A Model for Massless Gravity: The Maths that makes Interstellar Drives possible.

This paper presents a model for massless gravity. Stretching of space time via electromagnetic forces actign at discontinuities replaces gravitaitonal mass. A captured half photon model provied a natural mechanism for sampling the Ricci tensor. Charge is an artifict of repeaded temporal reflection of a captured half photon and corresponds to raised potential at the discontinuity. Eisteins field equations are derived from stress in spacetime. Removal for the need of a mass quanta point at continuous creation as the right model for the origin of matter in the universe. It also makes 'reaction massless star drives' achievable.