Stephen M. Barr is a professor of physics at the University of Delaware. He received his Ph.D. from Princeton University in 1978. He does research in theoretical particle physics, with emphasis primarily on “grand unified theories” and the cosmology of the early universe. He also writes and lectures extensively on the relation of science and religion. Many of his articles and reviews have appeared in First Things, on whose editorial advisory board he serves. He is the author of the book Modern Physics and Ancient Faith (Univ. of Notre Dame Press, 2003) and A Student’s Guide to Natural Science (Intercollegiate Studies Institute, 2006).