Gravity and electromagnetism at the sub-atomic level are reduced to straightforward dynamics/kinetics and use the same mechanism to derive both Newton's law of gravitation and Coulomb's law for electrostatics. Weak and strong interactions are also considered. Sub-atomic particles are all treated as speed of light particles which are either free, for example photons or confined, for example electrons (confined by boson vacuum pressure) and quarks (confined by boson pressure within their hadron). Confinement follows from an extension to Einstein's 1906 thought experiment on trapped radiation to deduce the mass/energy equation. Fixed angular momentum gives the relationship between mass/frequency and radius of orbit that control the outward centrifugal and containing centripetal forces that yield the gravitational and electrostatic force laws. Implications for gravity and cosmology include orbit orientation, boson blocking and expansion of the universe.