A growing number of commentators have, in recent years, noted the important affinities in the views of Immanuel Kant and Niels Bohr. While these commentators are correct, the picture they present of the connections between Bohr and Kant is painted in broad strokes; it is open to the criticism that these affinities are merely superficial. In this essay, I provide a closer, structural, analysis of both Bohr's and Kant's views that makes these connections more explicit. In particular, I demonstrate the (...) similarities between Bohr's argument, on the one hand, that neither the wave nor the particle description of atomic phenomena pick out an object in the ordinary sense of the word, and Kant's requirement, on the other hand, that both ‘mathematical’ (having to do with magnitude) and ‘dynamical’ (having to do with an object's interaction with other objects) principles must be applicable to appearances in order for us to determine them as objects of experience. I argue that Bohr's ‘complementarity interpretation’ of quantum mechanics, which views atomic objects as idealizations, and which licenses the repeal of the principle of causality for the domain of atomic physics, is perfectly compatible with, and indeed follows naturally from a broadly Kantian epistemological framework. (shrink)
The concepts of complementarity and entanglement are considered with respect to their significance in and beyond physics. A formally generalized, weak version of quantum theory, more general than ordinary quantum theory of physical systems, is outlined and tentatively applied to two examples.
Philosophers of the social sciences are increasingly convinced that macro-and micro-explanations are complementary. Whereas macro-explanations are broad, micro-explanations are deep. I distinguish between weak and strong complementarity: Strongly complementary explanations improve one another when integrated, weakly complementary explanations do not. To demonstrate the explanatory autonomy of different levels of explanation, explanatory pluralists mostly presuppose the weak form of complementarity. By scrutinizing the notions of explanatory depth and breadth, I argue that macro- and micro-accounts of the same phenomenon are (...) more often strongly complementary. This invites a revision of the pluralist position in which integration promotes explanatory progress. Key Words: explanatory pluralism social science explanatory depth explanatory breadth mechanism. (shrink)
The idea of complementarity already appears in William James’ (1890a, p. 206) Principles of Psychology in the chapter on “the relations of minds to other things”. Later, in 1927, Niels Bohr introduced complementarity as a fundamental concept in quantum mechanics. It refers to properties (observables) that a system cannot have simultaneously, and which cannot be simultaneously measured with arbitrarily high accuracy. Yet, in the context of classical physics they would both be needed for an exhaustive description of the (...) system. (shrink)
Summary. We discuss a specific way in which the notion of complementarity can be based on the dynamics of the system considered. This approach rests on an epistemic representation of system states, reflecting our knowledge about a system in terms of coarse grainings (partitions) of its phase space. Within such an epistemic quantization of classical systems, compatible, comparable, commensurable, and complementary descriptions can be precisely characterized and distinguished from each other. Some tentative examples are indicated that, we suppose, would (...) have been of interest to Pauli. (shrink)
In part-1, I shall outline the principle details of Bohr’s interpretation. Bohr’s basic interpretive insight is ‘ quantum inseparability’ . Complementarity of phenomena and a “revision to our attitude towards physical explanation” then follow. Together , these can be said to constitute Bohr’s general viewpoint of ‘complementarity’. Bohr does not quite clearly spell out the content of these three ideas; I do.
