E.P. Wigner, one of the leading scientists involved in the early development of nuclear technology, had always in mind its political and social implications. In the 60s persuing his goal of a peaceful open world he began to develop the concept of Civil Defense against nuclear attacks. Looking back one might see this as an alternative to the concept of the Nuclear Shield. The present volume contains a selection of Wigner's writings on this subject. It is annotated by Conrad Chester.

This study deals with the development of, and the current discussion about, the interpretation of quantum mechanics. The following topics are discussed: 1. The Copenhagen In terpretation; 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 the Epistemology of Quantum Mechanics; and 7. Quantum Mechanics and the Explanation of Life. The Bohr-Einstein dialogue on the validity of the quan tum mechanical description of physical reality lasted over two decades. Since the early nineteen-fifties, Eugene Wigner has provided much of the point and counterpoint of the continuing discussion on the interpretation and epistemolo gy of quantum mechanics. We have explored Wigner's views in some detail against the background of historical develop ment and current debate. Professor Eugene Wigner has sustained me over many years in my work on the conceptual development of mod ern physics by his kindness and encouragement. This study owes its existence to his direct inspiration, and to his suggestion to me in April 1971 that it would be of interest to write an account of the interpretation of quantum me chanics and the current discussion about it. XII PREFACE This study was completed in September 1972. Signifi cant new developments have occurred since then in the dis cussion of questions related to the epistemology of quan tum mechanics."

The fundamental conceptions of twentieth-century physics have profoundly influenced almost every field of modern thought and activity. Quantum Theory, Relativity, and the modern ideas on the Structure of Matter have contributed to a deeper understand ing of Nature, and they will probably rank in history among the greatest intellectual achievements of all time. The purpose of our symposium was to review, in historical perspective, the current horizons of the major conceptual structures of the physics of this century. Professors Abdus Salam and Hendrik Casimir, in their remarks at the opening of the symposium, have referred to its origin and planning. Our original plan was to hold a two-week symposium on the different aspects of five principal themes: 1. Space, Time and Geometry (including the structure of the universe and the theory of gravita tion),2. Quantum Theory (including the development of quantum mechanics and quantum field theory), 3. Statistical Description of Nature (including the discussion of equilibrium and non-equilibrium phenomena, and the application of these ideas to the evolution of biological structure), 4. The Structure of Matter (including the discus sion, in a unified perspective, of atoms, molecules, nuclei, elementary particles, and the physics of condensed matter), and finally, 5. Physical Description and Epistemo logy (including the distinction between classical and quantum descriptions, and the epistemological and philosophical problems raised by them).

Jagdish Mehra's historical account of the Solvay Conferences from 1911 to 1973 demonstrates not only the great influence which these conferences have had on the development of modern physics, but it also shows clearly how far-sighted and well planned were the intentions of Ernest Solvay when he took the initiative for organizing a new type of international conferences. In contrast to the conventional meetings in which reports are given on the successful solution of scientific problems, the Solvay Conferences were conceived to help directly in solving specific problems of unusual difficulty. The importance of the quantum structure of Nature had become well under stood already by 1911, but at that time there was no hope for an answer to the ex tremely difficult new questions posed by the atomic phenomena. The new conferences should therefore be devoted primarily to thorough discussions of such problems be tween a small number of the most competent physicists, and Ernest Solvay was guided by the hope that the discussions would eventually lead to a real and substantial progress. The earliest Solvay Conferences which I attended were those of 1927, 1930 and 1933, and they served this purpose extremely well. In 1926 the mathematical formalism of quantum-and wave-mechanics approached its final shape, but the interpretation was still controversial. Schrodinger hoped that his matter waves could be considered as waves in three-dimensional space and time, and that the discontinuous feature of quantum 'jumps' could be avoided thereby."

Not only was E.P. Wigner one of the most active creators of 20th century physics, he was also always interested in expressing his opinion in philosophical, political or sociological matters. This volume of his collected works covers a wide selection of his essays about science and society, about himself and his colleagues. Annotated by J. Mehra, this volume will become an important source of reference for historians of science, and it will be pleasant reading for every physicist interested in forming ideas in modern physics.

Not only was E.P. Wigner one of the most active creators of 20th century physics, he was also always interested in expressing his opinion in philosophical, political or sociological matters. This volume of his collected works covers a wide selection of his essays about science and society, about himself and his colleagues. Annotated by J. Mehra, this volume will become an important source of reference for historians of science, and it will be pleasant reading for every physicist interested in forming ideas in modern physics.

