Gravitoelectrodynamics

Abstract

The hybrid term of gravitoelectrodynamics has appeared in the literature quite recently, after the missions of Pioneer-10 and Pioneer-11 (and Voyager1 and 2 some time later) investigated the spatial distributions and time behavior of micron and submicron-size grains in the interplanetary medium. The dynamical patterns of such particles suggested the action of electromagnetic forces along with gravitation. In fact, that was something to be expected as dust grains in space are virtually always electrically charged, while the space is filled with electric and/or magnetic fields. Traditionally, it was believed that the spheres of prevailing influence of the gravitational or electromagnetic forces could be easily demarcated. The motion of large celestial bodies was assumed to be governed by forces of gravitation, while trajectories of charged microparticles (i.e. electrons and ions) were controlled by electromagnetic fields. This is certainly true, but the situation is different with electrically charged macroscopic particles of micron or submicron size for which the forces of the two kinds are equipotent, such that the introduction of the new term is justified. Curiously enough, this is a rare case where the linguistic process of term formation can be traced back. First, two distinct terms were used in the literature, i.e. gravitation and electrodynamics.