`Science is rooted in conversations.' The word is from Heisenberg but it becomes with Mara Beller a thesis for reconsidering the philosophy and history of science: how conversations were a cradle for the Copenhagen interpretation of quantum mechanics is the main topic of this book. This `dialogical' approach is moreover assumed to be quite general and it is proposed as a guideline for future investigations in the history of science. This work will certainly be important among historians of science. Its most valuable content is a wealth of information picked up from many sources, including the correspondence between the actors and later registered commentaries by many witnesses. There will be also undoubtedly much discussion of its conclusions and theses. They are extremely strong since, to mention but a few, one is told that the success of the Copenhagen interpretation is the result of a `fierce' propaganda strategy, and that Bohr could not really master physics (because of a weakness in mathematics), while the idea of complementarity, after a long discussion, is dismissed as `mythology'. Such new ideas will certainly find an enthusiastic approval from the adeherents of `new is beautiful', and will give rise to much discussion. What is missing most, however, in this book is a consideration of recent intensive renewals of interpretation arising from advances in both experiments and theory. The resulting conclusions are clearly different from Beller's: now that there are demonstrative versions of interpretation, one can fully appreciate why it was so difficult to justify logically and philosophically the Copenhagen interpretation (accordingly Bohr's stature would be enhanced rather than slighted). Mara Beller's inclination towards excessive statements is finally crowned when she says that her philosophical analysis `demonstrates the possibility and the need of a viable alternative to the orthodox interpretation' (most probably Bohmian mechanics). To have such an Aristotelian confidence in the power of philosophy and to be so assertive in a book where neither the word or notion of `decoherence' is mentioned indicate in my opinion the real nature of that book: too provocative to be wise.
Science is rooted in conversations.' The word is from Heisenberg but it becomes with Mara Beller a thesis for reconsidering the philosophy and history of science: how conversations were a cradle for the Copenhagen interpretation of quantum mechanics is the main topic of this book. This dialogical' approach is moreover assumed to be quite general and it is proposed as a guideline for future investigations in the history of science. This work will certainly be important among historians of science. Its most valuable content is a wealth of information picked up from many sources, including the correspondence between the actors and later registered commentaries by many witnesses. There will be also undoubtedly much discussion of its conclusions and theses. They are extremely strong since, to mention but a few, one is told that the success of the Copenhagen interpretation is the result of a fierce' propaganda strategy, and that Bohr could not really master physics (because of a weakness in mathematics), while the idea of complementarity, after a long discussion, is dismissed as mythology'. Such new ideas will certainly find an enthusiastic approval from the adeherents of new is beautiful', and will give rise to much discussion. What is missing most, however, in this book is a consideration of recent intensive renewals of interpretation arising from advances in both experiments and theory. The resulting conclusions are clearly different from Beller's: now that there are demonstrative versions of interpretation, one can fully appreciate why it was so difficult to justify logically and philosophically the Copenhagen interpretation (accordingly Bohr's stature would be enhanced rather than slighted). Mara Beller's inclination towards excessive statements is finally crowned when she says that her philosophical analysis demonstrates the possibility and the need of a viable alternative to the orthodox interpretation' (most probably Bohmian mechanics). To have such an Aristotelian confidence in the power of philosophy and to be so assertive in a book where neither the word or notion of `decoherence' is mentioned indicate in my opinion the real nature of that book: too provocative to be wise.
THE conceptual problems raised by the discovery of quantum effects have not been fully resolved after half a century. Part of the reason for this is undoubtedly to be found in the mutual ignorance which prevails between physicists and philosophers. In his book Heisenberg brings together a philosophically inclined temperament with an unrivalled knowledge of physics. The result is a book of very great interest, however much one might disagree with his conclusions. The collection of essays of which the other book is made up is intended to bring crucial conceptual problems in physics especially to the notice of philosophers. The design and intention of the collection is admirable for this is the proper way to overcome the departmentalization of interest that has left the deep conceptual problems still unresolved. Men like Heisenberg who combine philosophical temperament with scientic knowledge of great distinction are rare, and yet the difficulties can only be cleared up by the application of philosophical techniques of analysis to problems which are an intimate and difficult part of physics. A great deal of the interest of Heisenberg's book lies in the very comprehensive account he gives of the origin and growth of the Copenhagen school, and the way the new phenomena forced a largely unwelcome picture of nature upon Bohr and his friends. The most important chapter from a philosophical point of view is that in which Heisenberg defends this interpretation against the attacks to which it has been subjected. The essence of his argument for the interpretation can be summed up in two propositions. (i) The Copenhagen interpretation of physical theory, which depends upon the acceptance of the so-called Principle of Complementarity, is an inevitable and final interpretation. The reason for this is that there are only two possible general models for understanding given physical phenomena; a particle model or a wave model. These are exhaustive and exclusive because the former depends upon discontinuous and the latter upon continuous (using substance here in the traditional philosophical sense). If we find, as we do, that the two fundamental constituents of the universe, matter and radiation, each exhibit two classes of phenomena, one explainable only on a particle model and one on a wave model, then we are compelled to adopt a complementarity hypothesis and give up the idea of finding a single and uniform model for the understanding of phenomena. There are only two kinds of models; they are mutually exclusive; both are required; hence we either despair before an insoluble problem or adopt the Copenhagen interpretation. (2) Any serious criticism of this interpretation must offer an alternative
