The scientific career of John Stewart Bell was distinguished by its breadth and its quality. He made several very important contributions to scientific fields as diverse as accelerator physics, high energy physics and the foundations of quantum mechanics. This book contains a large part of J S Bell's publications, including those that are recognized as his most important achievements, as well as others that are for no good reason less well known. The selection was made by Mary Bell, Martinus Veltman and Kurt Gottfried, all of whom were involved with John Bell both personally and professionally throughout a large part of his life. An introductory chapter has been written to help place the selected papers in a historical context and to review their significance. This book comprises an impressive collection of outstanding scientific work of one of the greatest scientists of the recent past, and it will remain important and influential for a long time to come.
The scientific career of John Stewart Bell was distinguished by its breadth and its quality. He made several very important contributions to scientific fields as diverse as accelerator physics, high energy physics and the foundations of quantum mechanics. This book contains a large part of J S Bell's publications, including those that are recognized as his most important achievements, as well as others that are for no good reason less well known. The selection was made by Mary Bell, Martinus Veltman and Kurt Gottfried, all of whom were involved with John Bell both personally and professionally throughout a large part of his life. An introductory chapter has been written to help place the selected papers in a historical context and to review their significance. This book comprises an impressive collection of outstanding scientific work of one of the greatest scientists of the recent past, and it will remain important and influential for a long time to come.
Bell was a fine physicist. He did important work on accelerators and on nuclear and particle physics, but he will be mostly remembered for his seminal work on the foundations of quantum theory. It can be argued that Bell’s inequalities constitute both the fundamental mystery and the greatest opportunity of quantum theory. In work—taking an established component of physics and bringing in increased understanding and further challenges—he may be compared with Michael Faraday. Bell’s work was based on honesty, and honesty and integrity were also central to his personal life. John Bell’s honesty in his science, and his willingness to work steadily for its progress and to devote his time and efforts to help others to do the same, stand as guiding lights to those coming after him.
Introduction This contribution to the book in honour of J. S. Bell will probably differ from the remaining ones, in particular since only a part of it will be devoted to specific technical arguments. In fact I have considered it appropriate to share with the community of physicists interested in the foundational problems of our best theory the repeated interactions I had with him in the last four years of his life, the deep discussions in which we have been involved in particular in connection with the elaboration of collapse theories and their interpretation, and the contributions he gave to the development of this approach at a formal level, as well as championing it on repeated occasions. In brief, I intend to play here the role of one of those lucky persons who became acquainted with him personally, who has exchanged important views with him, who has learned a lot from his deep insight and conceptual lucidity, and, last but not least, whose scientific work has been appreciated by him. Moreover, due to the fact that this book intends to celebrate the 50th anniversary of the derivation of the fundamental inequality which bears his name, I will also devote a small part of the text to recalling his clearcut views about the locality issue, views that I believe have not been grasped correctly by a remarkable part of the scientific community. I will analyze this problem in quite general terms at the end of the paper. Some of Bell's Scientific Achievements Bell received bachelor's degrees in experimental physics and in mathematical physics at Queen'sUniversity of Belfast in the years 1948 and 1949, respectively, and a PhD in physics at the University of Birmingham. We all know very well that already at that time he was absolutely unsatisfied with the conceptual structure of quantum mechanics and with the way in which it was taught. This is significantly expressed by the statement he made during an interview to Jeremy Bernstein: I remember arguing with one of my professors, a Doctor Sloane, about that. I was getting very heated and accusing him, more or less, of dishonesty. He was getting very heated too and said, ‘You're going too far.’
This contribution to the book in honour of J.S. Bell will probably differ from the remaining ones, in particular since only a part of it will be devoted to specific technical arguments. In fact I have considered appropriate to share with the community of physicists interested in the foundational problems of our best theory the repeated interactions I had with him in the last four years of his life, the deep discussions in which we have been involved in particular in connection with the elaboration of collapse theories and their interpretation, the contributions he gave to the development of this approach, both at a formal level, as well as championing it on repeated occasions. In brief, I intend to play here the role of one of those lucky persons who became acquainted with him personally, who has exchanged important views with him, who has learned a lot from his deep insight and conceptual lucidity, and, last but not least, one whose scientific work has been appreciated by him. Moreover, due to the fact that this book intends to celebrate the 50th anniversary of the derivation of the fundamental inequality which bears his name, I will also devote a small part of the text to recall his clear cut views about the locality issue, views that I believe have not been grasped correctly by a remarkable part of the scientific community. I will analyze this problem in quite general terms at the end of the paper.
Abstract John Stewart Bell was one of the most significant physicists of the twentieth century; his work has led to a much enhanced understanding of quantum theory and what it says about the physical universe, particularly about realism, determinism, and locality. This book describes Bell's relatively humble origins and his struggles to obtain secondary and university education. It then describes his work at Harwell, where he made important theoretical contributions to the development of particle accelerators, in particular with his pioneering work on strong focussing. Later, he proved the extremely important CPT theorem. At CERN, Bell made a range of important theoretical contributions to elementary particle physics; these contributions include the physics of neutrinos, the existence of different types of neutrinos, the suitability of gauge theory for all physical interactions, and the Adler–Bell–Jackiw anomaly, which shows how classical symmetries are lost under quantum theory. In his work on quantum theory, he criticized the orthodox 'Copenhagen' interpretation of quantum theory, which did not allow the actual state of the physical world to be analysed. He showed that the famous von Neumann theorem, which claimed to show that 'hidden variables' were not allowed in quantum theory, was incorrect; his famous Bell's theorem, or Bell's inequality, showed that any such variables much be non-local. Bell's work led to greatly increased freedom in the discussion of quantum theory, and the development of quantum information theory.
John Stewart Bell (1928-1990) was one of the most important figures in twentieth-century physics, famous for his work on the fundamental aspects of the century's most important theory, quantum mechanics. While the debate over quantum theory between the supremely famous physicists, Albert Einstein and Niels Bohr, appeared to have become sterile in the 1930s, Bell was able to revive it and to make crucial advances - Bell's Theorem or Bell's Inequalities. He was able to demonstrate a contradiction between quantum theory and essential elements of pre-quantum theory - locality and causality. The book gives a non-mathematical account of Bell's relatively impoverished upbringing in Belfast and his education. It describes his major contributions to quantum theory, but also his important work in the physics of accelerators, and nuclear and elementary particle physics.