This book compares various approaches to the interpretation of quantum mechanics, in particular those which are related to the key words "the Copenhagen interpretation", "the antirealist view", "quantum logic" and "hidden variable theory". Using the concept of "correlation" carefully analyzed in the context of classical probability and in quantum theory, the author provides a framework to compare these approaches. He also develops an extension of probability theory to construct a local hidden variable theory. The book should be of interest for (...) physicists and philosophers of science interested in the foundations of quantum theory. (shrink)

Localist models of spreading activation (SA) and models assuming distributed representations offer very different takes on semantic priming, a widely investigated paradigm in word recognition and semantic memory research. In this study, we implemented SA in an attractor neural network model with distributed representations and created a unified framework for the two approaches. Our models assume a synaptic depression mechanism leading to autonomous transitions between encoded memory patterns (latching dynamics), which account for the major characteristics of automatic semantic priming in (...) humans. Using computer simulations, we demonstrated how findings that challenged attractor‐based networks in the past, such as mediated and asymmetric priming, are a natural consequence of our present model’s dynamics. Puzzling results regarding backward priming were also given a straightforward explanation. In addition, the current model addresses some of the differences between semantic and associative relatedness and explains how these differences interact with stimulus onset asynchrony in priming experiments. (shrink)

In the mid-nineteenth century George Boole formulated his ‘conditions of possible experience’. These are equations and ineqaulities that the relative frequencies of events must satisfy. Some of Boole's conditions have been rediscovered in more recent years by physicists, including Bell inequalities, Clauser Horne inequalities, and many others. In this paper, the nature of Boole's conditions and their relation to propositional logic is explained, and the puzzle associated with their violation by quantum frequencies is investigated in relation to a variety of (...) approaches to the interpretation of quantum mechanics. * While preparing this paper for publication I have learnt of the untimely death of Professor J. S. Bell, and I wish to dedicate the paper to his memory. This research was undertaken while I spent a sabbatical leave at Wolfson College, and the History and Philosophy of Science Department at the University of Cambridge. I would like to thank Michael Redhead and Jeremy Butterfield for their hospitality and for helpful discussions. A first draft of this paper has been distributed among the participants of the conference 'Einstein in Context' which was held in Israel, in April 1990.1 have benefited from the comments of many colleagues. I would like to thank in particular Arthur Fine who enlightened me on the prism models, David Albert. Maya Bar-Hillel. Yemima Ben-Menachem, Mara Beller. Simon Saunders, and Mark Steiner. This research is partially supported by the Edelstein Center for the History and Philosophy of Science at the Hebrew University. (shrink)

Paul’s Ricoeur’s Lectures on Ideology and Utopia are more pertinent than ever forty years later. The chapters in this book reflect the lectures’ original intricacy as the authors not only insightfully analyze them but also creatively apply them.

1. The Physical Church-Turing Thesis. Physicists often interpret the Church-Turing Thesis as saying something about the scope and limitations of physical computing machines. Although this was not the intention of Church or Turing, the Physical Church Turing thesis is interesting in its own right. Consider, for example, Wolfram’s formulation: One can expect in fact that universal computers are as powerful in their computational capabilities as any physically realizable system can be, that they can simulate any physical system . . . (...) No physically implementable procedure could then shortcut a computationally irreducible process. (Wolfram 1985) Wolfram’s thesis consists of two parts: (a) Any physical system can be simulated (to any degree of approximation) by a universal Turing machine (b) Complexity bounds on Turing machine simulations have physical significance. For example, suppose that the computation of the minimum energy of some system of n particles takes at least exponentially (in n) many steps. Then the relaxation time of the actual physical system to its minimum energy state will also take exponential time. (shrink)

A deterministic model that accounts for the statistical behavior of random samples of identical particles is presented. The model is based on some nonmeasurable distribution of spin values in all directions. The mathematical existence of such distributions is proved by set-theoretical techniques, and the relation between these distributions and observed frequencies is explored within an appropriate extension of probability theory. The relation between quantum mechanics and the model is specified. The model is shown to be consistent with known polarization phenomena (...) and the existence of macroscopic magnetism. Finally.. (shrink)

