Rudolph Arthur Marcus, the only son of Myer and Esther Cohen Marcus, was born on July 21, 1923, in Montreal, Canada. Marcus traced his interest in science to his high school years, when he explored mathematics and later chemistry. After graduating from high school, he attended McGill University, receiving his Bachelor of Science degree in 1943 and his doctorate in 1946. At McGill, he was supervised by Carl A. Winkler, who specialized in the rates of chemical reactions. Marcus's first work after McGill was in two research positions, one with the National Research Council (NRC) of Canada in Ottawa and the other at the University of North Carolina. At the NRC, he did experimental work under E. W. R. Steacie on free-radical reactions, which concern atoms or groups of atoms with unpaired valence electrons. While he was at the University of North Carolina, Marcus met Laura Hearne, a graduate student in sociology...