Abstract

The dependence of the frequency shift of photons on the cosine of the angle made with a gravitational field is an approximation because of the fact that the photon's trajectory changes such as to bring the photon closer to the mass as it passes. Therefore it dives up out of a slightly deeper well than it dived down into upon passing a mass. Therefore the red shift leaving will be slightly greater than the blue shift approaching. It follows that photons should have a slight residual red shift upon passing those masses in space that are either stationary, moving parallel to, or moving toward the trajectory. This shift is proposed as the main cause of the cosmological red shift since masses moving away from the trajectory should be a minority.