Neuroscience is an important component of the scientific attack on the problem of consciousness. However, most neuroscientists, viewing our discussions, see only conflict and discord, and no reason why quantum theory has any great relevance the dynamics of the conscious brain. It is therefore worthwhile, in this first plenary talk of the 2003 Tucson conference on “Quantum Approaches to the Understanding of Consciousness,” to focus on the central issue, which is the crucial role of “The Observer,” and specifically, (...) “The Mind of The Observer” in contemporary physical theory. I shall therefore review here this radical departure of present-day basic physics from the principles of classical physics, and then spell out some of its ramifications for neuroscience. (shrink)

All statements describing physical reality are derived through interpretation of measurement results that requires a theory of the measuring instruments used to make the measurements. The ultimate measuring instrument is our body which displays its measurement results in our mind. Since a physical theory of our mind-body is unknown, the correct interpretation of its measurement results is unknown. The success of the physical sciences has led to a tendency to treat assumption in physics as indisputable facts. This tendency hampers (...) the development of new theories capable of addressing the foundations of mind. To show the possibility that false interpretations of experimental results have lead to equally false projections onto physical reality may have happened, the double slit experiment and special relativity experiments are examined in detail. I will show that strongly held a-priory beliefs characterizing measurement instruments have lead to unjustified but widely held concepts in physical theories. For example the assumption that material bodies have minds can change the interpretation of experiments to produce alternative physical theories. Since some material bodies have minds this paper calls for a review of the conscious observer’s role in the execution and interpretation of fundamental physics experiments in order to verify or challenge the basic beliefs adopted in standard physical theories. (shrink)

In Dirac-Bergmann constrained dynamics, a first-class constraint typically does not _alone_ generate a gauge transformation. By direct calculation it is found that each first-class constraint in Maxwell's theory generates a change in the electric field E by an arbitrary gradient, spoiling Gauss's law. The secondary first-class constraint p^i,_i=0 still holds, but being a function of derivatives of momenta, it is not directly about E. Only a special combination of the two first-class constraints, the Anderson-Bergmann -Castellani gauge (...) generator G, leaves E unchanged. This problem is avoided if one uses a first-class constraint as the generator of a _canonical transformation_; but that partly strips the canonical coordinates of physical meaning as electromagnetic potentials and makes the electric field depend on the smearing function, bad behavior illustrating the wisdom of the Anderson-Bergmann Lagrangian orientation of interesting canonical transformations. The need to keep gauge-invariant the relation dot{q}- dH/dp= -E_i -p^i=0 supports using the primary Hamiltonian rather than the extended Hamiltonian. The results extend the Lagrangian-oriented reforms of Castellani, Sugano, Pons, Salisbury, Shepley, _etc._ by showing the inequivalence of the extended Hamiltonian to the primary Hamiltonian even for _observables_, properly construed in the sense implying empirical equivalence. Dirac and others have noticed the arbitrary velocities multiplying the primary constraints outside the canonical Hamiltonian while apparently overlooking the corresponding arbitrary coordinates multiplying the secondary constraints _inside_ the canonical Hamiltonian, and so wrongly ascribed the gauge quality to the primaries alone, not the primary-secondary team G. Hence the Dirac conjecture about secondary first-class constraints rests upon a false presupposition. The usual concept of Dirac observables should also be modified to employ the gauge generator G, not the first-class constraints separately, so that the Hamiltonian observables become equivalent to the Lagrangian ones such as the electromagnetic field F. (shrink)

System security is essential for the operation of the island microgrid. However, the system security is generally threatened due to the presence of physical uncertainties and cyber attacks. In this article, a novel sliding mode load control strategy is proposed for the microgrid to mitigate cyber attacks and physical uncertainties. Firstly, a high-order disturbance observer is designed to estimate the unmeasurable factors in the microgrid. Secondly, a HODO-based sliding mode control strategy is proposed where the estimated value observed by (...) the HODO is applied to the sliding mode surface and control law. It can better guarantee the security of the isolated microgrid. Then, the stability of the HODO-based SMC is demonstrated by Lyapunov stability theory. Finally, simulation results show that the proposed control strategy has excellent control performance. (shrink)

In this article I present the extracts and summary of heuristic and speculative observations on various aspects I feel are problematic in the practice of modern physics, the definitions and methods of which are the premise for the whole of Science. The illustrations will be fully developed in a later, more extensive and in-depth work in which some theoretical solutions will also be put forward; therefore in the interests of brevity all assertions will not be demonstrated fully in this (...) article. I will initially discuss the problem with thinking of Reality as basically being made up of ontologically autonomous “parts”; I will recall how the existence of the vacuum is demonstrated through the thermodynamic experiments about heat capacities run by W. Nernst and the experiments of W. Lamb and H. Casimir ; the vacuum will be defined as an object that precedes matter and space, and actually illustrated as an evolving singularity, which all existence draws from; the non-isolability... (shrink)

This book, as the Preface reports, is the first of a series from the Johns Hopkins Center for the History and Philosophy of Science. The essays in this book were invited from both historians of and philosophers of science on the general theme of "testing of hypotheses in modern physics by observation and experiment," accordingly none has been previously published.

Collaboration on the First Edition of Spacetime Physics began in the mid-1960s when Edwin Taylor took a junior faculty sabbatical at Princeton University where John Wheeler was a professor. The resulting text emphasized the unity of spacetime and those quantities (such as proper time, proper distance, mass) that are invariant, the same for all observers, rather than those quantities (such as space and time separations) that are relative, different for different observers. The book has become a standard introduction (...) to relativity. The Second Edition of Spacetime Physics embodies what the authors have learned during an additional quarter century of teaching and research. They have updated the text to reflect the immense strides in physics during the same period and modernized and increased the number of exercises, for which the First Edition was famous. Enrichment boxes provide expanded coverage of intriguing topics. An enlarged final chapter on general relativity includes new material on gravity waves, black holes, and cosmology. The Second Edition of Spacetime Physics provides a new generation of readers with a deep and simple overview of the principles of relativity. (shrink)

