The Standard Model is surely one of the major intellectual achievements of the twentieth century. In the late 1960s and early 1970s, decades of path-breaking experiments culminated in the emergence of a comprehensive theory of particle physics. This theory identifies the basic fundamental constituents of matter and describes all the forces of nature relevant at accessible energies – the strong, weak, and electromagnetic interactions.

Science progresses in a much more muddled fashion than is often pictured in history books. This is especially true of theoretical physics, partly because history is written by the victorious. Consequently, historians of science often ignore the many alternate paths that people wandered down, the many false clues they followed, the many misconceptions they had. These alternate points of view are less clearly developed than the final theories, harder to understand and easier to forget, especially as these are viewed years later, when it all really does make sense. Thus reading history one rarely gets the feeling of the true nature of scientific development, in which the element of farce is as great as the element of triumph.

The emergence of quantum chromodynamics, or QCD, is a wonderful example of the evolution from farce to triumph. During a very short period, a transition occurred from experimental discovery and theoretical confusion to theoretical triumph and experimental confirmation. We were lucky to have been young then, when we could stroll along the newly opened beaches and pick up the many beautiful shells that experiment had revealed.