including Born, Heisenberg, Pauli and Wigner.

Jordan died on 31 July 1980 in Hamburg, West Germany.