In 1885, during initial discussions of J. C. Maxwell's celebrated thermodynamic demon, Whiting(1) observed that the demon-like velocity selection of molecules can occur in a gravitationally bound gas. Recently, a gravitational Maxwell demon has been proposed which makes use of this observation [D. P. Sheehan, J. Glick, and J. D. Means, Found. Phys. 30, 1227 (2000)]. Here we report on numerical simulations that detail its microscopic phase space structure. Results verify the previously hypothesized mechanism of its paradoxical behavior. (...) This system appears to be the only example of a fully classical mechanical Maxwell demon that has not been resolved in favor of the second law of thermodynamics. (shrink)

Ontologies have been successfully used to assign semantics in the Semantic Web context, to support integration of data from different systems or different sources, and to enable reasoning. However, building ontologies is not a trivial task. Ontology reuse can help in this matter. The search and selection of ontologies to be reused should consider the alignment between their scope and the scope of the ontology being developed. In this paper, we discuss how goal modeling can be helpful in this context (...) and we present GO-FOR, a framework in which goals are the central elements to promote ontology reuse. GO-FOR comprises a conceptual architecture, a goal-oriented ontology development process and a supporting tool. In GO-FOR we introduce Goal-Oriented Ontology Patterns as a new type of pattern to be applied to develop ontologies in a goal-oriented approach. Results of the use of GO-FOR to build an ontology used to integrate patient examination data are also shown in this paper. (shrink)

REMARKS ON EVOLUTION AND TIME-SCALES, Graham Cairns-Smith; HODGSON'S BLACK BOX, Thomas Clark; DO HODGSON'S PROPOSITIONS UNIQUELY CHARACTERIZE FREE WILL?, Ravi Gomatam; WHAT SHOULD WE RETAIN FROM A PLAIN PERSON'S CONCEPT OF FREE WILL?, Gilberto Gomes; ISOLATING DISPARATE CHALLENGES TO HODGSON'S ACCOUNT OF FREE WILL, Liberty Jaswal; FREE AGENCY AND LAWS OF NATURE, Robert Kane; SCIENCE VERSUS REALIZATION OF VALUE, NOT DETERMINISM VERSUS CHOICE, Nicholas Maxwell; COMMENTS ON HODGSON, J.J.C. Smart; THE VIEW FROM WITHIN, Sean Spence; COMMENTARY ON HODGSON, Henry (...) Stapp. (shrink)

© 2017. The American Astronomical Society. All rights reserved.We present new observations of the low-mass companion to HD 984 taken with the Gemini Planet Imager as a part of the GPI Exoplanet Survey campaign. Images of HD 984 B were obtained in the J and H bands. Combined with archival epochs from 2012 and 2014, we fit the first orbit to the companion to find an 18 au orbit with a 68% confidence interval between 14 and 28 au, an eccentricity (...) of 0.18 with a 68% confidence interval between 0.05 and 0.47, and an inclination of 119°with a 68% confidence interval between 114°and 125°. To address the considerable spectral covariance in both spectra, we present a method of splitting the spectra into low and high frequencies to analyze the spectral structure at different spatial frequencies with the proper spectral noise correlation. Using the split spectra, we compare them to known spectral types using field brown dwarf and low-mass star spectra and find a best-fit match of a field gravity M6.5 ±1.5 spectral type with a corresponding temperature of K. Photometry of the companion yields a luminosity of log=2.88 ± 0.07 dex with DUSTY models. Mass estimates, again from DUSTY models, find an age-dependent mass of 34 ±1 to 95 ±4 M Jup. These results are consistent with previous measurements of the object. (shrink)

as Denniston pointed out in his note on the passage, ‘is difficult’. Various suggestions have been made to explain it, from Kvicala's emendation on the analogy of Medea 923, to Parmentier's note, ‘la joue blanche ou claire, c'est-à-dire en sa fleur de jeunesse’; but none is altogether convincing or satisfactory. May one, then, advance the idea of retaining as the Oxford recension does, not on the ground of faute de mieux, but for the sake of the very striking image it (...) contains? How to Cite This Article. (shrink)

"Neuroscience and Philosophy" begins with an excerpt from "Philosophical Foundations of Neuroscience," in which Maxwell Bennett and Peter Hacker question the ...

