Abstract

Einstein gives three predictions to support general relativity. However, the Einstein equation, which was first derived by Hilbert, has not been accurately confirmed beyond what the Maxwell-Newton Approximation can do. The gravitational redshifts, the bending light, and radar echo delay can be obtained from the Maxwell-Newton Approximation derived from Einstein's equivalence principle. As Gullstrand suspected, it is proven that there is no dynamic solution and thus the perihelion of Mercury cannot be derived from the Einstein equation. Moreover, the Hulse-Taylor experiment of binary pulsars actually supports a modified Einstein equation. So far, the only exception is the derivation of the metric for a charged particle because the electromagnetic energy-stress tensor is involved. It has been shown that this metric implies a repulsive force mq²/r³ between a charge q and a mass m, separated with a distance r. Thus, the experimental confirmation of this neutral force provides the only case to verify the static Einstein equation. Although it has been shown experimentally that a metal ball becomes lighter after charged with electrons, more detailed data are needed to confirm the repulsive force and distinguish its formula from claims of other theories.