How Bohr Specifically Adapted William James’s “Complementarity” for Physics Many Years After Bohr First Read James’s “Complementarity”: Setting the Historical Record Straight in Order That James’s Complementarity Can Be Properly Evaluated on Its Own Merits for Quantum Measurement
Today it is important to see James’s original complementarity in 1890 independently of Bohr’s discussions on complementarity in order that James’s conception can be properly evaluated as the model on its own merits for quantum measurement. On the basis of new evidence and a deeper analysis of previous evidence presented here, it is very reasonable to conclude based on Bohr’s own words that Bohr read James’s complementarity between approximately 1908 and 1912. An Appendix provides the relevant text from both Bohr’s Nobel biography and his interview with the American Institute of Physics to support this conclusion. Bohr’s description of significant events in his life are matched with dates in his Nobel biography, adding support to the conclusion. How Bohr specifically adapted James’s complementarity to physics is presented. Bohr’s discussion of “mental activity” is compared here to James’s definition of complementarity focusing on consciousness and is found to be extremely similar to James’s definition. In addition, a side by side comparison of James’s definition of complementarity and Bohr’s most important and well-known definition of complementarity for physics is presented. This comparison shows just how Bohr adapted James’s complementarity to Bohr’s complementarity for physics. Examining the chapters “The Stream of Thought”” (chapter 9 in James’s “The Principles of Psychology”) and “The Relation of Minds to Other Things” (chapter 8 in “The Principles of Psychology”) shows that the very evidence that James used to develop complementarity in “The Relation of Minds to Other Things” is discussed in “The Stream of Thought,” a chapter that Bohr acknowledged reading and concerning which he had a very high opinion. It is also made clear in the paper that Bohr was aware that he had a choice to adopt complementarity for physics along the lines of James’s complementarity, which he had read, and that he rejected this possibility. Instead, in his complementarity for physics, Bohr adopted a very different approach fundamentally based on the necessity of a physical interaction between a physical system and a physical measuring apparatus with an uncontrolled aspect to obtain a specific measurement result. Bohr attempted to apply the uncertainty principle to this uncontrolled feature of the physical interaction. Bohr’s approach has been the widely adopted framework for understanding quantum measurement since 1927. The historical description of complementarity in Bohr’s Nobel biography is discussed in light of the evidence presented and is shown to be incorrect. It is important to set the record straight regarding the origin of complementarity so that James’s complementarity is not seen as an appendage of Bohr’s version of complementarity for physics. Bohr’s attempt to extrapolate what his Nobel biography incorrectly states was complementarity originally developed by Bohr, which was for physics, to other fields confuses and detracts from the importance of James’s complementarity which was in fact the original. Bohr’s detour with his proposed necessity (and its proposed fundamental significance) of a physical interaction in the measuring process with an uncontrolled aspect in quantum mechanics has distracted attention away from the possible significance of James’s original concept in psychology to quantum measurement, including its evaluation on its own merits as to whether it provides the correct conceptual framework for this measurement.
Today it is important to see James’s original complementarity in 1890 independently of Bohr’s discussions on complementarity in order that James’s conception can be properly evaluated as the model on its own merits for quantum measurement. On the basis of new evidence and a deeper analysis of previous evidence presented here, it is very reasonable to conclude based on Bohr’s own words that Bohr read James’s complementarity between approximately 1908 and 1912. An Appendix provides the relevant text from both Bohr’s Nobel biography and his interview with the American Institute of Physics to support this conclusion. Bohr’s description of significant events in his life are matched with dates in his Nobel biography, adding support to the conclusion. How Bohr specifically adapted James’s complementarity to physics is presented. Bohr’s discussion of “mental activity” is compared here to James’s definition of complementarity focusing on consciousness and is found to be extremely similar to James’s definition. In addition, a side by side comparison of James’s definition of complementarity and Bohr’s most important and well-known definition of complementarity for physics is presented. This comparison shows just how Bohr adapted James’s complementarity to Bohr’s complementarity for physics. Examining the chapters “The Stream of Thought”” (chapter 9 in James’s “The Principles of Psychology”) and “The Relation of Minds to Other Things” (chapter 8 in “The Principles of Psychology”) shows that the very evidence that James used to develop complementarity in “The Relation of Minds to Other Things” is discussed in “The Stream of Thought,” a chapter that Bohr acknowledged reading and concerning which he had a very high opinion. It is also made clear in the paper that Bohr was aware that he had a choice to adopt complementarity for physics along the lines of James’s complementarity, which he had read, and that he rejected this possibility. Instead, in his complementarity for physics, Bohr adopted a very different approach fundamentally based on the necessity of a physical interaction between a physical system and a physical measuring apparatus with an uncontrolled aspect to obtain a specific measurement result. Bohr attempted to apply the uncertainty principle to this uncontrolled feature of the physical interaction. Bohr’s approach has been the widely adopted framework for understanding quantum measurement since 1927. The historical description of complementarity in Bohr’s Nobel biography is discussed in light of the evidence presented and is shown to be incorrect. It is important to set the record straight regarding the origin of complementarity so that James’s complementarity is not seen as an appendage of Bohr’s version of complementarity for physics. Bohr’s attempt to extrapolate what his Nobel biography incorrectly states was complementarity originally developed by Bohr, which was for physics, to other fields confuses and detracts from the importance of James’s complementarity which was in fact the original. Bohr’s detour with his proposed necessity (and its proposed fundamental significance) of a physical interaction in the measuring process with an uncontrolled aspect in quantum mechanics has distracted attention away from the possible significance of James’s original concept in psychology to quantum measurement, including its evaluation on its own merits as to whether it provides the correct conceptual framework for this measurement.
