These scientific papers of Richard Feynman are renowned for their brilliant content and the author s striking original style. They are grouped by topic: path integral approach to the foundations of quantum mechanics and quantum field theory, renormalized quantum electrodynamics, theory of superfluid liquid helium, theory of the Fermi interaction, polarons, gravitation, partons, computer theory, etc. Comments on Feynman s topics are provided by the editor, together with biographical notes and a complete bibliography of Feynman s publications.

Contents: Quantum Chemistry; Classical and Quantum Electrodynamics; Path Integrals and Operator Calculus: QED and Other Applications; Liquid Helium; Physics of Elementary Particles; Quantum Gravity; Computer Theory.

As its title indicates, this volume contains a selection of Feynman's important scientific papers together with short comments. Most of the papers contain pure research, but among them are scattered some articles that are largely pedagogical, such as published lectures that Feynman gave at advanced physics workshops and summer schools. As the editor I chose the papers and also provided the comments, except as indicated in the text. Such a selection cannot avoid arbitrariness, and I apologize to those who feel that their favorites may have been unjustly omitted.

In the course of preparation, I have consulted some physicists, historians, and others, whom I would like to thank: Tian Yu Cao, Michael Cohen, Don Ellis, Joan Feynman, and Robert Michaelson. Carl Iddings and Frank Vernon, Jr. sent me valuable information concerning their collaborations with Feynman which are included in Part III. Danny Hillis helped to orient me with regard to the papers on computers. I am especially indebted to Alexander Fetter for writing the commentary which appears with the liquid helium papers. I am also greatly obliged for the hospitality of Judith Goodstein and the staff at the Caltech Archives who assisted me when I was reading Feynman's unpublished documents, and provided the bibliography of Feynman's writings at the end of this volume. Finally, I wish to acknowledge the great help of the editors at World Scientific.