berkley's line of reasoning about sex and pain experience suggests a completely different perspective on sex differences in human experimental, clinical, and epidemiological pain research. Although physiological mechanisms may place women at greater risk for pain, women may have found ways to dampen the effect of these mechanisms. Nevertheless, it is a challenge to extrapolate physiological mechanisms in human phenomena from outcomes observed in animal models.

We present a general relativistic model of a spherical shell of matter with a perfect fluid on its surface coupled to an internal oscillator, which generalizes a model recently introduced by the authors to construct a self-gravitating interferometer. The internal oscillator evolution is defined with respect to the local proper time of the shell, allowing the oscillator to serve as a local clock that ticks differently depending on the shell’s position and momentum. A Hamiltonian reduction is performed on the system, (...) and an approximate quantum description is given to the reduced phase space. If we focus only on the external dynamics, we must trace out the clock degree of freedom, and this results in a form of intrinsic decoherence that shares some features with a proposed “universal” decoherence mechanism attributed to gravitational time dilation. We note that the proposed decoherence remains present in the limit of flat spacetime, emphasizing that the effect can be attributed entirely to proper time differences, and thus is not necessarily related to gravity. Whereas the effect described in vanishes in the absence of an external gravitational field, our approach bootstraps the gravitational contribution to the time dilation decoherence by including self-interaction, yielding a fundamentally gravitational intrinsic decoherence effect. (shrink)

The importance of the Unruh effect lies in the fact that, together with the related Hawking effect, it serves to link the three main branches of modern physics: thermal/statistical physics, relativity theory/gravitation, and quantum physics. However, different researchers can have in mind different phenomena when they speak of “the Unruh effect” in flat spacetime and its generalization to curved spacetimes. Three different approaches are reviewed here. They are shown to yield results that are sometimes concordant (...) and sometimes discordant. The discordance is disconcerting only if one insists on taking literally the definite article in “the Unruh effect.” It is argued that the role of linking different branches of physics is better served by taking “the Unruh effect” to designate a family of related phenomena. The relation between the Hawking effect and the generalized Unruh effect for curved spacetimes is briefly discussed. (shrink)

There is a persistent state of confusion regarding the nature of the Unruh effect. We will argue that, in contrast to some interpretations thereof, the effect does not represent any novel physics and that, by its very nature, the effect is fundamentally unmeasurable in all experiments of the kind that have been contemplated until now. Also, we discuss what aspects connected with this effect one might consider as possibilities to be explored empirically and what their (...) precise meaning may be regarding the issue at hand. (shrink)

We discuss the intertwined topics of Fulling non‐uniqueness and the Unruh effect. The Fulling quantization, which is in some sense the natural one for an observer uniformly accelerated through Minkowski spacetime to adopt, is often heralded as a quantization of the Klein‐Gordon field which is both physically relevant and unitarily inequivalent to the standard Minkowski quantization. We argue that the Fulling and Minkowski quantizations do not constitute a satisfactory example of physically relevant, unitarily inequivalent quantizations, and indicate what (...) it would take to settle the open question of whether a satisfactory example exists. A popular gloss on the Unruh effect has it that an observer uniformly accelerated through the Minkowski vacuum experiences a thermal flux of Rindler quanta. Taking the Unruh effect, so glossed, to establish that the notion of particle must be relativized to a reference frame, some would use it to demote the particle concept from fundamental status. We explain why technical results do not support the popular gloss and why the attempted demotion of the particle concept is both unsuccessful and unnecessary. Fulling non‐uniqueness and the Unruh effect merit attention despite these negative verdicts because they provide excellent vehicles for illustrating key concepts of quantum field theory and for probing foundational issues of considerable philosophical interest. (shrink)