Summary The paper considers Ernst' Cassirer's standpoint with reference to Euclidean geometry and the complementarity principle of quantum theory, interpreted as a choice between a causal description and a space-time description. The acceptance of the complementarity principle by Cassirer not only lands him off the Kantian path slightly, but it also leads him to some contradictions and incompatibilities within his own system of thought. 1. Accepting complementarity, Cassirer cannot still hold that there is an infinite hierarchy of (...) objective levels as he does towards the end of hisDeterminismus; and 2. accepting complementarity, Cassirer cannot still hold on to the observability principle of Leibniz. (shrink)
A coherent account of the connections and contrasts between the principles of complementarity and uncertainty is developed starting from a survey of the various formalizations of these principles. The conceptual analysis is illustrated by means of a set of experimental schemes based on Mach-Zehnder interferometry. In particular, path detection via entanglement with a probe system and (quantitative) quantum erasure are exhibited to constitute instances of joint unsharp measurements of complementary pairs of physical quantities, path and interference observables. The analysis (...) uses the representation of observables as positive-operator-valued measures (POVMs). The reconciliation of complementary experimental options in the sense of simultaneous unsharp preparations and measurements is expressed in terms of uncertainty relations of different kinds. The feature of complementarity, manifest in the present examples in the mutual exclusivity of path detection and interference observation, is recovered as a limit case from the appropriate uncertainty relation. It is noted that the complementarity and uncertainty principles are neither completely logically independent nor logical consequences of one another. Since entanglement is an instance of the uncertainty of quantum properties (of compound systems), it is moot to play out uncertainty and entanglement against each other as possible mechanisms enforcing complementarity. (shrink)
The concept of complementarity, originally deﬁned for non-commuting observables of quantum systems with states of non-vanishing dispersion, is extended to classical dynamical systems with a partitioned phase space. Interpreting partitions in terms of ensembles of epistemic states (symbols) with corresponding classical observables, it is shown that such observables are complementary to each other with respect to particular partitions unless those partitions are generating. This explains why symbolic descriptions based on an ad hoc partition of an underlying phase space description (...) should generally be expected to be incompatible. Related approaches with diﬀerent background and diﬀerent objectives are discussed. (shrink)
In his later years, Wesley Salmon believed that the two dominant models of scientific explanation (his own causal-mechanical model and the unificationist model) were reconcilable. Salmon envisaged a 'new consensus' about explanation: he suggested that the two models represent two 'complementary' types of explanation, which may 'peacefully coexist' because they illuminate different aspects of scientific understanding. This paper traces the development of Salmon's ideas and presents a critical analysis of his complementarity thesis. Salmon's thesis is rejected on the basis (...) of two objections, and an alternative view of the relation between different types of explanation is proposed. (shrink)
New sciences born or developed in the 20th century (information, materials, life science) are based on forms of complementarity that differ from the past. The paper discusses cognitive, or disciplinary, institutional, and technical complementarity. It argues that new sciences apply a reductionist explanatory strategy to complex multi-layered systems. In doing so the reductionist promise is falsified, generating the need for multi-level kinds of explanation (e.g. in post-genomic molecular biology), new forms of complementarity between scientific and non-scientific organizations, (...) and new forms of experimental and informational facilities. The paper develops the argument in theoretical terms, comparing it with the STS literature, and offers preliminary evidence based on the experience of Networks of Excellence. (shrink)
Uncertainty relations and complementarity of canonically conjugate position and momentum observables in quantum theory are discussed with respect to some general coupling properties of a function and its Fourier transform. The question of joint localization of a particle on bounded position and momentum value sets and the relevance of this question to the interpretation of position-momentum uncertainty relations is surveyed. In particular, it is argued that the Heisenberg interpretation of the uncertainty relations can consistently be carried through in a (...) natural extension of the usual Hilbert space frame of the quantum theory. (shrink)
The mental system of an individual usually generates a reality-model that includes a self-model and a world-model as fundamental components. Exceptional experiences (ExE) can be classified as subjectively experienced anomalies in the self-model or the world-model or in the relation of both. Empirical studies show significant correlations between specific patterns of ExE and socially and clinically relevant variables. In order to examine the ontological status of anomalous phenomena a psychophysical approach is presented in which the principle of complementarity is (...) of fundamental importance. Applying a generalized quantum theory to psychosocial and psychophysical systems, complementary aspects such as autonomy versus reliability or novelty versus confirmation are identified as possible local and global variables. The findings indicate that entanglement correlations could play a role in the occurrence of ExE and that specific psychological interventions can dissolve them. (shrink)
