Feminist, critical race, and postcolonial theories have established that social identities such as race and gender are mutually constitutive—i.e., that they “intersect.” I argue that “cultural appropriation” is never merely the appropriation of culture, but also of gender, sexuality, class, etc. For example, “white hipness” is the appropriation of stereotypical black masculinity by white males. Looking at recent videos from black male hip-hop artists, I develop an account of “postmillennial black hipness.” The inverse of white hipness, this (...) practice involves the appropriation, by black men, of stereotypical white gay masculinity and/or non-American, non-white femininity. I also argue that Shephard Fairey’s recent images of (mainly militant) non-Western women of color can be read as a new form of white hipness that revises the traditional logic in two ways: (1) by appropriating non-white femininity rather than masculinity, and (2) by adopting the practice of postmillennial black hipness itself. (shrink)
This paper summarizes the findings of a three-year exploratory qualitative study of teenage childbearing in 20 low-income multigeneration black families. Teenage childbearing in these families is part of an alternative life-course strategy created in response to socioenvironmental constraints. This alternative life-course strategy is characterized by an accelerated family timetable; the separation of reproduction and marriage; an age-condensed generational family structure; and a grandparental child-rearing system. The implications of these patterns for intergenerational family roles are discussed.
Presentism is, roughly, the metaphysical doctrine that maintains that whatever exists, exists in the present. The compatibility of presentism with the theories of special and general relativity was much debated in recent years. It has been argued that at least some versions of presentism are consistent with time-orientable models of general relativity. In this paper we confront the thesis of presentism with relativistic physics, in the strong gravitational limit where black holes are formed. We conclude that the presentist position (...) is at odds with the existence of black holes and other compact objects in the universe. A revision of the thesis is necessary, if it is intended to be consistent with the current scientific view of the universe. (shrink)
We model a black hole spacetime as a causal set and count, with a certain definition, the number of causal links crossing the horizon in proximity to a spacelike or null hypersurface Σ. We find that this number is proportional to the horizon's area on Σ, thus supporting the interpretation of the links as the “horizon atoms” that account for its entropy. The cases studied include not only equilibrium black holes but ones far from equilibrium.
This is a brief sequel to Max Black 's classic dialogue on the Identity of Indiscernibles. Interlocutor A defends the bundle theory by endorsing the view according to which Black 's world does not contain two indiscernible spheres but rather a single, bi-located sphere. His opponent, B, objects that A cannot distinguish such a world from a world with a single, uniquely located sphere, hence that the view in question adds nothing to A's original response to Black (...) 's challenge. A is simply denying that there can be worlds with two or more indiscernible entities. (shrink)
One of the most widespread objections to legalizing a market in human organs is that such legalization would stimulate the black market in human organs. Unfortunately, the proponents of this argument fail to explain how such stimulation will occur. To remedy thus, two accounts of how legalizing markets in human organs could stimulate the black market in them are developed in this paper. Yet although these accounts remedy the lacuna in the anti-market argument from the black market (...) neither of them provide reason to believe that legalizing an organ markets would stimulate the black market in organs. Despite its prevalence, then, the argument from the black market should be rejected. (shrink)
Despite the recent rise in articles by American philosophers willing to deal with race, the sophistication of American philosophy's conceptualizations of American racism continues to lag behind other liberal arts fields committed to similar endeavors. Whereas other fields like American studies, history, sociology, and Black studies have found the foundational works of Black scholars essential to "truly" understanding the complexities of racism, American philosophy-driven by the refusal of white philosophers to acknowledge and incorporate the foundational works of (...) class='Hi'>Black scholars at the turn of the century, as well as the relevant insights of contemporary race theorists-remains in a very real sense underdeveloped .. (shrink)
Clues about what Berkeley was planning to say about mind in his now-lost second volume of the Principles seem to abound in his Notebooks. However, commentators have been reluctant to use his unpublished entries to explicate his remarks about spiritual substances in the Principles and Dialogues for three reasons. First, it has proven difficult to reconcile the seemingly Humean bundle theory of the self in the Notebooks with Berkeley's published characterization of spirits as “active beings or principles.” Second, the fact (...) that Berkeley did not publish his Notebooks insights on mind has led some to claim that he later rejected his early views. Third, many of the Notebooks entries on mind have a ‘+’ sign next to them, which has been understood for decades to comprise a Black List of views about which Berkeley had doubts or subsequently rejected. In my dialogue, I describe how Berkeley's “congeries” account of mind (1) differs from Hume's bundle theory in a way that complements Berkeley's published remarks and (2) undercuts the claim that he later rejected his early views. Most importantly, (3) I show how a careful analysis of the British Library manuscript of the Notebooks refutes the Black List hypothesis. (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)
Crane envisions the speculative conjecture that intelligent civilizations might want and be able to produce black holes in the very far future. He implicitly suggests two main purposes of this enterprise: (i) energy production and (ii) universe production. We discuss those two options. The commentary is obviously highly speculative and should be read accordingly.