We discuss the intertwined topics of Fulling non-uniqueness and the Unruh effect. The Fulling quantization, which is in some sense the natural one for an observer uniformly accelerated through Minkowski spacetime to adopt, is often heralded as a quantization of the Klein-Gordon field which is both physically relevant and unitarily inequivalent to the standard Minkowski quantization. We argue that the Fulling and Minkowski quantizations do not constitute a satisfactory example of physically relevant, unitarily inequivalent quantizations, and indicate what (...) it would take to settle the open question of whether a satisfactory example exists. A popular gloss on the Unruh effect has it that an observer uniformly accelerated through the Minkowski vacuum experiences a thermal flux of Rindler quanta. Taking the Unruh effect, so glossed, to establish that the notion of particle must be relativized to a reference frame, some would use it to demote the particle concept from fundamental status. We explain why technical results do not support the popular gloss and why the attempted demotion of the particle concept is both unsuccessful and unnecessary. Fulling non-uniqueness and the Unruh effect merit attention despite these negative verdicts because they provide excellent vehicles for illustrating key concepts of quantum field theory and for probing foundational issues of considerable philosophical interest. (shrink)

We present a stochastic theory for the nonequilibriurn dynamics of charges moving in a quantum scalar field based on the worldline influence functional and the close-time-path (CTP or in-in) coarse-grained effective action method. We summarize (1) the steps leading to a derivation of a modified Abraham-Lorentz-Dirac equation whose solutions describe a causal semiclassical theory free of runaway solutions and without pre-acceleration patholigies, and (2) the transformation to a stochastic effective action, which generates Abraham-Lorentz-Dirac-Langevin equations depicting the fluctuations of a particle’s (...) worldline around its semiclassical trajectory. We point out the misconceptions in trying to directly relate radiation reaction to vacuum fluctuations, and discuss how, in the framework that we have developed, an array of phenomena, from classical radiation and radiation reaction to the Unruh effect, are interrelated to each other as manifestations at the classical, stochastic and quantum levels. Using this method we give a derivation of the Unruh effect for the spacetime worldline coordinates of an accelerating charge. Our stochastic particle-field model, which was inspired by earlier work in cosmological backreaction, can be used as an analog to the black hole backreaction problem describing the stochastic dynamics of a black hole event horizon. (shrink)

ABSTRACT When does a state of affairs constitute a harm to someone? Comparative accounts say that being worse off constitutes harm. The temporal version of the comparative account is seldom taken seriously, due to apparently fatal counterexamples. I defend the temporal version against these counterexamples, and show that it is in fact more plausible than the prominent counterfactual version of the account. Non-comparative accounts say that being badly off constitutes harm. However, neither the temporal comparative account nor the non-comparative account (...) can correctly classify all harms. I argue that we should combine them into a hybrid account of harm. The hybrid account is extensionally adequate and presents a unified view on the nature of harm. (shrink)

Many people believe that we have moral duties towards those we bring into existence in the short term: our children. Many people also believe that we have moral duties towards those we bring into existence in the long term: future generations. In this article, I explore how these beliefs are connected. I argue that the present generation is morally responsible for future generations in virtue of bringing them into existence. This responsibility entails moral duties to ensure that future people have (...) adequate life prospects. These duties are held directly towards future generations. I argue that this direct argument can overcome challenges that indirect arguments, which justify moral duties concerning future generations via moral duties towards present children, face. The upshot is that considerations from procreative ethics help to illustrate that the present generation stands in a morally relevant special relationship to future generations, a fact that is often overlooked in intergenerational ethics. (shrink)

Many people hold the constraint against doing harm, the view that the reason against doing harm is stronger than the reason against merely allowing harm, everything else being equal. Mogensen and MacAskill (2021) have recently argued that when considering indirect long-term consequences of our everyday behavior, the constraint against doing harm faces a problem: it has the absurd implication that we should do as little as possible in our lives. In this paper, I explore the view that, for behavior that (...) does not increase anyone’s ex ante risk of suffering harm, the reason against doing harm is not stronger than the reason against merely allowing harm, everything else being equal. I argue that this view is plausible, show how it solves the paralysis problem, and defend it against objections. (shrink)

In this paper, I defend the view that within a rights-based ethical framework, the moral status of future generations is best understood as that of present rightsholders. I argue that in this way it can be justified that we have obligations towards future generations. This justification in turn is of great relevance for many issues in moral theory and applied ethics. In the first part of the paper, I argue that the fact that future persons will have rights in the (...) future cannot fully account for present obligations. The missing link in this argument cannot be provided by approaches that infer those obligations mediately. In the second part of the paper, I argue that existing is not a necessary condition for being a rightsholder. First, our own future selves should be said to have rights even though they do not exist at present. Second, even at present, uncertainty challenges the relationship between rightsholders and obligation bearers: often enough, obligations depend on presuppositions or suspicions about other persons’ existence. In light of these cases, we should conceive of rightsholders as place holders, that is, sets of (actual) individuals whose existence or identity can be unknown or indetermined, with specific properties. Therefore, future generations can coherently be said to have rights now that correspond to our present obligations towards them. (shrink)