Explicit, quantitative procedures for identifying biodiversity priority areas are replacing the often ad hoc procedures used in the past to design networks of reserves to conserve biodiversity. This change facilitates more informed choices by policy makers, and thereby makes possible greater satisfaction of conservation goals with increased efficiency. A key feature of these procedures is the use of the principle of complementarity, which ensures that areas chosen for inclusion in a reserve network complement those already selected. This paper sketches (...) the historical development of the principle of complementarity and its applications in practical policy decisions. In the first section a brief account is given of the circumstances out of which concerns for more explicit systematic methods for the assessment of the conservation value of different areas arose. The second section details the emergence of the principle of complementarity in four independent contexts. The third section consists of case studies of the use of the principle of complementarity to make practical policy decisions in Australasia, Africa, and America. In the last section, an assessment is made of the extent to which the principle of complementarity transformed the practice of conservation biology by introducing new standards of rigor and explicitness. (shrink)
The photon box thought experiment can be considered a forerunner of the EPR-experiment: by performing suitable measurements on the box it is possible to ``prepare'' the photon, long after it has escaped, in either of two complementary states. Consistency requires that the corresponding box measurements be complementary as well. At first sight it seems, however, that these measurements can be jointly performed with arbitrary precision: they pertain to different systems (the center of mass of the box and an internal clock, (...) respectively). But this is deceptive. As we show by explicit calculation, although the relevant quantities are simultaneously measurable, they develop non-vanishing commutators when calculated back to the time of escape of the photon. This justifies Bohr's qualitative arguments in a precise way; and it illustrates how the details of the dynamics conspire to guarantee the requirements of complementarity. In addition, our calculations exhibit a ``fine structure'' in the distribution of the uncertainties over the complementary quantities: depending on when the box measurement is performed, the resulting quantum description of the photon differs. This brings us close to the argumentation of the later EPR thought experiment. (shrink)
A modified version of Young's experiment by Shahriar Afshar demonstrates that, prior to a ``which-way'' measurement indicating which slit a particle goes through, an interference pattern exists. It has been claimed that this result constitutes a violation of the Principle of Complementarity. This paper discusses the implications of this experiment and considers how Cramer's Transactional Interpretation accomodates the result. It is shown that the Afshar experiment is isomorphic in key respects to a a spin one-half particle prepared as ``spin (...) up along x'' and post-selected in a specific state of spin along z. It is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post-selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection. (shrink)
A modified version of Young's experiment by Shahriar Afshar demonstrates that, prior to what appears to be a ``which-way'' measurement, an interference pattern exists. Afshar has claimed that this result constitutes a violation of the Principle of Complementarity. This paper discusses the implications of this experiment and considers how Cramer's Transactional Interpretation easily accomodates the result. It is also shown that the Afshar experiment is isomorphic in key respects to a spin one-half particle prepared as ``spin up along x'' (...) and post-selected in a specific state of spin along z. The terminology ``which way'' or ``which-slit'' is critiqued; it is argued that this usage by both Afshar and his critics is misleading and has contributed to confusion surrounding the interpretation of the experiment. Nevertheless, it is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post-selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection. In addition, some new inferences about the interpretation of delayed choice experiments are drawn from the analysis. (shrink)
Bohr's interpretation of quantum mechanics has been criticized as incoherent and opportunistic, and based on doubtful philosophical premises. If so Bohr's influence, in the pre-war period of 1927-1939, is the harder to explain, and the acceptance of his approach to quantum mechanics over de Broglie's had no reasonable foundation. But Bohr's interpretation changed little from the time of its first appearance, and stood independent of any philosophical presuppositions. The principle of complementarity is itself best read as a conjecture of (...) unusually wide scope, on the nature and future course of explanations in the sciences (and not only the physical sciences). If it must be judged a failure today, it is not because of any internal inconsistency. (shrink)
Although it is, often considered a form of anti-realism, here it is argued that Bohr's complementarity viewpoint must accept entity realism based on its analysis of the causal interaction involved in observation. However, because Bohr accepts the quantum postulate he must reject the view that the goal of theory is to represent the independently existing object apart from observation. Thus he abandons the spectator account of knowledge and with it the correspondence theory of truth. In this respect his view (...) is parallel to the positions held by Hacking, Cartwright, and Ellis. (shrink)
Although Niels Bohr's notion of complementarity is usually referred to in the context of quantum mechanics, it is not of physical origin. Bohr derived it from the philosophical idea of a holistic entanglement of knowledge and action. Bohr's complementarity primarily refers to a key element of the pragmatist tradition, the reflective relation between the immediate experience of an object and the awareness of its objectification. Similar relations have been observed by Kurt Goldstein in his studies of brain-injured patients. (...) From a pragmatic point of view, Goldstein's idea of adequacy in biological knowledge might lead to novel approaches to current ethical questions in medicine as well as biotechnology. (shrink)
We show that Bohr's principle of complementarity between position and momentum descriptions can be formulated rigorously as a claim about the existence of representations of the CCRs. In particular, in any representation where the position operator has eigenstates, there is no momentum operator, and vice versa. Equivalently, if there are nonzero projections corresponding to sharp position values, all spectral projections of the momentum operator map onto the zero element.