Quantum Theory, together with the principles of special and general relativity, constitute a scientific revolution that has profoundly influenced the way in which we think about the universe and the fundamental forces that govern it. The Historical Development of Quantum Theory is a definitive historical study of that scientific work and the human struggles that accompanied it from the beginning. Drawing upon such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehra's personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history of quantum theory in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process. The Historical Development of Quantum Theory is science, history, and biography, all wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.

Quantum Theory, together with the principles of special and general relativity, constitute a scientific revolution that has profoundly influenced the way in which we think about the universe and the fundamental forces that govern it. The Historical Development of Quantum Theory is a definitive historical study of that scientific work and the human struggles that accompanied it from the beginning. Drawing upon such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehra's personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history of quantum theory in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process. The Historical Development of Quantum Theory is science, history, and biography, all wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.

Quantum Theory, together with the principles of special and general relativity, constitute a scientific revolution that has profoundly influenced the way in which we think about the universe and the fundamental forces that govern it. The Historical Development of Quantum Theory is a definitive historical study of that scientific work and the human struggles that accompanied it from the beginning. Drawing upon such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehra's personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history of quantum theory in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process. The Historical Development of Quantum Theory is science, history, and biography, all wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.

Quantum Theory, together with the principles of special and general relativity, constitute a scientific revolution that has profoundly influenced the way in which we think about the universe and the fundamental forces that govern it. The Historical Development of Quantum Theory is a definitive historical study of that scientific work and the human struggles that accompanied it from the beginning. Drawing upon such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehra's personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history of quantum theory in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process. The Historical Development of Quantum Theory is science, history, and biography, all wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.

A definitive historical study of this scientific work and the human struggles that accompanied it from the very beginning. Drawing on such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehras personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process, wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.

E.P. Wigner, one of the leading scientists involved in the early development of nuclear technology, had always in mind its political and social implications. In the 60s persuing his goal of a peaceful open world he began to develop the concept of Civil Defense against nuclear attacks. Looking back one might see this as an alternative to the concept of the Nuclear Shield. The present volume contains a selection of Wigner's writings on this subject. It is annotated by Conrad Chester.

Among the founding fathers of modern quantum physics few have contributed to our basic understanding of its concepts as much as E.P. Wigner. His articles on the epistemology of quantum mechanics and the measurement problem, and the basic role of symmetries were of fundamental importance for all subsequent work. He was also the first to discuss the concept of consciousness from the point of view of modern physics. G.G. Emch edited most of those papers and wrote a very helpful introduction into Wigner's contributions to Natural Philosophy. The book should be a gem for all those interested in the history and philosophy of science.

Quantum Theory, together with the principles of special and general relativity, constitute a scientific revolution that has profoundly influenced the way in which we think about the universe and the fundamental forces that govern it. The Historical Development of Quantum Theory is a definitive historical study of that scientific work and the human struggles that accompanied it from the beginning. Drawing upon such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehra's personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history of quantum theory in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process. The Historical Development of Quantum Theory is science, history, and biography, all wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.

Some time ago I published a small piece * dealing with a charming little essay on 'the state of ether in magnetic fields', which the sixteen-year-old Einstein had written while he was awaiting admission to the E. T. H. in Zurich. This paper sought to trace the continuity between Einstein's early interest in electrodynamics and his later work on the special and general relativity theories. On reading this paper, Professor Eugene Wigner asked me whether David Hilbert had not independently discovered the field equations of gravitation. ** His impression from his stay in Gottingen (where Wigner had been Hilbert's assistant for one year in the late nineteen-twenties) was that Hilbert had indeed done so, and he asked me if it was true. I replied to Professor Wigner about Hilbert's contribution to the theory of gravitation. t He kindly encouraged me to expand my account to deal with the intricate and exciting details of the early years in the formulation of the general relativity theory of gravitation. This is what I have sought to do in this study. Albert Einstein created the general relativity theory of gravitation and dominated its development through the rest of his life. His early work on the theory of gravitation, from 1912 to 1916, had the drama of high adventure. It culminated in the establishment of its foundations which have remained unassailed by the theoretical and experimental work of succeeding decades.

