The reluctant revolutionary -- The patent slave -- The golden Dane -- The quantum atom -- When Einstein met Bohr -- The prince of duality -- Spin doctors -- The quantum magician -- A late erotic outburst -- Uncertainty in Copenhagen -- Solvay 1927 -- Einstein forgets relativity -- Quantum reality -- For whom Bell's theorem tolls -- The quantum demon.

Einstein's philosophy of physics (as clarified by Fine, Howard, and Held) was predicated on his Trennungsprinzip, a combination of separability and locality, without which he believed objectification, and thereby "physical thought" and "physical laws", to be impossible. Bohr's philosophy (as elucidated by Hooker, Scheibe, Folse, Howard, Held, and others), on the other hand, was grounded in a seemingly different doctrine about the possibility of objective knowledge, namely the necessity of classical concepts. In fact, it follows from Raggio's Theorem (...) in algebraic quantum theory that - within an appropriate class of physical theories - suitable mathematical translations of the doctrines of Bohr and Einstein are equivalent. Thus - upon our specific formalization - quantum mechanics accommodates Einstein's Trennungsprinzip if and only if it is interpreted a la Bohr through classical physics. Unfortunately, the protagonists themselves failed to discuss their differences in this constructive way, since their debate was dominated by Einstein's ingenious but ultimately flawed attempts to establish the "incompleteness" of quantum mechanics. This aspect of their debate may still be understood and appreciated, however, as reflecting a much deeper and insurmountable disagreement between Bohr and Einstein about the knowability of Nature. Using the theological controversy on the knowability of God as a analogy, we can say that Einstein was a Spinozist, whereas Bohr could be said to be on the side of Maimonides. Thus Einstein's off-the-cuff characterization of Bohr as a 'Talmudic philosopher' was spot-on. (shrink)

According to the naturalistic normative axiology of Laudan's reticulated model of scientific change, empirical discoveries in the advance of science can provide a rational basis for axiological decisions concerning which epistemic goals scientific inquiry ought to pursue. The Bohr-Einstein debate over acceptance of quantum theory is analyzed as a case of axiological change. The participants' aims are incompatible due to different formulations of the goal of objective description, but neither doubts the realist commitment to the existence of microsystems (...) or the intention of quantum mechanics to provide knowledge of them. Thus the general aim of realism is not at issue. (shrink)

Many commentators have remarked in passing on the resonance between deconstructionist theory and certain ideas of quantum physics. In this book, Arkady Plotnitsky rigorously elaborates the similarities and differences between the two by focusing on the work of Niels Bohr and Jacques Derrida. In detailed considerations of Bohr's notion of complementarity and his debates with Einstein, and in analysis of Derrida's work via Georges Bataille's concept of general economy, Plotnitsky demonstrates the value of exploring these theories in (...) relation to each other. Bohr's term complementarity describes a situation, unavoidable in quantum physics, in which two theories thought to be mutually exclusive are required to explain a single phenomenon. Light, for example, can only be explained as both wave and particle, but no synthesis of the two is possible. This theoretical transformation is then examined in relation to the ways that Derrida sets his work against or outside of Hegel, also resisting a similar kind of synthesis and enacting a transformation of its own. Though concerned primarily with Bohr and Derrida, Plotnitsky also considers a wide range of anti-epistemological endeavors including the work of Nietzsche, Bataille, and the mathematician Kurt Gödel. Under the rubric of complementarity he develops a theoretical framework that raises new possiblilities for students and scholars of literary theory, philosophy, and philosophy of science. (shrink)

: Although Dirac rarely participated in the interpretational debates over quantum theory, it is traditionally assumed that his views were aligned with Heisenberg and Bohr in the so-called Copenhagen-Göttingen camp. However, an unpublished—and apparently unknown—lecture of Dirac's reveals that this view is mistaken; in the famous debate between Einstein and Bohr, Dirac sided with Einstein. Surprisingly, Dirac believed that quantum mechanics was not complete, that the uncertainty principle would not survive in the future physics, and that (...) a deterministic description of the microworld would be recovered. In this paper I show how we can make sense of this unpublished lecture in the context of Dirac's broader philosophy of quantum mechanics, and how our present understanding of Dirac's philosophical views must be revised. (shrink)

Einstein Versus Bohr is unlike other books on science written by experts for non-experts, because it presents the history of science in terms of problems, conflicts, contradictions, and arguments. Science normally "keeps a tidy workshop." Professor Sachs breaks with convention by taking us into the theoretical workshop, giving us a problem-oriented account of modern physics, an account that concentrates on underlying concepts and debate. The book contains mathematical explanations, but it is so-designed that the whole argument can be (...) followed with the math omitted. Professor Sachs' story begins with classical and nineteenth century physics, describes the early discoveries in particle theory, and introduces the "old" quantum theory, which evolved into the quantum mechanics of the Copenhagen School. Such important ideas as the Einstein Photon Box experiment and the Einstein-Podolsky-Rosen Paradox, and Schrodinger's Cat Paradox are clearly expounded, followed by a completely fresh explanation of relativity in conceptual terms, showing how apparent paradoxes can be removed by Einstein's own interpretation, especially that of his later years. Professor Sachs gives a detailed comparison of the fundamentals of the quantum and relativity theories, suggesting how the contradictions might be resolved. In an epilogue, he makes suggestions, with reference to religious notions, Taoism, and Buber's theory of I-Thou, for generalizing Einstein's approach beyond physics. (shrink)

