David J. Griffiths received his B.A. (1964) and Ph.D. (1970) from Harvard University. He taught at Hampshire College, Mount Holyoke College, and Trinity College before joining the faculty at Reed College in 1978. In 2001-02 he was visiting Professor of Physics at the Five Colleges (University of Massachusetts, Amherst, Mount Holyoke, Smith, and Hampshire), and in the spring of 2007 he taught Electrodynamics at Stanford. He retired in 2009. Griffiths is a Consulting Editor of The American Journal of Physics, and a Fellow of the American Physical Society. In 1997 he was awarded the Millikan Medal by the American Association of Physics Teachers. He has spent sabbaticals at SLAC, Lawrence Berkeley Laboratory, and University of California, Berkeley. Although his Ph.D. was in elementary particle theory, his recent research is in electrodynamics and quantum mechanics. He is the author of over fifty articles and four books: Introduction to Electrodynamics (4th edition, Cambridge, 2013), Introduction to Elementary Particles (2nd edition, 2008), Introduction to Quantum Mechanics (2nd edition, Cambridge, 2016), and Revolutions in Twentieth-Century Physics (Cambridge, 2012).