For pure physics, research Hamilton (professor recently recognized by the American Physical Society for research and mentoring), Williams (lots of Apker recipients), Wesleyan, Haverford (traditionally strong in physics), Bowdoin (strong in several sciences, including physics) and Reed (nuclear reactor on campus, so strong in physics; limited in geosciences, however). Some of these schools represent apparent reaches. However, based on your son’s academic level, a few represent matches. For generally safer admits, look into the University of Rochester and Lawrence.