Founding our analysis on the Geneva-Brussels approach to the foundations of physics, we provide a clarification and classification of the key concept of observation. An entity can be observed with or without a scope. In the second case, the observation is a purely non-invasive discovery process; in the first case, it is a purely invasive process, which can involve either creation or destruction aspects. An entity can also be observed with or without a full control over the observational (...) process. In the latter case, the observation can be described by a symmetry breaking mechanism, through which a specific deterministic observational process is selected among a number of potential ones, as explained in Aerts’ hidden measurement approach. This is what is called a product test, or product observation, whose consequences are that outcomes can only be predicted in probabilistic terms, as it is the case in typical quantum measurements. We also show that observations can be about intrinsic (stable) properties of the observed entity, or about relational (ephemeral) properties between the observer and observed entities; also, they can be about intermediate properties, neither purely classical, nor purely quantum. Our analysis allows us to propose a general conceptual characterization of quantum measurements, as observational processes involving three aspects: (1) product observations, (2) pure creation aspects and (3) ephemeral relational properties. We also discuss the important concept of non-spatiality and emphasize some of the differences and similarities between quantum and classical/relativistic observations. (shrink)

A summary is presented of the subquantum kinetics ether methodology, a type of unified field theory that successfully predicts a large number of physical phenomena. This utilizes a new approach to theory development that emphasizes the use of system theory and places theory development as primary and observation as secondary. The rationale is given for adopting an open system, process-based view of the physical universe and for choosing the Model G reaction system as a prospective “genetic code” for the physical (...) universe. Model G is shown to provide a viable model for the creation of subatomic particles from zero-point energy fluctuations. (shrink)

Objective: This cross-sectional questionnaire-based study aims to compare physical activity and nature exposure levels between people living in France and Germany during the lockdown. Furthermore, the secondary aim is to observe the relationship between perceived stress, psychological health, physical activity, and nature exposure in Germany and France during the coronavirus disease 2019 -related lockdown of April/May 2020.Methods: The study includes 419 participants who have completed the Perceived Stress Scale 10, the World Health Organization Quality of Life-BREF, the Godin-Shephard Leisure-Time Physical (...) Activity Questionnaire, the modified Nature Exposure Scale, and complementary questions related to the lockdown period from April 19 to May 11, 2020. Multiple regression models were constructed to evaluate the relationship of nature exposure and physical exercise with overall stress perception and psychological health in France and Germany when considering a broad range of covariates.Results: Exposure to nature during the lockdown, amount of physical activity ηp2 = 0.014, p < 0.001), and psychological health were greater in German compared with French participants. Godin Index and Nature Exposure Scale total score were both inversely correlated to stress perception and positively correlated to psychological health. The stress and psychological health regression models explained 10% of the results' variance. Physical activity was a significant for both models. Nature Exposure Scale total score was a significant predictor only for psychological health. When including all significant covariates, the regression models explained 30.7% for the perceived stress and 42.1% for the psychological health total overall variance.Conclusion: Physical activity and nature exposure are significant predictors of psychological health. Even though both variables are associated with stress perception, only physical activity is a significant predictor of stress perception. Our results suggest that physical activity and nature exposure were key factors to go through the lockdown period in France and Germany. (shrink)

Rovelli’s RQM is first characterized by contrast with both Everett’s and Bohr’s interpretations of quantum mechanics. Then, it is shown that a basic difficulty arises from the choice of formulating RQM in a naturalistic framework. Even though, according to Rovelli’s interpretation, statements about the world only make sense relative to certain naturalized observers described by means of quantum mechanics, this very meta-statement seems to make sense relative to a sort of super-observer which does not partake of the naturalized (...) status of ordinary observers. The difficulty is solved by substituting functional reference frames for physical (or naturalized) observers throughout. Instead of being relative to physical observers, statements about the state vector of physical systems are here relative to well-defined projects of probabilistic prediction which may be embodied by several physical observers. (shrink)

We outline an argument that a single-particle universe (a universe containing precisely one pointlike particle) can be described mathematically, in which observation can be considered meaningful despite the a priori impossibility of distinguishing between an observer and the observed. Moreover, we argue, such a universe can be observationally similar to the world we see around us. It is arguably impossible, therefore, to determine by experimental observation of the physical world whether the universe we inhabit contains one particle or many—modern (...) scientific theories cannot, therefore, be regarded as descriptions of ‘reality’, but are at best human artefacts. Our argument uses a formal model of spacetime that can be considered either relational or substantivalist depending on one’s preferred level of abstraction, and therefore suggests that this long-held distinction is also to some extent illusory. (shrink)

This is the first of two papers responding to ‘recent’ commentary on various aspects of hyperplane dependence by several authors. In this paper I focus on the issues of the relations of HD to state reduction and unitary evolution. The authors who’s comments I address here are Maudlin and Myrvold. In the second paper of this set I focus on HD dynamical variables and localizable properties and measurements and address comments of de Koning, Halvorson, Clifton and Wallace. Each paper (...) ends with some reflections on the implications of HD for the ontology of Minkowski space-time. To set the stage for my responses, I begin this paper with some general position statements designed to correct what seem to be widespread and erroneous construals of some of my views. Two central points are argued for in this first paper. First, dynamical evolution occurs not only within foliations of Minkowski space-time. Rather the transition from the physical state of affairs on any one hyperplane to any other, whether the hyperplanes intersect or are parallel, is always an instance of dynamical evolution between them, generated by some active combination of boost-like transformations and/or time-like translations and/or state reductions and ‘reconstructions’. This point gives rise to a generalized conception of a history of dynamical evolution, allowing for the use of parameterized families of hyperplanes that multiply cover some portions of space-time. Nevertheless, and this is the second central point, for any two generalized histories, H and H’, the quantum states for a system on all the hyperplanes of H from the asymptotic past up to some hyperplane, h, determine the quantum states for the system on all the hyperplanes of H’ from the asymptotic past up to any hyperplane, h’, such that h’ lies to the past of all those state reduction regions that lie to the future of all hyperplanes of H that are ‘earlier’ than h. Consideration of these results should defuse concerns that have been voiced about the coherence and consistency of HD. A position closely related to the second point has already been argued for by Myrvold. (shrink)

Observables on hypergraphs are described by event-valued measures. We first distinguish between finitely additive observables and countably additive ones. We then study the spectrum, compatibility, and functions of observables. Next a relationship between observables and certain functionals on the set of measures M(H) of a hypergraph H is established. We characterize hypergraphs for which every linear functional on M(H) is determined by an observable. We define the concept of an “effect” and show that observables are related to effect-valued measures. (...) Finally, we define “operational” transformations from M(H) to itself and show that they can be described as a certain combination of effects. (shrink)