SummaryThe Bohr‐Einstein debate on the interpretation of quantum mechanics may be viewed as a discussion on the epistemological status of knowledge gained by physics. It is shown that in fact the advent of quantum theory has led, in a new context, to an old philosophical controversy between epistemological realism and phenomenalism . An inquiry into this controversy, taking into account the contemporary understanding of quantum mechanics based on the axiomatic study of its foundations, leads to the conclusion that (...) contrary to widespread opinion, it is perfectly possible to formulate quantum mechanics in an entirely realistic manner according to the postulate of Einstein. We demonstrate that Bohr's episteme‐logy, in which the role of experimental arrangements in the physical description is taken as a starting point, does not necessarily imply phenomenlism, but may be justifiably considered as a complementary standpoint to the realistic epistemology of Einstein, which is based on the notion of a mental construction which pictures reality. (shrink)

Niels Bohr, founding father of modern atomic physics and quantum theory, was as original a philosopher as he was a physicist. This study explores several dimensions of Bohr's vision: the formulation of quantum theory and the problems associated with its interpretation, the notions of complementarity and correspondence, the debates with Einstein about objectivity and realism, and his sense of the infinite harmony of nature. Honner focuses on Bohr's epistemological lesson, the conviction that all our description of (...) nature is dependent on the words we use and the ways we can unambiguously use them. (shrink)

The objective of this article is to demonstrate how the historical debate between materialism and idealism, in the field of Philosophy, extends, in new clothes, to the field of Quantum Physics characterized by realism and anti-realism. For this, we opted for a debate, also historical, between the realism of Albert Einstein, for whom reality exists regardless of the existence of the knowing subject, and Niels Bohr, for whom we do not have access to the ultimate reality of the (...) matter, unless conditioning it to the existence of an observer endowed with rationality, position adopted in the Interpretation of Complementarity – posture that was expanded in 1935 when Bohr assumed a “relationalist” conception, according to which the quantum state is defined by the relationship between the quantum object and the entire measuring device. This is an extremely important debate, as it further consolidates the results of nascent Quantum Mechanics, guaranteeing Bohr the leadership of the orthodoxy based on the interpretation of complementarity. Here, when dealing with Quantum Theory, we will not make any distinction between the terms Quantum Physics, Quantum Theory or Quantum Mechanics. The entire discussion will be held under the name “Quantum Theory”. Theory that tries to analyze and describe the behavior of physical systems of reduced dimensions, close to the sizes of molecules, atoms and subatomic particles. We hope that the reader will appreciate the genius of these two titans in this field of Physics when they magnificently formulate the arguments that support the object of their defenses. (shrink)

Murdoch describes the historical background of the physics from which Bohr's ideas grew; he traces the origins of his idea of complementarity and discusses its meaning and significance. Special emphasis is placed on the contrasting views of Einstein, and the great debate between Bohr and Einstein is thoroughly examined. Bohr's philosophy is revealed as being much more subtle, and more interesting than is generally acknowledged.

Reading Bohr: Physics and Philosophy offers a new perspective on Niels Bohr's interpretation of quantum mechanics as complementarity, and on the relationships between physics and philosophy in Bohr's work, which has had momentous significance for our understanding of quantum theory and of the nature of knowledge in general. Philosophically, the book reassesses Bohr's place in the Western philosophical tradition, from Kant and Hegel on. Physically, it reconsiders the main issues at stake in the Bohr-Einstein (...) confrontation and in the ongoing debates concerning quantum physics. It also devotes greater attention than in most commentaries on Bohr to the key developments and transformations of his thinking concerning complementarity. Most significant among them were those that occurred, first, under the impact of Bohr's exchanges with Einstein and, second, under the impact of developments in quantum theory itself, both quantum mechanics and quantum field theory. The importance of quantum field theory for Bohr's thinking has not been adequately addressed in the literature on Bohr, to the considerable detriment to our understanding of the history of quantum physics. Filling this lacuna is one of the main contributions of the book, which also enables us to show why quantum field theory compels us to move beyond Bohr without, however, simply leaving him behind. (shrink)

The 1964 theorem of John Bell shows that no model that reproduces the predictions of quantum mechanics can simultaneously satisfy the assumptions of locality and determinism. On the other hand, the assumptions of signal locality plus predictability are also sufficient to derive Bell inequalities. This simple theorem, previously noted but published only relatively recently by Masanes, Acin and Gisin, has fundamental implications not entirely appreciated. Firstly, nothing can be concluded about the ontological assumptions of locality or determinism independently of each (...) other—it is possible to reproduce quantum mechanics with deterministic models that violate locality as well as indeterministic models that satisfy locality. On the other hand, the operational assumption of signal locality is an empirically testable (and well-tested) consequence of relativity. Thus Bell inequality violations imply that we can trust that some events are fundamentally unpredictable, even if we cannot trust that they are indeterministic. This result grounds the quantum-mechanical prohibition of arbitrarily accurate predictions on the assumption of no superluminal signalling, regardless of any postulates of quantum mechanics. It also sheds a new light on an early stage of the historical debate between Einstein and Bohr. (shrink)

