Van der Waals Interactions of Moving Particles with Surfaces of Cylindrical Geometry

General nonrelativistic theory has been developed and the expressions obtained for the tangential (dissipative) and radial (conservative) image forces and van der Waals forces (vdW) acting on charged and neutral particles when they move parallel to the axis of a cylinder with circular cross-section, or in the space between coaxial cylinders. Numerical calculations of vdW forces have been performed for metal (Au) and dielectric (Si) materials of cylinders (filaments) and Cs atoms at velocities ~107m/s. A remarkable result is that in the case of metal cylinders (atomic filaments and chains) the dynamic vdW potential can be repulsive for certain values of the velocity–distance parameter and the characteristic atomic frequency. In the case of a Si material, the dynamic vdW potential increases relative to the static one (by modulus) when the velocity–distance parameter Vω0/R changes from zero to ~1.3 and then tends to zero.

Quantum gravity for dummies

Dirac noted in his first paper on quantum electrodynamics [Proc. Roy. Soc. A 114, 243 (1927)] that, “The theory is non-relativistic only on account of the time being counted throughout as a c-number [classically], instead of being treated symmetrically with the space coordinates.” His suggestion for a relativistic theory of quantum mechanics is carried out here by describing the atom in configuration space as the action integral of a Lagrangian. Atomic structure is described with discrete coordinates in Minkowski space, while the atom itself resides in the curved space-time continuum of the gravitational field, the background space of quantum gravity. Although it does not meet the more ambitious goals of a string theory or loop quantum gravity, it is the first successful theory. In other words, it is the first theory to describe how gravitational fields interact with quanta at the microscopic level. This paper is dedicated to the thousands of theoretical physicists who have defended nonrelativistic theory since its inception in 1926 without questioning its limitations even as it lost touch with reality and became ever more difficult to believe.

A historical perspective on modified Newtonian dynamics

I review the history and development of modified Newtonian dynamics (MOND) beginning with the phenomenological basis as it existed in the early 1980s. I consider Milgrom’s papers of 1983 introducing the idea and its consequences for galaxies and galaxy groups, as well as the initial reactions, both negative and positive. The early criticisms were primarily on matters of principle, such as the absence of conservation laws and perceived cosmological problems; an important step in addressing these issues was the development of the Lagrangian-based nonrelativistic theory of Bekenstein and Milgrom. This theory led to the development of a tentative relativistic theory that formed the basis for later multifield theories of gravity. On an empirical level the predictive success of the idea with respect to the phenomenology of galaxies presents considerable challenges for cold dark matter. For MOND the essential challenge remains the absence of a generally accepted theoretical underpinning of the idea and, thus, cosmological predictions. I briefly review recent progress in this direction. Finally I discuss the role and sociology of unconventional ideas in astronomy in the presence of a strongly entrenched standard paradigm.

ENTROPIC-GRAVITY DERIVATION OF MOND

A heuristic entropic-gravity derivation has previously been given of the gravitational two-body force of modified Newtonian dynamics (MOND). Here, it is shown that another characteristic of MOND can also be recovered, namely, the external field effect (implying a violation of the Strong Equivalence Principle). In fact, the derivation gives precisely the modified Poisson equation which Bekenstein and Milgrom proposed as a consistent nonrelativistic theory of MOND.

CASIMIR PRESSURE IN MDS-STRUCTURES

The Casimir pressure on the dielectric layer in metal-dielectric-semiconductor (MDS) structures is calculated in the framework of the Lifshitz theory at nonzero temperature. In this calculation the standard parameters of semiconductor devices with a thin dielectric layer are used. We consider the thickness of a layer decreasing from 40 to 1 nm. At the shortest thickness the Casimir pressure achieves 8 MPa. At small thicknesses the results are compared with the predictions of nonrelativistic theory.