Kuhnʼs influential book, The Structure of Scientific Revolutions,1 is often viewed as a revolt against empiricist philosophy of science. However, Friedman has reminded us lately2 that the book was commissioned by logical positivists, who were delighted with the result. In fact, the book was part of the International Encyclopedia of United Science initiated by members of the Vienna Circle, whose first volumes were published in 1938.3 The project aimed at providing a systematic positivist perspective on all the sciences, from logic (...) and mathematics through linguistics and on to psychology and sociology. The publication of Structure as volume 12 of the encyclopedia was greeted enthusiastically by the editor, Carnap, as can be learned from the letters he wrote to Kuhn. There are several reasons for this reaction. First, as noted by Friedman, there is a resemblance between Kuhnʼs notion of changing paradigms and Carnapʼs philosophical ideas. Logical empiricism is “logical” because of its central tenet that scientific knowledge is the organization of facts within a conceptual structure; the existence of an appropriate conceptual structure is a precondition for the very possibility of scientific inquiry. Unlike Kant, however, the logical empiricists believed that the conceptual. (shrink)

Boltzmann’s approach to statistical mechanics is widely believed to be conceptually superior to Gibbs’ formulation. However, the microcanonical distribution often fails to behave as expected: The ergodicity of the motion relative to it can rarely be established for realistic systems; worse, it can often be proved to fail. Also, the approach involves idealizations that have little physical basis. Here we take Khinchin’s advice and propose a de…nition of equilibrium that is more realistic: The de…nition re‡ects the fact that the system (...) is made of a great number of particles, and implies that all measurable macroscopic observables have steady values. (shrink)

We develop and defend the thesis that the Hilbert space formalism of quantum mechanics is a new theory of probability. The theory, like its classical counterpart, consists of an algebra of events, and the probability measures defined on it. The construction proceeds in the following steps: (a) Axioms for the algebra of events are introduced following Birkhoff and von Neumann. All axioms, except the one that expresses the uncertainty principle, are shared with the classical event space. The only models for (...) the set of axioms are lattices of subspaces of inner product spaces over a field K. (b) Another axiom due to Soler forces K to be the field of real, or complex numbers, or the quaternions. We suggest a probabilistic reading of Soler's axiom. (c) Gleason's theorem fully characterizes the probability measures on the algebra of events, so that Born's rule is derived. (d) Gleason's theorem is equivalent to the existence of a certain finite set of rays, with a particular orthogonality graph (Wondergraph). Consequently, all aspects of quantum probability can be derived from rational probability assignments to finite "quantum gambles". (e) All experimental aspects of entanglement- the violation of Bell's inequality in particular- are explained as natural outcomes of the probabilistic structure. (f) We hypothesize that even in the absence of decoherence macroscopic entanglement can very rarely be observed, and provide a precise conjecture to that effect .We also discuss the relation of the present approach to quantum logic, realism and truth, and the measurement problem. (shrink)

The paper proposes a solution to the problem with Odysseus’ kingship in the Odyssey by maintaining that Odysseus is not officially considered dead. Consequently, Telemachus cannot inherit the position of king and Penelope must leave Odysseus’ household before remarrying. After discussing the modern concept of legal death and previous interpretations of the Ithacan situation, the paper focusses on Athena's speech at 1.275–92. A close reading demonstrates that erecting a cenotaph to Odysseus would be tantamount to a modern declaration of death (...) in absentia, since it will render Penelope a widow and Telemachus the head of the household. This legal convention chimes with the Homeric depiction of Hades. (shrink)

Can the axioms of probability theory and the classical patterns of statistical inference ever be falsified by observation? Various possible answers to this question are examined in a set theoretical context and in relation to the findings of microphysics.

A local "resolution" of the Einstein-Podolsky-Rosen Paradox by way of a mechanical analogue (roul ette) is presented together with some notes regarding the consequences of such models for the foundations of mathematics and the theory of probability.