There is confusion among scholars of Bohr as to whether he should be categorized as an instrumentalist (see Faye 1991) or a realist (see Folse 1985). I argue that Bohr is a realist, and that the confusion is due to the fact that he holds a very special view of realism, which did not coincide with the philosophers’ views. His approach was sometimes labelled instrumentalist and other times realist, because he was an instrumentalist on the theoretical level, but (...) a realist on the level of models. Such a realist position is what I call phenomenological realism. In this paper, and by taking Bohr’s debate with Einstein as a paradigm, I try to prove that Bohr was such a realist. (shrink)

In concluding his ‘Autobiographical notes’, Albert Einstein explained that the purpose of his exposition was to ‘show the reader how the efforts of a life hang together and why they have led to expectations of a definite form’. Einstein's remarks tell of a coherence between personal ‘strivings and searchings’ and scientific activity, which has all but vanished in the midst of the current trend of social constructivism in history of science. As Nancy Nersessian recently pointed out, in the (...) process of illuminating complex relationships between scientific activity and its social context, ‘socio-historical analysis has “black-boxed” the individual scientist’. Has the pendulum swung too far? In reaction to the preceding great-man hagiographie approach to the history of science, the social constructivists have largely ‘thrown the baby out with the bathwater’; consideration of individual scientists' personal approaches to science was unnecessarily expunged with the removal of ‘genius’ as an explanatory tool. (shrink)

It is shown how the development of physics has involved making explicit what were homocentric projections which had heretofore been implicit, indeed inexpressible in theory. This is shown to support a particular notion of the invariant as the real. On this basis the divergence in ideals of physical intelligibility between Bohr and Einstein is set out. This in turn leads to divergent, but explicit, conceptions of objectivity and completeness for physical theory. *I am indebted to Dr. G. McLelland. (...) Professor F. Rohrlich and an anonymous referee of this journal for several improvements in the formulation of the paper. (shrink)

At the start of the twentieth century, the first quantum revolution upset our vision of the world. New physics offered surprising realities, such as wave-particle duality, and led to major inventions: the transistor, the laser, and computer's integrated circuits. Less known is the second quantum revolution, arguably initiated in 1935 during a debate between giants Albert Einstein and Niels Bohr. This revolution is still unfolding. Its revolutionaries--including the author of this short accessible book, Nobel Prize-winning physicist Alain Aspect--explore (...) the notion of entangled particles, able to interact at seemingly impossible distances. Aspect has investigated entangled particles since the beginning of the 1980s and has helped to show how entanglement may both upend existing technologies, like cryptography, and usher in entirely new ones, like quantum computing. Explaining this physics of the future, this work tells a story of how philosophical debates can shape new realities. (shrink)

This article clarifies Bohr's position by focusing on the work he did in nuclear physics and scattering theory.

Piercing incisively and deeply into the nature of the overlapping of the material andmental realms. Aage Petersen uncovers the reciprocal relations between quantum physics and theconcepts of metaphysics and epistemology, assessing the extent to which each has influenced theother. The author is eminently qualified to undertake this important work, which grew out of hisclose contact with Neils Bohr and his Copenhagen school during the years 1952-1962.Although themathematical formalism of quantum physics has long since been established, the question of itsphysical (...) interpretation is not yet closed, and the question of its philosophical interpretationremains in a formative state. The most widely accepted physical interpretation of the quantalformalism emerged from discussions between Bohr and Heisenberg in the winter of 1926-1927. ThisCopenhagen Interpretation centers around the relations of indeterminacy around the relations ofindeterminacy and the concept of complementarity, and was refined but not radically altered in theyears following, especially during the famous debate with Einstein on the completeness possible inthe description of events. The philosophical interpretation has proceeded along two principal lines:Bohr's emphasis on complementarity as a unifying concept, and Heisenberg's exploration of therelationship of quantum physics to the traditional categories of philosophy.To Bohr's mind, thecentral feature of human knowledge is the distinction between subject and object. The indeterminacyof the placing of the partition between instrument and system, which played so large a part inquantal description was, Bohr believed, an expression of the general relation between the knower andthe knowable. He thus sought to find relationships of complementarity in areas beyond quantumphysics.Quantum physics and traditional philosophy certainly relate enough to interact--even thoughthe effects of interaction may produce uncertain results. Heisenberg's view also emphasizes thatscience describes, not nature itself, but the interplay between nature and man, nature as affectedby man's method of questioning, thus denying the school of philosophical thought that began withDescartes' sharp separation of the World and the I.The author's investigation leads him as well tobelieve that complementarity is deeply linked to the basis of philosophy, but that the details ofthe relationship are so obscure that some other feature of quantum physics that makes amore directconnection with philosophy should be sought. He is led to choose the idea of correspondence as suchfeature. This idea played a key role in the development of the matrix version of the formalism andof the Copenhagen interpretation.Mathematically, the idea of correspondence was seen to imply thatquantal formalisms should emerge as generalizations of classical entities, that matrix mechanics wasa generalization of classical Hamiltonian mechanics. It is in this possibility of treating thetraditional categories of philosophy as limits of a more general scheme, or as analogies of a deeperorder, that the fruitfulness of the correspondence idea lies. (shrink)