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)
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)
I hope that this wonderful book, written with a passionate and sympathetic intelligence, reaches a wide audience. It's not an easy read, for Janice Haaken deliberately spins a dense web of reference, pursuing paths across the contemporary psycho-political landscape. But her scholarship is marvellously diverse and well-directed, and her writing easily shifts between sad or playful fantasy, and insistently engaged political or empirical analysis.
We present a framework for analyzing black hole backreaction from the point of view of quantum open systems using influence functional formalism. We focus on the model of a black hole described by a radially perturbed quasi-static metric and Hawking radiation by a conformally coupled massless quantum scalar field. It is shown that the closed-time-path (CTP) effective action yields a non-local dissipation term as well as a stochastic noise term in the equation of motion, the Einstein–Langevin equation. Once (...) the thermal Green's function in a Schwarzschild background becomes available to the required accuracy, the strategy described here can be applied to obtain concrete results on backreaction. We also present an alternative derivation of the CTP effective action in terms of the Bogolyubov coefficients, thus making a connection with the interpretation of the noise term as measuring the difference in particle production in alternative histories. (shrink)
An extended scale relativity theory, actively developed by one of the authors, incorporates Nottale's scale relativity principle where the Planck scale is the minimum impassible invariant scale in Nature, and the use of polyvector-valued coordinates in C-spaces (Clifford manifolds) where all lengths, areas, volumes⋅ are treated on equal footing. We study the generalization of the ordinary point-particle quantum mechanical oscillator to the p-loop (a closed p-brane) case in C-spaces. Its solution exhibits some novel features: an emergence of two explicit scales (...) delineating the asymptotic regimes (Planck scale region and a smooth region of a quantum point oscillator). In the most interesting Planck scale regime, the solution recovers in an elementary fashion some basic relations of string theory (including string tension quantization and string uncertainty relation). It is shown that the degeneracy of the first collective excited state of the p-loop oscillator yields not only the well-known Bekenstein–Hawking area-entropy linear relation but also the logarithmic corrections therein. In addition we obtain for any number of dimensions the Hawking temperature, the Schwarschild radius, and the inequalities governing the area of a black hole formed in a fusion of two black holes. One of the interesting results is a demonstration that the evaporation of a black hole is limited by the upper bound on its temperature, the Planck temperature. (shrink)
Theorizing Black Feminisms outlines some of the crucial debates going on among Black feminists today. In doing so it brings together a collection of some of the most exciting work by Black women scholars. The book encompasses a wide range of diverse subjects and refuses to be limited by notions of disciplinary boundaries or divisions between theory and practice. Theorizing Black Feminisms combines essays on literature, sociology, history, political science, anthropology, and art. As such it will (...) be vital reading for anyone--activist, student, artist or scholar--interested in exploring the multidisciplinary possibilities for Black feminism. Most importantly, each essay in the volume begins with the assumption that Black women are not simply victims of various oppressions. Rather, they are visionary and pragmatic agents of change. Contributors: Evelyn Barbee, University of Wisconsin; Rose Brewer, University of Minnesota; Cheryl Clarke, Rutgers University; Johnnetta Cole, Spelman College; Cindy Courville, Occidental College; Beverly Guy-Sheftall, Spelman College; Marilyn Little, University of Wisconsin; Nellie McKay, University of Wisconsin; O'molara Ogundipe, Rutgers University; Christine Obbo, Wayne State University; Loretta Ross, Center for Democratic Renewal, Atlanta. (shrink)
An analysis of some of the applications of Clifford space relativity to the physics behind the modified black hole entropy-area relations, rainbow metrics, generalized dispersion and minimal length stringy uncertainty relations is presented.