O presente estudo teve como objeto a Sociedade de São Vicente de Paulo - SSVP, e visou analisar a crise institucional da associação, relacionando-a com a crise religiosa contemporânea, tendo em vista a dificuldade na admissão de novos quadros para a entidade, como também a complexidade da manutenção de seus membros. A motivação do trabalho foi compreender como a crise socioreligiosa contemporânea contribui para esse processo, valendo-se também da observação empírica nas reuniões, festas e eventos realizados pela instituição. Buscou-se ainda (...) identificar alguns fatores externos e internos à instituição, e suas implicações, que estão contribuindo para esse desequilíbrio. Para isso, foi utilizado como método principal de coleta de dados a pesquisa bibliográfica, em fontes e documentos da SSVP, como a Regra e o Regulamento; boletins, revistas e atas da entidade, como também obras de autores que estudam a SSVP. Houve também, metodologicamente, a observação através da presença numa Conferência Vicentina, pertencente ao Conselho Central Sagrados Corações. Bibliograficamente, ainda foram analisadas algumas obras de pesquisadores que refletem sobre a realidade religiosa contemporânea, abordando temas como secularização, modernidade, pluralismo religioso, crise de sentido, transmissão religiosa, crise religiosa contemporânea, mobilidade social e religiosa e juventude, a fim de entender de que maneira tais temas podem ajudar na análise do catolicismo e, consequentemente, da crise institucional da SSVP. A dissertação procurou refletir sobre perspectivas e as novas demandas sociais que podem desafiar a entidade a dialogar com a sociedade contemporânea, especialmente com os jovens, oferecendo um horizonte de renovação e de futuro para o carisma da entidade. Para uma entidade centenária, se tornou difícil para os próprios vicentinos incluir seus familiares, sobretudo os próprios filhos, para o trabalho dentro da associação. A análise realizada confirmou a hipótese que realmente a entidade atravessa uma crise sem precedentes e que serão necessárias inovações, aberturas, estratégias e novas pedagogias, se houver interesse em mudar, enfrentar os desafios atuais e renovar a SSVP e seu carisma. Para isso, ela precisará contar com a força e o dinamismo da juventude e de seus membros e dirigentes. A pesquisa realizada no Programa de Pós-graduação em Ciências da Religião da PUC Minas foi desenvolvida na Área de Concentração “Religião e Cultura” e na Linha de Pesquisa “Religião, Política e Educação”. (shrink)

este artigo aborda algumas passagens do prólogo de A condição humana de Hannah Arendt e destaca algumas projeções sobre o futuro. O propósito da investigação é acompanhar a pergunta da autora sobre o que “estamos fazendo”? Este acompanhamento assinala que as realizações científicas daquela época, em meados do século XX, circunscreveram o contexto de fundo da autora. Mas, passados mais de meio século, esta pergunta feita por Arendt motivada pelas realizações científicas, deve ser recolocada em um contexto mais atualizado. O (...) artigo se dedica a esta atualização, para tanto aprofunda as principais preocupações de Arendt com o futuro. A resposta encontrada após o desenvolvimento do texto em duas partes, ainda com o foco na pergunta sobre “o que estamos fazendo?”, reflete as dinâmicas tecnológicas e sociais dos anos mais recentes. De forma mais precisa, a resposta assinala uma preocupante ligação entre a geração de um artificialismo e a “objetividade do mundo”. (shrink)

Why do we not see large macroscopic objects in entangled states? There are two ways to approach this question. The first is dynamic. The coupling of a large object to its environment cause any entanglement to decrease considerably. The second approach, which is discussed in this paper, puts the stress on the difficulty of observeing a large-scale entanglement. As the number of particles n grows we need an ever more precise knowledge of the state and an ever more carefully designed (...) experiment, in order to recognize entanglement. To develop this point we consider a family of observables, called witnesses, which are designed to detect entanglement. A witness W distinguishes all the separable (unentangled) states from some entangled states. If we normalize the witness W to satisfy tr W 1 for all separable states , then the efficiency of W depends on the size of its maximal eigenvalue in absolute value; that is, its operator norm W . It is known that there are witnesses on the space of n qubits for which W is exponential in n. However, we conjecture that for a large majority of n-qubit witnesses W O n log n . Thus, in a nonideal measurement, which includes errors, the largest eigenvalue of a typical witness lies below the threshold of detection. We prove this conjecture for the family of extremal witnesses introduced by Werner and Wolf [Phys. Rev. A 64, 032112 (2001)]. (shrink)

