Newtonian gravity is reviewed and an attempt is made to combine it with special relativity, first by expanding the sources from mass to more general mass-energy, and then by considering relativistic force predictions. The gravito-electro-magnetic field equations are developed by analogy with Maxwell’s equations, and using dynamical source configurations familiar from the study of E&M. In addition to the fields, there are predicted particle interactions, like the bending of light, that go beyong Newtonain gravitational forces. Finally, it is clear that this attempt to combine gravity and special relativity lacks the necessary self-coupling of the gravitational field, which carries energy and therefore acts as its own source.

Geodesics are introduced and the geodesic equation analysed for the geometries introduced in chapter 2, using variation principles of classical mechanics. Geodesic motino on a sphere is described as well as the Coriolis effect and the Sagnac effect. Newtonian gravity is derived as the non-relativistic limit of geodesic motion in space-time. Geodesics in an expanding universe and heat death is described. Geodesics in Schwarzschild space-time are treated in detail: the precession of the perihelion of Mercury; the bending of light by the Sun; Shapiro time delay; black holes and the event horizon. Gravitational waves and gravitational lensing are also covered.

Newton's Universal Law of Gravitation is compared and contrasted to Coulomb’s Law and the differences highlighted. Tides are discussed, and the Equivalence Principle and how it leads to the notion of curved space-times is explained.

This chapter discusses the geometry of space and the notion of time assumed in Newtonian mechanics. This discussion will also serve to review aspects of mechanics and special relativity that will be important for later developments. Newtonian mechanics assumes a geometry for space and a particular idea for time. The laws of Newtonian mechanics take their standard and simplest forms in inertial frames. Using the laws of mechanics, an observer in an inertial frame can construct a clock that measures the time. Coordinate transformations can make the connection between different inertial frames. Newtonian mechanics assumes there is a single notion of time for all inertial observers. We explore Newtonian gravity and the Principle of Relativity: that identical experiments carried out in different inertial frames give identical results.