The black hole information paradox arises from an apparent conflict between the Hawking black hole radiation and the fact that time evolution in quantum mechanics is unitary. The trouble is that while the former suggests that information of a system falling into a black hole disappears, the latter implies that information must be conserved. In this work we discuss the current divergence in views regarding the paradox, we evaluate the role that objective collapse theories could play in (...) its resolution and we propose a link between spontaneous collapse events and microscopic virtual black holes. (shrink)
Physical arguments stemming from the theory of black-hole thermodynamics are used to put constraints on the dynamics of closed-string tachyon condensation in Scherk–Schwarz compactifications. A geometrical interpretation of the tachyon condensation involves an effective capping of a noncontractible cycle, thus removing the very topology that supports the tachyons. A semiclassical regime is identified in which the matching between the tachyon condensation and the black-hole instability flow is possible. We formulate a generalized correspondence principle and illustrate it in several (...) different circumstances: an Euclidean interpretation of the transition from strings to black holes across the Hagedorn temperature and instabilities in the brane-antibrane system. (shrink)
The Schwarzschild solution has played a fundamental conceptual role in general relativity, and beyond, for instance, regarding event horizons, spacetime singularities and aspects of quantum field theory in curved spacetimes. However, one still encounters the existence of misconceptions and a certain ambiguity inherent in the Schwarzschild solution in the literature. By taking into account the point of view of an observer in the interior of the event horizon, one verifies that new conceptual difficulties arise. In this work, besides providing a (...) very brief pedagogical review, we further analyze the interior Schwarzschild black hole solution. Firstly, by deducing the interior metric by considering time-dependent metric coefficients, the interior region is analyzed without the prejudices inherited from the exterior geometry. We also pay close attention to several respective cosmological interpretations, and briefly address some of the difficulties associated to spacetime singularities. Secondly, we deduce the conserved quantities of null and timelike geodesics, and discuss several particular cases in some detail. Thirdly, we examine the Eddington–Finkelstein and Kruskal coordinates directly from the interior solution. In concluding, it is important to emphasize that the interior structure of realistic black holes has not been satisfactorily determined, and is still open to considerable debate. (shrink)
According to prevailing theory, relativistic degenerate stars with masses beyond the Chandrasekhar and Oppenheimer–Volkoff (OV) limits cannot achieve hydrostatic equilibrium through either electron or neutron degeneracy pressure and must collapse to form stellar black holes. In such end states, all matter and energy within the Schwarzschild horizon descend into a central singularity. Avoidance of this fate is a hoped-for outcome of the quantization of gravity, an as-yet incomplete undertaking. Recent studies, however, suggest the possibility that known quantum processes may (...) intervene to arrest complete collapse, thereby leading to equilibrium states of macroscopic size and finite density. I describe here one such process which entails pairing (or other even-numbered association) of neutrons (or constituent quarks in the event of nucleon disruption) to form a condensate of composite bosons in equilibrium with a core of degenerate fermions. This process is analogous to, but not identical with, the formation of hadron Cooper pairs that give rise to neutron superfluidity and proton superconductivity in neutron stars. Fermion condensation to composite bosons in a star otherwise destined to collapse to a black hole facilitates hydrostatic equilibrium in at least two ways: (1) removal of fermions results in a decrease in the Fermi level which stiffens the dependence of degeneracy pressure on fermion density, and (2) phase separation into a fermionic core surrounded by a self-gravitating condensate diminishes the weight which must be balanced by fermion degeneracy pressure. The outcome is neither a black hole nor a neutron star, but a novel end state, a “fermicon star,” with unusual physical properties. (shrink)