We consider the set of all matrices of the form pij = tr[W (Ei ⊗ Fj)] where Ei, Fj are projections on a Hilbert space H, and W is some state on H ⊗ H. We derive the basic properties of this set, compare it with the classical range of probability, and note how its properties may be related to a geometric measures of entanglement.

According to a prominent view in Jewish-Halakhic literature, “mitzvot (commandments) require intention.” That is, to fulfill one’s obligation in performing a commandment, one must intend to perform the act because it’s a mitzvah; one must take the fact that one’s act is a mitzvah as her reason for doing the action. I argue that thus understood, this Halakhic view faces a revised version of Thomas Hurka’s recent dilemma for structurally similar views in ethics: either it makes it a necessary condition (...) for the act’s being a mitzvah that one has a false belief about the act’s Halakhic status, or it commits proponents of the “mitzvot require intention” view to a sort of rational failure in performing the mitzvot. The dilemma arises, however, only if we interpret this Halakhic view as requiring one to have a belief about her act’s Halakhic status in order for it to have this status. I suggest that the dilemma can be avoided by interpreting the intention requirement as requiring a make-belief, instead of a belief. Under this understanding, Halakha (or God) doesn’t care about why one performs an act of a mitzvah, but rather about how she does it; how she sees and experiences her action. This suggests another form of worship central to Judaism—worship via make-believing. (shrink)

We develop a systematic approach to quantum probability as a theory of rational betting in quantum gambles. In these games of chance, the agent is betting in advance on the outcomes of several (finitely many) incompatible measurements. One of the measurements is subsequently chosen and performed and the money placed on the other measurements is returned to the agent. We show how the rules of rational betting imply all the interesting features of quantum probability, even in such finite gambles. These (...) include the uncertainty principle and the violation of Bell's inequality among others. Quantum gambles are closely related to quantum logic and provide a new semantics for it. We conclude with a philosophical discussion on the interpretation of quantum mechanics. (shrink)

This article deals with the topics of nihilism and technology within the horizon of Western societies. More precisely, we research what is the most determining element in the relationship between nihilism and technology. To develop this research, we seek a concept of nihilism that is integrated into the scenario that emerged after the modern era, therefore integrating not only the 20th century, but also the 21st century. This concept is achieved through consideration of the effects of historicism according to Leo (...) Strauss' analysis in his work Natural Right and History. Next, the issues relating to the control of technology are analyzed and answered through Feenberg's position, which shows different conceptions of what would be considered the philosophy of technology. Finally, the conclusion is that, in the relationship between nihilism and technology, nihilism remains the most determining, because the dimensions specific to historicism still remain integrated and active in the institutions of democratic societies in the 21st century, despite the proposal to invent new institutions made by Feenberg. (shrink)

Semantic priming has long been recognized to reflect, along with automatic semantic mechanisms, the contribution of controlled strategies. However, previous theories of controlled priming were mostly qualitative, lacking common grounds with modern mathematical models of automatic priming based on neural networks. Recently, we introduced a novel attractor network model of automatic semantic priming with latching dynamics. Here, we extend this work to show how the same model can also account for important findings regarding controlled processes. Assuming the rate of semantic (...) transitions in the network can be adapted using simple reinforcement learning, we show how basic findings attributed to controlled processes in priming can be achieved, including their dependency on stimulus onset asynchrony and relatedness proportion and their unique effect on associative, category-exemplar, mediated and backward prime-target relations. We discuss how our mechanism relates to the classic expectancy theory and how it can be further extended in future developments of the model. (shrink)

