According to the preprint by the same author titled "1887 Michelson-Morley experiment: a new analysis with computer assistance" (https://doi.org/10.31219/osf.io/27nxu), the M-M experiment is suggested to be concluded as delivering no result instead of reporting a null result. This means Newton's conception of absolute space may still be a valid proposal for advancement of physics.With this recognition of the 1887 Michelson-Morley experiment, I combined Einstein's idea of finite speed gravity with Newton's conception of absolute space, by which the two meliorated gravity models were established. In these models, two gravitating objects alternately play their role as the source or the target mass of the working gravitational field, so that the doctrine of the field theory—“gravity effective only when its field reaches its target by traveling at finite speed” could be applied to each of the said models. Since there should be no reason for real space, i.e., absolute space, making the instantaneous output of a gravitational field elongate longer or shorter in certain radial directions than the rest, it is logical that the radial speed of a gravitational field should be definite and consistent with the absolute space.By using this supplementary assumption to the field theory of gravity, the fluctuation of gravity and the meliorated radar wave measurement were mathematically derived, and the elliptical orbits of planets with their changes in precession were tentatively explained.