The requirement of gauge invariance for the Schwinger-DeWitt equations, interpreted as a manifestly covariant quantum theory for the evolution of a system in spacetime, implies the existence of a five-dimensional pre-Maxwell field on the manifold of spacetime and “proper time” τ. The Maxwell theory is contained in this theory; integration of the field equations over τ restores the Maxwell equations with the usual interpretation of the sources. Following Schwinger's techniques, we study the Green's functions for the five-dimensional (...) hyperbolic field equations for both signatures ± [corresponding to O(4, 1) or O(3, 2) symmetry of the field equations] of the proper time derivative. The classification of the Green's functions follows that of the four-dimensional theory for “massive” fields, for which the “mass” squared may be positive or negative, respectively. The Green's functions for the five-dimensional field are then given by the Fourier transform over the “mass” parameter. We derive the Green's functions corresponding to the principal part ΔP and the homogeneous function Δ 1 ; all of the Green's functions can be expressed in terms of these, as for the usual field equations with definite mass. In the O(3, 2) case, the principal part function has support for x2⩾τ2, corresponding to spacelike propagation, as well as along the light cone x2=0 (for τ=0). There can be no transmission ofinformation in spacelike directions, with this propagator, since the Maxwell field, obtained by integration over τ, does not contain this component of the support. Measurements are characterized by such an integration. The spacelike field therefore can dynamically establish spacelike correlations. (shrink)

The contemporary view of the fundamental role of time in physics generally ignores its most obvious characteric, namely its flow. Studies in the foundations of relativistic mechanics during the past decade have shown that the dynamical evolution of a system can be treated in a manifestly covariant way, in terms of the solution of a system of canonical Hamilton type equations, by considering the space-time coordinates and momenta ofevents as its fundamental description. The evolution of the events, as functions of (...) a universal invariant world, or historical, time, traces out the world lines that represent the phenomena (e.g., particles) which are observed in the laboratory. The positions in time of each of the events, i.e., the time of their potential detection, are, in this framework, controlled by this universal parameter τ, the time at which they are generated (and may proceed in the positive or negative sense). We find that the notion of thestate of a system requires generalization; at any given τ, it involves information about the system at timest(τ) ≠ τ. The correlation of what may be measured att(τ) with what is generated at τ is necessarily quite rigid, and is related covariantly to the spacelike correlations found in interference experiments. We find, furthermore, that interaction with Maxwell electromagnetism leads back to a static picture of the world, with no real evolution. As a consequence of this result, and the requirement of gauge invariance for the quantum mechanical evolution equation, we conclude that electromagnetism is described by a pre-Maxwell field, whose τ-integral (or asymptotic behavior as τ → ∞) may be identified with the Maxwell field. We therefore consider the world of events in space time, interacting through τ-dependent pre-Maxwell fields, as far as electrodynamics is concerned, as the objective dynamical reality. Our perception of the world, through laboratory detectors and our eyes, are based onintegration over τ over intervals sufficiently large to obtain an aposteriori description of the phenomena which coincides with the Maxwell theory. Fundamental notions, such as the conservation of charge, rest on this construction. The decomposition of the common notion of time into two essentially different aspects, one associated with an unvarying flow, and the second with direct observation subject to dynamical modification, has profound philosophical consequences, of which we are able to explore here only a few. (shrink)

We give an example in which it is possible to understand quantum statistics using classical concepts. This is done by studying the interaction of chargedmatter oscillators with the thermal and zeropoint electromagnetic fields characteristic of quantum electrodynamics and classical stochastic electrodynamics. Planck's formula for the spectral distribution and the elements of energy hw are interpreted without resorting to discontinuities. We also show the aspects in which our model calculation complement other derivations of blackbody radiation spectrum without quantum assumptions.

In 1885, during initial discussions of J. C. Maxwell's celebrated thermodynamic demon, Whiting (1) observed that the demon-like velocity selection of molecules can occur in a gravitationally bound gas. Recently, a gravitational Maxwell demon has been proposed which makes use of this observation [D. P. Sheehan, J. Glick, and J. D. Means, Found. Phys. 30, 1227 (2000)]. Here we report on numerical simulations that detail its microscopic phase space structure. Results verify the previously hypothesized mechanism of its paradoxical (...) behavior. This system appears to be the only example of a fully classical mechanical Maxwell demon that has not been resolved in favor of the second law of thermodynamics. (shrink)

There have been many claims that quantum mechanics plays a key role in the origin and/or operation of biological organisms, beyond merely providing the basis for the shapes and sizes of biological molecules and their chemical affinities. These range from Schr¨odinger’s suggestion that quantum fluctuations produce mutations, to Hameroff and Penrose’s conjecture that quantum coherence in microtubules is linked to consciousness. I review some of these claims in this paper, and discuss the serious problem of decoherence. I advance some further (...) conjectures about quantum information processing in bio-systems. Some possible experiments are suggested. © 2004 Elsevier Ireland Ltd. All rights reserved. (shrink)

Institute of Theoretical Astronomy, University of Cambridge, Cambridge, UK 3fS. received 28th August 1970, in final revised form 1st July 1971..

An inquiry into the nature of the universe draws out the implications of the quantum theory and argues that our universe is only one among many possible universes and that other universes may exist.