If p(x 1 ,...,x n ) and q(x 1 ,...,x n ) are two logically equivalent propositions then p(π (x 1 ),...,π (x n )) and q(π (x 1 ),...,π (x n )) are also logically equivalent where π is an arbitrary permutation of the elementary constituents x 1 ,...,x n . In Quantum Logic the invariance of logical equivalences breaks down. It is proved that the distribution rules of classical logic are in fact equivalent to the meta-linguistic rule of (...) universal substitution and that the more restrictive structure of the substitution group of Quantum Logic prevents us from defining truth in a classical fashion. These observations lead to a more profound understanding of the Logic of Quantum Mechanics and of the role that symmetry principles play in that theory. (shrink)

Martin Heidegger’s writings on Hegel are notoriously difficult but show an essential engagement between two of the foundational thinkers of phenomenology. Joseph Arel and Niels Feuerhahn provide a clear and careful translation of Volume 68 of the Complete Works, which is comprised of two shorter texts—a treatise on negativity, and a penetrating reading of Hegel’s Phenomenology of Spirit. In this volume, Heidegger relates his interpretation of Hegel to his own thought on the event, taking up themes developed in Contributions (...) to Philosophy. While many parts of the text are fragmentary in nature, these interpretations are considered some of the most significant as they bring Hegel into Heidegger’s philosophical trajectory. (shrink)

We present a general method for obtaining all Bell inequalities for a given experimental setup. Although the algorithm runs slowly, we apply it to two cases. First, the Greenberger-Horne-Zeilinger setup with three observers each performing one of two possible measurements. Second, the case of two observers each performing one of three possible experiments. In both cases we obtain hundreds of inequalities. Since this is the set of all inequalities, the one that is maximally violated in a given quantum state must (...) be among them. We demonstrate this fact with a few examples. We also note the deep connection between the inequalities and classical logic, and their violation with quantum logic. (shrink)

Two elements of corporate governance—the strength of ethical executive leadership and the internal audit function (IAF hereafter)—provide guidance to accounting managers making decisions involving uncertainty. We examine the joint effect of these two factors, manipulated at two levels (strong, weak), in an experiment in which accounting professionals decide whether to book a questionable journal entry (i.e., a journal entry for which a reasonable business case can be made but there is no supporting documentation). We find that ethical leadership and the (...) IAF interact to determine the likelihood that accountants book the entry. Specifically, accountants are less likely to book a questionable journal entry when there is a weak ethical leader and a strong IAF compared to all other conditions. In addition, we find that accountants question the appropriateness and ethicalness of the request to book an undocumented journal entry more in the weak ethical leader and strong IAF condition than in the other conditions. These results suggest that the IAF has a different impact on financial reporting decisions depending on the ethicalness of executive leadership and that a strong IAF may cause accountants to question the appropriateness and ethicalness of an undocumented journal entry when combined with weak ethical leadership. We also find that the interactive effect of ethical leadership and the IAF on an accountant’s decision is fully mediated by his/her perception of the moral intensity of the issue. Thus, accountants, who perceive greater moral intensity associated with booking the entry, are less willing to do so. (shrink)

Este artigo aborda as definições de objeto técnico conforme a filosofia de Gilbert Simondon, com foco nas críticas à perspectiva antropocêntrica da técnica. Investiga-se se o objeto técnico, na sua demanda por uma cultura técnica e no próprio processo de evolução/concretização, apresenta um caráter não antropocêntrico. Tal apelo não antropocêntrico pode ser evidenciado pelo avanço das técnicas de comunicação e processamento, como observado nos modelos de inteligência artificial da segunda metade do século XXI. O artigo explora esses aspectos do objeto (...) técnico, destacando as contribuições da filosofia de Simondon para a compreensão da realidade tecnológica contemporânea. (shrink)

