Using a model quantum clock, I show how the velocity of a relativistic particle can be measured. The results are used to analyse the long-standing problem of the velocity..

L'article explore le sens que peut avoir le symbole du Règne de Dieu aujourd'hui dans le contexte asiatique. Après une courte histoire du symbole, l'article présente six défis que l'Asie pose à son usage en un discours théologique en contexte asiatique. La seconde partie passe en revue l'usage fait du symbole du Règne de Dieu par certains théologiens asiatiques contemporains: les théologiens Tissa Balasuriya et Aloysius Pieris du Sri Lanka, les théologiens Coréens du minjung, et le théologien presbytérien du Taiwan (...) Choan-Seng Song. En se basant sur les oeuvres de ces théologiens et à la suite de la théologie de la libération, la dernière partie essaie de montrer comment les six défis posés plus tôt peuvent être résolus dans la perspective de la philosophie confucianiste. (shrink)

Using a model quantum clock, I evaluate an expression for the time of a nonrelativistic quantum particle to transit a piecewise geodesic path in a background gravitational field with small spacetime curvature (gravity gradient), in the case that the apparatus is in free fall. This calculation complements and extends an earlier one (Davies 2004) in which the apparatus is fixed to the surface of the Earth. The result confirms that, for particle velocities not too low, the quantum and classical transit (...) times coincide, in conformity with the principle of equivalence. I also calculate the quantum corrections to the transit time when the de Broglie wavelengths are long enough to probe the spacetime curvature. The results are compared with the calculation of Chiao and Speliotopoulos (2003), who propose an experiment to measure the foregoing effects. (shrink)

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).

Inconsistencies in the usual interpretation of the absorber theory of radiation are exposed which invalidate an experiment proposed recently by Heron and Pegg. An earlier experiment by Partridge necessarily gave a null result owing to absorption on the far side of the Earth of any advanced radiation which may have been present.

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)

The fine structure constant α ≡ e2/ c ≈ 1/137 is one of the fundamental parameters of the standard model of particle physics. There is a long history of attempts to derive the measured value of α from an underlying theory, or exhibit it in the form of a compact mathematical expression [2–4, 6, 8, 14–16]. The most significant advance in this endeavour was made by Dirac, who showed that if magnetic monopoles exist, with magnetic charge μ, then..

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.