The seminal work by one of the most important thinkers of the twentieth century, Physics and Philosophy is Werner Heisenberg's concise and accessible narrative of the revolution in modern physics, in which he played a towering role. The outgrowth of a celebrated lecture series, this book remains as relevant, provocative, and fascinating as when it was first published in 1958. A brilliant scientist whose ideas altered our perception of the universe, Heisenberg is considered the father of quantum physics; he is (...) most famous for the Uncertainty Principle, which states that quantum particles do not occupy a fixed, measurable position. His contributions remain a cornerstone of contemporary physics theory and application. Book jacket. (shrink)

Presents German physicist Werner Heisenberg's 1958 text in which he discusses the philosophical implications and social consequences of quantum mechanics and other physical theories.

Aiming to unravel the mystery of quantum mechanics, this book is concerned with questions about action-at-a-distance, holism, and whether quantum mechanics gives a complete account of microphysical reality. With rigorous arguments and clear thinking, the author provides an introduction to the philosophy of physics.

It was shown by de Broglie and Bohm that the concept of a deterministic particle trajectory is compatible with quantum mechanics. It is demonstrated by explicit construction that there exists another more general deterministic trajectory interpretation. The method exploits an internal angular degree of freedom that is implicit in the Schrödinger equation, in addition to the particle position. The de Broglie-Bohm model is recovered when the new theory is averaged over the internal freedom. The model exhibits a strong form of (...) entanglement which implies a primary role for the wavefunction of the Universe. The conditions of autonomy are examined, and the viability of the theory is established by application to the measurement problem. (shrink)

We consider the problem of whether there are deterministic theories describing the evolution of an individual physical system in terms of the definite trajectories of its constituent particles and which stay in the same relation to quantum mechanics as Bohmian mechanics but which differ from the latter for what concerns the trajectories followed by the particles. Obviously, one has to impose on the hypothetical alternative theory precise physical requirements. We analyze various such constraints and we show step by step how (...) to meet them. This way of attacking the problem turns out to be useful also from a pedagogical point of view since it allows one to recall and focus on some relevant features of Bohm's theory. One of the central requirements we impose on the models we are going to analyze has to do with their transformation properties under the transformation of the extended Galilei group. In a context like the one we are interested in, one can put forward various requests that we refer to as physical and genuine covariance and invariance. Other fundamental requests are that the theory allows the description of isolated physical systems as well as that it leads to a solution (in the same sense as Bohmian mechanics) of the measurement problem. We show that, even when all the above conditions are taken into account, there are infinitely many inequivalent (from the point of view of the trajectories) bohmian-like theories reproducing the predictions of quantum mechanics. This raises some interesting questions about the meaning of Bohmian mechanics. (shrink)

In this paper I describe the history of the surreal trajectories problem and argue that in fact it is not a problem for Bohm's theory. More specifically, I argue that one can take the particle trajectories predicted by Bohm's theory to be the actual trajectories that particles follow and that there is no reason to suppose that good particle detectors are somehow fooled in the context of the surreal trajectories experiments. Rather than showing that Bohm's theory predicts the wrong particle (...) trajectories or that it somehow prevents one from making reliable measurements, such experiments ultimately reveal the special role played by position and the fundamental incompatibility between Bohm's theory and relativity. They also provide a striking example of the theory-ladenness of observation. (shrink)

In the _The Undivided Universe_, David Bohn and Basil Hiley present a radically different approach to quantum theory. They develop an interpretation of quantum mechanics which gives a clear, intuitive understanding of its meaning and in which there is a coherent notion of the reality of the universe without assuming a fundamental role for the human observer. With the aid of new concepts such as active information together with non-locality, they provide a comprehensive account of all the basic features of (...) quantum mechanics, including the relativistic domain and quantum field theory. It is shown that, with the new approach, paradoxical or unsatisfactory features associated with the standard approaches, such as the wave-particle duality and the collapse of the wave function, do not arise. Finally, the authors make new suggestions and indicate some areas in which one may expect quantum theory to break down in a way that will allow for a test. _The Undivided Universe_ is an important book especially because it provides a different overall world view which is neither mechanistic nor reductionist. This view will ultimately have radical implications not only in physics but also in our general approach to all areas of life. (shrink)

First published in 1995. Routledge is an imprint of Taylor & Francis, an informa company.

In the The Undivided Universe, David Bohn and Basil Hiley present a radically different approach to quantum theory.

