In the 1930s, physics was in a crisis. There appeared to be no way to reconcile the new theory of quantum mechanics with Einstein's theory of relativity. Several approaches had been tried and had failed. In the post-World War II period, four eminent physicists rose to the challenge and developed a calculable version of quantum electrodynamics (QED), probably the most successful theory in physics. This formulation of QED was pioneered by Freeman...