A naive introduction of a dependency of the mass of a black hole on the Schwarzschild time coordinate results in singular behavior of curvature invariants at the horizon, violating expectations from complementarity. If instead a temporal dependence is introduced in terms of a coordinate akin to the river time representation, the Ricci scalar is nowhere singular away from the origin. It is found that for a shrinking mass scale due to evaporation, the null radial geodesics that generate the horizon (...) are slightly displaced from the coordinate singularity. In addition, a changing horizon scale significantly alters the form of the coordinate singularity in diagonal (orthogonal) metric coordinates representing the space-time. A Penrose diagram describing the growth and evaporation of an example black hole is constructed to examine the evolution of the coordinate singularity. (shrink)
Historically, for Black writers, literary fiction has been a site for transforming the discursive disciplinary spaces of political oppression. From 19th century “slave narratives” to the 20th century, Black novelists have created an impressive literary counter-canon in advancing liberatory struggles. W.E.B. Du Bois argued that “all art is political.” Many Black writers have used fiction to create spaces for political and social freedom—from the early work of Harriet Wilson’s Our Nig; or, Sketches from the Life of a (...) Free Black (1859)—to the enduring works of the Harlem Renaissance (Toomer, Hurston, and Schuyler)—to the great revolutionary Black literature after WWII (Wright, Baldwin, Williams)—to contemporary Black writers (Toni Morrison, Edward Jones, Samuel Delany)—Black fictive space continues to be a necessary site for resistance. Black literary fiction is a vast counter-canon to mainstream literature which unquestioningly reinforces global white supremacy, capitalistic political oppressions, and the dominance/subordinance relations upon which they depend. (shrink)
Two studies examined human perceptions of dog personality attributes based upon exposure to pictures of dogs of select breeds. The proposed hypotheses evaluated the validity of “big, black dog syndrome”—whereby large, black dog breeds are reportedly spurned for adoption due to negatively perceived personality attributes—by assessing each dog’s relative trait dominance and affiliation based upon a taxonomy drawn from the eight-factor interpersonal circumplex. Results of two separate studies indicated that among participants’ ratings, breed-specific differences were more powerful predictors (...) of interpersonal trait attributions than the color or size of the dog. In general, with the exception of the golden retriever, black labs were perceived as consistently less dominant and less hostile than other large breeds, contrary to the assumption that large, black dogs are viewed negatively. (shrink)
The Einstein-conformally coupled scalar field system is studied in the presence of a cosmological constant. We consider a massless or massive scalar field with no additional self-interaction, and spherically symmetric black hole geometries. When the cosmological constant is positive, no scalar hair can exist and the only solution is the Schwarzschild–de Sitter black hole. When the cosmological constant is negative, stable scalar field hair exists provided the mass of the scalar field is not too large.