These articles and speeches by the Nobel Prize-winning physicist date from 1934 to 1958. Rather than expositions on quantum physics, the papers are philosophical in nature, exploring the relevance of atomic physics to many areas of human endeavor. Includes an essay in which Bohr and Einstein discuss quantum and_wave equation theories. 1961 edition.

This book is a critical introduction to the long-standing debate concerning the conceptual foundations of quantum mechanics and the problems it has posed for physicists and philosophers from Einstein to the present. Quantum theory has been a major infulence on postmodernism, and presents significant problems for realists. Keeping his own realist position in check, Christopher Norris subjects a wide range of key opponents and supporters of realism to a high and equal level of scrutiny. With a characteristic combination of (...) rigour and intellectual generosity, he draws out the merits and weaknesses from opposing arguments. In a sequence of closely argued chapters, Norris examines the premises of orthodox quantum theory, as developed most influentially by Bohr and Heisenberg, and its impact on varous philosophical developments. These include the ideas developed by W.V Quine, Thomas Kuhn, Michael Dummett, Bas van Fraassen, and Hilary Puttnam. In each case, Norris argues, these thinkers have been influenced by the orthodox construal of quantum mechanics as requiring drastic revision of principles which had hitherto defined the very nature of scientific method, causal explanati and rational enquiry. Putting the case for a realist approach which adheres to well-tried scientific principles of causal reasoning and inference to the best explanation, Christopher Norris clarifies these debates to a non-specialist readership and scholars of philosophy, science studies and the philosophy of science alike. Quantum Theory and the Flight From Realism suggests that philosophical reflection can contribute to a better understanding of these crucial, current issues. (shrink)

This dissertation is an attempt to defend two founders of quantum theories, Niels Bohr and Wolfgang Pauli, against various anti-realist readings. These readings claim that Bohr's and Pauli's interpretations of quantum mechanics are based on a denial of the reality of the external world, and that their debates with Albert Einstein are over realism. But I argue that the differences between their views and Einstein's are neither about the reality of the external world, nor about the (...) reality of theoretical entities in general. Rather, the differences are about the reality of this or that particular theoretical entity and the viability of this or that particular idea of physics. Although in 1972 Clifford Hooker gave an adequate and then-comprehensive discussion of Bohr's ideas countering anti-realist readings, his work has been forgotten by a new generation of interpreters such as Arthur Fine and Mara Beller who read anti-realism into Bohr's ideas. One aim of this dissertation is to revive Hooker's defense of Bohr and to counter such misreadings. ;A second contribution this dissertation makes consists in an elaboration of Pauli's views. Pauli wrote extensively on many philosophical issues, and made important contributions to the debates between Einstein, Bohr and himself. However, his views are unfairly ignored by most philosophers of quantum mechanics, and when considered, are at best quickly dismissed as anti-realist. In my dissertation, I discuss Pauli's rich ideas on physics and philosophy and show that Pauli is not an anti-realist. In particular, Bohr's and Pauli's views on a problem introduced in a paper by Einstein, Boris Podolsky, and Nathan Rosen are discussed in detail. The close examination of Bohr's and Pauli's views also shows that there are significant differences between them, suggesting the inadequacy of the generic term "the Copenhagen school," often used to refer indiscriminately to their views. Through my studies of Bohr's and Pauli's ideas, I hope to show the inadequacy of using metaphysical doctrines such as realism and anti-realism to gain either a full understanding of general problems in physics, or an understanding of the ideas of these working physicists in particular. (shrink)

Einstein, philosophical belief and physical theory -- Introduction to quantum theory -- Quantum theory, the Bohr-Einstein debate -- Physics and society.

It is not so long ago that philosophers and scientists thought of science as an objective and value-free enterprise. But since the heyday of positivism, it has become obvious that values, norms, and standards have an indispensable role to play in science. You may even say that these values are the real issues of the philosophy of science. Whatever they are, these values constrain science at an ontological, a cognitive, a methodological, and a semantic level for the purpose of making (...) science a rational pursuit of knowledge. I think, however, that a good place to look for them is in the rise of quantum mechanics and in the debate between Bohr and Einstein on its interpretation, not because similar cognitive values are not shaping scientific rationality elsewhere, but because they surface in the debate whenever a new revolutionary paradigm is about to take over the scene. (shrink)