All sciences have epistemic assumptions, a language for expressing their theories or models, and symbols that reference observables that can be measured. In most sciences the language in which their models are expressed are not the focus of their attention, although the choice of language is often crucial for the model. On the contrary, biosemiotics, by definition, cannot escape focusing on the symbol–matter relationship. Symbol systems first controlled material construction at the origin of life. At this molecular level it (...) is only in the context of open-ended evolvability that symbol–matter systems and their functions can be objectively defined. Symbols are energy-degenerate structures not determined by laws that act locally as special boundary conditions or constraints on law-based energy-dependent matter in living systems. While this partial description holds for all symbol systems, cultural languages are much too complex to be adequately described only at the molecular level. Genetic language and cultural languages have common basic requirements, but there are many significant differences in their structures and functions. (shrink)

Finetuning and Naturalness are extra-empirical theory assessments that reflect our expectation how scientific theories should provide an intuitive understanding about the foundations underlying the observed phenomena. Recently, the absence of new physics at the LHC and the theoretical evidence for a multiverse of alternative physical realities, predicted by our best fundamental theories, have casted doubts about the validity of these concepts. In this essay we argue that the discussion about Finetuning should not predominantly concentrate on the desired features a (...) fundamental theory is expected to have, but rather on the question what a theory needs to qualify as fundamental in the first place. By arguing that a fundamental description of the Universe should possess zero entropy, we develop a ‘holistic’ concept for the most fundamental layer of reality: The fundamental description of the Universe is the Universe itself, understood as an entangled quantum state. Adopting a universal applicability of quantum mechanics, in this framework the behavior of subsystems can be understood as the perspectival experience of an entangled quantum Universe perceived through the “lens of decoherence”. In this picture the fundamental reality is non-local, and finetuned coincidences in effective theories may be understood in a way similar to EPR-correlations. This notion provides a fresh view on the topic of Naturalness and Finetuning since it suggests that Finetuning problems and hints for anthropic explanations are an artifact of theories building up on subsystems rather than on the fundamental description. Recent work in quantum gravity aiming at an understanding of spacetime geometry from entanglement entropy could be interpreted as a first sign of such a paradigm shift. (shrink)

Time, along with concepts as space and matter, is bound to be a central concept of any physical theory. The chapter first discusses how time is treated similarly in quantum and classical theories. It then provides a few references on time‐reversal. The chapter discusses three chosen authors' (Paul Busch, Jan Hilgevoord and Jos Uffink) clarifications of uncertainty principles in general. Next, the chapter follows Busch in distinguishing three roles for time in quantum physics. They are external time, intrinsic (...) time and observable time. It also provides a brief discussion on time operators, in particular Pauli's influential proof. Finally, the chapter talks about time‐energy uncertainty principles with intrinsic times. (shrink)

Exploiting the skills of others enables individuals to reduce the risks and costs of resource innovation. Social corvids are known to possess sophisticated social and physical cognitive abilities. However, their capacity for imitative learning and its inter-individual transmission pattern remains mostly unexamined. Here we demonstrate the large-billed crows' ability to learn problem-solving techniques by observation and the dominance-dependent pattern in which this technique is transmitted. Crows were allowed to observe one of two box-opening behaviours performed by a dominant or subordinate (...) demonstrator and then tested regarding action and technique. The observers successfully opened the box on their first attempts by using non-matching actions but matching techniques to those observed, suggesting emulation. In the subsequent test sessions, dominant observers (i.e. those dominant to the bird acting as demonstrator) consistently used the learned technique, whereas subordinates (i.e. those subordinate to the bird acting as demonstrator) learned alternative techniques by explorative trial and error. Our findings demonstrate crows' capacity to learn by observing behaviours and the effect of dominance on transmission patterns of behavioural skills. Keywords: social learning; imitation; emulation; affordance; culture; innovation. (shrink)

Exploiting the skills of others enables individuals to reduce the risks and costs of resource innovation. Social corvids are known to possess sophisticated social and physical cognitive abilities. However, their capacity for imitative learning and its inter-individual transmission pattern remains mostly unexamined. Here we demonstrate the large-billed crows' ability to learn problem-solving techniques by observation and the dominance-dependent pattern in which this technique is transmitted. Crows were allowed to observe one of two box-opening behaviours performed by a dominant or subordinate (...) demonstrator and then tested regarding action and technique. The observers successfully opened the box on their first attempts by using non-matching actions but matching techniques to those observed, suggesting emulation. In the subsequent test sessions, dominant observers consistently used the learned technique, whereas subordinates learned alternative techniques by explorative trial and error. Our findings demonstrate crows' capacity to learn by observing behaviours and the effect of dominance on transmission patterns of behavioural skills. Keywords: social learning; imitation; emulation; affordance; culture; innovation. (shrink)

In a recent paper in this journal, Kosso ([2000]) discussed the observational status of continuous symmetries of physics. While we are in broad agreement with his approach, we disagree with his analysis. In the discussion of the status of gauge symmetry, a set of examples offered by 't Hooft ([1980]) has influenced several philosophers, including Kosso; in all cases the interpretation of the examples is mistaken. In this paper, we present our preferred approach to the empirical significance of symmetries, (...) re-analysing the cases of gauge symmetry and general covariance. Direct and indirect empirical significance Global and local continuous symmetries Gauge symmetry 3.1 Local gauge symmetry 3.1.1 Discussion of the first claim 3.1.2 Discussion of the second claim 3.2 Global gauge symmetry Space-time symmetries Direct and indirect empirical significance again Conclusion. (shrink)

At first glance singularity would seem to be necessarily opposed to the physical sciences, indeed to any kind of science. As the hallowed saying goes: “Science deals only in universals.” According to this view, the aim of any true scientific endeavor must be the discovery of universals or, in other words, the value of such an endeavor is based on its ability to explain phenomena in terms of universals. The status of singularity in science is a direct result of (...) this approach. Singularity is associated with the presence, either in a person or an object, of an unusual or exceptional quality, or of an individual trait. Singularity so conceived must therefore be seen as inherently compromising the aims of any scientific endeavor, since the purpose of that endeavor is universality as defined above. In this sense, the basis of scientific explication is the ability to determine a feature common to a collection of objects, thus allowing them to be explained by deductive reasoning. This common feature can therefore not be individual, if individual is understood as unusual or exceptional. (shrink)

