Six Not-so-easy Pieces: Einstein's Relativity, Symmetry, and Space-time by Richard P Feynman
These SIX NOT-SO-EASY PIECES are drawn from Feynman's celebrated introductory course of lectures on physics. They delve into the most revolutionary discovery of twentieth-century physics: Einstein's theory of relativity. 'In these lectures everything you've ever heard about Feynman's wit and genius comes true' -- John Horgan