After completing the final version of his general theory of relativity in November 1915, Albert Einstein wrote a book about relativity for a popular audience. His intention was "to give an exact insight into the theory of relativity to those readers who, from a general scientific and philosophical point of view, are interested in the theory, but wh "Hanoch Gutfreund, professor emeritus of theoretical physics at the Hebrew University of Jerusalem, and Jurgen Renn, director of the Max Planck Institute for the History of Science in Berlin, augment the 100th anniversary edition of [Relativity] with a reading companion to make Einstein's thinking clearer to present-day readers."---Mike Perricone, Symmetry Magazine