Reviews Hidden Harmonies: The Lives and Times of the Pythagorean Theorem by Robert and Ellen Kaplan Share this:EmailFacebookTwitterPinterestPocketRedditPrint By Science News January 14, 2011 at 1:54 pm Inspired by their Harvard-based math program, two educators delve into the history and uses of the Pythagorean theorem. HIDDEN HARMONIES: THE LIVES AND TIMES OF THE PYTHAGOREAN THEOREM BY ROBERT AND ELLEN KAPLAN Bloomsbury Press, 2011, 304 p., $25.