Gordon Baym has remained at Illinois since his arrival; a frequent visitor to Nordita and the Niels Bohr Institute in Copenhagen, he has also been a visiting professor at the Universities in Tokyo, Kyoto and Nagorya. His principal research interests have been in the physics of condensed matter in systems ranging from liquid helium to neutron stars and high energy nuclear collisions. He is also the author of Lectures in Quantum Mechanics. Leo P. Kadanoff left Urbana for Brown University in 1969 and thereafter joined the faculty of the University of Chicago in 1978, where he is presently the John D. and Catherine T. MacArthur Distinguished Service Professor of Physics. After his early research in Green’s functions, he returned to study of critical phenomena near phase transitions, and then toward models of urban growth; his research is now aimed at turbulence and chaos in many-particle systems. For his work is critical phenomena, he received the Buckley prize of the American Physical Society, the Wolf Foundation award, and the Elliot Cresson medal of the Franklin Institute. Gordon Baym has remained at Illinois since his arrival; a frequent visitor to Nordita and the Niels Bohr Institute in Copenhagen, he has also been a visiting professor at the Universities in Tokyo, Kyoto and Nagorya. His principal research interests have been in the physics of condensed matter in systems ranging from liquid helium to neutron stars and high energy nuclear collisions. He is also the author of Lectures in Quantum Mechanics. Leo P. Kadanoff left Urbana for Brown University in 1969 and thereafter joined the faculty of the University of Chicago in 1978, where he is presently the John D. and Catherine T. MacArthur Distinguished Service Professor of Physics. After his early research in Green’s functions, he returned to study of critical phenomena near phase transitions, and then toward models of urban growth; his research is now aimed at turbulence and chaos in many-particle systems. For his work is critical phenomena, he received the Buckley prize of the American Physical Society, the Wolf Foundation award, and the Elliot Cresson medal of the Franklin Institute. David Pines is research professor of physics at the University of Illinois at Urbana-Champaign. He has made pioneering contributions to an understanding of many-body problems in condensed matter and nuclear physics, and to theoretical astrophysics. Editor of Perseus’ Frontiers in Physics series and former editor of American Physical Society’s Reviews of Modern Physics, Dr. Pines is a member of the National Academy of Sciences, the American Philosophical Society, a foreign member of the USSR Academy of Sciences, a fellow of the American Academy of Arts and Sciences, and of the American Association for the Advancement of Science. Dr. Pines has received a number of awards, including the Eugene Feenberg Memorial Medal for Contributions to Many-Body Theory; the P.A.M. Dirac Silver Medal for the Advancement of Theoretical Physics; and the Friemann Prize in Condensed Matter Physics.