This book is the third volume of the Theoretical Minimum series. The firstvolume, The Theoretical Minimum: What You Need to Know to Start DoingPhysics, covered classical mechanics, which is the core of any physicseducation. We will refer to it from time to time simply as Volume I. Thesecond book (Volume II) explains quantum mechanics and its relationship toclassical mechanics. This third volume covers special relativity and classicalfield theory. The books in this series run parallel to Leonard Susskind’svideos, available on the Web through Stanford University (seewww.theoreticalminimum.com for a listing). While covering the same generaltopics as the videos, the books contain additional details and topics that don’tappear in the videos.