The fundamental conceptions of twentieth-century physics have profoundly influenced almost every field of modern thought and activity. Quantum Theory, Relativity, and the modern ideas on the Structure of Matter have contributed to a deeper understand ing of Nature, and they will probably rank in history among the greatest intellectual achievements of all time. The purpose of our symposium was to review, in historical perspective, the current horizons of the major conceptual structures of the physics of this century. Professors Abdus Salam and Hendrik Casimir, in their remarks at the opening of the symposium, have referred to its origin and planning. Our original plan was to hold a two-week symposium on the different aspects of five principal themes: 1. Space, Time and Geometry (including the structure of the universe and the theory of gravita tion),2. Quantum Theory (including the development of quantum mechanics and quantum field theory), 3. Statistical Description of Nature (including the discussion of equilibrium and non-equilibrium phenomena, and the application of these ideas to the evolution of biological structure), 4. The Structure of Matter (including the discus sion, in a unified perspective, of atoms, molecules, nuclei, elementary particles, and the physics of condensed matter), and finally, 5. Physical Description and Epistemo logy (including the distinction between classical and quantum descriptions, and the epistemological and philosophical problems raised by them).

Quantum Theory, together with the principles of special and general relativity, constitute a scientific revolution that has profoundly influenced the way in which we think about the universe and the fundamental forces that govern it. The Historical Development of Quantum Theory is a definitive historical study of that scientific work and the human struggles that accompanied it from the beginning. Drawing upon such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehra's personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history of quantum theory in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process. The Historical Development of Quantum Theory is science, history, and biography, all wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.

Quantum Theory, together with the principles of special and general relativity, constitute a scientific revolution that has profoundly influenced the way in which we think about the universe and the fundamental forces that govern it. The Historical Development of Quantum Theory is a definitive historical study of that scientific work and the human struggles that accompanied it from the beginning. Drawing upon such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehra's personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history of quantum theory in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process. The Historical Development of Quantum Theory is science, history, and biography, all wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.

Quantum Theory, together with the principles of special and general relativity, constitute a scientific revolution that has profoundly influenced the way in which we think about the universe and the fundamental forces that govern it. The Historical Development of Quantum Theory is a definitive historical study of that scientific work and the human struggles that accompanied it from the beginning. Drawing upon such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehra's personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history of quantum theory in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process. The Historical Development of Quantum Theory is science, history, and biography, all wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.

Quantum Theory, together with the principles of special and general relativity, constitute a scientific revolution that has profoundly influenced the way in which we think about the universe and the fundamental forces that govern it. The Historical Development of Quantum Theory is a definitive historical study of that scientific work and the human struggles that accompanied it from the beginning. Drawing upon such materials as the resources of the Archives for the History of Quantum Physics, the Niels Bohr Archives, and the archives and scientific correspondence of the principal quantum physicists, as well as Jagdish Mehra's personal discussions over many years with most of the architects of quantum theory, the authors have written a rigorous scientific history of quantum theory in a deeply human context. This multivolume work presents a rich account of an intellectual triumph: a unique analysis of the creative scientific process. The Historical Development of Quantum Theory is science, history, and biography, all wrapped in the story of a great human enterprise. Its lessons will be an aid to those working in the sciences and humanities alike.||Comments by distinguished physicists on "The Historical Development of Quantum Theory":||"¿the most definitive work undertaken by anyone on this vast and most important development in the history of physics. Jagdish Mehra, trained in theoretical physics under Pauli, Heisenberg, and Dirac, pursued the vision of his youth to write about the historical and conceptual development of quantum theory in the 20th century¿This series of books on the HDQT has thus become the most authentic and permanent source of our knowledge of how quantum theory, its extensions and applications developed. My heartfelt congratulations."|-Hans A. Bethe, Nobel Laureate||"A thrilling and magnificent achievement!"|-Subrahmanyan Chandrasekhar, FRS, Nobel Laureate||"¿capture(s) precisely, accurately, and thoroughly the very essence and all the fundamental details of the theory, and that is a remarkable achievement¿I have greatly enjoyed reading these books and learned so many new things from them. This series of books will remain a permanent source of knowledge about the creation and development of quantum theory. Congratulations!"|-Paul A. Dirac, FRS, Nobel Laureate||"The wealth and accuracy of detail in 'The Historical Development of Quantum Theory' are breathtaking."|-Richard P. Feynman, Nobel Laureate