On Sun, Jan 28, 2018 at 12:32 PM, <mix...@bigpond.com> wrote: ...which would make sense if light simply followed the curvature of space. >
The curvature of spacetime is perhaps an abstraction that gets in the way of understanding in this instance. It is equivalent to the gravitational influence of two or more bodies on one another. Having a massive body be able to tug on a photon, while the photon does not tug on the massive body in the opposite direction, reminds me vaguely of a description of a rowboat with oars, where the rower is somehow able to use the oars to push the boat forward, while the water is not pushed in the opposite direction. I suspect that if one ponders the suggestion of light not having "gravitational mass" long enough, it should be possible to come up with an experiment that will demonstrate a violation of conservation of momentum. Eric
