Retarded Gravitation Theory

TL;DR

This paper introduces a Lorentz-covariant retarded gravity theory that explains spacecraft anomalies and galaxy rotation curves without dark matter, and suggests new laboratory tests for gravity.

Contribution

It presents a novel retarded gravitational theory based on time-asymmetric equations, linking gravity to velocity and retarded positions, with potential explanations for astrophysical phenomena.

Findings

Explains flyby anomalies as v/c effects due to Earth's rotation.

Suggests velocity drag in RGT accounts for galaxy rotation curves.

Proposes laboratory tests to validate or refute RGT.

Abstract

We propose a Lorentz-covariant theory of gravity, and explain its theoretical origins in the problem of time in Newtonian physics. In this retarded gravitation theory (RGT), the gravitational force depends upon both retarded position and velocity, and the equations of motion are time-asymmetric retarded functional differential equations. We explicitly solve these equations, under simplifying assumptions, for various NASA spacecraft. This shows that the differences from Newtonian gravity, though tiny within the solar system, are just appropriate to explain the flyby anomaly as a v/c effect due to earth's rotation. The differences can, however, be large in the case of a spiral galaxy, and we show that the combined velocity drag from a large number of co-rotating stars enormously speeds up a test particle. Thus, the non-Newtonian behaviour of rotation curves in a spiral galaxy may be explained as being due to velocity drag rather than dark matter. RGT can also be tested in the laboratory. It necessitates a reappraisal of current laboratory methods of determining the Newtonian gravitational constant G. Since RGT makes no speculative assumptions, its refutation would have serious implications across physics.