_Resumo_: este artigo analisa a interpretação de Foucault sobre Kant com o foco na complexidade das relações entre o trabalho filosófico, em geral, e o mundo concreto. O escopo do artigo é delimitado por esta análise de Foucault, especialmente, sobre dois textos de Kant: _O que é o iluminismo? _e _Antropologia de um ponto de vista pragmático_. Investiga-se a possibilidade de um acesso a um espaço anterior a qualquer orientação ética específica, deslocando-se, assim, do conjunto de elaborações éticas da tradição (...) filosófica. Primeiramente, destacam-se os diferentes posicionamentos possíveis assumidos pelos filósofos, em geral, em seu trabalho perante o mundo concreto. A seguir mostra-se a existência de uma ambigüidade latente no trabalho filosófico, a qual permite concluir que há sim um espaço prévio, dentro do qual o filósofo pode ou não compreender a sua situação histórica e o seu lugar no mundo. Todos estes elementos são expostos mediante o acompanhamento da análise realizada por Foucault. (shrink)

More specifically, one notices that X1  X2, P1  P2  0 where X1, X2 are the position operators for the first and second particles respectively, and P1, P2 their momenta operators. This means that, in principle, one can prepare the pair of particles with simultaneously known values of X1  X2 and P1  P2. Then the knowledge of the value of P2 allows to infer the value of P1.(However, performing the experiment with these continuous variables is technically (...) impossible and it remains a thought experiment.). (shrink)

This article is about the conception of “us” or that identifies the set of humans and highlights them ahead others living beings. Thus, a discourse about “us” always needs a base of support and points in a direction. This point implies, even if minimally, a direction of the human being projected in a future. To discuss about this human direction and would verify as its characteristics, in the first section we expose some opinions of philosophy through contributions of Heidegger and (...) Kant. In the second section, the conception of “us” will be analyzed through the most recent phenomena of technical world. The final conclusion points out that the human direction provided by the technology, adapts well to certain characteristics. A possible solution to deal with technological human direction is the involvement of philosophy with certain aspects of the technical world, already available, and to make the promotion of a space for reflection. (shrink)

Resumo : este artigo analisa a apropriação que Agamben faz das concepções heideggerianas de facticidade e Ereignis. Esta apropriação é analisada dentro do escopo da obra Homo Sacer. O desenvolvimento destas duas seções busca responder a seguinte pergunta: como se explica a passagem da ontologia para dentro da filosofia política em Agamben? Para responder esta pergunta, na primeira seção, busca-se compreender uma ampliação possível dos problemas da dominação da técnica. Na segunda seção, estes problemas são submetidos a uma perspectiva biolítica (...) apresentada por Agamben. A resposta mostra que Agamben aproxima as concepções de Heidegger com o tema da indistinção entre poder constituinte e poder constituído, direcionando-se para uma releitura da relação potência e ato com o poder. (shrink)

Esta investigação trata da diferença entre as áreas da filosofia, mas essa diferenciação necessita de uma forma plausível e não dogmática em seu proceder. Para encontrar uma forma de diferenciar cada área interna da filosofia, utilizou-se uma comparação inicial com as ciências e se buscou oprocesso argumentativo como um fator principal de diferenciação. Isso se expressa mais diretamente no problema de pesquisa, que visa a investigar se as diferentes áreas filosóficas também possuem diferentes processos deargumentação. A relevância desta investigação se (...) encontra na identificação de determinadas tensões entre as áreas filosóficas. O resultado mostra que os diferentes conteúdos tratados pelas distintas áreas filosóficas exercem um efeito importante sobre os processos argumentativos. Para fins de delimitação, optou-se por duas áreas da filosofia: a lógica e a ética. (shrink)

