Although the laws of thermodynamics are well established for black hole horizons, much less has been said in the literature to support the extension of these laws to more general settings such as an asymptotic de Sitter horizon or a Rindler horizon (the event horizon of an asymptotic uniformly accelerated observer). In the present paper we review the results that have been previously established and argue that the laws of black hole thermodynamics, as well as (...) their underlying statistical mechanical content, extend quite generally to what we call here “causal horizons.” The root of this generalization is the local notion of horizon entropy density. (shrink)

Recent developments point to a breakdown in the generalized second law of thermodynamics for theories with Lorentz symmetry violation. It appears possible to construct a perpetual motion machine of the second kind in such theories, using a black hole to catalyze the conversion of heat to work. Here we describe and extend the arguments leading to that conclusion. We suggest the inference that local Lorentz symmetry may be an emergent property of the macroscopic world with origins in a microscopic (...) second law of causal horizon thermodynamics. (shrink)

An analogue of Hawking's black hole area theorem is proved for Friedmann-type cosmological models with event horizons. The generalised second law of thermodynamics is investigated in cases where the horizon shrinks.

The modeling of black holes is an important desideratum for any quantum theory of gravity. Not only is a classical black hole metric sought, but also agreement with the laws of black hole thermodynamics. In this paper, we describe how these goals are achieved in string theory. We review black hole thermodynamics, and then explicate the general stringy derivation of classical spacetimes, the construction of a simple black hole solution, and the derivation of its entropy. With that in (...) hand, we address some important philosophical and conceptual questions: the confirmatory value of the derivation, the bearing of the model on recent discussions of the so-called ‘information paradox’, and the implications of the model for the nature of space. (shrink)

In the most of existing cosmological investigations, the isotropic space–time models have been considered. In the present work, we focus on beyond this limitation and discuss the influence of anisotropy from thermodynamical perspective. The main goal of this study is to discuss the first and the generalized second laws of thermodynamics in an expanding anisotropic inhomogeneous model of the cosmos from the teleparallel gravity perspective, which is filled with the baryonic matter interacting with the dark energy and the cold (...) dark matter by assuming the cosmos as a thermodynamical system, which is bounded by a dynamical horizon. (shrink)

In this work, we have investigated the validity of the generalized second law of thermodynamics in logamediate and intermediate scenarios of the universe bounded by the Hubble, apparent, particle and event horizons using and without using first law of thermodynamics. We have observed that the GSL is valid for Hubble, apparent, particle and event horizons of the universe in the logamediate scenario of the universe using first law and without using first law. Similarly the GSL is valid for (...) all horizons in the intermediate scenario of the universe using first law. Also in the intermediate scenario of the universe, the GSL is valid for Hubble, apparent and particle horizons but it breaks down whenever we consider the universe enveloped by the event horizon. (shrink)

In this short paper we make a proposal that the second law of thermodynamics holds true for a closed physical system consisting of pure antimatter in the thermodynamical limit, but in a reversed form. We give two plausible arguments in favour to this proposal: one refers to the CPT theorem of relativistic quantum field theories while the other one is based on general thermodynamical arguments. However in our understanding the ultimate validity or invalidity of this idea can be decided (...) only by future physical experiments. As a consequence of the proposal we argue that the dynamical evolution of pure macroscopic antimatter systems can be very different from that of ordinary matter systems in the sense that sufficiently massive antimatter systems could have stronger tendency to form black holes during time evolution than their ordinary counterparts. Taking into account the various uniqueness theorems in black hole physics as well, as a result, antimatter could tracelessly disappear behind black hole event horizons faster in time than ordinary matter. The observed asymmetry of matter and antimatter could then be explained even if their presence in the Universe was symmetric in the beginning. (shrink)

The generalized second law of thermodynamics states that entropy always increases when all event horizons are attributed with an entropy proportional to their area. We test the generalized second law by investigating the change in entropy when dust, radiation and black holes cross a cosmological event horizon. We generalize for flat, open and closed Friedmann–Robertson–Walker universes by using numerical calculations to determine the cosmological horizon evolution. In most cases, the loss of entropy from within the cosmological (...) class='Hi'>horizon is more than balanced by an increase in cosmological event horizon entropy, maintaining the validity of the generalized second law of thermodynamics. However, an intriguing set of open universe models shows an apparent entropy decrease when black holes disappear over the cosmological event horizon. We anticipate that this apparent violation of the generalized second law will disappear when solutions are available for black holes embedded in arbitrary backgrounds. (shrink)