Many people think that the moral reason against doing harm is stronger than the moral reason against allowing harm. What should these people think about doing and allowing good? I address this question by distinguishing two ways of understanding the doing/allowing distinction. The agency view implies that the moral reason for doing good is stronger than the moral reason for allowing good. The imposition view implies that the moral reason against preventing good is stronger than the moral reason against failing (...) to do good. I defend the imposition view and explore its implications for the comparative strength of harm-based and benefit-based reasons. (shrink)

Recent work by Ingmar Persson and Jason Hanna has posed an interesting new challenge for deontologists: How can they account for so-called cases of letting oneself do harm? In this article, I argue that cases of letting oneself do harm are structurally similar to real-world cases such as climate change, and that deontologists need an account of the moral status of these cases to provide moral guidance in real-world cases. I then explore different ways in which deontologists can solve this (...) challenge and argue that the most promising way to conceive of cases of letting oneself do harm is as nonstandard cases of allowing harm, supplemented with an additional argument for the moral relevance of one's own agency. The upshot is that cases of letting oneself do harm are both more theoretically challenging and practically important than has been acknowledged. (shrink)

Many people believe that we have a moral reason to benefit others. However, this reason is commonly thought to be weaker than the reason against harming others. This might explain why relatively little attention has been paid to the morality of benefiting in non-identity cases. My aim is to convince you, in the next few paragraphs, that this is a decisive oversight. The non-identity problem arises in cases of harming and in cases of benefiting alike. It is therefore broader in (...) scope than is often acknowledged. The most promising solutions of the non-identity problem are harm-based, but such solutions will need to provide suitable accounts of both harming and benefiting. (shrink)

During the COVID-19 pandemic governments across the globe have provided unparalleled support to private sector firms. As a result, new oversight mechanisms are urgently needed, to enable society to assess and, if necessary, redress, moves by firms which have taken government aid. Many jurisdictions have seen the introduction of ‘piecemeal’ conditionality on different pots of aid. This paper argues that a better response would be to adopt a more unified approach. In particular, the paper explores the social licence framework as (...) a potential way to ‘build back better’. It is argued that the nature of the implicit social contract between society and the private sector provides the normative force underpinning demands for a social purpose for business, and that this purpose in turn can be used to specify the conditions firms must meet to legitimise their operations. The paper then considers three core elements involved in any introduction of a social licence framework, and surveys the potential benefits and challenges that might emerge in moving towards a social licence framework. (shrink)

Im Vergleich mit anderen rechtsphilosophischen Schriften Platons - etwa der Politeia - hat der Dialog "Kriton" in Kontinentaleuropa bisher wenig Beachtung gefunden. Anders als im anglo-amerikanischen Wissenschaftsraum fanden sich bisher nur vereinzelte Stellungnahmen in Gesamtdarstellungen zu Platons Philosophie.Die Monographie folgt den Ereignissen und Gedankengangen der Dialogpartner und rekonstruiert erstmals umfassend den rechtsphilosophischen Gehalt der Schrift, das heiat die zugunsten der Pflicht zum Rechtsgehorsam vorgebrachten Argumente. Diese Rekonstruktion fuhrt zu der Erkenntnis, daa Platon im "Kriton" eine konsistente und mit seinen anderen (...) (Fruh-) Schriften kompatible Begrundung fur die Pflicht zum Rechtsgehorsam geliefert hat, die im Kern auch heute noch bedenkenswert ist.Die Analyse ist daher nicht nur fur eine vollstandige Erfassung der gewichtigen Rechtsphilosophie Platons, sondern auch fur die gegenwartige Diskussion um die Gehorsamspflicht von Nutzen. (shrink)

