John Norton is an internationally recognized expert in the science of Albert Einstein. He has published extensively on Einstein's discoveries of general relativity, special relativity and the light quantum and also on philosophical aspects of Einstein's work. He has been a contributing editor to the publication of Einstein's collected papers and serves on the publication project's advisory board. His most notable achievement was the analysis of the "Zurich Notebook," which contains private calculations made by Einstein in preparation for his greatest discovery, the general theory of relativity. In 2005, Professor Norton was an invited speaker at many conferences celebrating the centenary of Einstein's annus mirabilis of 1905, including events in Washington, London, Berlin, Tenerife, Jerusalem, Pasadena, Florence and Bern in Switzerland. Professor Norton has taught in the Department of History and Philosophy of Science, University of Pittsburgh, since 1983. He was its Chair from 2000-2005 and, since 2005, has been the Director of the Center for Philosophy of Science, University of Pittsburgh, which is the world's leading research institute in philosophy of science. In an earlier career, Professor Norton was a chemical engineer and worked for Shell Refining making gasoline. That, he remarks, was worthwhile work, but pondering Einstein, his discoveries and a wide range of problems in history and philosophy of science is infinitely more entertaining.