In this paper we study in details a system of two weakly coupled harmonic oscillators from the point of view of Bohm’s interpretation of quantum mechanics. This system may be viewed as a simple model for the interaction between a photon and a photodetector. We obtain exact solutions for the general case. We then compute approximate solutions for the case where one oscillator is initially in its first excited state (a single photon) reaching the other oscillator in its ground state (...) (the photodetector). The approximate solutions represent the state of both oscillators after the interaction, which is not an eigenstate of the individual hamiltonians for each oscillator, and therefore the energies for each oscillator do not exist in the Copenhagen interpretation of Quantum Mechanics. We use the approximate solutions that we obtained to compute Bohmian trajectories and to study the energy transfer between the oscillators. We conclude that, even using the Bohmian view, the energy of each individual oscillator is not well defined, as the nonlocal quantum potential is not negligible even after the coupling is turned off. (shrink)

The main current application of placebo is in clinical research. The term placebo effect refers to diverse non-specific, desired or non-desired effects of substances or procedures and interactions between patient and therapist. Unpredictability of the placebo effect necessitates placebo-controlled designs for most trials. Therapeutic and diagnostic use of placebo is ethically acceptable only in few well-defined cases. While "therapeutic" application of placebo almost invariably implies deception, this is not the case for its use in research. Conflicts may exist between the (...) therapist's Hippocratic and scientific obligations. The authors provide examples in neuropsychiatry, illustrating that objective scientific data and well-considered guidelines may solve the ethical dilemma. Placebo control might even be considered an ethical obligation but some provisos should be kept in mind: (a) no adequate therapy for the disease should exist and/or (presumed) active therapy should have serious side-effects; (b) placebo treatment should not last too long; (c) placebo treatment should not inflict unacceptable risks, and (d) the experimental subject should be adequately informed and informed consent given. (shrink)

In this paper we study in details a system of two weakly coupled harmonic oscillators from the point of view of Bohm's interpretation of quantum mechanics. This system may be viewed as a simple model for the interaction between a photon and a photodetector. We obtain exact solutions for the general case. We then compute approximate solutions for the case where one oscillator is initially in its first excited state (a single photon) reaching the other oscillator in its ground state (...) (the photodetector). The approximate solutions represent the state of both oscillators after the interaction, which is not an eigenstate of the individual hamiltonians for each oscillator, and therefore the energies for each oscillator do not exist in the Copenhagen interpretation of Quantum Mechanics. We use the approximate solutions that we obtained to compute Bohmian trajectories and to study the energy transfer between the oscillators. We conclude that, even using the Bohmian view, the energy of each individual oscillator is not well defined, as the nonlocal quantum potential is not negligible even after the coupling is turned off. (shrink)

Notions of purity, perfection, or immaculateness have powered our imagination over the ages. Various images of perfection have held sway in their hallowed times, providing secure streams for channelling human energy. Unfortunately, with the unfolding of the human drama on the world stage, all the images of perfection have suffered damage, epoch on epoch. Different responses have emerged to attempt a restoration. Revival of some of the old images is one such response. Production of new images to serve as worthwhile (...) anchors of value and meaning is another common response. For reasons possibly known only to philosophers and historians, the enterprise called modern science has got thickly embroiled in this civilisational process--first, as the culprit behind the decline of some of the established images, then as the producer of new images, and now, perhaps, as a constant reminder of the perpetual lack of purity and immaculateness in all things human. (shrink)

Here are the 18 guidance points contained in the UNAIDS document on Ethical Considerations in HIV Preventive Vaccine Research, reproduced by kind permission of the Joint United Nations Programme on HIV/AIDS.

It was shown by de Broglie and Bohm that the concept of a deterministic particle trajectory is compatible with quantum mechanics. It is demonstrated by explicit construction that there exists another more general deterministic trajectory interpretation. The method exploits an internal angular degree of freedom that is implicit in the Schrödinger equation, in addition to the particle position. The de Broglie-Bohm model is recovered when the new theory is averaged over the internal freedom. The model exhibits a strong form of (...) entanglement which implies a primary role for the wavefunction of the Universe. The conditions of autonomy are examined, and the viability of the theory is established by application to the measurement problem. (shrink)

We discuss the application of the de Broglie-Bohm theory of relativistic spin-1/2 particles to the Klein paradox andzitterbewegung.

The geometrical structures implicit in the de Broglie waves associated with a relativistic charged scalar quantum mechanical particle in an external field are analyzed by employing the ray concept of the causal interpretation. It is shown how an osculating Finslerian metric tensor, a torsion tensor, and a tetrad field define respectively the strain, the dislocation density, and the Burgers vector in the “natural state” of the wave, which is a non-Riemannian space of distant parallelism. A quantum torque determined by the (...) quantum potential is introduced and the example of a screw dislocated wave is discussed. (shrink)

In his discussion of Virgilian imitations of Lucretian phraseology Cyril Bailey examines the phenomenon of what he terms the ‘doublet’, that is, the procedure whereby Virgil imitates separate elements of a Lucretian phrase at different points in his own work. Take, for example, De Rerum Natura 1. 210–12: esse videlicet in terris primordia rerum, quae nos fecundas vertentes vomere glebas terraique solum subigentes cimus ad ortus.

The Bell–Kochen–Specker theorem shows that, in any Hilbert space of dimension of at least 3, it is impossible to assign noncontextual definite values to all observables in such a way that the quantum-mechanical predictions are reproduced. This leaves open the issue of what subsets of observables may be assigned definite values. Clifton has shown that, for a system of at least two continuous degrees of freedom, it is not possible to assign simultaneous noncontextual values to two coordinates and their conjugate (...) momenta. In this Letter, it is shown that, for a system of a single continuous degree of freedom, it is not possible to assign noncontextual values to the coordinate and its conjugate momenta that satisfy a continuity assumption herein called the ‘ -Product Rule’.  2002 Elsevier Science B.V. All rights reserved. (shrink)