We analyze the rather unusual properties of some exact solutions in 2D dilaton gravity for which infinite quantum stresses on the Killing horizon can be compatible with regularity of the geometry. In particular, the Boulware state can support a regular horizon. We show that such solutions are contained in some well-known exactly solvable models (for example, RST). Formally, they appear to account for an additional coefficient B in the solutions (for the same Lagrangian which contains also “traditional” solutions) (...) that gives rise to the deviation of temperature T from its Hawking value T H . The Lorentzian geometry, which is a self-consistent solution of the semiclassical field equations, in such models, is smooth even at B≠0 and there is no need to put B=0 (T=T H ) to smooth it out. We show how the presence of B≠0 affects the structure of spacetime. In contrast to “usual” black holes, full fledged thermodynamic interpretation, including definite value of entropy, can be ascribed (for a rather wide class of models) to extremal horizons, not to nonextreme ones. We find also new exact solutions for “usual” black holes (with T=T H ). The properties under discussion arise in the weak-coupling regime of the effective constant of dilaton-gravity interaction. Extension of features, traced in 2D models, to 4D dilaton gravity leads, for some special models, to exceptional nonextreme black holes having no own thermal properties. (shrink)

This essay undertakes a critique of recent trends in affect theory from the standpoint of the “human motor”: a trope that presupposes a thermodynamic psychophysiology distended between energy conservation and entropy. In the course of reanimating thermodynamic motifs in Marx's labor power metabolics and Freud's trauma energetics, the essay broaches entropics as a poetics of depletion that offsets affect theories promoting open-system metaphors. Open-system affect theory sometimes amalgamates emancipatory post-humanist gestures inherited from Gilles Deleuze and Félix Guattari with neuroscientific terms. (...) In the course of “liberating” affect from subject-oriented topoi, this “liberation-scientistic” admixture expropriates organic matter's degeneration over time. An “entropical” perspective also challenges Antonio Negri's Spinozaist affect conceived as a capacitating power that encounters obstacles but never limits. Both “liberation scientism” and “capacitation rhetoric” mimic capital's abstraction in infinitely expanding its potential to extract surplus value from finitely embodied labor. With enervation and deterioration at its crux, entropics illuminates how people might feel individuated by their respective struggles to safeguard scarce energy and forestall “heat death” while navigating simultaneous demands. The question is whether or not open-system motifs in affect theory can effectively register the political force of this struggle with depletion and present or imminent debilitation as its common ground. (shrink)

In a previous paper by Pollock and Singh, it was proven that the total entropy of de Sitter space-time is equal to zero in the spatially flat case K=0. This result derives from the fundamental property of classical thermodynamics that temperature and volume are not necessarily independent variables in curved space-time, and can be shown to hold for all three spatial curvatures K=0,±1. Here, we extend this approach to Schwarzschild space-time, by constructing a non-vacuum interior space with line element (...) ds 2=e2λ(r) dt 2−e−2λ(r) dr 2−r 2(dθ 2+sin2 θdϕ 2), where $\mathrm{e}^{2{\lambda }(r)}=-\frac{1}{2}(1-\frac{r^{2}}{R_{0}^{2}})$ , which matches onto the vacuum exterior Schwarzschild metric in such a way that e2λ and d(e2λ )/dr are both continuous at the Schwarzschild radius R 0=2M. Then we show that the volume entropy is equal to A/4, where $A\equiv 4\pi R_{0}^{2}$ is the area of the apparent horizon, as found by Hawking. (shrink)