James’s complementarity works very well with the proofs that are at the heart of null and positive measurements in quantum mechanics. It is important for the physics community to know that complementarity originated in psychology in 1890, in the work of William James, to know James’s finding that “the total possible consciousnesses may be split into parts which coexist but mutually ignore each other, and share the objects of knowledge between them.” The human observer is central in James’s formulation of complementarity. Consciousness and knowledge are essential. It appears that James’s concept of complementarity may truly characterize what Carroll is referring to as the epistemic option. It seems it is likely the correct conceptual model for quantum mechanical measurement. For example, there can be no hidden physical variables with a null measurement because the outcome of a null measurement as discussed above is not dependent on a physical interaction. Bohr was open to ideas from psychology. Bohr borrowed James’s complementarity and adapted it for physics by introducing an unavoidable physical interaction between a physical measuring instrument and the physical system measured. This physical interaction has an aspect that cannot be controlled. This lack of control allowed Bohr to apply the uncertainty principle. Bohr’s complementarity for physics is unwarranted. Once there is a logical proof that the electron will not pass through one of the slits, the wave component associated with the slit through which the electron does not pass vanishes. No superposition is possible because that wave component has vanished. Contrary to Mermin, Bohr did acknowledge a significant quantum measurement problem. Bohr held to his view discussed above of complementarity for physics instead of adopting James’s approach where the knowing individual is directly related to the physical system measured as an object of knowledge. Perhaps through the collaboration of physics and other fields, in particular psychology, further progress can be made in developing a self-consistent view of quantum mechanical measurement that is supported by empirical evidence.
Quantum complementarity is a fundamental feature of quantum systems and has captivated the physics research community for nearly a century, with significant advancements emerging in recent decades. This review traces the historical evolution of the concept of complementarity, beginning with Bohr's original formulation. It then explores its modern quantification through complementarity relations and its profound connection to the foundational postulates of quantum theory. Furthermore, it delves into key related developments, such as the operational definition of complementarity in the context of incompatible observables, its potential links with quantum uncertainty relations and contextuality, its various applications, and other pertinent topics. This review aims to serve physicists interested in quantum resources, quantum correlations, and the foundational principles of quantum mechanics.
SUMMARYThe article contains the result of an attempt to examine analytically and critically the usefulness in psychology of Niels Bohr's concept of complementarity.In the first section it is shown through quotations (from (1) and (2)) that Bohr actually applies “complementarity” with two meanings in physics: 1. Special complementarity: The relation between two sets of concepts which supplement each other but mutually exclude each other.2. General complementarity: A description that includes the conditions of observation under which a phenomenon has been produced.In the second section it is shown through quotations how Bohr through the use of the concept of complementarity forms four analogies between atomic physics and psychology, namely: 1) the subject-object relation, 2) the determinism-indeterminism relation, 3) the thought-emotion relation, and 4) the instinct-reason relation. The first two relations are examples of general complementarity, the two last ones are examples of special complementarity.In ...
I: Hoffding as Mentor.- I.- 1. Harald Hoffding, His Life and Thought.- 2. Hoffding and Bohr Senior.- II.- 1. The Ekliptika Circle.- 2. Bohr and William James.- 3. Bohr and Kierkegaard.- 4. The Student Bohr on Formal Logic.- III.- 1. The Friendship.- 2. The Years Around 1927.- 3. Hoffding on Complementarity.- IV.- 1. Hoffding's Theory of Knowledge.- 2. Totality as a Category.- 3. Hoffding's Philosophy of Mind and Psychology of Free Will.- 4. Hoffding on Biology.- 5. Analogy and Scientific Progress.- II: Bohr and the Atomic Description of Nature.- V.- 1. The Principle of Correspondence.- 2. The Search for an Interpretation.- VI.- 1. Complementarity.- 2. Quantum Mechanics and Psychology.- 3. Bohr on Biology.- VII.- 1. The Objectivity of Knowledge.- 2. The EPR Discussion.- 3. The Conditions for Description.- VIII.- 1. Bohr and Realism.- 2. Hoffding on Reality.- 3. Objective Anti-Realism.- Epilogue: The Legacy.- Notes.
