Interview in five sessions in March, April, and November 1998 with Peter Goldreich, Lee A. DuBridge Professor of Astrophysics and Planetary Physics 1981-2003 (emeritus 2003), with joint appointments in the Division of Physics, Mathematics & Astronomy and the Division of Geological & Planetary Sciences. He begins by discussing his family background and early education at Bronx High School of Science; engineering physics at Cornell; graduate work at Cornell with Thomas Gold on solar-system dynamics (PhD 1963). Postdoc with Donald Lynden-Bell at Cambridge; work on spiral density waves in galaxies. Friendship with Wallace Sargent. Assistant professorship at UCLA. Joins Caltech faculty 1966 as associate professor, with joint appointments in...