The use of a photomultiplier to measure the reduction in counting statistics noise (from the usual N1/2 form) which is expected to occur for squeezed coherent light is shown to lead to no reduction or to an increase of the noise unless the number of photons in a fundamental measuring time of the photomultiplier is very large. This fundamental time is estimated to be less than 10−13 sec for ordinary detectors. A technique for using squeezed states for determining the time (...) a photomultiplier takes to detect the presence of a photon is presented. (shrink)

The Deck Romania case is intended for MBA and Executive Education programs and focuses on the ‘gritty’ aspects of business in emerging market countries. It is particularly powerful in combining traditional managerial concerns like emerging market strategy and global supplier relationships with the larger challenges of cross-cultural and country differences in the conduct of business. Deck is a U.S.-based automotive supplier and part of a joint venture in Romania. In October 2006 the JV needed to expand to meet the needs (...) of one of its major global customers, Renault. The investment would be to support Renault-Dacia’s highly successful new world car, the Logan. But the question of expansion reveals that the JV does not meet many of Deck’s global manufacturing and business practice criteria. Deck’s dilemma is how to respond to the pressure from its global customer to make a substantial investment in a small market that may not meet financial or business practice expectations. (shrink)

The Deck Romania case is intended for MBA and Executive Education programs and focuses on the ‘gritty’ aspects of business in emerging market countries. It is particularly powerful in combining traditional managerial concerns like emerging market strategy and global supplier relationships with the larger challenges of cross-cultural and country differences in the conduct of business. Deck is a U.S.-based automotive supplier and part of a joint venture in Romania. In October 2006 the JV needed to expand to meet the needs (...) of one of its major global customers, Renault. The investment would be to support Renault-Dacia’s highly successful new world car, the Logan. But the question of expansion reveals that the JV does not meet many of Deck’s global manufacturing and business practice criteria. Deck’s dilemma is how to respond to the pressure from its global customer to make a substantial investment in a small market that may not meet financial or business practice expectations. (shrink)

We obtained an exact solution for a uniformly accelerated Unruh–DeWitt detector interacting with a massless scalar field in (3 + 1) dimensions which enables us to study the entire evolution of the total system, from the initial transient to late-time steady state. We find that the conventional transition probability of the detector from its initial ground state to excited states, as derived from time-dependent perturbation theory over an infinitely long duration of interaction, is valid only in the transient stage (...) and is invalid for cases with proper acceleration smaller than the damping constant. We also found that, unlike in (1 + 1)D results, the (3 + 1)D uniformly accelerated Unruh– DeWitt detector in a steady state does emit a positive radiated power of quantum nature at late-times, but it is not connected to the thermal radiance experienced by the detector in the Unruh effect proper. (shrink)

We show how Berry phase can be used to construct a precision quantum thermometer. An important advantage of our scheme is that there is no need for the thermometer to acquire thermal equilibrium with the sample. This reduces measurement times and avoids precision limitations. We also discuss how such methods can be used to detect the Unruh effect.

Problems with the conceptual foundations of quantum mechanics date back to attempts by Max Born, Niels Bohr, Werner Heisenberg, as well as many others in the 1920s to continue to employ the classical concept of a particle in the context of the quantum world. The experimental observations at the time and the assumption that the classical concept of a particle was to be preserved have led to an enormous literature on the foundations of quantum mechanics and a great deal of (...) confusion then and now among non-physicists and students in any field that involves quantum theory. It is the historical approach to the teaching of quantum mechanics that is at the root of the problem. Spacetime is the arena within which quantum mechanical phenomena take place. For this reason, several Appendices are devoted to the nature of spacetime as well as to topics that can help us understand it such as vacuum fluctuations, the Unruh effect and Hawking radiation. Because of the success of quantum mechanical calculations, those who wish to understand the foundations of the theory are often given the apocryphal advice, "just ignore the issue and calculate". It is hoped that this book will help dispel some of the dismay, frustration, and confusion among those who refuse to take to heart this admonition. (shrink)

