We discuss the possible breakdown of Lorentz invariance—at distances greater than the Planck length—from both the theoretical and the phenomenological point of view. The theoretical tool to deal with such a problem is provided by a “deformation” of the Minkowski metric, with parameters dependent on the energy of the physical system considered. Such a deformed metric realizes, for any interaction, the “solidarity principle” between interactions and spacetime geometry (usually assumed for gravitation), according to which the peculiar features (...) of every interaction determine—locally—its own spacetinie structure. The generalized theory of relativity, based on the locally deformed Minkowski spacetime, is called “deformed special relativity” (DSR). In the first part of the paper, we give the foundations and the basic laws of DSR. In the second part, we analyze some experimental data, which admit an interpretation in terms of the DSR formalism and are, therefore, candidates for displaying a breakdown of the Lorentz symmetry. They are (i) the superluminal propagation of evanescent electromagnetic waves in waveguides, (ii) the meanlife of the KS 0, (iii) the Bose-Einstein correlation in pion production and (iv) the comparison of clock rates in the gravitational field of Earth. Such analysis provides us with the explicit forms of the related deformed metrics as functions of the energy, thus putting in evidence, in all four cases (and therefore for all four fundamental interactions), departures from the usual Minkowski metric. This preliminary evidence for a broken Lorentz invariance may be regarded as the signature of possible nonlocal effects involved in the processes examined. Moreover, the corresponding deformed metrics obtained by our analysis provide an effective dynamical description of the interactions (at least in the energy range considered). (shrink)

An experiment aimed at detecting a DC voltage across a conductor induced by the steady magnetic field of a coil, carried out in 1998, provided a positive (although preliminary) evidence for such an effect, which might be interpreted as a breakdown of local Lorentz invariance. We repeated in 1999 the same experiment with a different experimental apparatus and a sensitivity improved by two orders of magnitude. The results obtained are discussed here in detail. They confirm the findings of the previous (...) experiment, and show, among the others, that the effect is independent of the direction of the current. A possible interpretation of the results is given in terms of a geometric description of the gravitational and the electromagnetic interactions by means of phenomenological, energy-dependent metrics. (shrink)

I describe how relativistic field theory generalizes the paradigm property of material systems, the possession of mass, to the requirement that they have a mass–energy–momentum density tensor T µ associated with them. I argue that T µ does not represent an intrinsic property of matter. For it will become evident that the definition of T µ depends on the metric field g µ in a variety of ways. Accordingly, since g µ represents the geometry of spacetime itself, the properties (...) of mass, stress, energy, and momentum should not be seen as intrinsic properties of matter, but as relational properties that material systems have only in virtue of their relation to spacetime structure. (shrink)

Evidence and theory ranging from traditional philosophy to contemporary cognitive research support the hypothesis that consciousness has a two-part structure: a focused region of articulated experience surrounded by a field of relatively unarticulated, vague experience.William James developed an especially useful phenomenological analysis of this "fringe" of consciousness, but its relation to, and potential value for, the study of cognition has not been explored. I propose strengthening James′ work on the fringe with a functional analysis: fringe experiences work to radically (...) condense context information in consciousness; are vague because a more explicit representation of context information would overwhelm consciousness′ limited articulation capacity; help mediate retrieval functions in consciousness; and contain a subset of monitoring and control experiences that cannot be elaborated in focal attention and are "ineffable." In general, the phenomenology of the fringe is a consequence of its cognitive functions, constrained by consciousness′ limited articulation capacity. Crucial to monitoring and control is the feeling of "rightness." Rightness functions as a summary index of cognitive integration, representing, in the fringe, the degree of positive fit between a given conscious content and its parallel, unconsciously encoded context. Rightness appears analogous to the connectionist metric of global network integration, known variously as goodness-of-fit, harmony, or minimum energy. (shrink)