A possible way out of the conundrum of quantum gravity is the proposal that general relativity (GR) emerges from an underlying microscopic description. Despite recent interest in the emergent gravity program within the physics as well as the philosophy community, an assessment of the general motivation for this idea is lacking at the moment. We intend to fill this gap in the literature by discussing the main arguments in favour of the hypothesis that the metric field and its dynamics are (...) emergent. First, we distinguish between microstructure inspired from GR, such as through quantization or discretization, and microstructure that is not directly motivated from GR, such as strings, quantum bits or condensed matter fields. The emergent gravity approach can then be defined as the view that the metric field and its dynamics are derivable from the latter type of microstructure. Subsequently, we assess in how far the following properties of (semi-classical) GR are suggestive of underlying microstructure: (1) the metric's universal coupling to matter fields, (2) perturbative non-renormalizability, (3) black hole thermodynamics, and (4) the holographic principle. In the conclusion we formalize the general structure of the plausibility arguments put forward. (shrink)

Jacob Bekenstein's identification of black hole event horizon area with entropy proved to be a landmark in theoretical physics. In this paper we trace the subsequent development of the resulting generalized second law of thermodynamics (GSL), especially its extension to incorporate cosmological event horizons. In spite of the fact that cosmological horizons do not generally have well-defined thermal properties, we find that the GSL is satisfied for a wide range of models. We explore in particular the case of (...) an asymptotically de Sitter universe filled with a gas of small black holes as a means of casting light on the relative entropic ‘worth’ of black hole versus cosmological horizon area. We present some numerical solutions of the generalized total entropy as a function of time for certain cosmological models, in all cases confirming the validity of the GSL. (shrink)

The black hole information loss paradox is a catch-all term for a family of puzzles related to black hole evaporation. For almost 50 years, the quest to elucidate the implications of black hole evaporation has not only sustained momentum, but has also become increasingly populated with proposals that seem to generate more questions than they purport to answer. Scholars often neglect to acknowledge ongoing discussions within black hole thermodynamics and statistical mechanics when analyzing the paradox, including the interpretation of (...) Bekenstein-Hawking entropy, which is far from settled. To remedy the dialectical gridlock, I have formulated an overarching, unified framework, which I call ``Black Hole Paradoxes'', that integrates the debates and taxonomizes the relevant `camps' or philosophical positions. -/- I demonstrate that black hole evaporation within Hawking's semi-classical framework insinuates how late-time Hawking radiation is an entangled global system, a contradiction in terms. The relevant forms of information loss are associated with a decrease in maximal Boltzmann entropy and an increase in global von Neumann entropy respectively, which engender what I've branded the ``paradox of phantom entanglement''. Prospective solutions are then tasked with demonstrating how late-time Hawking radiation is either exclusively an entangled subsystem, in which a black hole remnant lingers as an information safehouse, or exclusively an unentangled global system, in which information is evacuated to the exterior. -/- The disagreement between safehouse and evacuation solutions boils down to the statistical interpretation of thermodynamic black hole entropy, i.e., Bekenstein-Hawking entropy. Safehouse solutions attribute Bekenstein-Hawking entropy to a minority of black hole degrees of freedom, those that are associated with the horizon. Evacuation solutions, in contrast, attribute Bekenstein-Hawking entropy to all black hole degrees of freedom. I argue that the interpretation of Bekenstein-Hawking entropy is the litmus test to vet the overpopulated proposal space. So long as any proposal rejecting Hawking's original calculation independently derives black hole evaporation, globally conserves degrees of freedom and entanglement, preserves a version of semi-classical gravity at sub-Planckian scales, and describes black hole thermodynamics in statistical terms, then it counts as a genuine solution to the paradox. (shrink)

Bekenstein proposed that the spectrum of horizon area of quantized black holes must be discrete and uniformly spaced. We examine this proposal in the context of spherically symmetric charged black holes in a general class of gravity theories. By imposing suitable boundary conditions on the reduced phase space of the theory to incorporate the thermodynamic properties of these black holes and then performing a simplifying canonical transformation, we are able to quantize the system exactly. The resulting spectra of (...) class='Hi'>horizon area, as well as that of charge are indeed discrete. Within this quantization scheme, near-extremal black holes (of any mass) turn out to be highly quantum objects, whereas extremal black holes do not appear in the spectrum, a result that is consistent with the postulated third law of black hole thermodynamics. (shrink)

