Edward Fredkin’s computer career started in 1956 when the Air Force assigned him to work at MIT’s Lincoln Laboratories. In 1968 he started at MIT as a full professor. From 1971 to 1974 he was the Director of CSAIL (formerly “LCS” or “Project MAC”). He spent a year at Caltech as a Fairchild Distinguished Scholar, working with Richard Feynman, and was a Professor of Physics at Boston University for 6 years. More recently he has been a Distinguished Career Professor at Carnegie Mellon University and also a Visiting Professor at MIT. Fredkin has been broadly interested in computation: hardware and software. He is the inventor of many things including the Trie data structure, the Fredkin Gate and the Billiard Ball Model. Fredkin and his students did pioneering work on cellular automata and reversible computing. He has also been involved in computer vision, chess and other areas of AI research. Fredkin also works at the intersection of theoretical issues in the physics of computation and computational models of physics. He recently developed Salt, a model of computation based on fundamental conservation laws from physics.