The term ‘supervenience’ has acquired central status in contemporary philosophy in the wake of Davidson’s discussion of mental e physical properties. We want to recover Davidson’s original setting and to tackle the same problem by an alternative route, which resorts to a phenomenological approach. The notion of supervenience emerges at the crossroad between three theses: 1) the background of ontological monism; 2) the interpretation of monism as physicalism; 3) the dependence of mental events on physical events. ‘Supervenience’ bears the (...) task to express simultaneously the ontological dependence of the mental on the physical and the apparent irreducibility of the former to the latter. In this framework, we are going, first, to grant ontological monism while rejecting physicalism. We will argue for an ontological framework that acknowledges some of the reasons of classical idealism, without abandoning a materialist framework. Secondly, we are going to show why intentional phenomena can never be regarded as epiphenomena. This move recommends a renewed methodological ‘respect’ for phenomena, consistent with the phenomenological tradition. Thirdly, by reinterpreting the old notion of formal causality, we will make room for an understanding of ‘mental causation’ that avoids both dualism and any violation of the principle of conservation of energy. In conclusion, we are going to argue that the reasons that originally motivated the introduction of ‘supervenience’ are inconsistent and that, in the theoretical context that we argue for, resorting to the notion of supervenience is either superfluous or misleading. (shrink)

This study deals with the problem of radar waveform design based on the weighted mutual information and the difference of two mutual information metrics in signal-dependent interference. Since the target and clutter information are included in the received signal at the beginning of the design, DMI-based waveform is designed according to the following criterion: maximizing the MI between the received signal and target impulse response while minimizing the MI between the received signal and the clutter impulse response. This (...) criterion is equivalent to maximizing the difference between the first MI and the second MI. Then maximizing the difference of two types of MI is used as the objective function, and the optimization model with the transmitted waveform energy constraint is established. In order to solve it, we resort to maximum marginal allocation method to find the DMI-based waveform. Since DMI-based waveform does not allocate energy to the frequency band where the clutter power spectral density is greater than the target PSD, we propose to weight the MI-based waveform and DMI-based waveform to synthesize the final optimal waveform. It could provide different trade-offs between two types of MI. Simulation results show the proposed algorithm is valid. (shrink)

The questions of what represents space-time in GR, the status of gravitational energy, the substantivalist-relationalist issue, and the exceptional status of gravity are interrelated. If space-time has energy-momentum, then space-time is substantival. Two extant ways to avoid the substantivalist conclusion deny that the energy-bearing metric is part of space-time or deny that gravitational energy exists. Feynman linked doubts about gravitational energy to GR-exceptionalism, as do Curiel and Duerr; particle physics egalitarianism encourages realism about gravitational (...) class='Hi'>energy. In that spirit, this essay proposes a third possible view about space-time, one involving a particle physics-inspired non-perturbative split that characterizes space-time with a constant background _matrix_, a sort of vacuum value, thus avoiding the inference from gravitational _energy to substantivalism. On this proposal, space-time is, where eta=diag is a spatio-temporally constant numerical signature matrix, a matrix already used in GR with spinors. The gravitational potential, to which any gravitational energy can be ascribed, is g_{\mu\nu}- eta, an _affine_ geometric object with a tensorial Lie derivative and a vanishing covariant derivative. This non-perturbative split permits strong fields, arbitrary coordinates, and arbitrary topology, and hence is pure GR by almost any standard. This razor-thin background, unlike more familiar backgrounds, involves no extra gauge freedom and so lacks their obscurities and carpet lump-moving. After a discussion of Curiel's GR exceptionalist denial of the localizability of gravitational energy and his rejection of energy conservation, the two traditional objections to pseudotensors, coordinate dependence and nonuniqueness, are explored. Both objections are inconclusive and getting weaker. A literal interpretation involving infinitely many energies corresponding by Noether's first theorem to the infinite symmetries of the _action_ largely answers Schroedinger's false-negative coordinate dependence problem. Bauer's false-positive objection has multiple answers. Non-uniqueness might be handled by Nester et al.'s finding physical meaning in multiplicity in relation to boundary conditions, by an optimal candidate, or by Bergmann's identifying the non-uniqueness and coordinate dependence ambiguities as one. (shrink)

