The goal of elementary particle physics is to achieve a unified understanding of fundamental forces (gravitational, electromagnetic and nuclear) and elementary particlesin terms of concise and beautiful mathematical principles. This program was pioneered by Einstein, who lacked sufficient experimental information to achieve a unified field theory. Building on the lessons of the last 25 years we may now be on the verge of realizing Einstein’s dream. Curiously, superstring theory, the prime candidate for the unified theory, was initially developed to solve a completely different problem.
The strong nuclear force that binds quarks together inside protons, neutrons and other hadrons was not yet understood in the 1960s. During that decade, theorists faced the challenge of finding a simple explanation for the wealth of data that the experimentalists were producing with their large accelerators. I was a student in Berkeley, where Professors Geoffrey Chew, Stanley Mandelstam and others were developing ideas such ...