Niels Bohr was born on October 7, 1885. He was one of the great innovators in physical science in the twentieth century. It so happens that 1985 also marks fifty years since the long discussions, which had begun in the 1920s between Albert Einstein and Bohr on the philosophical problems of quantum physics, attained their apogee. An article co-authored by Einstein, B. Podolsky, and N. Rosen, "Can Quantum Mechanics Be Considered a Complete Description of Physical Reality?," (...) was published in 1935 in the journal Physical Review. According to Bohr, "by virtue of its clarity and, it would seem, flawless argumentation, the work of Einstein, Podolsky, and Rosen has created excitement among physicists and played a great role in the discussion of general philosophical questions of physics." Precisely as a result of the publication of this article, the critical position of Einstein concerning quantum mechanics became known to a broader circle of physicists. In the same year, Bohr responded to Einstein and his co-authors with an article under the same title. (shrink)

The empirical validity of the locality (LOC) principle of relativity is used to argue in favour of a local hidden variable theory (HVT) for individual quantum processes. It is shown that such a HVT may reproduce the statistical predictions of quantum mechanics (QM), provided the reproducibility of initial hidden variable states is limited. This means that in a HVT limits should be set to the validity of the notion of counterfactual definiteness (CFD). This is supported by the empirical evidence that (...) past, present, and future are basically distinct. Our argumentation is contrasted with a recent one by Stapp resulting in the opposite conclusion, i.e. nonlocality or the existence of faster-than-light influences. We argue that Stapp’s argumentation still depends in an implicit, but crucial, way on both the notions of hidden variables and of CFD. In addition, some implications of our results for the debate between Bohr and Einstein, Podolsky and Rosen are discussed. (shrink)

Application in science has its own structure, distinct from the structure of theoretical science, and therefore needs its own philosophy. The covering power of a formal scientific theory is no guide to its explanatory power. Explanation is too much to ask of a fundamental scientific theory. This is seen by considering two strands of the Born-Einstein debate: first the explanatory power of quantum mechanics and second, the reality of unobserved properties. The function of theoretical physics is to describe rather (...) than to explain. Some techniques are a standard part of theory; while some aread hoc to the problems at hand. Very few of the derivations in mathematical physics are explanatory. This shows distinctly separate structures for theory and for application. (shrink)

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)

The author looks at the continuing debate about the meaning of quantum theory. The historical development of the theory is traced from the turn of the century through to the 1930's, and the famous debate between Niels Bohr and Albert Einstein.

The strangeness of modern physics has sparked several popular books--such as The Tao of Physics--that explore its affinity with Eastern mysticism. But the founders of quantum mechanics were educated in the classical traditions of Western civilization and Western philosophy. In Nature Loves to Hide, physicist Shimon Malin takes readers on a fascinating tour of quantum theory--one that turns to Western philosophical thought to clarify this strange yet inescapable explanation of reality. Malin translates quantum mechanics into plain English, explaining its origins (...) and workings against the backdrop of the famous debate between Niels Bohr and the skeptical Albert Einstein. Then he moves on to build a philosophical framework that can account for the quantum nature of reality. He shows, for instance, how Platonic and Neoplatonic thought resonates with quantum theory. He draws out the linkage between the concepts of Neoplatonism and the more recent process philosophy of Alfred North Whitehead. The universe, Whitehead wrote, is an organic whole, composed not of lifeless objects, but "elementary experiences." Beginning with Whitehead's insight, Malin shows how this concept of "throbs of experience" expresses quantum reality, with its subatomic uncertainties, its constituents that are waves and also particles, its emphasis on acts of measurement. Once any educated person could explain the universe as a vast Newtonian web of cause and effect, but since quantum theory, reality again appears to be richer and more mysterious than we had thought. Writing with broad humanistic insight and deep knowledge of science, and using delightful conversations with fictional astronauts Peter and Julie to explain more difficult concepts, Shimon Malin offers a profound new understanding of the nature of reality--one that shows a deep continuity with aspects of our Western philosophical tradition going back 2500 years, and that feels more deeply satisfying, and truer, than the clockwork universe of Newton. (shrink)

Introduction -- Light and life -- Biology and atomic physics -- Natural philosophy and human cultures -- Discussion with Einstein on epistemological problems in atomic physics -- Unity of knowledge -- Atoms and human knowledge -- Physical science and the problem of life.

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)

Seit ihrer Verurteilung vor allem im Deutschen Idealismus hatte die Popularphilosophie, in der zweiten Halfte des 18. Jahrhunderts eine der einflussreichsten Stromungen, einen faden Beigeschmack. Dabei verstand sich die Diskussion uber eine Philosophie, die mehr Nahe zum Leben der Menschen suchte, als Teil der umfassenden Selbstverstandnisdebatte von Aufklarung insgesamt. Vor allem die Auseinandersetzung mit der kritischen Philosophie Kants zwang dazu, Anspruch, Grenzen und Moglichkeiten popularer Philosophie zu uberdenken. So wurde Popularitat zu Programm und Problem von Philosophie, damals wie heute. - (...) Der vorliegende Band zeichnet die Geschichte der Popularphilosophie nach: ihre Vorgeschichte, die Diskussion im 18. und ihre Nachklange im 19. und fruhen 20. Jahrhundert bis hin zur gegenwartigen Auseinandersetzung. Since its condemnation, above all by German idealism, popular philosophy, which had been one of the most influential movements of the 18th century, had a negative connotation. The discussion about a philosophy which tried to get closer to peoples lives did however see itself as a part of the widespread debate on self-understanding of Enlightenment as a whole. It was mainly the study of Kant's critical philosophy which forced people to rethink the demands, limitations and possibilties of popular philosophy. Thus popularity became the agenda and the problem of philosophy, then as now. This volume traces the history of popular philosophy: its previous history, the discussion in the 18th century and its reverberations in the 19th and early 20th centuries up to the present time. (shrink)