The question of the existence of gravitational stress-energy in general relativity has exercised investigators in the field since the inception of the theory. Folklore has it that no adequate definition of a localized gravitational stress-energetic quantity can be given. Most arguments to that effect invoke one version or another of the Principle of Equivalence. I argue that not only are such arguments of necessity vague and hand-waving but, worse, are beside the point and do not address the heart of (...) the issue. Based on a novel analysis of what it may mean for one tensor to depend in the proper way on another, which, en passant, provides a precise characterization of the idea of a "geometric object", I prove that, under certain natural conditions, there can be no tensor whose interpretation could be that it represents gravitational stress-energy in general relativity. It follows that gravitational energy, such as it is in general relativity, is necessarily non-local. Along the way, I prove a result of some interest in own right about the structure of the associated jet bundles of the bundle of Lorentz metrics over spacetime. I conclude by showing that my results also imply that, under a few natural conditions, the Einstein field equation is the unique equation relating gravitational phenomena to spatiotemporal structure, and discuss how this relates to the non-localizability of gravitational stress-energy. (shrink)

The development of nuclear energy technologies in the second half of the 20th century came with great hopes of rebuilding nations recovering from the devasta-tion of the Second World War or recently released from colonial rule. In coun-tries like France, India, the USA, Canada, Russia, and the United Kingdom, nuclear energy became the symbol of development towards a modern and technologically advanced future. However, after more than six decades of experi-ence with nuclear energy production, and in the (...) aftermath of the Fukushima nuclear disaster, it is safe to say that nuclear energy production is not without its problems.Some of these problems have their origins in the very materiality of the technolo-gies involved. For example, not only does the use of highly radioactive materials give rise to risks for the current generation (e.g., in the potential for disaster when reactors melt down) but high-level radioactive waste from nuclear energy production presents a serious intergenerational problem for which an acceptable final solution or its implementation remains elusive. Moreover, nuclear energy technologies have specific social and political consequences. For example, they have been said to be authoritarian technologies (Winner, 1980), requiring cen-tralized authority, secrecy, and technocratic decision-making. While some of these problems could have been foreseen before nuclear energy technologies were introduced, others only arose after these technologies were already integrated into the social and infrastructural fabric of our lives. Addition-ally, new technologies (e.g., Generation III, III+ and IV reactors) are still being developed, bringing with them new and uncertain hazards and risks. Ignorance and uncertainty about the possible deleterious effects of introducing a new technology are inevitable, especially if the technology is complex, large time-scales are involved, or risks depend on social or political factors unforeseen in the design stage. However, this should not deter us from developing and intro-ducing new technologies. Rather, it should motivate us to organize these ‘exper-iments’ with new technologies in society in such a way that we can learn about their possible hazards and risks as effectively and responsibly as possible (van de Poel, 2011, 2015). In this way, it is possible to minimize risks and avoid unwant-ed moral, social or political developments. However, organizing such experi-ments responsibly also means that one could come to the conclusion that continuing an experiment is no longer responsible or desirable. Should we be prepared for such a scenario, and if so, how could we do that? One possible strategy to tackle this issue is that the technology and its introduction should be reversible. The aim of this thesis is to further explore this strategy by answering the following main research question (RQ) and accompanying subquestions (SQ):RQ: What are the implications of reversibility for the responsible develop-ment and implementation of nuclear energy technologies?SQ1: Under what conditions can nuclear energy technologies be considered reversible?SQ2: Why should nuclear energy technologies be reversible?SQ3: If so, how could the reversibility of nuclear energy technologies be achieved?After the introductory chapter 1, the chapters that form the main body of this dissertation each provide a distinct contribution to answering the three subques-tions and, by extension, the main research question. Guided by three historical case studies of nuclear energy technology development (i.e., India, France and the USA), chapter 2 answers the first subquestion by formulating the two condi-tions under which it can be considered reversible, i.e., 1) the ability to stop the further development and deployment of a that technology in society, and 2) the ability to undo the undesirable outcomes (material, institutional or symbolic) of the development and deployment of the technology. Chapter 3 subsequently tackles the second subquestion by establishing the general desirability of technological reversibility by virtue of its relation to responsibility in Emmanuel Levinas’ ethical phenomenology. It argues that technology development is a legitimate response to responsibility but inevitably falls short of the responsibility that inspires it, incessantly calling for technological and political change in the process. Having thus argued that nuclear energy technologies should ideally be reversible, chap-ters 4 and 5 work towards