Julian Schwinger was one of the leading theoretical physicists of the twentieth century. His contributions are as important, and as pervasive, as those of Richard Feynman, with whom he shared the 1965 Nobel Prize for Physics. Yet, while Feynman is universally recognized as a cultural icon, Schwinger is little known even to many within the physics community. In his youth, Julian Schwinger was a nuclear physicist, turning to classical electrodynamics after World War II. In the years after the war, he (...) was the first to renormalize quantum electrodynamics. Subsequently, he presented the most complete formulation of quantum field theory and laid the foundations for the electroweak synthesis of Glashow, Weinberg, and Salam, and he made fundamental contributions to the theory of nuclear magnetic resonance, to many-body theory, and to quantum optics. He developed a unique approach to quantum mechanics, measurement algebra, and a general quantum action principle. His discoveries include 'Feynman's' parameters and 'Glauber's' coherent states; in later years he also developed an alternative to operator field theory which he called Source Theory, reflecting his profound phenomenological bent. His late work on the Thomas-Fermi model of atoms and on the Casimir effect continues to be an inspiration to a new generation of physicists. This biography describes the many strands of his research life, while tracing the personal life of this private and gentle genius. (shrink)

Development of the Physicist's Conception of Nature P. A. M. Dime When one looks back over the development of physics, one sees that it can be pictured as a ...

In this paper, the main outlines of the discussions between Niels Bohr with Albert Einstein, Werner Heisenberg, and Erwin Schrödinger during 1920–1927 are treated. From the formulation of quantum mechanics in 1925–1926 and wave mechanics in 1926, there emerged Born's statistical interpretation of the wave function in summer 1926, and on the basis of the quantum mechanical transformation theory—formulated in fall 1926 by Dirac, London, and Jordan—Heisenberg formulated the uncertainty principle in early 1927. At the Volta Conference in Como in (...) September 1927 and at the fifth Solvay Conference in Brussels the following month, Bohr publicly enunciated his complementarity principle, which had been developing in his mind for several years. The Bohr-Einstein discussions about the consistency and completeness of qnautum mechanics and of physical theory as such—formally begun in October 1927 at the fifth Solvay Conference and carried on at the sixth Solvay Conference in October 1930—were continued during the next decades. All these aspects are briefly summarized. (shrink)

In this study, I discuss the development of the ideas of Josiah Willard Gibbs' Elementary Principles in Statistical Mechanics and the fundamental role they played in forming the modern concepts in that field. Gibbs' book on statistical mechanics became an instant classic and has remained so for almost a century.

Max Planck introduced the concept of zero-point energy in spring 1911. In the early struggles to establish the concept of the energy-quantum, it provided a helpful heuristic principle, to guide as well as supplement the efforts of some leading physicists in understanding the laws that applied in the atomic domain. The history and growth of this concept, and its application in the general development of quantum theory during the past many decades are studied under three principal headings: (1) The Birth (...) of the Concept of zero-Point Energy; (2) Does Zero-Point Energy Really Exist? and (3) The Ground State of Quantum Systems. (shrink)

In this series of articles the early life and work of the young Julian Schwinger is explored. After a brilliant beginning at Columbia University, where he received his Ph.D., Schwinger went to work with J. Robert Oppenheimer in Berkeley. His stay, work, and interactions with Oppenheimer are discussed.

In this series of articles the early life and work of the young Julian Schwinger are explored. In this first article, Schwinger's childhood, growing-up, and early education are discussed.

In this series of articles the early life and work of the young Julian Schwinger are explored. In the present article, we discuss Schwinger's winding up his work at the MIT Radiation Laboratory, being offered a tenured professorship at Harvard University, getting married, and settling down into a highly productive teaching and research career.

In this series of articles the early life and work of the young Julian Schwinger are explored. In the present article, Schwinger's work at the MIT Radiation Laboratory during the Second World War is described.

In this series of articles the life and work of the young Julian Schwinger are explored. In this second article in the series, Schwinger's work at Columbia University, up to the completion of his doctorate and a little after, is discussed. Schwinger soon matured into a brilliant theoretical physicist.

This article is in three parts. Part I gives an account of Erwin Schrödinger's growing up and studies in Vienna, his scientific work—first in Vienna from 1911 to 1920, then in Zurich from 1920 to 1925—on the dielectric properties of matter, atmospheric electricity and radioactivity, general relativity, color theory and physiological optics, and on kinetic theory and statistical mechanics. Part II deals with the creation of the theory of wave mechanics by Schrödinger in Zurich during the early months of 1926; (...) he laid the foundations of this theory in his first two communications toAnnalen der Physik. Part III deals with the early applications of wave mechanics to atomic problems—including the demonstration of equivalence of wave mechanics with the quantum mechanics of Born, Heisenberg, and Jordan, and that of Dirac—by Schrödinger himself and others. The new theory was immediately accepted by the scientific community. (shrink)

This article (Part II) deals with the creation of the theory of wave mechanics by Erwin Schrödinger in Zurich during the early months of 1926; he laid the foundations of this theory in his first two communications toAnnalen der Physik. The background of Schrödinger's work on, and his actual creation of, wave mechanics are analyzed.

This paper deals with the development of, and the current discussion about, the interpretation of quantum mechanics. The following topics are discussed: 1. The Copenhagen Interpretation, 2. Formal Problems of Quantum Mechanics, 3. Process of Measurement and the Equation of Motion, 4. Macroscopic Level of Description, 5. Search for Hidden Variables, 6. The Notion of “Reality” and Epistemology of Quantum Mechanics, 7. Quantum Mechanics and the Explanation of Life.The Bohr‐Einstein dialogue on the validity of the quantum mechanical description of physical (...) reality lasted over two decades. Since the early nineteen fifties, Wiper has provided much of the point and counterpoint of the continuing discussion on the interpretation and epistemology of quantum mechanics. We have explored Wiper's views in some detail against the background of historical development and current debate. (shrink)

This article (Part III) deals with the early applications of wave mechanics to atomic problems—including the demonstration of the formal mathematical equivalence of wave mechanics with the quantum mechanics of Born, Heisenberg, and Jordan, and that of Dirac—by Schrödinger himself and others. The new theory was immediately accepted by the scientific community.

This paper deals with the development of, and the current discussion about, the interpretation of quantum mechanics. The following topics are discussed: 1. The Copenhagen Interpretation, 2. Formal Problems of Quantum Mechanics, 3. Process of Measurement and the Equation of Motion, 4. Macroscopic Level of Description, 5. Search for Hidden Variables, 6. The Notion of “Reality” and Epistemology of Quantum Mechanics, 7. Quantum Mechanics and the Explanation of Life.The Bohr‐Einstein dialogue on the validity of the quantum mechanical description of physical (...) reality lasted over two decades. Since the early nineteen fifties, Wiper has provided much of the point and counterpoint of the continuing discussion on the interpretation and epistemology of quantum mechanics. We have explored Wiper's views in some detail against the background of historical development and current debate. (shrink)