Physicalists commonly argue that conscious experiences are nothing more than states of the brain, and that conscious qualia are observer-independent, physical properties of the external world. Although this assumes the ‘mantle of science,’ it routinely ignores the findings of science, for example in sensory physiology, perception, psychophysics, neuropsychology and comparative psychology. Consequently, although physicalism aims to ‘naturalise’ consciousness, it gives an unnatural account of it. It is possible, however, to develop a natural, nonreductive, reflexive model of how consciousness relates (...) to the brain and the physical world. This paper introduces such a model and how it construes the nature of conscious experience. Within this model the physical world as perceived (the phenomenal world) is viewed as part of conscious experience not apart from it. While in everyday life we treat this phenomenal world as if it is the “physical world”, it is really just one biologically useful representation of what the world is like that may differ in many respects from the world described by physics. How the world as perceived relates to the world as described by physics can be investigated by normal science (e.g. through the study of sensory physiology, psychophysics and so on). This model of consciousness appears to be consistent with both third-person evidence of how the brain works and with first-person evidence of what it is like to have a given experience. It also views consciousness as an integral part and natural expression of the world—in a manner true to the spirit (if not to the detail) of Whitehead’s philosophy. -/- . (shrink)

This is the second of two papers responding (somewhat belatedly) to ‘recent’ commentary on various aspects of hyperplane dependence (HD) by several authors. In this paper I focus on the issues of the general need for HD dynamical variables, the identification of physically meaningful localizable properties, the basis vectors representing such properties and the relationship between the concepts of ‘localizable within’ and ‘measureable within’. The authors responded to here are de Koning, Halvorson, Clifton and Wallace. In the first paper (...) of this set (Fleming 2003b) I focused on the issues of the relations of HD to state reduction and unitary evolution and addressed comments of Maudlin and Myrvold. The central conclusion argued for in this second paper (§§ 5, 7) is the non-existence of strictly localizable objects or measurement processes and the consequent undermining of the principle of universal microcausality. This contrasts with the existence of strictly localizable properties and results in the consequent priority of the concept of ‘localizable within’ over ‘measureable within’. The paper opens with discussions of the need for and status of HD dynamical variables which are responses to anonymous queries. (shrink)

According to theories of quantum gravity, spacetime may be non-fundamental. The implications of this observation are now widely debated in the philosophy of quantum gravity. In this paper we argue that what is often discussed under the umbrella term of `spacetime emergence' in the philosophy of quantum gravity literature in fact consists of a plethora of distinct and even highly different problems. We therefore advocate to cast such debates more specifically in terms of emergent spatiotemporal aspects as is already done (...) in the physics literature. We first show how ambiguous the notion of spacetime is and offer five understandings of what the problem of spacetime emergence may still amount to. We then argue, however, that there are many philosophical problems relating to spacetime emergence and that none of the five understandings picks out a problem that is exceptional among these. Next, we observe that different spatiotemporal aspects are emergent in different quantum gravity approaches whereby speaking of quantum gravity collectively is problematic. Finally, we illustrate how inquiries about spacetime emergence are actually aided by conducting the investigation at the level of specific spatiotemporal aspects. (shrink)

The article analyzes the problem of physical theory nature and its criteria in the context of several concepts of modern physics. Such physical concepts allow multiple possible universes (the last usually happens to be a random consequence of the theory). Since the study requires several universe models, which basic principles (physical laws) can vary, the two theories have become the objects of analysis: the first, which includes the concept of eternal inflation, the second – the string cosmology (the (...) string landscape). Both theories allow for a large variation of physical laws (no matter, whether these are fundamentally different physical laws or different versions of the same basic principles). The amount of dark energy (cosmological constant) has been selected as a physical law parameter, changing its value in possible universes.The analysis of the physical theories, which allow a multiplicity of universes, has shown that the standard requirements for the theory, which connect its veracity with the criteria of observability and the need for validation of our universe basic principles, are not entirely consistent. Theoretical physics is moving towards the formulization of models that become a real (in some cases, apparently irresistible) challenge for experimental verification. The article proves that such verification probably can not be required in several physical theories, since, in particular, the postulation of this kind of connection between theory and reality is no more than a manifestation of anthropocentrism. However, the theory can trace more general grounds that lie beyond the scope of human observation. (shrink)

Descartes was both metaphysician and natural philosopher. He used his metaphysics to ground portions of his physics. However, as should be a commonplace but is not, he did not think he could spin all of his physics out of his metaphysics a priori, and in fact he both emphasized the need for appeals to experience in his methodological remarks on philosophizing about nature and constantly appealed to experience in describing his own philosophy of nature. During the 1630s, he (...) offered empirical support for the basic principles of his natural philosophy, while also promising to provide a metaphysical justification. He offered the metaphysical justification in the Meditations and Principles. and claimed absolute certainty for it. At the same time, he recognized that the particular postulated mechanisms of his natural philosophy did not reach that standard of certainty. These mechanisms were supported by empirical testing or confirming of causes through observed effects. (shrink)

In the 20th century the infiltration of scientific elements into philosophical currents not only reached its maximum, but also science itself became a "philosophical factor". We look at these processes in physics starting from the fall of mechanistic philosophy. The advent of relativity theory and quantum mechanics has changed physics as science and raised a host of philosophical questions. Traditionally philosophical questions concerning space, time and causality cannot be any longer considered with no help of these theories. Relativistic (...) cosmology and its observational successes in the last decades of the century, for the first time in the history of human thought, provided a global framework for both science and philosophy. And the current search for the final unifying theory of physics leads directly to the most foundational questions of an ontological character. We argue that the success of the 20th century physics strongly suggests a kind of structuralist ontology. /// No século XX, a infiltração de elementos científicos nas correntes filosóficas não só alcançou o seu máximo, mas também é verdade que a própria ciência se tornou um "factor filosófico". O presente artigo considera estes processos na física, a começar com a decadência da filosofia mecanicista. O advento da teoria da relatividade e da mecânica quântica transformou a física enquanto ciência e levantou uma plêiade de questões filosóficas. Questões tradicionais acerca do espaço, do tempo e da causalidade não podem mais ser consideradas sem o contributo destas teorias. A cosmologia relati-vista e os seus sucessos observacionais nas últimas décadas do século passado, e isso pela primeira vez na história do pensamento humano, fornecem um esquema global tanto para a ciência como para a filosofia. Além disso, a busca corrente de uma última teoria unificadora da física conduz directamente às questões mais fundacionais de carácter ontológico. O autor do artigo defende que os sucessos da física do século XX sugerem fortemente uma espécie de ontologia estruturalista. (shrink)