Ninety years ago in 1927, at an international congress in Como, Italy, Niels Bohr gave an address which is recognized as the first instance in which the term "complementarity", as a physical concept, was spoken publicly [1], revealing Bohr's own thinking about Louis de Broglie's "duality". Bohr had very slowly accepted duality as a principle of physics: close observation of any quantum object will reveal either wave-like or particle-like behavior, one or the other of two fundamental and complementary features. Little disagreement exists today about complementarity's importance and broad applicability in quantum science. Book-length scholarly examinations even provide speculations about the relevance of complementarity in fields as different from physics as biology, psychology and social anthropology, connections which were apparently of interest to Bohr himself (see Jammer [2], Murdoch [3] and Whitaker [4]). Confusion evident in Como following his talk was not eliminated by Bohr's article [1], and complementarity has been subjected to nine decades of repeated examination ever since with no agreed resolution. Semi-popular treatments [5] as well as expert examinations [6-9] show that the topic cannot be avoided, and complementarity retains its central place in the interpretation of quantum mechanics. However, recent approaches by our group [10-13] and others [14-20] to the underlying notion of coherence now allow us to present a universal formulation of complementarity that may signal the end to the confusion. We demonstrate a new relationship that constrains the behavior of an electromagnetic field (quantum or classical) in the fundamental context of two-slit experiments. We show that entanglement is the ingredient needed to complete Bohr's formulation of complementarity, debated for decades because of its incompleteness.
Complementarity and Deconstruction: Plotnitsky's Analysis and Beyond Makoto Katsumori Akita University The philosophical thought of the modern physicist Niels Bohr (1885–1962), which revolves around the concept of complementarity, has long been a major subject of historical and philosophical inquiry. Many prior studies of Bohr's complementarity, however, seem to be limited by the fact that they largely proceed within the conceptual frames of the "mainstream" philosophy of science. This being the case, his radical questioning of traditional scientific and philosophical notions—such as the unambiguity of concepts and words—has not been adequately addressed, insofar as these notions are uncritically presupposed by the commentators themselves. In other words, Bohr's thought has often been interpreted under certain tacit premises of scientific rationality that are precisely of the kind targeted by his epistemological critique. In recent years, however, there have emerged new approaches to Bohr's idea of complementarity that place it in different, less conventional, philosophical contexts. Among the most notable of these is Arkady Plotnitsky's endeavor to connect Bohr's complementarity with Jacques Derrida's project of deconstruction. In the present article, based on my recent doctoral dissertation,1 I take up this contribution by Plotnitsky as a suitable point of reference from which to [End Page 435] explore anew Bohr's thought with its radical philosophical implications. After outlining Bohr's complementarity argument and Plotnitsky's reading thereof (in the first and second sections, respectively), I will examine a series of problems that seem to face, or to be left unsolved by, Plotnitsky's account (in the third section). This critical appraisal will finally lead me to sketch a new interpretive approach of my own (in the fourth section), which both extends and delimits the intersections between complementarity and deconstruction. As regards the historical development of Bohr's complementarity, I will largely restrict myself to the period between 1927 and 1950, in which the most crucial of his innovative ideas seem to have been presented. I. Bohr's Idea of Complementarity In his 1927 lecture delivered in Como, Italy, entitled "The Quantum Postulate and the Recent Development of Atomic Theory," Niels Bohr introduced the concept and framework of complementarity as a pivotal idea in his interpretation of quantum theory. From then on, he continually developed the idea of complementarity with regard not only to quantum theory but to other fields of knowledge as well. In what follows, I will first outline his complementarity argument in its "early" period, stretching from 1927 to the mid-thirties,—or, more precisely, until just before his 1935 debate with EPR.2 Bohr starts by noting that "our usual description of physical phenomena is based entirely on the idea that the phenomena concerned may be observed without disturbing them appreciably."3 This notion of physical phenomena as undisturbed by observation underlies all of classical physics and is still maintained in the theory of relativity. However, Bohr continues, a new situation has arisen with the development of quantum theory, specifically with "the so-called quantum postulate, which attributes to any atomic process an essential discontinuity, or rather individuality, completely foreign to the classical theories"; this "individuality" implies that "any observation of atomic phenomena will involve an interaction with the [End Page 436] agency of observation not to be neglected" (PWNB, 1: 53–54.). In more specific terms, any observation aimed at space-time coordination brings about an exchange of momentum and energy with the measuring rods and clocks. It is crucial here that this interaction between the object and the instrument of observation is not simply unavoidable, but "uncontrollable," which represents a "feature of irrationality" brought into the description of nature (PWNB, 1: 68, 91). For insofar as the measuring instruments are to fulfill their purpose, the interaction itself cannot be taken into account, and thus the magnitude of the disturbance always remains unknown. It follows, in Bohr's view, that "an independent reality in the ordinary physical sense can neither be ascribed to the phenomena nor to the agencies of observation...