Rob Clifton was one of the most brilliant and productive researchers in the foundations and philosophy of quantum theory, who died tragically at the age of 38. Jeremy Butterfield and Hans Halvorson collect fourteen of his finest papers here, drawn from the latter part of his career (1995-2002), all of which combine exciting philosophical discussion with rigorous mathematical results. Many of these papers break wholly new ground, either conceptually or technically. Others resolve a vague controversy intoa precise technical problem, which (...) is then solved; still others solve an open problem that had been in the air for soem time. All of them show scientific and philosophical creativity of a high order, genuinely among the very best work in the field. The papers are grouped into four Parts. First come four papers about the modal interpretation of quantum mechanics. Part II comprises three papers on the foundations of algebraic quantum field theory, with an emphasis on entanglement and nonlocality. The two papers in Part III concern the concept of a particle in relativistic quantum theories. One paper analyses localization; the other analyses the Unruh effect (Rindler quanta) using the algebraic approach to quantum theory. Finally, Part IV contains striking new results about such central issues as complementarity, Bohr's reply to the EPR argument, and no hidden variables theorems; and ends with a philosophical survey of the field of quantum information. The volume includes a full bibliography of Clifton's publications. Quantum Entanglements offers inspiration and substantial reward to graduates and professionals in the foundations of physics, with a background in philosophy, physics, or mathematics. (shrink)

According to a Received View, relativistic quantum field theories (RQFTs) do not admit particle interpretations. This view requires that particles be localizable and countable, and that these characteristics be given mathematical expression in the forms of local and unique total number operators. Various results (the Reeh-Schlieder theorem, the Unruh Effect, Haag's theorem) then indicate that formulations of RQFTs do not support such operators. These results, however, do not hold for nonrelativistic QFTs. I argue that this is due to (...) the absolute structure of the classical spacetimes associated with such theories. This suggests that the intuitions that underlie the Received View are non-relativistic. Thus, to the extent that such intuitions are inappropriate in the relativistic context, they should be abandoned when it comes to interpreting RQFTs. (shrink)

Some physicists and philosophers argue that unitarily inequivalent representations in quantum field theory are mathematical surplus structure. Support for that view, sometimes called ‘algebraic imperialism’, relies on Fell’s theorem and its deployment in the algebraic approach to QFT. The algebraic imperialist uses Fell’s theorem to argue that UIRs are ‘physically equivalent’ to each other. The mathematical, conceptual, and dynamical aspects of Fell’s theorem will be examined. Its use as a criterion for physical equivalence is examined in detail and it is (...) proven that Fell’s theorem does not apply to the vast number of representations used in the algebraic approach. UIRs are not another case of theoretical underdetermination, because they make different predictions about ‘classical’ operators. These results are applied to the Unruh effect where there is a continuum of UIRs to which Fell’s theorem does not apply. _1_ Introduction _2_ Weak Equivalence and Physical Equivalence _3_ Mathematical Overview of Algebraic Quantum Field Theory _4_ Fell’s Theorem and Philosophical Responses to Weak Equivalence _5_ Weak Equivalence in C*-Algebras and W*-Algebras _6_ Classical Equivalence and Weak Equivalence _7_ Interlude: Is Weak Equivalence Really Physical Equivalence? _8_ The Unruh Effect _9_ Time Evolution and Symmetries _10_ Conclusions Appendix. (shrink)

We discuss the Starobinskii-Unruh process for the Kerr black hole. We show how this effect is related to the theory of squeezed states. We then consider a simple model for a highly relativistic rotating star and show that the Starobinskii-Unruh effect is absent.

A novel photon-based proton model is developed. A proton’s ground state is assumed to be coherent to the degree that all of its mass-energy precipitates into a single uncharged spherical structure. A quantum vortex, initiated by the strong force, but sustained in the proton’s ground state by the circular Unruh effect and a spherical Rindler horizon, is proposed to confine the proton’s mass-energy in its ground state. A direct connection between the circular Unruh effect, the zitterbewegung (...) effect, spin, and general relativity is proposed. Such a structure acts as an uncharged zitterbewegung fermion, and may explain neutrino mass. A ground-state proton’s central zitterbewegung fermion is assumed to be surrounded by a halo of charge shells of both signs. Virtual photon standing waves are assumed to synchronize the inner shell with the central zitterbewegung fermion. The charge shells are proposed to be associated with isospin and proton g-factor. There are only two model inputs—proton mass and quantized electronic charge—and just one adjustable parameter. The adjustable parameter, reduced only by about 0.4% from an initial estimate, provides the proton’s experimentally determined magnetic moment to arbitrary precision. The resulting modeled proton charge radius agrees very well with the 2018 CODATA value. Magnetic moment and charge radius are calculated algebraically in a manner easily understood by undergraduate physics students. This proposed ground-state proton model could be considered a low-energy approximation to a full quantum chromodynamical proton model. (shrink)

