Gravitational Relativity

The Gravitational Equations are a topological
system that describe the properties of spacetime
and the mass-energy (E = mc^2) within it.
Consider the following: spacetime tells mass how
to move, and mass tells spacetime how to curve.
This can explain why the speed of light (or of
any massless particle) in a vacuum is the same
for all observers, regardless of their relative
motion or the motion of the source of light.