It is often said that planets follow a "straight line" through space time. The argument goes that a star like our sun curves space, and the planets follow this path. The argument is also made that light is bent around suns because of this space curvature.
But here's the question: planets and asteroids and space dust will all follow the same orbit (if at the same distance from the sun) regardless of mass. But light doesn't follow the same path. If we explain both light bending and planet orbitals by "the sun curves space," then what is the mechanism by which masses follow a different curved path than that which light follows?