For more than 30 years, Richard P. Feynman's three-volume Lectures on Physics has been known worldwide as the classic resource for students and professionals alike. Ranging from the most basic principles of Newtonian physics through such formidable theories as Einstein's general relativity, superconductivity, and quantum mechanics, Feynman's lectures stand as a monument of clear exposition and deep insight. This timeless audio serves as a comprehensive library of essential physics by a legend in science.Volume 20 includes "The Theory of Gravitation", "Curved Space", "The Relation of Wave and Particle Viewpoints", and more.