In this essay I examine various aspects of the nearcentury-long debate concerning the conceptualfoundations of quantum mechanics and the problems ithas posed for physicists and philosophers fromEinstein to the present. Most crucial here is theissue of realism and the question whether quantumtheory is compatible with any kind of realist orcausal-explanatory account which goes beyond theempirical-predictive data. This was Einstein's chiefconcern in the famous series of exchanges with NielsBohr when he refused to accept the truth orcompleteness of a doctrine (orthodox (...) QM) which ruledsuch questions to be strictly inadmissible. I discussthe later history of quantum-theoretical debate withparticular reference to the issue of nonlocality,i.e., the phenomenon of superluminal(faster-than-light) interaction betweenwidely-separated particles. Then I show how thestandard `Copenhagen' interpretation of QM hasinfluenced current anti-realist orontological-relativist approaches to philosophy ofscience. Indeed, there are clear signs that somephilosophers have retreated from a realist positionvery largely in response to just these problems. So itis important to ask exactly why – on what scientificor philosophical grounds – any preferred alternative(causal-realist) construal should have been ruled outas a matter of orthodox QM wisdom. Moreconstructively, my paper presents various arguments infavour of one such alternative, the `hidden-variables'theory developed since the early 1950s by David Bohmand consistently marginalised by proponents of theCopenhagen doctrine. (shrink)

Erwin Schrödinger and Werner Heisenberg were the originators of two approaches, known respectively as “wave mechanics” and “matrix mechanics”, to what is now called “quantum mechanics” or “quantum theory”. The two approaches appear to be extremely different, both in their technical forms, and in their philosophical underpinnings. Heisenberg arrived at his theory by effectively renouncing the idea of trying to represent a physical system, such as a hydrogen Bohr's atom model for example, as a structure in space—time, but instead, (...) following the lead of Einstein's 1905 theory of relativity, representing only empirically observable properties, such as the transition amplitudes between the stationary states of the atom. These amplitudes can be arranged in square arrays of numbers. In Heisenberg's scheme these arrays, and other like them, are combined according to certain rules that were later recognized by Max Born to be the rules of matrix multiplication. The whole scheme is abstract and mathematical, and avoids using any space—time picture of what is going on at the atomic level. Schrödinger, on the other hand, represented the electron in an atom by a cloudlike wave surrounding the nucleus. This is a space—time structure that, superficially at least, is more in line with the classical physical theories of the eighteenth and nineteenth centuries. -/- Niels Bohr invited Schrödinger to come to Copenhagen to present his ideas, and to discuss this subject with himself, Heisenberg, and others. Schrödinger arrived in Copenhagen on October 1st, 1926, and was immediately intensively engaged by Bohr and the others in a “debate” that lasted for days. Eventually, Schrödinger become ill, and was confined in Bohr's home to a bed, upon which Bohr sat, continuing the discussion. Schrödinger finally exclaimed “If all the quantum jumping is here to stay, then I am sorry that I ever became involved in quantum mechanics”. Bohr replied, “But we are glad that you did!”. (shrink)

An homage to the men and women of science, and an exposition of Einstein's place in scientific history In this fascinating collection of articles and speeches, Albert Einstein reflects not only on the scientific method at work in his own theoretical discoveries, but also eloquently expresses a great appreciation for his scientific contemporaries and forefathers, including Johannes Kepler, Isaac Newton, James Clerk Maxwell, Max Planck, and Niels Bohr. While Einstein is renowned as one of the foremost (...) innovators of modern science, his discoveries uniquely his own, through his own words it becomes clear that he viewed himself as only the most recent in a long line of scientists driven to create new ways of understanding the world and to prove their scientific theories. Einstein's thoughtful examinations explain the "how" of scientific innovations both in his own theoretical work and in the scientific method established by those who came before him. This authorized Philosophical Library book features a new introduction by Neil Berger, PhD, and an illustrated biography of Albert Einstein, which includes rare photos and never-before-seen documents from the Albert Einstein Archives at the Hebrew University of Jerusalem. "What place does the theoretical physicist's picture of the world occupy among all these possible pictures? It demands the highest possible standard of rigorous precision in the description of relations, such as only the use of mathematical language can give" -Albert Einstein, "Principles of Research" Albert Einstein (1879-1955) was born in Germany and became an American citizen in 1934. A world-famous theoretical physicist, he was awarded the 1921 Nobel Prize for Physics and is renowned for his Theory of Relativity. In addition to his scientific work, Einstein was an influential humanist who spoke widely about politics, ethics, and social causes. After leaving Europe, Einstein taught at Princeton University. His theories were instrumental in shaping the atomic age. Neil Berger, an associate professor emeritus of mathematics, taught at the University of Illinois at Chicago in the Mathematics, Statistics, and Computer Science department from 1968 until his retirement in 2001. He was the recipient of the first Monroe H. Martin Prize (1975), which is now awarded by the University of Maryland every five years for a singly authored outstanding applied mathematics research paper. He has published numerous papers and reviews in his fields of expertise, which include elasticity, tensor analysis, scattering theory, and fluid mechanics. (shrink)

