 He obtained his PhD at the University of Washington with a thesis entitled "Sixth Order Charge Renormalization Constant," under Marshall Baker, 1970, calculating the divergent part of the inverse charge renormalization constant in quantum electrodynamics to sixth order in perturbation theory in Feynman gauge to verify the gauge invariance of the calculation.In 1972, he was a postdoc in the area of general relativity at the University of Maryland.In 1976, he joined the United States Army Research Laboratory (then called the Harry Diamond Laboratory).