Despite Michel Serres’s caution with figures of the limit, border, and boundary which philosophy and social theory put into play, his work can fruitfully be read as a proposal to rethink limits for a social and natural contract. By following up on the intimate connection between limits and law in his work, this paper shines a light on Serres’s argument for a parallelism of limits and laws; and particularly highlights the partially underacknowledged role of entropy for this matter. First, attention (...) will be drawn to the role of topological boundaries for Serres’s structural consideration of a natural contract in a number of his works (e.g., The Natural Contract, Atlas, Hominescence), in order to demonstrate the indispensable connection between topological boundaries, a topologically conceived ethics, and a topological approach to law. This grounds the argument for a second step, which will focus on the role of entropy and entropic difference for his understanding of processes of social organization as well as a proposal of a “new natural contract.” Similarly, this will emphasize the linkages between entropic figures of the limit and respective conceptions of a contract. This “new natural contract,” as Serres calls it, not only goes a long way in connecting themes around thermodynamic and informational entropy of the early Hermès series to his later employments of entropy in social theory, but also integrates different criticisms of his earlier natural contract and critiques of a Western-centric form of naturalism. The aim of this paper is to show that Serres’s approach to entropy engenders a reconsideration of a natural contract that not only thoroughly integrates his own non-essentialist and non-dualistic understanding of nature, but that opens up a horizon of resonances with feminist and postcolonial critiques of the Anthropocene. (shrink)

Tasked with the challenge to build better and better computers, quantum computing and classical computing face the same conundrum: the success of classical computing systems. Small quantum computing systems have been demonstrated, and intermediate-scale systems are on the horizon, capable of calculating numeric results or simulating physical systems far beyond what humans can do by hand. However, to be commercially viable, they must surpass what our wildly successful, highly advanced classical computers can already do. At the same time, those (...) classical computers continue to advance, but those advances are now constrained by thermodynamics, and will soon be limited by the discrete nature of atomic matter and ultimately quantum effects. Technological advances benefit both quantum and classical machinery, altering the competitive landscape. Can we build quantum computing systems that out-compute classical systems capable of some \(10^{30}\) logic gates per month? This article will discuss the interplay in these competing and cooperating technological trends. (shrink)

This paper presents a philosophical analysis of the structure of black holes, focusing on the event horizon and its fundamental status. While black holes have been at the centre of countless paradoxes arising from the attempt to merge quantum mechanics and general relativity, recent experimental discoveries have emphasised their importance as objects for the development of Quantum Gravity. In particular, the statistical mechanical underpinning of black hole thermodynamics has been a central research topic. The Quantum Membrane Paradigm, proposed (...) by Wallace (Stud Hist Philos Sci Part B 66:103-117, 2019), posits a real membrane made of black hole microstates at the black hole horizon to provide a statistical mechanical understanding of black hole thermodynamics from an exterior observer’s point of view. However, we argue that the Quantum Membrane Paradigm is limited to low-energy Quantum Gravity and needs to be modified to avoid reference to geometric notions, such as the event horizon, which presumably do not make sense in the non-spatiotemporal context of full Quantum Gravity. Our proposal relies on the central dogma of black hole physics. It considers recent developments, such as replica wormholes and entanglement wedge reconstruction, to provide a new framework for understanding the nature of black hole horizons in full Quantum Gravity. (shrink)

The Unruh-Wald scenario for mining quantum black holes is applied to de Sitter space. The following questions are addressed: Will the generalized second law of thermodynamics be maintained for de Sitter horizons? Does the mining process allow the recovery of unlimited energy from the cosmological gravitational field? The evaporation of a black hole in de Sitter space is also investigated in the context of the second law.

Macroscopic irreversible processes emerge from fundamental physical laws of reversible character. The source of the local irreversibility seems to be not in the laws themselves but in the initial and boundary conditions of the equations that represent the laws. In this work we propose that the screening of currents by black hole event horizons determines, locally, a preferred direction for the flux of electromagnetic energy. We study the growth of black hole event horizons due to the cosmological expansion and accretion (...) of cosmic microwave background radiation, for different cosmological models. We propose generalized McVittie co-moving metrics and integrate the rate of accretion of cosmic microwave background radiation onto a supermassive black hole over cosmic time. We find that for flat, open, and closed Friedmann cosmological models, the ratio of the total area of the black hole event horizons with respect to the area of a radial co-moving space-like hypersurface always increases. Since accretion of cosmic radiation sets an absolute lower limit to the total matter accreted by black holes, this implies that the causal past and future are not mirror symmetric for any spacetime event. The asymmetry causes a net Poynting flux in the global future direction; the latter is in turn related to the ever increasing thermodynamic entropy. Thus, we expose a connection between four different “time arrows”: cosmological, electromagnetic, gravitational, and thermodynamic. (shrink)