This book gives a clear and comprehensive exposition of Niels Bohr's philosophy of physics. Bohr's ideas are of major importance, for they are the source of the Copenhagen interpretation of quantum physics; yet they are obscure, and call for the sort of close analysis that this book provides. The book describes the historical background of the physics from which Bohr's ideas grew. The core of the book is a detailed analysis of Bohr's arguments for complementarity and of the interpretation which he put upon it. Special emphasis is placed throughout on the contrasting views of Einstein, and the great debate between Bohr and Einstein is thoroughly examined. The book traces the philosophical influences on Bohr, and unravels the realist and anti-realist strands in his thinking. Bohr's philosophy is critically assessed in the light of recent developments in the foundations of quantum physics (the work of Bell and others) and in philosophy (the realism-anti-realism debate) and it is revealed as being much more subtle and sophisticated than it is generally taken to be. While the book will be of interest to specialists, it is written in a style that will make it accessible to those who have no specialist knowledge of the relevant physics and philosophy.
This novel text directly addresses common claims and misconceptions around quantum mechanics and presents a fresh and modern understanding of this fundamental and essential physical theory. It begins with a non-mathematical introduction to some of the more controversial topics in the foundations of quantum mechanics. For those more familiar with the theoretical framework of quantum mechanics, the text moves on to a general introduction to quantum field theory, followed by a detailed discussion of cutting-edge topics in this area such as decoherence and spontaneous coherence. Several important philosophical problems in quantum mechanics are considered, and their interpretations are compared, notably the Copenhagen and many-worlds interpretations. The inclusion of frequent real-world examples, such as superconductors and superfluids, ensures the book remains grounded in modern research. This book will be a valuable resource for students and researchers in both physics and the philosophy of science interested in the foundations of quantum mechanics.
Of all the many rival interpretations of quantum mechanics, none is more important or influential than the Copenhagen interpretation. Unfortunately, there is no one Copenhagen interpretation of quantum mechanics. If one uses the expression, and everyone does, one should not think of the Copenhagen interpretation as a single consistent interpretation of the theory. Philosophers of physics tend to use the expression ‘the Copenhagen interpretation of quantum mechanics’ as a label covering a variety of different interpretations all of which either originate with Niels Bohr or were invented by him, his colleagues and guests at the Institute for Theoretical Physics in Copenhagen beginning in the middle 1920s. Perhaps one should say that the Copenhagen interpretation in this diffuse sense goes back farther than this, back even before the rise of the new quantum mechanics. Heisenberg tells the story of a boat trip he, Bohr, and some friends took from Copenhagen to the island of Fyn around the time when the then new quantum mechanics was being developed. Bohr, ‘full of the new interpretation of quantum theory’, talked of ‘the difficulties of language, of the limitations of all our means of expressing ourselves’ and of how these limitations had been expressed ‘in the foundation of atomic theory in a mathematically lucid way’. ‘Finally,’ Heisenberg ends the story, ‘one of the friends remarked drily, “But, Niels, this is not really new, you said exactly the same ten years ago”
Classical mechanics and quantum mechanics are two of the most successful scientific theories ever discovered, and yet how they can describe the same world is far from clear: one theory is deterministic, the other indeterministic; one theory describes a world in which chaos is pervasive, the other a world in which chaos is absent. Focusing on the exciting field of 'quantum chaos', this book reveals that there is a subtle and complex relation between classical and quantum mechanics. It challenges the received view that classical and quantum mechanics are incommensurable, and revives another, largely forgotten tradition due to Niels Bohr and Paul Dirac. By artfully weaving together considerations from the history of science, philosophy of science, and contemporary physics, this book offers a new way of thinking about intertheory relations and scientific explanation. It will be of particular interest to historians and philosophers of science, philosophically-inclined physicists, and interested non-specialists.
The theoretical and experimental context within which the “Copenhagen Interpretation” of quantum theory was generated is underemphasized by recent critics of the Bohr-Heisenberg philosophy. When an interpretation of a theory has been as successful as this one has been, there is little practical warrant for the “alternative interpretations” which have, since Bohm, been receiving prominence. Indeed, these are not even genuine alternatives; although rich in provocative prose, they provide not a scrap of algebra with which to organize the practical physicist's thinking. Several objections to the Bohr interpretation are critically examined, as is also a particular use of the correspondence principle which has seemed to cast doubt on the Copenhagen ideas.