A proper understanding of black hole complementarity as a response to the information loss paradox requires recognizing the essential role played by arguments for the applicability and limitations of effective semiclassical theories. I argue that this perspective sheds important light on the arguments advanced by Susskind, Thorlacius, and Uglum—although ultimately I argue that their position is unsatisfactory. I also consider the argument offered by ’t Hooft for the breakdown of microcausality around black holes, and conclude that it relies on (...) a mistaken treatment of measurement collapse. There is, however, a legitimate argumentative role for black hole complementarity, exemplified by the position of Kiem, Verlinde, and Verlinde, that calls for a more subtle analysis of the limitations facing our effective theories. (shrink)
This paper is the sequel of a previous one where we have introduced a paraconsistent logic termed paraclassical logic to deal with 'complementary propositions'. Here, we enlarge upon the discussion by considering certain 'meaning principles', which sanction either some restrictions of 'classical' procedures or the utilization of certain 'classical' incompatible schemes in the domain of the physical theories. Here, the term 'classical' refers to classical physics. Some general comments on the logical basis of a scientific theory are also put in (...) between the text, motivated by the discussion of complementarity. (shrink)
Presentations of black hole complementarity by van Dongen and de Haro, as well as by 't Hooft, suffer from a mistaken claim that interactions between matter falling into a black hole and the emitted Hawking-like radiation should lead to a failure of commutativity between space-like-related observables localized inside and outside the black hole. I show that this conclusion is not supported by our standard understanding of quantum interactions. We have no reason to believe that near-horizon interactions will threaten microcausality. (...) If these interactions reliably transfer information to the outgoing radiation, then this response to Hawking's information loss argument should amount to a version of the bleaching scenario. I argue that the challenge facing black hole complementarity is that of reconciling this commitment to bleaching with the expectation that the event horizon will be locally unremarkable. This challenge is most promisingly met by proposals that postulate a consistent account of the limitations of our local semi-classical theories, but no support is added to these postulates by appeals to verificationism or to the interactions considered by 't Hooft. (shrink)
Following discussions by Callicott and Zimmerman, I argue that much of deep ecology’s critique of science is based on an outdated image of natural science. The significance of the quantum revolution for environmental issues does not lie in its alleged intrusion of the subjective consciousness into the physicists’ description of nature. Arguing from the viewpoint of Niels Bohr’s framework of complementarity,I conclude that Bohr’s epistemological lesson teaches that the object of description in physical science must be interaction and that (...) it is now mistaken to imagine that physical science aims to represent nature in terms of properties it possesses apart from interaction. (shrink)
Niels Bohr famously argued that a consistent understanding of quantum mechanics requires a new epistemic framework, which he named complementarity. This position asserts that even in the context of quantum theory, classical concepts must be used to understand and communicate measurement results. The apparent conflict between certain classical descriptions is avoided by recognizing that their application now crucially depends on the measurement context.
