The assumption of identity of properties of a body stationary in a gravitational field and of a body falling under an inverse square law of attraction, previously used to account for optical phenomena, is applied to dynamical phenomena by the extension of the same assumption to mass. Force equations corresponding to the gravitational mass <i>m</i><sub>0</sub>/(γ-<i>r</i>˙<sup>2</sup>/<i>c</i><sup>2</sup>γ-r<sup>2</sup>θ<sup>2</sup>/<i>c</i><sup>2</sup>)<sup>½</sup> are derived, which when solved for a planetary orbit, give the observed advance of perihelion of Mercury.
HERBERT E. IVES, "The Behavior of an Interferometer in a Gravitational Field. II. Application to a Planetary Orbit," J. Opt. Soc. Am. 38, 413-416 (1948)