A (Higgs vacuum)–(spacetime geometry) reciprocity principle is proposed and its consequences are explored. While it has been established that configurations of the spacetime metric tensor field, associated with acceleration with respect to local inertial frames, cause the vacuum to become thermalized, it is asserted that the converse is also possible. An appropriate thermal vacuum, through dynamical mass generation, can cause particles to propagate in a spacetime with a Minkowski metric, as if they were in a spacetime with a non-Minkowski metric. (...) The two points of view are equivalent and interchangeable. Invoking the reciprocity principle in the case of the Unruh effect in an accelerated frame, a mechanism is analyzed whereby in the context of the minimal standard model a gradient in the vacuum expectation value of the Higgs field in the direction of acceleration produces an effective inertial force on an accelerated material body. (shrink)

The adaptation of the Kramers-Kronig dispersion relations to the causal localization structure of QFT led to an important project in particle physics, the only one with a successful closure. The same cannot be said about the subsequent attempts to formulate particle physics as a pure S-matrix project.The feasibility of a pure S-matrix approach are critically analyzed and their serious shortcomings are highlighted. Whereas the conceptual/mathematical demands of renormalized perturbation theory are modest and misunderstandings could easily be corrected, the correct understanding (...) about the origin of the crossing property requires the use of the mathematical theory of modular localization and its relation to the thermal KMS condition. These new concepts, which combine localization, vacuum polarization and thermal properties under the roof of modular theory, will be explained and their potential use in a new constructive (nonperturbative) approach to QFT will be indicated. The S-matrix still plays a predominant role but, different from Heisenberg’s and Mandelstam’s proposals, the new project is not a pure S-matrix approach. The S-matrix plays a new role as a “relative modular invariant”. (shrink)

Combining physics, mathematics and computer science, quantum computing and its sister discipline of quantum information have developed in the past few decades from visionary ideas to two of the most fascinating areas of quantum theory. General interest and excitement in quantum computing was initially triggered by Peter Shor (1994) who showed how a quantum algorithm could exponentially “speed-up” classical computation and factor large numbers into primes far more efficiently than any (known) classical algorithm. Shor’s algorithm was soon followed by several (...) other algorithms that aimed to solve combinatorial and algebraic problems, and in the years since theoretical study of quantum systems serving as computational devices has achieved tremendous progress. Common belief has it that the implementation of Shor’s algorithm on a large scale quantum computer would have devastating consequences for current cryptography protocols which rely on the premise that all known classical worst-case algorithms for factoring take time exponential in the length of their input (see, e.g., Preskill 2005). Consequently, experimentalists around the world are engaged in attempts to tackle the technological difficulties that prevent the realisation of a large scale quantum computer. But regardless whether these technological problems can be overcome (Unruh 1995; Ekert and Jozsa 1996; Haroche and Raimond 1996), it is noteworthy that no proof exists yet for the general superiority of quantum computers over their classical counterparts. -/- The philosophical interest in quantum computing is manifold. From a social-historical perspective, quantum computing is a domain where experimentalists find themselves ahead of their fellow theorists. Indeed, quantum mysteries such as entanglement and nonlocality were historically considered a philosophical quibble, until physicists discovered that these mysteries might be harnessed to devise new efficient algorithms. But while the technology for harnessing the power of 50–100 qubits (the basic unit of information in the quantum computer) is now within reach (Preskill 2018), only a handful of quantum algorithms exist, and the question of whether these can truly outperform any conceivable classical alternative is still open. From a more philosophical perspective, advances in quantum computing may yield foundational benefits. For example, it may turn out that the technological capabilities that allow us to isolate quantum systems by shielding them from the effects of decoherence for a period of time long enough to manipulate them will also allow us to make progress in some fundamental problems in the foundations of quantum theory itself. Indeed, the development and the implementation of efficient quantum algorithms may help us understand better the border between classical and quantum physics (Cuffaro 2017, 2018a; cf. Pitowsky 1994, 100), and perhaps even illuminate fundamental concepts such as measurement and causality. Finally, the idea that abstract mathematical concepts such as computability and complexity may not only be translated into physics, but also re-written by physics bears directly on the autonomous character of computer science and the status of its theoretical entities—the so-called “computational kinds”. As such it is also relevant to the long-standing philosophical debate on the relationship between mathematics and the physical world. (shrink)

