In his last essay just weeks before his death at the age of 91, David S. Nivison says, "Breaking into a formal system - such as a chronology - must be like breaking into a code. If you are successful, success will show right off." Since the late 1970's Nivison has focused his scholarship on breaking the code of Three Dynasties (Xia, Shang, Zhou) chronology by establishing an innovative methodology based on mourning periods, astronomical phenomenon, and numerical manipulations derived from them. Nivison is most readily known in the field for revising (and then revising again) the date of the...