Carl Friedrich Freiherr von Weizsäcker German physicist and philosopher was born 28 June 1912 in Kiel Germany first of two sons of Ernst Freiherr von Weizsäcker and Marianne von Weizsäcker. His father a German diplomat and state secretary in the Foreign Office during World War II died in 1951. His brother Richard Freiherr von Weizsäcker was president of the Federal Republic of Germany (1984–1994).
Between 1929 and 1933 Weizsäcker studied physics astronomy and mathematics in Berlin Göttingen and Leipzig. Among his teachers had been Werner Heisenberg and Niels Bohr. From 1933 to 1936 he did research first in Leipzig and then at the Berlin Kaiser-Wilhelm-Institutes for Chemistry and Physics. He studied the bonding energies of atomic nuclei in the field of microphysics (Bethe-Weizsäcker-Formel, Tröpfchenmodell, 1935) and researched the nuclear processes delivering energy in the interior of stars (Bethe-Weizsäcker-Zyklus, 1937/1938).
In 1942 Weizsäcker was elected Professor of Theoretical Physics in Strasbourg. He remained in this position until 1945. One year later he became head of the department at the Max Planck Institute for Physics in Germany. In that year he presented a theory of the origin of the planetary system.
Between 1957 and 1969 Weizsäcker taught philosophy in Hamburg. During this time he published on the origin of stars (1959) and published his Weltformel in 1966. He was appointed Gifford Lecturer at the University of Glasgow for 1959–1961. His first lecture series delivered during the session 1959–1960 was published as a book The Relevance of Science. Creation and Cosmogony in 1964.
In the 1950s Weizsäcker discussed the responsibility a scientist has for his work. He belonged to the group of eighteen physicists (‘Göttinger Achtzehn’) who declared their rejection of the use of nuclear weapons (‘Göttinger Erklärung’). One of them was Otto Hahn. Weizsäcker became a fellow of the Deutsche Gesellschaft für Friedens- und Konfliktforschung and initialized the foundation of the Max-Planck-Institute in Starnberg Germany for research into living conditions in a scientific-technical world. He was director of this Institute from 1970 to 1980.
Zum Weltbild der Physik was published in 1943, Geschichte der Natur in 1948. Die Tragweite der Wissenschaft appeared in 1964. Further publications are Die Einheit der Natur (1971) Fragen zur Weltpolitik (1975) Der Garten des Menschlichen (1977) Aufbau der Physik (1985) Bewusstseinswandel (1988) Die Zukunft des Friedens in Europa (1990) and his philosophical main work Zeit und Wissen (1992).
In 1958 Weizsäcker was presented with the Max Planck Medal and became a member of the order Pour le mérite for science and arts in 1961. In 1963 he was awarded the Friedenspreis des Deutschen Buchhandels.
