"The whole thing was basically an experiment," Richard Feynmansaid late in his career, looking back on the origins of hislectures. The experiment turned out to be hugely successful,spawning a book that has remained a definitive introduction tophysics for decades. Ranging from the most basic principles ofNewtonian physics through such formidable theories as generalrelativity and quantum mechanics, Feynman's lectures stand as amonument of clear exposition and deep insight. Now, we arereintroducing the printed books to the trade, fully corrected, forthe first time ever, and in collaboration with Caltech. Timelessand collectible, the lectures are essential reading, not just forstudents of physics but for anyone seeking an introduction to thefield from the inimitable Feynman.