It was recently suggested that quantum field theory is not fundamental but emerges from the loss of phase space information about matter crossing causal horizons. Possible connections between this formalism and Verlinde’s entropic gravity and Jacobson’s thermodynamic gravity are proposed. The holographic screen in Verlinde’s formalism can be identified as local Rindler horizons and its entropy as that of the bulk fields beyond the horizons. This naturally resolves some issues on entropic gravity. The quantum fluctuation of the fields is the (...) origin of the thermodynamic nature of entropic gravity. It is also suggested that inertia is related to dragging Rindler horizons. (shrink)

I describe how gravitational entropy is intimately connected with the concept of gravitational heat, expressed as the difference between the total and free energies of a given gravitational system. From this perspective one can compute these thermodyanmic quantities in settings that go considerably beyond Bekenstein's original insight that the area of a black hole event horizon can be identified with thermodynamic entropy. The settings include the outsides of cosmological horizons and spacetimes with NUT charge. However the interpretation of gravitational (...) entropy in these broader contexts remains to be understood. (shrink)

Using quantum liquids one can simulate the behavior of the quantum vacuum in the presence of the event horizon. The condensed matter analogs demonstrate that in most cases the quantum vacuum resists formation of the horizon, and even if the horizon is formed different types of the vacuum instability develop, which are faster than the process of Hawking radiation. Nevertheless, it is possible to create the horizon on the quantum-liquid analog of the brane, where the vacuum (...) life-time is long enough to consider the horizon as the quasistationary object. Using this analogy we calculate the Bekenstein entropy of the near-extremal and extremal black holes, which comes from the fermionic microstates in the region of the horizon—the fermion zero modes. We also discuss how the cancellation of the large cosmological constant follows from the thermodynamics of the vacuum. (shrink)

This article argues that most of the approaches to the foundations of statistical mechanics have severed their link with the original foundational project, the project of demonstrating how real mechanical systems can behave thermodynamically.

We live in an age of impotence. Stuck between global war and global finance, between identity and capital, we seem to be incapable of producing the radical change that is so desperately needed. Is there still a way to disentangle ourselves from a global order that shapes our politics as well as our imagination? In his most systematic book to date, renowned Italian theorist Franco Berardi tackles this question through a solid yet visionary analysis of the three fundamental concepts of (...) Possibility, Potency, and Power. Characterizing Possibility as the content, Potency as the energy, and Power as the form, Berardi suggests that the road to emancipation unravels from the awareness that the field of the possible is only limited, and not created, by the power structures that implement it. Other futures and other worlds are always already inscribed within the present, despite power's attempt at keeping them invisible. Overcoming any temptation of giving in to despair or nostalgia, Berardi proposes the notion of 'futurability' as a way to remind us that even within the darkness of our current crisis lies dormant the horizon of possibility. (shrink)

The theme of Aesthetics in Present Future concerns the new chances the arts have and the deep changes they are undergoing, due to the new media, and the digital world in which we are growingly immersed. That this world is to be understood from an aesthetic point of view, become clear if we think of how much of what we produce, and observe and study is offered through images in particular and perceptual means in general.

This text provides a brief portrait of teacher induction programs in place in the school boards in Quebec and an analysis of three major support systems used. The analysis is based on both the descriptive documents integration programs posted on the website of the Carrefour national de l’insertion professionnelle en enseignement (CNIPE) as well as a review of research. Ce texte présente un bref portrait des programmes d’insertion professionnelle mis en place dans les commissions scolaires québécoises ainsi qu’une analyse de (...) trois des principaux dispositifs de soutien utilisés. L’analyse se base à la fois sur les documents descriptifs des programmes d’insertion mis en ligne sur le site web du Carrefour national de l’insertion professionnelle en enseignement (CNIPE) ainsi que sur une recension des recherches. (shrink)