specific strategies to achieve technological reversibil-ity. Chapter 4 first investigates the processes that make it difficult to stop the further development and implementation of a nuclear energy technology in society, thus provid-ing input on how to fulfill the first condition for the reversibility of nuclear energy technologies. To do so, it presents a phenomenological perspective on technology and its adoption based on the work of Alfred Schutz. It also explores different ways in which technology adoption drives the processes of path depend-ence towards technological lock-in. Chapter 5 examines the history of geological disposal of high-level radioactive waste in the USA. It identifies a number of concrete policy pitfalls that could lead to lock-in and that should consequently be avoided. It also presents a number of general design strategies that could facilitate the undoing of undesirable consequences of a technology, thus providing input on how to fulfill the second condition for the reversibility of nuclear energy technol-ogies.Chapter 6 summarizes the central findings of the thesis and explains how these help to answer the research questions. On top of this, it reflects on a number of complications connected to reversibility considerations. Based on this, it is concluded that the question of irreversibility and reversibility is context- and technology-specific and a matter of degree. The chapter concludes with a reflec-tion on generalizations and limitations of the results. Finally, chapter 7 discusses the implications of this dissertation’s results for responsibly experimenting with nuclear energy technologies in society. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:BOOK REVIEWS 91 The passage which permitted such an interpretation is the following: This self-command is very different at different times.... Can we give any reason for these variations, except experience? Where then is the power of which we pretend to be conscious? Is there not here, either in a spiritual or a material substance, or both, some secret mechanism or structure of parts, upon which the effect depends...?" (...) (Enquiry, p. 68). This rhetorical question is, on the contrary, intended as the part of the third argument for the thesis "that even this command of the will gives us no real idea of force or energy" (Enquiry, p. 67). There is no evidence in the Enquiries that Hume concluded that self is a substance. On p. 45, Anderson "suggests that Hume employs 'impression'...in a less frequent usage, however.., to be a pressure, or pattern of light, or other means whereby objects are applied to the external organs of sense"t On p. 65 and also on p. 173, it is argued fallaciously that, "Hume considers mathematical ideas, like all other ideas, to be existences. If this be true, then the necessary relations ~mpposed to obtain among mathematical ideas cannot be discerned even though these ideas themselves be fully known." Now it is a matter of debate whether Hume believed that all mathematical ideas are derived from impressions (see my controversy with Flew on this issue, in Ratio, Vol. VI, No. 2, "Hume on Pure and Applied Geometry," and Flew's article, "Did Hume Distinguish Pure and Applied Geometry?," Ratio, Vol. VIII, No. 1). But even if we assume that this is his belief, it does not follow at all that the logical relations among these ideas are contingent. As Pap argued a long time ago, "A sensationalist might maintain that all the concepts that constitute a given proposition are derived from experience and might nevertheless admit that proposition itself is a priori in the sense of requiring no empirical verification in order to be assertable as true." Thus, Hume the sensationalist admitted that a priori knowledge is possible in mathematics, which is conversant exclusively about "relations of ideas" and not about "matters of fact." Finally, in the last chapter, it is argued that, "Hume's own suggestion concerning these three natural relations (resemblance, contiguity, and cause and effect) is that they are fundamentally material--that they consist in a certain characteristic movement of the animal spirit in the brain" (p. 163)I1 That, "The necessity is the relationship between cause and effect, Hume's remarks suggest, is ultimately their identity in essence. One passage which we have noted indicates that cause and effect are inseparable, and by use of Hume's own maxims we may strictly infer from their inseparability their identity" (p. 165)II And that, "Although Hume's doctrine of matter is ultimately of central importance in his system, his beginnings in moral philosophy doubtless led him to turn his attention away from the topic of matter" (p. 175). This book, though replete with quotations from Hume's works and exhibiting a great amount of microscopic observations, represents a mistaken view of Hume's epistemology. ~ARHANG ZABEEIq Roosevelt University, Chicago Hegel's Phenomenology. Dialogues on the Life of Mind. By Jacob Loewenberg. (La Salle, Ill. : The Open Court Publ. Co., 1965.Pp. xv + 377.) Hegel's Phenomenology o] Spirit, intriguing in its richness, has long remained one of the most forbidding of philosophical classics. Unfortunately, commentaries, though altogether indispensable, are sparse. Heretofore, the reader found himself referred mainly to two foreign language studies, G. A. Gabler's Kritik des Be~usst~ein~ of 1835, and J. Hyppolite's Gen~se et structure de la Phdnomdnologie de l'esprit; no full-scale work in English was available. And 92 HISTORY OF PHILOSOPHY even the reader prepared to turn to these works might register disenchantment: Gabler deals with two fifths of the book only, and Hyppolite is at times too close to the text to be much help. What remains is comment in the framework of more general studies of Hegel's philosophy (Royce, Haering, Kroner, Stace, Findlay and others). In this situation Loewenberg's contribution marks a... (shrink)