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)
Stationary spacetimes containing a black hole have several properties akin to those of atoms. For instance, such spacetimes have only three classical degrees of freedom, or observables, which may be taken to be the mass, the angular momentum, and the electric charge of the hole. There are several arguments supporting a proposal originally made by Bekenstein that quantization of these classical degrees of freedom gives an equal spacing for the horizon area spectrum of black holes. We review some (...) of these arguments and introduce a specific Hamiltonian quantum theory of black holes. Our Hamiltonian quantum theory gives, among other things, a discrete spectrum for the classical observables, and it produces an area spectrum which is closely related to Bekenstein's proposal. We also present a foamlike model of horizons of spacetime. In our model spacetime horizon consists of microscopic Schwarzschild black holes. Applying our Hamiltonian approach to this model we find that the entropy of any horizon is one quarter of its area. (shrink)
This study investigates the extent to which South African listed corporations voluntarily disclose information on black economic empowerment (BEE) in their annual and sustainability reports using a sample of 75 listed corporations from 2003 to 2009. BEE is a form of socio-economic affirmative action championed by the African National Congress (ANC)-led government to address historical imbalances in business participation and ownership in South Africa. We find that block ownership and institutional ownership are negatively associated with the extent of BEE (...) disclosures, whereas government ownership, board diversity (age, education, ethnicity, nationality and occupation), board size and non-executive directors are positively related to the extent of BEE disclosures. By contrast, dual board leadership structure and gender diversity are not significantly associated with BEE disclosures. Our results are robust when controlling for firm-level characteristics, fixed-effects and alternative disclosure proxies. Our results are largely consistent with the predictions of agency, legitimacy, resource dependence and stakeholder theories. (shrink)
_ Source: _Volume 9, Issue 2, pp 146 - 158 In the _De abstinentia_ Porphyry is the first philosopher to give an exact definition of _goeteia_or _black magic_saying: “All black magic is accomplished through the opposite sort [i.e. evil] daemons. This paper will be presented in two parts: in the first part, there is the description about the difference between Magic—the sacred science of the Persian Magi —, and the black magic ; in the second part, using Porphyry’s (...) definition of black magic and other philological data, it’s shown that Porphyry was not merely a philosopher interested in black magic in a theoretical manner, but also a practicing sorcerer. (shrink)
The black hole information problem provides important clues for trying to piece together a quantum theory of gravity. Discussions on this topic have generally assumed that in a consistent theory of gravity and quantum mechanics, quantum theory is unmodified. In this review, we discuss the black hole information problem in the context of generalisations of quantum theory. In this preliminary exploration, we examine black holes in the setting of generalised probabilistic theories, in which quantum theory and classical (...) probability theory are special cases. We are able to calculate the time it takes information to escape a black hole, assuming that information is preserved. In quantum mechanics, information should escape pure state black holes after half the Hawking photons have been emitted, but we find that this get’s modified in generalisations of quantum mechanics. Likewise the black-hole mirror result of Hayden and Preskill, that information from entangled black holes can escape quickly, also get’s modified. We find that although information exits the black hole as predicted by quantum theory, it is fairly generic that it fails to appear outside the black hole at this point—something impossible in quantum theory due to the no-hiding theorem. The information is neither inside the black hole, nor outside it, but is delocalised. (shrink)
This essay brings Critical Whiteness Studies into liberationist Christian ethics in order to analyze white Protestant responses to the 1969 Black Manifesto, which demanded reparations from white churches. The essay's primary argument is that the absence of a sense of white moral agency among white Protestants manifested itself in behaviors and rhetoric that ensured whiteness went unacknowledged, which caused Protestant responses to the Manifesto to fail. A related argument is that white behavior and rhetoric were particularly dramatic because of (...) the call for reparations. Reparations assume that race is a material relationship in which there has been a perpetrator and a victim, rendering the acknowledgment of white agency unavoidable. This essay thus analyzes several ways in which whites can be seen turning away from white selves, turning a scrutinizing gaze instead to Black selves and, in the process, absenting white agency from the work of racial justice. (shrink)
In British Columbia, brown bears , black bears , and cougars must relate to growing human populations. This study examines age- and gender-related attitudes to these animals in the urbanizing, agriculturally significant, intermontane city of Kamloops. Most respondents, especially women, feared cougars and bears, saw bears as more troublesome than cougars, and were concerned for child and adult safety. More middle-aged and older participants perceived brown bears as dangerous to companion animals, and black bears as troublesome, than did (...) younger participants, and more middle-aged participants perceived brown bears as troublesome than did younger and older participants. Opinions favored trapping and removal of animals rather than shooting or toleration, but more younger participants opted for shooting, whereas more middle-aged and older participants opted for toleration and removal. Majorities agreed that the animals serve useful functions, women more than men for cougars, middle-aged more than old or young for bears, but saw only cougars as increasing their quality of life. These findings contribute to knowledge about human-wildlife relations, an important first step toward more efficient local and more general conservation policy. (shrink)