The author looks at the continuing debate about the meaning of quantum theory. The historical development of the theory is traced from the turn of the century through to the 1930's, and the famous debate between Niels Bohr and Albert Einstein.

Building on a previously published contextualization of Marco Buzzoni’s Neo- Kantian account of scientific thought-experiments, this paper examines the explanatory power of this account. It is argued that Buzzoni’s account suffers from a number of shortcomings. Einstein’s clock-in-the-box thought experiment facilitates the demonstration of these deficits. In the light of both the identified inadequacies of Buzzoni’s account and the long-standing history of Kantian approaches to thought experiments, this paper finally sketches an alternative Neo-Kantian account. This alternative utilizes Michael Friedman’s (...) reading of Kant’s a priori within a Kuhnian account of thought experiments along the lines of conceptual constructivism as anticipated by Georg Lichtenberg and further developed recently by Tamar Gendler. (shrink)

According to the standard view, the so-called ‘Copenhagen interpretation’ of quantum mechanics originated in discussions between Bohr and Heisenberg in 1927, and was defended by Bohr in his classic debate with Einstein. Yet recent scholarship has shown Bohr’s views were never widely accepted, let alone properly understood, by his contemporaries, many of whom held divergent views of the ‘Copenhagen orthodoxy’. This paper examines how the ‘myth of the Copenhagen interpretation’ was constructed by situating it in the (...) context of Soviet Marxist critique of quantum mechanics in the 1950s and the response by physicists such as Heisenberg and Rosenfeld. (shrink)

This book offers an up-to-date insight into the early philosophical debate on Einsteinian relativity. The essays explore the reception and interpretation of Einstein’s ideas by some of the most important philosophical schools of the time, such as logical positivism (Reichenbach), neo-Kantianism (Cassirer, Natorp), critical realism (Sellars), and radical empiricism (Mach). The book is aimed at physicists and historians of science researching the epistemological implications of the theory of relativity, as well as to scholars in philosophy interested in understanding how (...) leading philosophical figures of the early twentieth century reacted to the relativistic revolution. (shrink)

This introduction to one of the liveliest and most popular fields in philosophy is written specifically for a beginning readership with no background in philosophy or science. Step-by-step analyses of the key arguments are provided and the philosophical heart of the issues is revealed without recourse to jargon, maths, or logical formulas. The book introduces Einstein's revolutionary ideas in a clear and simple way, along with the concepts and arguments of philosophers, both ancient and modern that have proved of (...) lasting value. Specifically, the theories of the ancient Greek philosophers, Zeno, Euclid and Parmenides are considered alongside the ideas of Newton, Leibniz and Kant as well as the giants of twentieth-century physics, Einstein and Lorentz. The problems at the heart of the philosophy of space and time, such as change, motion, infinity, shape, and inflation, are examined and the seismic impact made by relativity theory and quantum theory is assessed in the light of the latest research. The writing is lucid and entertaining, allowing a beginning readership to grasp some difficult concepts while offering the more experienced reader a succinct and illuminating presentation of the state of the debate. "Space, Time and Einstein" shows the reader the excitement of scientific discovery and the beauty of theory in the search for answers to these fundamental questions. (shrink)

Logical positivism had an important impact on the Danish intellectual climate before World War Two. During the thirties close relations were established between members of the Vienna Circle and philosophers and scientists in Copenhagen. This influence not only affected Danish philosophy and science; it also impinged on the cultural avant-garde and via them on the public debate concerning social and political reforms. Hand in hand with the positivistic ideas you find functionalism emerging as a new heretical language in art, architecture, (...) and design. Not surprisingly, you may say, since the logical positivists’ wishes of stripping philosophy of metaphysics is spiritually similar to the functionalists’ desire to get rid of symbols and ornaments. One event more than anything confirmed the connection between the Vienna Circle, Denmark, and the rest of the Nordic countries. For a short while Copenhagen became the centre for the Circle’s activities when in 1936 the 2nd Inter national Congress for the Unity of Science was held there between June 21 and 26. A photograph, taken during the conference, shows many of the participants sitting in the hall of Carlsberg’s honorary mansion where Niels Bohr was living at the time. Among the audience you find Otto Neurath , Carl Gustav Hempel and Karl Popper , but also some of the more prominent Danish scientists and scholars whose world views were congenial with the logical positivists. (shrink)