Observables have a dual nature in both classical and quantum kinematics: they are at the same time quantities, allowing to separate states by means of their numerical values, and generators of transformations, establishing relations between different states. In this work, we show how this twofold role of observables constitutes a key feature in the conceptual analysis of classical and quantum kinematics, shedding a new light on the distinguishing feature of the quantum at the kinematical level. We first take a (...) look at the algebraic description of both classical and quantum observables in terms of Jordan–Lie algebras and show how the two algebraic structures are the precise mathematical manifestation of the twofold role of observables. Then, we turn to the geometric reformulation of quantum kinematics in terms of Kähler manifolds. A key achievement of this reformulation is to show that the twofold role of observables is the constitutive ingredient defining what an observable is. Moreover, it points to the fact that, from the restricted point of view of the transformational role of observables, classical and quantum kinematics behave in exactly the same way. Finally, we present Landsman’s general framework of Poisson spaces with transition probability, which highlights with unmatched clarity that the crucial difference between the two kinematics lies in the way the two roles of observables are related to each other. (shrink)

Observables have a dual nature in both classical and quantum kinematics: they are at the same time quantities, allowing to separate states by means of their numerical values, and generators of transformations, establishing relations between different states. In this work, we show how this twofold role of observables constitutes a key feature in the conceptual analysis of classical and quantum kinematics, shedding a new light on the distinguishing feature of the quantum at the kinematical level. We first take a (...) look at the algebraic description of both classical and quantum observables in terms of Jordan–Lie algebras and show how the two algebraic structures are the precise mathematical manifestation of the twofold role of observables. Then, we turn to the geometric reformulation of quantum kinematics in terms of Kähler manifolds. A key achievement of this reformulation is to show that the twofold role of observables is the constitutive ingredient defining what an observable is. Moreover, it points to the fact that, from the restricted point of view of the transformational role of observables, classical and quantum kinematics behave in exactly the same way. Finally, we present Landsman’s general framework of Poisson spaces with transition probability, which highlights with unmatched clarity that the crucial difference between the two kinematics lies in the way the two roles of observables are related to each other. (shrink)

This is a chapter from my book Perception (Routledge). I explain the physical state view of sensory experience (Papineau, McLaughlin, others). I criticize an argument against it based on the "transparency observation". Then I develop two alternative arguments against it. The first is a Leibniz's Law argument based on the essentially externally directed character of some experiences. The second concerns "brains in vats". Finally I consider a recent response due to David Papineau, which involves rejecting essential external directedness.

Phenomenal consciousness is often thought to involve a first-person perspective or point of view which makes available to the subject categorically private, first-person facts about experience, facts that are irreducible to third-person physical, functional, or representational facts. This paper seeks to show that on a representational account of consciousness, we don't have an observational perspective on experience that gives access to such facts, although our representational limitations and the phenomenal structure of consciousness make it strongly seem that we (...) do. Qualia seem intrinsic and functionally arbitrary, and thus categorically private, because they are first-order sensory representations that are not themselves directly represented. Further, the representational architecture that on this account instantiates conscious subjectivity helps to generate the intuition of observerhood, since the phenomenal subject may be construed as outside, not within, experience. Once the seemings of private phenomenal facts and the observing subject are discounted, we can understand consciousness as a certain variety of neurally instantiated, behaviour controlling content, that constituted by an integrated representation of the organism in the world. Neuroscientific research suggests that consciousness and its characteristic behavioural capacities are supported by widely distributed but highly integrated neural processes involving communication between multiple functional sub- systems in the brain. This 'global workspace' may be the brain's physical realization of the representational architecture that constitutes consciousness. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Journal of the History of Ideas 62.1 (2001) 99-119 [Access article in PDF] Animism and Empiricism: Copernican Physics and the Origins of William Gilbert's Experimental Method John Henry In the second year of this journal's run, way back in 1941, appeared Edgar Zilsel's classic and still widely cited paper on The Origins of William Gilbert's Experimental Method. 1 Focusing on Gilbert's De magnete of 1600, undoubtedly a seminal (...) text in the history of the experimental method, 2 Zilsel argued that Gilbert borrowed his methodology from elite craftsmen, artisans, and other manual workers involved in mining, smelting, smithing, compass making, navigation, sailing, and other activities which involved working with iron or with magnets. 3 On its appearance the paper contributed to a growing and still continuing debate in the history of science about the relative importance of scholars and craftsmen in the origins of modern science. Although Zilsel's general thesis has been critically evaluated in terms of that wider debate, 4 his very specific claims about the [End Page 99] role of elite craftsmen in providing Gilbert with a ready-made experimental method, have never been properly considered. This paper attempts to reassess Zilsel's claims about the origin of Gilbert's experimental method and, in so doing, to arrive at a richer understanding of what Gilbert was trying to do in De magnete and to suggest an alternative source for his experimentalism.The first thing to note about Zilsel's argument is that it had two strands. 5 One of these pointed to actual experimental techniques used by Gilbert and showed that they can all be found in earlier writings on magnets. To be more specific, the techniques in question are to be found either in the thirteenth-century "Letter on the Magnet" written by Petrus Pergrinus or Pierre de Maricourt, first published in 1558, or in The Newe Attractive, a work on the magnetic compass written by a retired mariner, Robert Norman, first published in 1581 but reprinted three times before 1600. 6 The second strand did not involve experiments at all, with one notable exception, but simply implied or suggested that Gilbert's experimental techniques must have been inspired by miners and foundrymen, or navigators and instrument makers. The problem here, as others have objected, 7 is that it is by no means clear that elite craftsmen were engaged in performing experiments in anything like the sense of the word required for the argument to cut any ice. For Zilsel, however, "we cannot doubt that many of [the miners and foundrymen of the period], stimulated to improvements by economic competition, were wont to try new techniques and to observe natural processes." 8 A few sentences later we are told that it is "obvious" that "among such manual labourers there were experimentalists, though experimentalists with practical aims only and without theoretical knowledge." 9 [End Page 100]The philosopher of science at this point might legitimately want to suggest that an experiment is not an experiment unless it is testing a theory, but we do not have to enter into such arguable niceties. 10 We can see that there is something profoundly tendentious in Zilsel's claims simply by reading on. At this point Zilsel mentioned the only experiment specifically referred to in this strand of his argumentation. Quoting Gilbert, Zilsel showed that Gilbert himself must have descended into a mine in order, as Zilsel says, "to verify the hypothesis" that the polarity of a magnet derives from the polarity of the earth: We had a twenty pounds' heavy loadstone dug and hauled out after having first observed and marked its ends in its vein. Then we put the stone in a wooden tub on water, so that it could turn freely. Immediately the surface which had looked to the North in the mine turned itself to the North on the water. 11Zilsel did not make the absurd claim that Gilbert must have seen miners doing this kind of experiment, but he did all he could to... (shrink)

