Observations in high-energy physics

My instructions this morning were to give a survey of the subject we call elementary particle physics, emphasizing the experimental aspects. I will choose what I believe to be interesting and exciting and try to see how we got where we are. The objects we call elementary particles have changed over the years and Fig. 1 is meant to illustrate this.

As you know, the macrobaryon falls just as fast as the macrolepton. The systematic search for the simple objects and their interactions may well have begun with Galileo in Pisa—the first, incidentally, almost vertical linear accelerator.