This book comprises all of John Bell's published and unpublished papers in the field of quantum mechanics, including two papers that appeared after the first edition was published. It also contains a preface written for the first edition, and an introduction by Alain Aspect that puts into context Bell's great contribution to the quantum philosophy debate. One of the leading expositors and interpreters of modern quantum theory, John Bell played a major role in the development of our current understanding of (...) the profound nature of quantum concepts. First edition Hb (1987): 0-521-33495-0 First edition Pb (1988): 0-521-36869-3. (shrink)

From the beginning, the implications of quantum theory for our most general understanding of the world have been a matter of intense debate. Einstein argues that the theory had to be regarded as fundamentally incomplete. Its inability, for example, to predict the exact time of decay of a single radioactive atom had to be due to a failure of the theory and not due to a permanent inability on our part or a fundamental indeterminism in nature itself. In 1964, John (...) Bell derived a theorem which showed that any deterministic theory which preserved locality would have certain consequences for measurements performed at a distance from one another. An experimental check seems to show that these consequences are not, in fact, realized. The correlation between the sets of events is much stronger than any local deterministic theory could allow. What is more, this stronger correlation is precisely that which is predicted by quantum theory. The astonishing result is that local deterministic theories of the classical sort seem to be permanently excluded. Not only can the individual decay not be predicted, but no future theory can ever predict it. The contributors in this volume wrestle with this conclusion. Some welcome it; others leave open a return to at lease some kind of deterministic world, one which must however allow something like action-at-a distance. How much lit it? And how can one avoid violating relativity theory, which excludes action-at-a-distance? How can a clash between the two fundamental theories of modern physics, relativity and quantum theory, be avoided? What are the consequences for the traditional philosophic issue of causality explanation and objectivity? One thing is certain; we can never return to the comfortable Newtonian world where everything that happened was, in principle, predictable and where what happened at one measurement site could not affect another set of measurements being performed light-years away, at a distance that a light-signal could not bridge. Contributors: James T. Cushing, Abner Shimony, N. David Mermin, Jon P. Jarrett, Linda Wessels, Bas C. van Fraassen, Jeremy Butterfield, Michael L. G. Redhead, Henry P. Stapp, Arthur Fine, R. I. G. Hughes, Paul Teller, Don Howard, Henry J. Folse, and Ernan McMullin. (shrink)

Why does one theory "succeed" while another, possibly clearer interpretation, fails? By exploring two observationally equivalent yet conceptually incompatible views of quantum mechanics, James T. Cushing shows how historical contingency can be crucial to determining a theory's construction and its position among competing views. Since the late 1920s, the theory formulated by Niels Bohr and his colleagues at Copenhagen has been the dominant interpretation of quantum mechanics. Yet an alternative interpretation, rooted in the work of Louis de Broglie in the (...) early 1920s and reformulated and extended by David Bohm in the 1950s, equally well explains the observational data. Through a detailed historical and sociological study of the physicists who developed different theories of quantum mechanics, the debates within and between opposing camps, and the receptions given to each theory, Cushing shows that despite the preeminence of the Copenhagen view, the Bohm interpretation cannot be ignored. Cushing contends that the Copenhagen interpretation became widely accepted not because it is a better explanation of subatomic phenomena than is Bohm's, but because it happened to appear first. Focusing on the philosophical, social, and cultural forces that shaped one of the most important developments in modern physics, this provocative book examines the role that timing can play in the establishment of theory and explanation. (shrink)

Abner Shimony is one of the most eminent of present-day philosophers of science, whose work has exerted a profound influence in both the philosophy and physics communities. This two-volume 1993 collection of his essays written over a period of forty years explores the interrelations between science and philosophy. Shimony regards the knowing subject as an entity in nature whose faculties must be studied from the points of view of evolutionary biology and empirical psychology. He maintains that the twentieth century is (...) one of the great ages of metaphysics, given the deep implications of quantum mechanics, relativity theory and molecular biology. Nevertheless he rejects the thesis that mentality is entirely explicable in physical terms and argues that mind has a fundamental place in nature. Though distinguishing between values and scientifically established facts, Shimony holds that the sense of wonder cultivated by the natural sciences is one of the noblest of human values. (shrink)

Although skeptical of the prohibitive power of no-hidden-variables theorems, John Bell was himself responsible for the two most important ones. I describe some recent versions of the lesser known of the two (familiar to experts as the "Kochen-Specker theorem") which have transparently simple proofs. One of the new versions can be converted without additional analysis into a powerful form of the very much better known "Bell's Theorem," thereby clarifying the conceptual link between these two results of Bell.