This paper deals with a number of technical achievements that are instrumental for a dis-solution of the so-called "Hole Argument" in general relativity. Such achievements include: 1) the analysis of the "Hole" phenomenology in strict connection with the Hamiltonian treatment of the initial value problem. The work is carried through in metric gravity for the class of Christoudoulou-Klainermann space-times, in which the temporal evolution is ruled by the "weak" ADM energy; 2) a re-interpretation of "active" diffeomorphisms as "passive and (...) metric-dependent" dynamical symmetries of Einstein's equations, a re-interpretation which enables to disclose their (up to now unknown) connection to gauge transformations on-shell; understanding such connection also enlightens the real content of the Hole Argument or, better, dis-solves it together with its alleged "indeterminism"; 3) the utilization of the Bergmann-Komar "intrinsic pseudo-coordinates", defined as suitable functionals of the Weyl curvature scalars, as tools for a peculiar gauge-fixing to the super-hamiltonian and super-momentum constraints; 4) the consequent construction of a "physical atlas" of 4-coordinate systems for the 4-dimensional "mathematical" manifold, in terms of the highly non-local degrees of freedom of the gravitational field (its four independent "Dirac observables"). Such construction embodies the "physical individuation" of the points of space-time as "point-events", independently of the presence of matter, and associates a "non-commutative structure" to each gauge fixing or four-dimensional coordinate system; 5) a clarification of the multiple definition given by Peter Bergmann of the concept of "(Bergmann) observable" in general relativity. This clarification leads to the proposal of a "main conjecture" asserting the existence of i) special Dirac's observables which are also Bergmann's observables, ii) gauge variables that are coordinate independent (namely they behave like the tetradic scalar fields of the Newman-Penrose formalism). A by-product of this achievements is the falsification of a recently advanced argument asserting the absence of (any kind of) "change" in the observable quantities of general relativity. 6) a clarification of the physical role of Dirac and gauge variables as their being related to "tidal-like" and "inertial-like" effects, respectively. This clarification is mainly due to the fact that, unlike the standard formulations of the equivalence principle, the Hamiltonian formalism allows to define notion of "force" in general relativity in a natural way; 7) a proposal showing how the physical individuation of point-events could in principle be implemented as an experimental setup and protocol leading to a "standard of space-time" more or less like atomic clocks define standards of time. We conclude that, besides being operationally essential for building measuring apparatuses for the gravitational field, the role of matter in the non-vacuum gravitational case is also that of "participating directly" in the individuation process, being involved in the determination of the Dirac observables. This circumstance leads naturally to a peculiar new kind of "structuralist" view of the general-relativistic concept of space-time, a view that embodies some elements of both the traditional "absolutist" and "relational" conceptions. In the end, space-time point-events maintain a "peculiar sort of objectivity". Some hints following from our approach for the quantum gravity programme are also given. (shrink)

Opaqueness of pp collisions is evaluated at three CERN-ISR energies. Comparisons with predictions of the factorizable eikonal models and the scaling hypothesis are made. It appears that results are in favor of the factorizable models.