Abstract This essay is a response to three review articles on two recently published books dealing with aspects of Hinduism and science: Jonathan Edelmann's Hindu Theology and Biology: The Bhāgavata Purāṇa and Contemporary Theory, and my own, Hindu Perspectives on Evolution: Darwin, Dharma and Design. The task set by the editor of Zygon for the three reviewers was broad: they could make specific critiques of the two books, or they could use them as starting points to engage in a broad (...) discussion of Hinduism and science, or religion and science in general. In my response, I first provide a fairly detailed reply to David Gosling's many critiques of my book, and in the process call into question his Advaitic conciliation of Hinduism and science. Thomas Ellis's thesis of basic incompatibility between Hinduism and science is much closer to my own viewpoint. One of the main objectives of my book was to explain and illustrate this incompatibility with specific regard to Hindu and Darwinian perspectives on evolution. In this essay I provide a few examples in support of Ellis's incompatibility thesis, encompassing both epistemological and metaphysical dissonances. Finally, I reflect upon Varadaraja V. Raman's wide-ranging exposition on the all-encompassing nature of the Hindu tradition that readily accommodates both religious and scientific quests for knowledge. Raman uses the two books only as starting points for his own thoughts, without reference to my book. I confine myself, accordingly, to a brief critique of his complementarity approach to Hinduism and science, and of his radical inclusivism that enfolds basically all philosophical positions into the warm embrace of the Hindu tradition, including even the extreme antireligious materialism of the Cārvāka. (shrink)
We offer an argument for the extended mind based on considerations from brain development. We argue that our brains develop to function in partnership with cognitive resources located in our external environments. Through our cultural upbringing we are trained to use artefacts in problem solving that become factored into the cognitive routines our brains support. Our brains literally grow to work in close partnership with resources we regularly and reliably interact with. We take this argument to be in line with (...)complementarity or “second-wave” defences of the extended mind that stress the functional differences between biological elements and external, environmental resources in putative cases of extended cognition. Complementarity defences argue that many of the kinds of cognition humans excel at can only be accomplished by brains working together with a body that directly manipulates and acts on the world [Rowlands (1999); Menary (2007); Sutton (2010)]. We argue that complementarity and functionalist defences of the extended mind aren’t opposed, but that complementarity considerations can provide much needed and hitherto under exploited leverage in defending EMT. Moreover, the developmental work we will describe adds extra weight to the complementarity case for EMT. (shrink)
This article examines the convergence between Italian relational sociology, developed by Pierpaolo Donati and introduced here by Emmanuele Morandi, and critical realism. Whilst the latter is preoccupied with relations between people and structures, Donati sees the whole social order as a relational entity sui generis. Consequently, relational sociology can provide a fuller account of ‘social integration’ than critical realism, which concentrates upon ‘malintegration’ because of its transformative potential. This difference is viewed as a potential source of synergy between these two (...) versions of realism. (shrink)
The debate between emergentists and reductionists rests on the observation that in many situations, in which it seems desirable to work with a coherent and unified discourse, key predicates fall into different groups, such that pairs of members one taken from each group, cannot be co-predicated of some common subject. Must we settle for ‘island’ discourses in science and human affairs or is some route to a unified discourse still open? To make progress towards resolving the issue the conditions under (...) which such segregations of predicates seem inexorable must be brought out. The distinction between determinable and determinate properties throws light on some aspects of this problem. Bohr’s concept of complementarity, when combined with Gibson’s idea of an affordances as a special class of dispositional properties is helpful. Several seeming problems melt away, for example, how it is possible for a group of notes to become hearable as a melody. The mind-body problem and the viability of the project of reducing biology to chemistry and physics are two issues that are more difficult to deal with. Are mental phenomena, such as feelings and memories emergent from material systems or are they actually material properties themselves? Are the attributes of living beings emergent from certain accidental but long running collocations of chemical reactions, or are they nothing but chemical phenomena? If emergent, in what way are they distinctive from that from which they emerge? (shrink)
The paper examines philosophical issues that arise in contexts where one has many different models for treating the same system. I show why in some cases this appears relatively unproblematic (models of turbulence) while others represent genuine difficulties when attempting to interpret the information that models provide (nuclear models). What the examples show is that while complementary models needn’t be a hindrance to knowledge acquisition, the kind of inconsistency present in nuclear cases is, since it is indicative of a lack (...) of genuine theoretical understanding. It is important to note that the differences in modeling do not result directly from the status of our knowledge of turbulent flows as opposed to nuclear dynamics—both face fundamental theoretical problems in the construction and application of models. However, as we shall, the ‘problem context(s)’ in which the modeling takes plays a decisive role in evaluating the epistemic merit of the models themselves. Moreover, the theoretical difficulties that give rise to inconsistent as opposed to complementary models (in the cases I discuss) impose epistemic and methodological burdens that cannot be overcome by invoking philosophical strategies like perspectivism, paraconsistency or partial structures. (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.