We review the spiritual cosmology of the 20th-century Indian mystic and yogi Sri Aurobindo. Our aim is twofold. First to furnish a basic philosophical understanding of Aurobindo’s vision, and secondly, that of making a comparative analysis with present scientific knowledge that could furnish an alternative metaphysical interpretation of the physical world. The rationale of our study is to question whether the observation of the physical world from the standpoint of the mystic experience could suggest some new theoretical framework for (...) the metaphysical ontology of the world itself. Taking perspectives from the states of consciousness described by mystics may furnish us with a deeper understanding of the material and metaphysical character of physical categories such as matter, energy, force, space, time, and space-time. This is an introductory overview of Aurobindo’s relevance for physical sciences and the conceptual foundations of physics, with particular attention paid to quantum physics. (shrink)

Summary The mesotrons, or mesons, were the first elementary particles observed to be inherently unstable. This essay offers a reconstruction of the stream of researches related to mesotron decay, and examines how these researches shaped some of the basic concepts and practices of the emerging field of particle physics. Mass measurements could not settle the question of whether the mesons were a homogeneous kind of particles or an assortment of particles with different masses. The assumption of a single (...) mass prevailed not on experimental grounds but because the mesons were identified tentatively with the carriers of the nuclear force according to a theory formulated by Hideki Yukawa. The identification gained currency because it entailed the prediction of meson decay, and thereby upheld the promise of a unified explanation of nuclear and cosmic-ray phenomena. In turn, the observation of decay and the measurement of the mean lifetime created the conditions for investigating the nuclear interactions of mesons at rest. Interest in these interactions was heightened, immediately after WWII, by the prospect of building and using accelerators to acquire knowledge about fundamental nuclear processes. Using decay to study nuclear capture, however, led to the realization that there exist not only different kinds of mesons but also two nuclear forces. (shrink)

We examine a publication by Euler, De novo genere oscillationum, written in 1739 and published in 1750, in which he derived for the first time, the differential equation of the (undamped) simple harmonic oscillator under harmonic excitation, namely the motion of an object acted on by two forces, one proportional to the distance traveled, the other varying sinusoidally with time. He then developed a general solution, using two different methods of integration, making extensive use of direct and inverse sine (...) and cosine functions. After much manipulation of the resulting equations, he proceeded to an analysis of the periodicity of the solutions by varying the relation between two parameters, $$a$$ and $$b$$, eventually identifying the phenomenon of resonance in the case where $$2b=a$$. This is shown to be nothing more than the equality between the driving frequency and the natural frequency of the oscillator, which, indeed, characterizes the phenomenon of resonance. Graphical representations of the behavior of the oscillator for different relations between these parameters are given. Despite having been a brilliant discovery, Euler’s publication was not influential and has been neglected by scholars and by specialized publications alike. (shrink)

Every physical theory has two different forms of mathematical equations to represent its target systems: the dynamical and the kinematical. Kinematical constraints are differentiated from equations of motion by the fact that their particular form is fixed once and for all, irrespective of the interactions the system enters into. By contrast, the particular form of a system's equations of motion depends essentially on the particular interaction the system enters into. All contemporary accounts of the structure and semantics of physical theory (...) treat dynamics, i.e., the equations of motion, as the most important feature of a theory for the purposes of its philosophical analysis. I argue to the contrary that it is the kinematical constraints that determine the structure and empirical content of a physical theory in the most important ways: they function as necessary preconditions for the appropriate application of the theory; they differentiate types of physical systems; they are necessary for the equations of motion to be well posed or even just cogent; and they guide the experimentalist in the design of tools for measurement and observation. It is thus satisfaction of the kinematical constraints that renders meaning to those terms representing a system's physical quantities in the first place, even before one can ask whether or not the system satisfies the theory's equations of motion. (shrink)

Is change missing in Hamiltonian Einstein–Maxwell theory? Given the most common definition of observables, observables are constants of the motion and nonlocal. Unfortunately this definition also implies that the observables for massive electromagnetism with gauge freedom are inequivalent to those of massive electromagnetism without gauge freedom. The alternative Pons–Salisbury–Sundermeyer definition of observables, aiming for Hamiltonian–Lagrangian equivalence, uses the gauge generator G, a tuned sum of first-class constraints, rather than each first-class constraint separately, and implies equivalent observables for equivalent (...) massive electromagnetisms. For General Relativity, G generates 4-dimensional Lie derivatives for solutions. The Lie derivative compares different space-time points with the same coordinate value in different coordinate systems, like 1 a.m. summer time versus 1 a.m. standard time, so a vanishing Lie derivative implies constancy rather than covariance. Requiring equivalent observables for equivalent formulations of massive gravity confirms that G must generate the 4-dimensional Lie derivative for observables. These separate results indicate that observables are invariant under internal gauge symmetries but covariant under external gauge symmetries, but can this bifurcated definition work for mixed theories such as Einstein–Maxwell theory? Pons, Salisbury and Shepley have studied G for Einstein–Yang–Mills. For Einstein–Maxwell, both \ and \ are invariant under electromagnetic gauge transformations and covariant under 4-dimensional coordinate transformations. Using the bifurcated definition, these quantities count as observables, as one would expect on non-Hamiltonian grounds. (shrink)

Brian Pitts has recently claimed to show via straightforward calculation that, at least in the case of Hamiltonian electromagnetism, an arbitrary first-class constraint ``generates not a gauge transformation, but a bad physical change'' (Annals of Physics 351 (2014) pp.382-406; arXiv:1310.2756). We show, via a straightforward calculation, that a transformation generated by an arbitrary first-class constraint relates gauge-equivalent phase space points, vindicating orthodoxy. Pitts, however, is primarily concerned with transformations of entire histories, rather than of instantaneous states. We (...) show that, even in this context, a transformation generated by an arbitrary first-class constraint is also a gauge transformation, once the empirically observed electric field is correctly identified via its dynamical interactions with charge, and not simply given stipulatively as a certain combination of the potential and its derivatives. (shrink)