Friedmann–Robertson–Walker (FRW) space–time with bulk viscosity in the context of f(R) gravity is considered. The field equations are solved for the Power and Exponential volumetric expansion. Two types of functional relationship i.e. f(R) = R + bRm and f(R)=R-λ4R\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \,f(R) = R - \frac{{\lambda^{4} }}{R} $$\end{document} are investigated. The Phantom, Chaplygin gas and Tachyon fields are discussed. It is observed that the universe is open and inflationary.

This study shows how precise simple analytical solutions for the generalized Dirac equation with repulsive vector and attractive energy-dependent Lorentz scalar potentials, position-dependent mass potential, and a tensor interaction term can be obtained within the framework of both similarity transformation and the asymptotic iteration methods. These methods yield a significant improvement over existing approaches and provide more plausible and applicable ways in explaining the pseudospin symmetry’s breaking mechanism in nuclei.

In this paper, we aim at rethinking the concept of obesity in a way that better captures the connection between underlying medical aspects, on the one hand, and an individual’s developmental history, on the other. Our proposal rests on the idea that obesity is not to be understood as a phenotypic trait or character; rather, obesity represents one of the many possible states of a more complex phenotypic trait that we call ‘energy metabolism.’ We argue that this apparently simple (...) conceptual shift can help solve important theoretical misconceptions regarding the genetics, epigenetics, and development of obesity. In addition, we show that our proposal can be fruitfully paired with the concept of developmental channeling of a trait, which connects to the study of the plasticity and canalization of complex traits. Finally, we discuss the potential impact of our approach on the assessment, treatment, and social narratives of obesity. (shrink)

We present a new approach to the mathematical objects of General Relativity in terms of which a generic f(R)-gravity theory gravitation is written in a first-order (à la Palatini) formalism, and introduce the concept of Dark Metric which could bypass the emergence of disturbing concepts as Dark Energy and Dark Matter. These issues are related to the fact that General Relativity could not be the definitive theory of Gravitation due to several shortcomings that come out both from theoretical and (...) experimental viewpoints. At large scales, the attempts to match it with the recent observational data lead to invoke Dark Energy and Dark Matter as the bulk components of the cosmic fluid. Since no final evidence, at fundamental level, exists for such ingredients, it could be useful to reconsider the gravitational sector in order to see if suitable extensions of General Relativity could solve the shortcomings present at infrared scales. (shrink)

Abstract:Designers whose projects are inspired by a community’s unique sense of spatial identity often focus on a site’s observable context, i.e. historic forms and surface aesthetics. Focus on typological components, however, overlooks generative relationships between the phenomenology of place and human energy investment. Recognizing Kubler’s dictum that material history is an observable continuum then, at its most fundamental level, the history of spatial production is the history of energy use. For most of human history, place was a unique (...) socio-cultural expression because it fused energy expenditure with site-specific conditions, including climate, topography and materials. This paper introduces the concept of burden distance, the distance needed to travel to material sources and bring them back from origin points to their place of use. This proposed concept parallels Walter Christaller’s Central Place Theory idea of “range,” but applied in terms phenomenological implications of energy investment and placemaking. Understanding burden distance and its role in placemaking, is an important step in identifying why built environments have a spatial specificity that contributes to mitigate spatial alienation and instead root people to their built environment. (shrink)

There are two main ideas that inform the current reflection in the philosophy of mind, namely that the content of mental states is constitutively dependent on worldly, environmental facts and that phenomenology depends only on the intrinsic features of a subject. The question I shall address is whether it is possible to preserve both ideas within a strong intentionalist account. In other words, as the title goes: Can phenomenology be narrow if content is wide and phenomenology is claimed to (...) depend on intentionality? The paper has the following structure: I shall start by presenting a triad which seems to rule out the possibility of preserving both content externalism and phenomenological internalism. Then, after having claimed that the only way in which a strong intentionalist could stick to those two ideas is to make the phenomenal character of a mental state independent for its individuation on the mental state’s content, I shall present what I take to be the only possible variety of which is compatible with such a move. (shrink)

This book integrates Hegel's The Phenomenology of Spirit and contemporary conversations about energy. By interpreting actuality as energy in the Hegelian corpus, the author provides a new lens for understanding the dialectical project and the energy⁰́₁starved condition of our contemporaneity.

