This landmark text offers a rigorous full-year graduate level course on gravitation physics, teaching students to: € Grasp the laws of physics in flat spacetime € Predict orders of magnitude € Calculate using the principal tools of modern geometry € Predict all levels of precision € Understand Einstein's geometric framework for physics € Explore applications, including pulsars and neutron stars, cosmology, the Schwarzschild geometry and gravitational collapse, and gravitational waves € Probe experimental tests of Einstein's theory € Tackle advanced topics such as superspace and quantum geometrodynamics  The book offers a unique, alternating two-track pathway through the subject: € In many chapters, material focusing on basic physical ideas is designated as Track 1. These sections together make an appropriate one-term advanced/graduate level course (mathematical prerequisites: vector analysis and simple partial-differential equations). The book is printed to make it easy for readers to identify these sections. € The remaining Track 2 material provides a wealth of advanced topics instructors can draw from to flesh out a two-term course, with Track 1 sections serving as prerequisites.