Today many philosophers of mind accept that the two cortical streams of visual processing in humans can be distinguished in terms of conscious experience. The ventral stream is thought to produce representations that may become conscious, and the dorsal stream is thought to handle unconscious vision for action. Despite a vast literature on the topic of the two streams, there is currently no account of the way in which the relevant empirical evidence could fit with basic Husserlian phenomenology of vision. (...) Here I offer such an account. In this article, I show how the empirical evidence ought to be understood in a way that is informed by phenomenology. The differences in the two streams are better described as differences in spatial and temporal processing. Rather than simply “unconscious,” the dorsal stream can be better described as making a special contribution to what Husserl identified as the visual horizon. (shrink)

This paper discusses citizenship in Finnish religious education in relation to human security. It traces the characteristics of human security that connect citizenship, religion, and education in Finnish policy documents. The article focuses on basic education. Its data were analyzed employing qualitative content analysis. The findings indicate that citizenship in Finnish RE entails personal security concerns dealing with psychological and human rights issues. These are found to be essentially human security as conceptualized by the United Nations. However, Finnish policy documents (...) sparingly utilize human security in explicit terms. Finland rather emphasizes the practical applications of human security. Incorporation of explicit global citizen and human rights issues into RE in the new Finnish curriculum seems to project critical global citizenship. This is found to promote human security. Following Finland’s bid for practical application of human security, we recommend that human security be explicitly integrated into the Finnish RE curriculum. (shrink)

Este artículo propone valorar la contemplación de la belleza como una guía existencial en la vida del hombre. La belleza como horizonte de sentido aparece de forma muy especial en las obras de arte, pero también nos acompaña en la vida ética así como en nuestra actividad científica, pues la capacidad de contemplar la belleza debe estar en todas nuestras actividades y es muestra de una psique sana. De la misma manera, aborda este artículo aborda el “narcisismo” como una vía (...) no auténtica de acercarse a la belleza, y propone el correcto ejercicio del gusto como una forma para encontrar belleza, aún cuando en ocasiones no sea fácil encontrarla en el mundo. (shrink)

La figure du savant et son rôle, dans le temps de l'exil et de la perte de la prophétie depuis la chute du Second Temple, est analysée à partir d'une lecture du Guide des perplexes de Maïmonide, rabbin, philosophe et médecin (1138-1204).

This article explores the moral complexities and inconsistencies in the perception of fish welfare; mainly, that fish lack the ability to suffer and, therefore, exist outside of humanity’s moral horizon. The science behind fish sentience has advanced to the point where a serious discussion on the human-fish relationship is warranted. It is argued that enough scientific evidence exists to provide evidence for fish sentience and suffering. However, for those unconvinced in light of the lack of both scientific and popular (...) consensus, the precautionary principle, where we treat fish as if they may suffer, will ultimately be advocated as an appropriate approach to fish welfare. (shrink)

The present papers brings up Cassirer’s idea of philosophy through the few and scattered remarks that he makes about non-European traditions of thought. While Cassirer’s philosophy of culture theorizes symbolic functions through an examination of symbolic forms, he only implicitly talks about culture as such. However, since culture is the unity of symbolic forms and in and by itself a cultural form, culture is always related to other cultures. And hence, one culture is not the sole possible and implies – (...) to cite Wilhelm von Humboldt – a particular Weltansicht. So, firstly, how does Cassirer’s philosophy of culture relate to what is always present as its background, i.e. to European culture? And, secondly, how does his notion of philosophy relate to the cultural setting that it emerges from? To address these question, two paths seem possible: on the one hand, the top-down analysis from his philosophy of culture through to a determination of cultures based on different, but complementary modes of symbolization; and on the other hand, a bottom up analysis by beginning from Cassirer’s own comments and thoughts on non-European traditions. Since this path is rather unsystematic, it can serve as a counter narrative to Cassirer’s own systematic position. While both paths are pertinent and not mutually exclusive, in the present paper only the bottom-up analysis will be discussed. (shrink)

The theme of Aesthetics in Present Future concerns the new chances the arts have and the deep changes they are undergoing, due to the new media, and the digital world in which we are growingly immersed. That this world is to be understood from an aesthetic point of view, become clear if we think of how much of what we produce, and observe and study is offered through images in particular and perceptual means in general.