Is there any ecological purpose in assuming that perception for action exists only through a global array of energy? Unlike Stoffregen & Bardy, who assume that behavior consists of movements, we would argue that behavior consists of a stable coupling between perception and action achieved through experience in an adaptive context. Determining target position in an aiming manual task and temporal control of impact movement illustrate that patterns of energy used for action are task-dependent.

It has long been thought that observing distinctive traces of quantum gravity in a laboratory setting is effectively impossible, since gravity is so much weaker than all the other familiar forces in particle physics. But the quantum gravity phenomenology community today seeks to do the (effectively) impossible, using a challenging novel class of `tabletop' Gravitationally Induced Entanglement (GIE) experiments, surveyed here. The hypothesized outcomes of the GIE experiments are claimed by some (but disputed by others) to provide a `witness' of (...) the underlying quantum nature of gravity in the non-relativistic limit, using superpositions of Planck-mass bodies. We inspect what sort of achievement it would possibly be to perform GIE experiments, as proposed, ultimately arguing that the positive claim of witness is equivocal. Despite various sweeping arguments to the contrary in the vicinity of quantum information theory or given low-energy quantum gravity, whether or not one can claim to witness the quantum nature of the gravitational field in these experiments decisively depends on which out of two legitimate modelling paradigms one finds oneself in. However, by situating GIE experiments in a tradition of existing experiments aimed at making gravity interestingly quantum in the laboratory, we argue that, independently of witnessing or paradigms, there are powerful reasons to perform the experiments, and that their successful undertaking would indeed be a major advance in physics. (shrink)

If we live on the weak brane with zero effective cosmological constant in a warped 5D bulk spacetime, gravitational waves and brane fluctuations can be generated by a part of the 5D Weyl tensor and carries information of the gravitational field outside the brane. We consider on a cylindrical symmetric warped FLRW background a U self-gravitating scalar field coupled to a gauge field without bulk matter. It turns out that brane fluctuations can be formed dynamically, due to the modified (...) class='Hi'>energy–momentum tensor components of the scalar-gauge field. As a result, we find that the late-time behavior could significantly deviate from the standard evolution of the universe. The effect is triggered by the time-dependent warpfactor with two branches of the form \}\) constants) and the modified brane equations comparable with a dark energy effect. This is a brane-world mechanism, not present in standard 4D FLRW, where the large disturbances are rapidly damped as the expansion proceed. Because gravity can propagate in the bulk, the cosmic string can build up a huge angle deficit by the warpfactor and can induce massive KK-modes felt on the brane. Disturbances in the spatial components of the stress-energy tensor cause cylindrical symmetric waves, amplified due to the presence of the bulk space and warpfactor. They could survive the natural damping due to the expansion of the universe. It turns out that one of the metric components becomes singular at the moment the warp factor develops an extremum. This behavior could have influence on the possibility of a transition from acceleration to deceleration or vice versa. (shrink)

Substrate independence and mind-body functionalism claim that thinking does not depend on any particular kind of physical implementation. But real-world information processing depends on energy, and energy depends on material substrates. Biological evidence for these claims comes from ecology and neuroscience, while computational evidence comes from neuromorphic computing and deep learning. Attention to energy requirements undermines the use of substrate independence to support claims about the feasibility of artificial intelligence, the moral standing of robots, the possibility that (...) we may be living in a computer simulation, the plausibility of transferring minds into computers, and the autonomy of psychology from neuroscience. (shrink)

A prominent view of phenomenal consciousness combines two claims: (i) the identity conditions of phenomenally conscious states can be fully accounted for in terms of these states’ representational content; (ii) this representational content can be fully accounted for in non-phenomenal terms. This paper presents an argument against this view. The core idea is that the identity conditions of phenomenally conscious states are not fixed entirely by what these states represent (their representational contents), but depend in part on how they represent (...) (their representational attitudes or modes). The argument highlights the myriad liabilities and difficulties one must accrue when one tries to appeal only to what phenomenally conscious states represent in accounting for their phenomenal individuation. (shrink)