HEISENBERG, WERNER

born Dec. 5, 1901, Wurzburg, Ger. died Feb. 1, 1976, Munich Werner Heisenberg, c. 1925. in full Werner Karl Heisenberg German physicist and philosopher who discovered a way to formulate quantum mechanics in terms of matrices (1925). For that discovery, he was awarded the Nobel Prize for Physics for 1932. In 1927 he published his indeterminacy, or uncertainty, principle, upon which he built his philosophy and for which he is best known. He also made important contributions to the theories of the hydrodynamics of turbulence, the atomic nucleus, ferromagnetism, cosmic rays, and elementary particles, and he planned the first post-World War II German nuclear reactor, at Karlsruhe, then in West Germany. In his philosophical and methodological writings, Heisenberg was much influenced by Niels Bohr and Albert Einstein. From the former he derived the concepts of the social and dialogical character of scientific invention; the principle of correspondence (pragmatic and model-theoretical continuity) between macrophysics and microphysics; the permanence, though not the universality, of classical physics; the "interactive," rather than passive, role of the scientific observer in microphysics; and, consequently, the contextualized character of microphysical theories. From Einstein he derived the concepts of simplicity as a criterion of the central order of nature; scientific realism (i.e., science describing nature itself, not merely how nature can be manipulated); and the theory-ladenness of scientific observations. He was coauthor with Bohr of the philosophy of complementarity. In his later work he conceived of a central order in nature, consisting of a set of universal symmetries expressible in a single mathematical equation for all systems of particulate matter. As a public figure, he actively promoted the peaceful use of nuclear energy after World War II and, in 1957, led other German scientists in opposing a move to equip the West German Army with nuclear weapons. He was, in 1954, one of the organizers of the Conseil Europen pour la Recherche Nuclaire (CERN; later, Organisation Europene pour la Recherche Nuclaire) in Geneva. Additional reading Books by Heisenberg include The Physical Principles of the Quantum Theory (1930, reissued 1950; originally published in German, 1930), his most important work, containing themes of early papers amplified into a treatise, Philosophic Problems of Nuclear Science (1952, reissued 1966; originally published in German, 8th enlarged ed., 1949), a collection of his early essays, Physics and Philosophy: The Revolution in Modern Science (1958, reissued 1989), his Gifford lectures, Physics and Beyond (1971; originally published in German, 1969), a memoir of his early life, and Across the Frontiers (1974, reissued 1990; originally published in German, 1971), collected essays and occasional lectures. Biographical material is found in Armin Hermann, Werner Heisenberg, 1901-1976, trans. from German (1976); Carl Friedrich von Weizscker and Bartel Leendert van der Waerden, Werner Heisenberg (1977), in German; Elisabeth Heisenberg, Inner Exile: Recollections of a Life with Werner Heisenberg (1984; originally published in German, 1980); and David C. Cassidy, Uncertainty: The Life and Science of Werner Heisenberg (1992). Heisenberg's role in the German wartime atomic program is chronicled in Leslie R. Groves, Now It Can Be Told: Story of the Manhattan Project (1962, reprinted 1983). Collections of essays in honour of Heisenberg include Fritz Bopp (ed.), Werner Heisenberg und die Physik unserer Zeit (1961); Heinrich Pfeiffer (ed.), Denken und Umdenken: Zu Werk und Wirkung von Werner Heisenberg (1977); and Peter Breitenlohner and H. Peter Drr (eds.), Unified Theories of Elementary Particles (1982). Studies of Heisenberg's philosophy of science include Patrick A. Heelan, Quantum Mechanics and Objectivity (1965); and Max Jammer, The Philosophy of Quantum Mechanics: The Interpretations of Quantum Mechanics in Historical Perspective (1974), and The Conceptual Development of Quantum Mechanics, 2nd ed. (1989), which provide the most complete study of Heisenberg's contribution to quantum mechanics.