The old Bohr–Einstein debate about the completeness of quantum mechanics (QM) was held on an ontological ground. The completeness problem becomes more tractable, however, if it is preliminarily discussed from a semantic viewpoint. Indeed every physical theory adopts, explicitly or not, a truth theory for its observative language, in terms of which the notions of semantic objectivity and semantic completeness of the physical theory can be introduced and inquired. In particular, standard QM adopts a verificationist theory of truth (...) that implies its semantic nonobjectivity; moreover, we show in this paper that standard QM is semantically complete, which matches Bohr's thesis. On the other hand, one of the authors has provided a Semantic Realism (or SR) interpretation of QM that adopts a Tarskian theory of truth as correspondence for the observative language of QM (which was previously mantained to be impossible); according to this interpretation QM is semantically objective, yet incomplete, which matches EPR's thesis. Thus, standard QM and the SR interpretation of QM come to opposite conclusions. These can be reconciled within an integrationist perspective that interpretes non-Tarskian theories of truth as theories of metalinguistic concepts different from truth. (shrink)

After reminding the main issues at stake in the famous Einstein–Bohr debate initiated in 1935, we tentatively propose a way to get them closer, thus shedding a new light on this historical discussion.

Untimely -- "More Einsteinian than Einstein" -- Science or philosophy? -- The twin paradox -- Bergson's achilles' heel -- Worth mentioning? -- Bergson writes to Lorentz -- Bergson meets Michelson -- The debate spreads -- Back from Paris -- Two months later -- Logical positivism -- The immediate aftermath -- An imaginary dialog -- "Full-blooded" time -- The previous spring -- The church -- The end of universal time -- Quantum mechanics -- Things -- Clocks and wristwatches -- Telegraph, (...) telephone, and radio -- Atoms and molecules -- Einstein's films: reversible -- Bergson's movies: out-of-control -- Microbes and ghosts -- One new point: recording devices -- Bergson's last comments -- Einstein's last thoughts. (shrink)

This essay examines various issues surrounding the orthodox interpretation of quantum mechanics. These began with the famous debate between Einstein and Bohr on the topics of quantum uncertainty, wave-particle dualism, and nonlocal interaction. Where Bohr maintained the in-principle ‘completeness’ of orthodox QM - i.e., the conceptual impossibility that it should ever be subject to major revision - Einstein argued that it must be incomplete since it failed to provide any adequate interpretation. Until recently the orthodox doctrine (...) continued to hold sway despite counter-arguments advanced by David Bohm and others of a realist persuasion. In their view there is no reason to accept the veto on supposing particles to possess simultaneous objective values of position and momentum. That we cannot precisely determine those values has to do with certain well-defined limits on our powers of observation/measurement rather than with any intrinsic ‘strangeness’ about microphysical objects and events. Bohm’s theory perfectly matches the established predictive and empirical results while providing a credible realist ontology that avoids any drastic break with the principles of causal realism and inference to the best, most rational explanation. My article discusses the way that Bohm’s heterodox account was often rejected out of hand by proponents of the Copenhagen doctrine. I also review some recent studies - by Beller, Cushing, and Holland - which have either declared strongly in favour of Bohm or challenged the prevailing bias by offering a historically contextualised account of how the orthodox theory took hold. (shrink)

STILLWATER, MINNESOTA—Two men sit at a long table, oblivious to the breakfast-time commotion. One moves a coffee cup from one side of a water glass to the other. “If I look here and don’t see the cup,” he says to the other, “then I know it must be there.” It sounds like a “deep” exchange between swotty young philosophy majors. But the fellow moving the cup has gray hair— and a Nobel Prize in physics. Sliding the porcelain, Anthony Leggett of (...) the University of Illinois, Urbana-Champaign, explains how scientists might try to see past the strictures of quantum mechanics, the bizarre theory that governs the behavior of tiny objects and clashes with our everyday notions of reality. “None of the existing interpretations of quantum mechanics as a theory of the entire world is satisfactory,” Leggett says to John Preskill, a physicist at the California Institute of Technology in Pasadena. Leggett, Preskill, and 22 other physicists, philosophers, and historians have gathered here for the Seven Pines Symposium.* Packed into a slightly ramshackle lodge in a wooded state park, the scholars—all of them men—will share their insights, suites of rooms without telephones, and meals of roast quail and pheasant at a long communal table. Perhaps not since the famous Solvay Conferences of the early 20th century, at which Niels Bohr and Albert Einstein debated the meaning of quantum theory in their free time, has physics seemed so genteel. Each year, the symposium tackles another of physics’ enduring puzzles: the nature of the vacuum, the concept of a f ield, the meaning of time. The aim is not to resolve the mysteries but to seed new lines of inquiry, says Roger Stuewer, a historian at the University of Minnesota, Twin Cities, and chair of the symposium’s advisory board. “When we get the best people together,” he says, “ideas are planted that in some intangible way will influence what they do in the future.” Those germinating ideas are watered with a mellow Zinfandel and nourished with succulent steak. This year, attendees spent 5 days grappling with the implications of quantum mechanics, which have perplexed physi.. (shrink)