H Epstein Diagrams for the General Theory of Relativity
We learn from Epstein diagrams how objects spontaneously begin to fall, and how clocks tick more slowly under the influence of stronger gravitation. To do so we need only to bend our familiar Epstein STR diagrams a bit ... The nice thing is that we can maintain the basic axiom: Everything always moves through space-time at the speed of light. Out of this arises a new variant of the twin paradox. As usual we'll investigate this quantitatively. We then interpret the results using the principle of maximum proper time. The fifth section presents Epstein diagrams in an elegant rolled version. Finally, we let Epstein show us how the curvature of space alone bends the inertial trajectories of fast objects. Here we anticipate qualitatively some experiments that we will handle quantitatively in I.