An Electromagnetic Theory of Gravitation

An Electromagnetic Theory of Gravitation.—An electric system in a medium whose specific inductive capacity $k$ varies from point to point tends to move in the direction of increasing $k$. It is suggested that if we assume the specific inductive capacity of the ether to vary near matter, gravitation may be explained as a result of this tendency. In a medium in which at a distance $r$ from a mass $m$, $k=\mathrm{I}+\frac{m}{r}$, it is shown that a rigid electrostatic system would be acted on by a force directed toward $m$ and equal to $\frac{m{m}^{\prime }}{r^2}$, where $m^{\prime }$ in the electromagnetic mass of the system. But in order to explain the observed deflection of light by the sun we must have $k=\mathrm{I}+\frac{2m}{r}$; and this will not give the force $\frac{m{m}^{\prime }}{r^2}$ unless the system contracts in the ratio of $\mathrm{I}:\mathrm{I}-\frac{m}{r}$. A physical explanation of this assumed contraction is suggested. If the system with the mass $m^{\prime }$ is also supposed to modify $k$, it is necessary to take into account the energy changes in $m$ and in the ether. The effect of gravitation on the frequency of the light emitted by an atom, which was predicted by Einstein, can be easily deduced from the present theory.