The author is primarily concerned with the explanation of behavior in regard to (1) the mecanical model, (2) the effects of physical-organic processes on behavior, (3) the lack of understanding between philosophers and psychologists as to sufficient conditions for predicting a behavioral event, (4) conditions leading to expalantions of behavior that could predict behavior exclusive of any antecedent psychological behavior, and (5) variations of the mechanical-model introducing differing sorts of explanation. (staff).

Recent advances in string theory and inflationary cosmology have led to a surge of interest in the possible existence of an ensemble of cosmic regions, or “universes”, among the members of which key physical parameters, such as the masses of elementary particles and the coupling constants, might assume different values. The observed values in our cosmic region are then attributed to an observer selection effect (the so-called anthropic principle). The assemblage of universes has been dubbed “the multiverse”. In this paper (...) we review the multiverse concept and the criticisms that have been advanced against it on both scientific and philosophical grounds. (shrink)

Given a physical system, one knows that there is a logical duality between its properties and its states. In this paper, we choose its states as the undefined notions of our axiomatic construction. In fact, by means of well-motivated assumptions expressed in terms of a transition probability function defined on the set of all pure states of the system, we construct a system of elementary propositions, i.e., a complete orthomodular atomic lattice satisfying the covering law. We also study in this (...) framework the important notion of compatibility of propositions, and we define the superpositions and the mixtures of the states of the physical system. (shrink)

An instrument to assess 'ethical sensitivity' has been developed. The instrument presents four clinical vignettes and the respondent is asked to list the ethical issues related to each vignette. The responses are classified, post hoc, into the domains of autonomy, beneficence and justice. This instrument was used in 1990 to assess the ethical sensitivity of students in all four medical classes at the University of Toronto. Ethical sensitivity, as measured by this instrument, is not related to age or grade-point average. (...) Sensitivity increases between the 1st and 2nd year and then decreases throughout the rest of undergraduate medical training, such that the 4th-year students identify fewer issues than those entering medical school. Students expressing a career choice of family medicine identify more issues than their peers. Several problems with the use of the instrument and the interpretation of the data were found. Nonetheless, these findings, if reproducible, are important and their meaning needs further discussion. (shrink)

In this sweeping survey, acclaimed science writers Paul Davies and John Gribbin provide a complete overview of advances in the study of physics that have revolutionized modern science. From the weird world of quarks and the theory of relativity to the latest ideas about the birth of the cosmos, the authors find evidence for a massive paradigm shift. Developments in the studies of black holes, cosmic strings, solitons, and chaos theory challenge commonsense concepts of space, time, and matter, and demand (...) a radically altered and more fully unified view of the universe. (shrink)

Paperback reissue of a book first published in 1991. The authors demonstrate how the materialistic and mechanistic world-view that has dominated western culture and science during the last few centuries is being challenged by the findings of modern physics, ranging from relativity to quantum physics. Includes a bibliography and an index. British-born, Davies is a well-known physicist and has written many other books including 'The Mind of God', winner of the 1992 Eureka Science Book Prize. He is currently professor of (...) mathematical physics at the University of Adelaide. Gribbin trained as an astrophysicist and is now a full-time science writer in Britain. (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.

It is widely accepted that EinstcinRi7;s general theory of relativity is an satisfactory description of gravity 0nly in the macroscopic limit, where quantum eiTcc1;s may be neglected. Presumably this theory is inapplicable at the Planck length, but recently much attention has been devoted to gravitational theory at intermediate length scales where quantum affects 0f matter are inescapable, but where there is an general assumption that the gravitational Held may bc treated as a classical background, augmented if necessary by quamtizcd linearized (...) pertur-. (shrink)

Aim To study the views of people in a largely Muslim country, Kuwait, of the acceptability of a life-ending action such as physician-assisted suicide (PAS). Method 330 Kuwaiti university students judged the acceptability of PAS in 36 scenarios composed of all combinations of four factors: the patient's age (35, 60 or 85 years); the level of incurability of the illness (completely incurable vs extremely difficult to cure); the type of suffering (extreme physical pain or complete dependence) and the extent to (...) which the patient requests a life-ending procedure, euthanasia or PAS (no request, some form of request, repeated requests). In all scenarios, the patients were women who were receiving the best possible care. The ratings were subjected to cluster analysis and analyses of variance. Results Five clusters were found. For 44%, PAS was always very unacceptable, no matter what the circumstances. For 23%, it was unacceptable, but less so if the patient was older or requested it repeatedly. For 16%, it was unacceptable if the patient was young but was acceptable if the patient was elderly. For 5%, it was unacceptable if the patient had extreme pain but was acceptable if completely dependent. For 11%, it was unacceptable if the patient did not request it but acceptable if she did. Conclusion The majority of the Kuwaiti university students opposed PAS either categorically or with a slight variation according to circumstances. Nonetheless, a minority approved of PAS in some cases, particularly when the patient was elderly. (shrink)