O experimento de Afshar foi proposto recentemente como sendo uma violação do princípio de complementaridade. Reconhecendo a novidade trazida pelo experimento, argumentamos que ele permite um refinamento de tal princípio, a partir do estabelecimento de dois pontos: (1) a possibilidade de modificar o "tipo" de fenômeno (onda ou partícula) sem alterar o estado quântico, e (2) a constatação de que o tipo de fenômeno, associado a um quantum detectado, refere-se a um trecho determinado percorrido pelo objeto quântico. O primeiro ponto (...) é explorado em interferômetros de Mach-Zehnder, com dispositivos de polarização e na montagem dupla de Unruh. O segundo ponto salienta que um fenômeno pode ser corpuscular com respeito a uma região e ondulatório com respeito a outra, estando a novidade de Afshar na proposta de uma maneira de constatar ambos simultaneamente. A restrição (1) acaba tendo um efeito desprezível no experimento de Afshar. Afshar's experiment was recently proposed as a violation of the principle of complementarity. Acknowledging the novelty brought by the experiment, we argue that it allows a refinement of this principle, with the establishment of two points: (1) the possibility of modifying the "type" of phenomenon (wave or particle) without changing the quantum-mechanical state, and (2) the recognition that the type of phenomenon, associated to a detected quantum, refers to a specific region traversed by the quantum object. The first point is explored in Mach-Zehnder interferometers, with polarization devices and in Unruh's double setup. The second point emphasizes that a phenomenon can be corpuscular with respect one region and undulatory with respect to another. Afshar's originality lies in his proposal of a way of ascertaining both simultaneously. Restriction (1) turns out having a negligible effect in Afshar's experiment. (shrink)

In his speech to an assembly of « corporate citizens » at the conference « Fibers and Textiles for the Future » at the University of Tampere in Finland, Hank Hardy Unruh of the WTO explains all the advantages of freedom and remote labor: After all, the American South, a great producer of textiles in its time, gained nothing from its localization of slavery. But remote labor demands close-up forms of surveillance and therefore creates a new market, for which (...) the WTO proposes a « textile solution » ... By passing themselves off as the representatives of an unbearable new world order to which businessmen and technocrats have not ceased to assent, the Yes Men create au extremely effective form of invisible theater, intervening’ in real situations and using various media to deliver their parodic and precise critique of neoliberal ideology. (shrink)

The structure of the thermal equilibrium state of a weakly interacting Bose gas is of current interest. We calculate the density matrix of that state in two ways. The most effective method, in terms of yielding a simple, explicit answer, is to construct a generating function within the traditional framework of quantum statistical mechanics. The alternative method, arguably more interesting, is to construct the thermal state as a vector state in an artificial system with twice as many degrees of freedom. (...) It is well known that this construction has an actual physical realization in the quantum thermodynamics of black holes, where the added degrees of freedom correspond to the second sheet of the Kruskal manifold and the thermal vector state is a state of the Unruh or the Hartle–Hawking type. What is unusual about the present work is that the Bogolubov transformation used to construct the thermal state combines in a rather symmetrical way with Bogolubov's original transformation of the same form, used to implement the interaction of the nonideal gas in linear approximation. In addition to providing a density matrix, the method makes it possible to calculate efficiently certain expectation values directly in terms of the thermal vector state of the doubled system. (shrink)

Charlotte Unruh has recently put forward a hybrid account of what it is to suffer harm – one that combines comparative and non‐comparative elements. We raise two problems for Unruh's account. The first concerns killing and death; the second concerns the causing of temporarily low or high welfare.