Michael E. Peskin received his doctorate in physics from Cornell University and has held research appointments in theoretical physics at Harvard, Cornell, and CEN Saclay. In 1982, he joined the staff of the Stanford Linear Accelerator centre, where he is now Professor of Physics. Daniel V. Schroeder received his doctorate in physics from Stanford University in 1990. He held visiting appointments at Pomona College before joining the faculty of Weber State University, where he is now Associate Professor of Physics. Michael E. Peskin received his doctorate in physics from Cornell University and has held research appointments in theoretical physics at Harvard, Cornell, and CEN Saclay. In 1982, he joined the staff of the Stanford Linear Accelerator centre, where he is now Professor of Physics. Daniel V. Schroeder received his doctorate in physics from Stanford University in 1990. He held visiting appointments at Pomona College before joining the faculty of Weber State University, where he is now Associate Professor of Physics.