The concept of mass is one of the most fundamental notions in physics, comparable in importance only to those of space and time. But in contrast to the latter, which are the subject of innumerable physical and philosophical studies, the concept of mass has been but rarely investigated. Here Max Jammer, a leading philosopher and historian of physics, provides a concise but comprehensive, coherent, and self-contained study of the concept of mass as it is defined, interpreted, and applied (...) in contemporary physics and as it is critically examined in the modern philosophy of science. With its focus on theories proposed after the mid-1950s, the book is the first of its kind, covering the most recent experimental and theoretical investigations into the nature of mass and its role in modern physics, from the realm of elementary particles to the cosmology of galaxies.The book begins with an analysis of the persistent difficulties of defining inertial mass in a noncircular manner and discusses the related question of whether mass is an observational or a theoretical concept. It then studies the notion of mass in special relativity and the delicate problem of whether the relativistic rest mass is the only legitimate notion of mass and whether it is identical with the classical mass. This is followed by a critical analysis of the different derivations of the famous mass-energy relationship E = mc2 and its conflicting interpretations. Jammer then devotes a chapter to the distinction between inertial and gravitational mass and to the various versions of the so-called equivalence principle with which Newton initiated his Principia but which also became the starting point of Einstein's general relativity, which supersedes Newtonian physics. The book concludes with a presentation of recently proposed global and local dynamical theories of the origin and nature of mass.Destined to become a much-consulted reference for philosophers and physicists, this book is also written for the nonprofessional general reader interested in the foundations of physics. (shrink)

Most interpretations of Quantum Mechanics alternative to Copenhagen interpretation try to avoid the dualistic flavor of the latter. One of the basic goals of the former is to avoid the ad hoc introduction of observers and observations as an inevitable presupposition of physics. Non-Copenhagen interpretations usually trust in decoherence as a necessary mechanism to obtain a well-defined, observer-free transition from a unitary quantum description of the universe to classicality. Even though decoherence does not solve the problem of the (...) definite outcomes, it helps to explain why we do not observe superpositions and, according to Zurek’s existential interpretation, why a specific preferred basis emerges through system–environment interactions. The aim of this paper is to show why such interpretation ends up begging the question and provides little progress in understanding the quantum-to-classical transition; the ultimate reason being that preferred bases always correlate to human observation. Benefitting from the technical discussion, some remarks will be offered in the last section regarding the role of classical observations as a necessary condition to make workable the formalism of Quantum Mechanics and scientific activity itself. (shrink)

The development of physical theory is one of our greatest intellectual achievements. Its products--the currently prevailing theories of physics, astronomy, and cosmology--have proved themselves to possess intrinsic beauty and to have enormous explanatory and predictive power. This anthology of primary readings chronicles the birth and maturation of five such theories (the heliocentric theory, the electromagnetic field theory, special and general relativity, quantum theory, and the big bang theory) in the words of the scientists who brought them to life. It (...) is the first historical account that captures the rich substance of these theories, each of which represents a fascinating story of the interplay of evidence and insight--and of dialogue among great minds. Readers sit in with Copernicus, Kepler, and Galileo as they overturn the geocentric universe; observe the genius of Faraday and Maxwell as they "discover" the electromagnetic field; look over Einstein's shoulder as he works out the details of relativity; listen in as Einstein and Bohr argue for the soul of quantum mechanics in the Completeness Debate; and watch as Hubble and others reveal the history of the universe. The editors' approach highlights the moments of discovery that rise from scientific creativity, and the presentation humanizes the scientific process, revealing the extent to which great scientists were the first to consider the philosophical implications of their work. But, most significantly, the editors offer this as their central thesis: although each was ushered in by a revolution, and each contains counterintuitive elements that delayed its acceptance, these five theories exhibit a continuous rational development that has led them to a permanent place in the worldview of science. Accessible to the general reader yet sufficiently substantive that working scientists will find value in it, The Tests of Time offers an intimate look into how physical theory has been developed, by the brilliant people who have developed it. (shrink)

This thesis is a work of experimental physics, a search for new physics with the ATLAS experiment. I post this thesis on the PhilArchive because it includes a pedagogical summary of quantum mechanics and the standard model of particle physics in the combination of chapters 1-2 and appendix A. This was my attempt at the end of my PhD of giving a bird's eye view of the standard model, with a thorough bibliography of the publication trail that (...) lead to its development. I find myself pointing to it at philosophy conferences. // -/- This thesis presents a review of work on the performance of the reconstruction and identification of hadronic tau decays and studies of events reconstructed with a ditau final state with the ATLAS detector at the Large Hadron Collider. The first cut-based tau identification used with ATLAS data and the first observations of W→τν and Z→ττ at ATLAS are described, as well as many of the issues concerning the calibration and systematic uncertainties of reconstructed taus. The first measurement of the Z→ττ cross section at ATLAS with 2010 dataset is reviewed. Last, results are presented from the first search for high-mass resonances decaying to ττ at ATLAS with the 2011 dataset. (shrink)

According to a widespread view, which can be traced back to Russell’s famous attack on the notion of cause, causal notions have no legitimate role to play in how mature physical theories represent the world. In this paper I first critically examine a number of arguments for this view that center on the asymmetry of the causal relation and argue that none of them succeed. I then argue that embedding the dynamical models of a theory into richer causal structures (...) can allow us to decide between models in cases where our observational data severely underdetermine our choice of dynamical models. (shrink)

Bohmian mechanics is arguably the most naively obvious embedding imaginable of Schr¨ odinger’s equation into a completely coherent physical theory. It describes a world in which particles move in a highly non-Newtonian sort of way, one which may at first appear to have little to do with the spectrum of predictions of quantum mechanics. It turns out, however, that as a consequence of the defining dynamical equations of Bohmian mechanics, when a system has wave function ψ its configuration is (...) typically random, with probability density ρ given by |ψ|2, the quantum equilibrium distribution. It also turns out that the entire quantum formalism, operators as observables and all the rest, naturally emerges in Bohmian mechanics from the analysis of “measurements.” This analysis reveals the status of operators as observables in the description of quantum phenomena, and facilitates a clear view of the range of applicability of the usual quantum mechanical formulas. (shrink)

