The author points out what he considers to be some erroneous assumptions in Einstein's theories of relativity. This allowed going beyond these theories in the development of a non-relativistic, unified theory of gravitation and electromagnetism. What causes gravity and establishes the speed of light is described. The possibility of faster than light travel is discussed. Included are new ideas about the structure of atoms, the emission of photons and the interaction of gravity with atoms and photons. Also presented is the part played by gravity in the formation of black holes, the Big Bang, the expanding Universe and dark matter. A structure of the Cosmos is described that could lead to future Big Bangs.