Rom Harré thinks that the Emergence–Reduction debate, conceived as a vertical problem, is partly ill posed. Even if he doesn’t wholly reject the traditional definition of an emergent property as a property of a collection but not of its components, his point is that this definition doesn’t exhaust all the dimensions of emergence. According to Harré there is another kind (or dimension) of emergence, which we may call—somewhat paradoxically—“horizontal emergence”: two properties of a substance are horizontally emergent relative to each (...) other if they cannot be displayed in the same conditions. Contrary to vertical emergence, horizontal emergence is a symmetrical relation. Harré endorses horizontal emergentism. I argue that this position faces a principled difficulty: it makes it impossible to bind different horizontally emergent discourses in an interesting way. Physics and biology for example become “island” discourses, each speaking of a distinct kind of entities. The only way to ensure that two different discourses can relate to the same entity is to reintroduce verticality into the picture. (shrink)
Argument and explanation are distinct forms of reasoning with an underappreciated complementary relationship. In this essay I define these terms precisely, identify the mischief that results from conflating them, elucidate their complementary relationship and employ this relationship to provide a fruitful approach to analyzing the logical structure of the common editorial.
Discussions of the interpretation of quantum theory are at present obstructed by (1) the increasing axiomania in physics and philosophy which replaces fundamental problems by problems of formulation within a certain preconceived calculus, and (2) the decreasing (since 1927) philosophical interest and sophistication both of professional physicists and of professional philosophers which results in the replacement of subtle positions by crude ones and of dialectical arguments by dogmatic ones. More especially, such discussions are obstructed by the ignorance of both opponents, (...) and also defenders of the Copenhagen point of view, as regards the arguments which once were used in its defence. The publication of Bunge's Quantum Theory and Reality and especially of Popper's contribution to it are taken as an occasion for the restatement of Bohr's position and for the refutation of some quite popular, but surprisingly naive and uninformed objections against it. Bohr's position is distinguished both from the position of Heisenberg and from the vulgarized versions which have become part of the so-called "Copenhagen Interpretation" and whose inarticulateness has been a boon for all those critics who prefer easy victories to a rational debate. Einstein's main counterargument is discussed, and Bohr's refutation restated. The philosophical background and earlier forms of Bohr's views are stated also. Considering that these views are more detailed, better adapted to the facts of the microdomain than any existing alternative it follows that fundamental discussion must first return to them. Their uniqueness is not asserted, however. Here the author still maintains that a hundred shabby flowers are preferable to a single blossom, however exquisite. But a hundred shabby flowers plus an exquisite blossom are more desirable still. (shrink)
The purpose of this paper is to demonstrate the usefulness of the concept of possibility , and not merely that of actuality , for an inquiry into the bodily constitution of experience. The paper will study how the possibilities of action that may (or may not) be available to the subject help to shape the meaning attributed to perceived objects and to the situation occupied by the subject within her environment. This view will be supported by reference to empirical evidence (...) provided by recent and current research on the perceptual estimation of distances and the effects brought about by the use of a tool on the organisation of our perceived immediate space. (shrink)
E. Schrödinger's ideas on interpreting quantum mechanics have been recently re-examined by historians and revived by philosophers of quantum mechanics. Such recent re-evaluations have focused on Schrödinger's retention of space–time continuity and his relinquishment of the corpuscularian understanding of microphysical systems. Several of these historical re-examinations claim that Schrödinger refrained from pursuing his 1926 wave-mechanical interpretation of quantum mechanics under pressure from the Copenhagen and Göttingen physicists, who misinterpreted his ideas in their dogmatic pursuit of the complementarity doctrine and (...) the principle of uncertainty. My analysis points to very different reasons for Schrödinger's decision and, accordingly, to a rather different understanding of the dialogue between Schrödinger and N. Bohr, who refuted Schrödinger's arguments. Bohr's critique of Schrödinger's arguments predominantly focused on the results of experiments on the scattering of electrons performed by Bothe and Geiger, and by Compton and Simon. Although he shared Schrödinger's rejection