In this brief clip (1:43) from the University of Southern California, renowned Israeli biochemist and biophysicist Arieh Warshel explains in simple terms the scientific research that earned him the Nobel Prize in Chemistry in 2013, along with fellow Israeli Michael Levitt and Austrian-American Martin Karplus. Warshel and his colleagues have developed a computer program that simulates biochemical and biophysical reactions, enabling scientists to solve complex problems that were, until then, unsolved mysteries.