In this paper, we draw on Foucault's and Deleuze's theorisations of discipline and control, respectively, to understand a teacher accountability system in the US state of Texas: the Texas Teacher Evaluation and Support System (hereafter, T-TESS). Specifically, we focus on the interplay of physical and virtual modes of governance – which we develop here as physical–virtual hybridity – and the techniques that make these physical and virtual domains compatible via language interoperability, with T-TESS deployed as a representative empirical case to (...) show how such technologies work to govern teacher subjectivity. First, in-person appraiser meetings and observations re-code teachers’ linguistic behaviours, so their physical bodies and practices can become legible to and interoperable with the hybrid T-TESS system. This avoids any possible syntax errors between the linguistic expression of physical teacher speech and the digital coding language of T-TESS. Second, these digital bodies of data can now be viewed as proxies for the physical teacher body in the classroom, allowing the constant modulation in physical space (teacher bodies) and digital space (bodies of data). This is the physical–virtual hybridity of T-TESS, whereby discipline and control work symbiotically to govern both the physical and the digital expressions of teachers and their teaching. In this way, the disciplining of teachers’ language has profound effects on teachers’ bodies, both corporeal and digital. (shrink)

This book provides the reader with a detailed and captivating account of the story where, for the first time, physicists ventured into proposing a new force of nature beyond the four known ones - the electromagnetic, weak and strong forces, and gravitation - based entirely on the reanalysis of existing experimental data. Back in 1986, Ephraim Fischbach, Sam Aronson, Carrick Talmadge and their collaborators proposed a modification of Newton's Law of universal gravitation. Underlying this proposal were three tantalizing pieces (...) of evidence: 1) an energy dependence of the CP (particle-antiparticle and reflection symmetry) parameters, 2) differences between the measurements of G, the universal gravitational constant, in laboratories and in mineshafts, and 3) a reanalysis of the Eötvos experiment, which had previously been used to show that the gravitational mass of an object and its inertia mass were equal to approximately one part in a billion. The reanalysis revealed that, contrary to Galileo's position, the force of gravity was in fact very slightly different for different substances. The resulting Fifth Force hypothesis included this composition dependence and also added a small distance dependence to the inverse-square gravitational force. Over the next four years numerous experiments were performed to test the hypothesis. By 1990 there was overwhelming evidence that the Fifth Force, as initially proposed, did not exist. This book discusses how the Fifth Force hypothesis came to be proposed and how it went on to become a showcase of discovery, pursuit and justification in modern physics, prior to its demise. In this new and significantly expanded edition, the material from the first edition is complemented by two essays, one containing Fischbach's personal reminiscences of the proposal, and a second on the ongoing history and impact of the Fifth Force hypothesis from 1990 to the present. <. (shrink)

In this paper, I reconstruct an argument of Aristidis Arageorgis against empirical underdetermination of the state of a physical system in a C*-algebraic setting and explore its soundness. The argument, aiming against algebraic imperialism, the operationalist attitude which characterized the first steps of Algebraic Quantum Field Theory, is based on two topological properties of the state space: being T1 and being first countable in the weak*-topology. The first property is possessed trivially by the state space while the (...) latter is highly non-trivial, and it can be derived from the assumption of the algebra of observables’ separability. I present some cases of classical and of quantum systems which satisfy the separability condition, and others which do not, and relate these facts to the dimension of the algebra and to whether it is a von Neumann algebra. Namely, I show that while in the case of finite-dimensional algebras of observables the argument is conclusive, in the case of infinite-dimensional von Neumann algebras it is not. In addition, there are cases of infinite-dimensional quasilocal algebras in which the argument is conclusive. Finally, I discuss Porrmann's construction of a net of local separable algebras in Minkowski spacetime which satisfies the basic postulates of Algebraic Quantum Field Theory. (shrink)

The term coherence is used in many connections. We often speak of coherent reasoning, coherent activities, coherent bodies, and coherent phenomena. In science this term is often used to indicate continuity of a structure in space and time. If many individuals can simultaneously observe similar sets of coherent phenomena, we infer with some justification, first, that the phenomena observed have some kind of correspondence with activities in an external world, that is, a world independent of the existence of the (...) individual observers, and second, that the coherence itself is an attribute of the external world. In a recently published article, to which I shall make several references in this paper, I have called attention to the fact that the science of physics is based on the form and the changes in form of an immediately observed phenomenological world, called the physical world, which can be completely characterized as a structure in space and time. In his analysis of the foundations of the science of physics Eddington has clearly shown that theoretical physics deals exclusively with structures of the type described in the mathematical theory of groups, and that our knowledge of the physical world could have been reached by our sense of vision alone. Coherence in the physical world is that characteristic of the structure which describes the more or less permanent relationship between phenomena in different parts of space at approximately the same time, or a regular sequence in the changing phenomena at approximately the same region of space. (shrink)

This is the first comprehensive translation of the expanded French version of E.F.F. Chladni's Traité d'Acoustique, using Chladni's 1802 Die Akustik for reference and clarification. Chladni's experiments and observations with sound and vibrations profoundly influenced the development of the field of Acoustics. The famous Chladni diagrams along with other observations are contained in Die Akustik, published in German in 1802 and Traité d'Acoustique, a greatly expanded version, published in French in 1809. The present translation was undertaken by Robert T. (...) Beyer, PhD (1920-2008), noted acoustician, Professor of Physics at Brown University, and Gold Medal recipient of the Acoustical Society of America. Along with many other projects completed over the course of his career, Dr. Beyer translated Von Neumann's seminal work, Mathematical Foundations of Quantum Mechanics from the original German, spent 30 years translating Russian physics treatises and journals, served as editor of the English translation of the Soviet Journal of Experimental and Theoretical Physics, and also authored Sounds of our Times: Two Hundred Years of Acoustics. Represents the first comprehensive English translation of a seminal work in acoustics Translated by a prominent acoustician, and former Gold Medal recipient of the Acoustical Society of America In addition to the classic experiments with glass plates and violin bows, covers topics in music, architecture, and anatomy of human and animal hearing Appeals to a wide audience in physics, acoustics, and history of science. (shrink)

In the early seventeenth century Galileo broke free from the hold of ancient Platonic and Aristotelian philosophy. He drastically changed the framework through which we view the natural world when he asserted that we should base our theory of reality on what we can observe rather than pure thought. In the process, he invented what we would come to call science. This set the stage for all the breakthroughs that followed--from Kepler to Newton to Einstein. But in the early twentieth (...) century when quantum physics, with its deeply complex mathematics, entered into the picture, something began to change. Many physicists began looking to the equations first and physical reality second. As we investigate realms further and further from what we can see and what we can test, we must look to elegant, aesthetically pleasing equations to develop our conception of what reality is. As a result, much of theoretical physics today is something more akin to the philosophy of Plato than the science to which the physicists are heirs. In The Dream Universe, Lindley asks what is science when it becomes completely untethered from measurable phenomena? (shrink)