of full-blown classical entities, Bohr argued that these results demonstrated the corpuscular nature of atomic interactions. I argue that it was Schrödinger's agreement with Bohr's critique, not the dogmatic pressure, which led him to give up pursuing his interpretation for 7 yr. Bohr's critique reflected his deep understanding of Schrödinger's ideas and motivated, at least in part, his own pursuit of his complementarity principle. However, in 1935 Schrödinger revived and reformulated the wave-mechanical interpretation. The revival reflected N. F. Mott's novel wave-mechanical treatment of particle-like properties. R. Shankland's experiment, which demonstrated an apparent conflict with the results of Bothe–Geiger and Compton–Simon, may have been additional motivation for the revival. Subsequent measurements have proven the original experimental results accurate, and I argue that Schrödinger may have perceived even the reformulated wave-mechanical approach as too tenuous in light of Bohr's critique. (shrink)
Process philosophy endeavors to replace the classical ontology of substances by a process ontology centered on the notions of change and transition. We argue that the substantial and processual approach are mutually complementary in the sense of a generalized quantum theory which is not limited to physical phenomena. From this point of view, restricting oneself to either substance ontology or process ontology would be as ill-advised as exclusively relying on position or momentum representations in physics. A new view on Zeno's (...) paradox lends itself. The meaning of a 'mental energy' observable, complementary to 'internal time', and its relationship to acategorial states of the human mind will be tentatively discussed. (shrink)
Like science, engineering engages in analysis and synthesis. But whereas scientists tend to break matter down to its most basic building blocks, engineers ultimately aim to assemble myriad components into a complex system. Because the components are heterogeneous, engineers must integrate knowledge in many areas, and multidisciplinary teamwork is common practice. Like science, engineering covers both the general and the particular. But whereas scientists tend to design particular experiments for discovering general laws of nature, engineers tend to formulate general principles (...) for designing particular artifacts. Modern engineering has developed general theories about large types of artificial systems, notably information, control, and computation theories. These engineering theories are most effective for designing concrete artifacts, yet their abstract theorem-proof format is closer to pure mathematics than the format of physical theories, which are closer to applied mathematics. The apparent paradox accentuates the engineering emphasis on creating things rather than discovering phenomena already existent. (shrink)
The apparent underdetermination of the formalism of quantum field theory (QFT) as between a particle and a field interpretation is studied in this paper through a detour over the problem of unifying QFT with general relativity. All we have at present is a partial or approximate unification, QFT in non-Minkowskian spaces. The nature of this hybrid and the problem of its internal consistency are discussed. One of its most striking implications is that particles do not have an observer-independent existence. We (...) trace the ways in which physicists reacted to this at first highly implausible ontological consequence. We conclude that quantum fields rather than particles are after all the basic entities in QFT. (shrink)
In information theory there is a fundamental principle, usually referred to as the informational “uncertainty principle”, which expresses a limitation of any information processing system (or agent) in terms of a relation between the system's response property and its inherent processing capacity. From this principle, it can be argued that a salutary strategy for dealing with conflicting information processing requirements is to adopt various complementary processes (or channels). Donald M. MacKay had attempted to relate the informational uncertainty principle to spatial (...) and temporal response properties of neurons in the mammalian visual cortex, and suggested that the spatial and the temporal aspects of such neurons are complementary. I attempt to extend his efforts and to show that the informational uncertainty principle may indeed underlie many complementary relations exhibited in human perception and cognition, such as the relation between the two principal processing streams in vision and the relation between parallel and serial processes in cognition. (shrink)
The authors regard opiates as the primary neural substrate for social attachment, and peptide hormones as subsidiary. One may instead conclude from their evidence that oxytocin, vasopressin, and opiates play complementary roles in attachment. Oxytocin and vasopressin relate to different aspects of emotional experience, and opiates to quiescence from long-term attachment. This is related to intimacy versus affiliation.