Statistical learning is often taken to lie at the heart of many cognitive tasks, including the acquisition of language. One particular task in which probabilistic models have achieved considerable success is the segmentation of speech into words. However, these models have mostly been tested against English data, and as a result little is known about how a statistical learning mechanism copes with input regularities that arise from the structural properties of different languages. This study focuses on statistical word segmentation in (...) Arabic, a Semitic language in which words are built around consonantal roots. We hypothesize that segmentation in such languages is facilitated by tracking consonant distributions independently from intervening vowels. Previous studies have shown that human learners can track consonant probabilities across intervening vowels in artificial languages, but it is unknown to what extent this ability would be beneficial in the segmentation of natural language. We assessed the performance of a Bayesian segmentation model on English and Arabic, comparing consonant-only representations with full representations. In addition, we examined to what extent structurally different proto-lexicons reflect adult language. The results suggest that for a child learning a Semitic language, separating consonants from vowels is beneficial for segmentation. These findings indicate that probabilistic models require appropriate linguistic representations in order to effectively meet the challenges of language acquisition. (shrink)

We argue that the intractable part of the measurement problem -- the 'big' measurement problem -- is a pseudo-problem that depends for its legitimacy on the acceptance of two dogmas. The first dogma is John Bell's assertion that measurement should never be introduced as a primitive process in a fundamental mechanical theory like classical or quantum mechanics, but should always be open to a complete analysis, in principle, of how the individual outcomes come about dynamically. The second dogma is the (...) view that the quantum state has an ontological significance analogous to the significance of the classical state as the 'truthmaker' for propositions about the occurrence and non-occurrence of events, i.e., that the quantum state is a representation of physical reality. We show how both dogmas can be rejected in a realist information-theoretic interpretation of quantum mechanics as an alternative to the Everett interpretation. The Everettian, too, regards the 'big' measurement problem as a pseudo-problem, because the Everettian rejects the assumption that measurements have definite outcomes, in the sense that one particular outcome, as opposed to other possible outcomes, actually occurs in a quantum measurement process. By contrast with the Everettians, we accept that measurements have definite outcomes. By contrast with the Bohmians and the GRW 'collapse' theorists who add structure to the theory and propose dynamical solutions to the 'big' measurement problem, we take the problem to arise from the failure to see the significance of Hilbert space as a new kinematic framework for the physics of an indeterministic universe, in the sense that Hilbert space imposes kinematic objective probabilistic constraints on correlations between events. (shrink)

The intuition guiding the de…nition of computation has shifted over time, a process that is re‡ected in the changing formulations of the Church-Turing thesis. The theory of computation began with logic and gradually moved to the capacity of …nite automata. Consequently, modern computer models rely on general physical principles, with quantum computers representing the extreme case. The paper discusses this development, and the challenges to the Church-Turing thesis in its physical form, in particular, Kieu’s quantum computer and relativistic hyper-computation. Finally, (...) the robustness of the boundary between polynomial and exponential time complexity is considered in connection with quantum computers and quantum information theory. (shrink)

A classical gas at equilibrium satisfies the locality conditionif the correlations between local fluctuations at a pair of remote small regions diminish in the thermodynamic limit. The gas satisfies a strong locality conditionif the local fluctuations at any number of remote locations have no (pair, triple, quadruple....) correlations among them in the thermodynamic limit. We prove that locality is equivalent to a certain factorizability condition on the distribution function. The analogous quantum condition fails in the case of a freeBose gas. (...) Next we prove that strong locality is equivalent to the total factorizability of the distribution function, and thus (given Liourille’s theorem) to the Maxwell Boltzmann distribution for an ideal gas. (shrink)

The distribution function associated with a classical gas at equilibrium is considered. We prove that apart from a factorisable multiplier, the distribution function is fully determined by the correlations among local momenta fluctuations. Using this result we discuss the conditions which enable idealised local observers, who are immersed in the gas and form a part of it, to determine the distribution 'from within'. This analysis sheds light on two views on thermodynamic equilibrium, the 'ergodic' and the 'thermodynamic limit' schools, and (...) the relations between them. It also provides an outline for a new definition of equilibrium that is weaker than full ergodicity. Finally, we briefly discuss the possibility that the distribution can be determined by external observers. (shrink)

Consider the set Q of quantum correlation vectors for two observers, each with two possible binary measurements. Quadric (hyperbolic) inequalities which are satis…ed by every q 2 Q are proved, and equality holds on a two dimensional manifold consisting of the local boxes, and all..