Imposing Order On A Profusion of Particles
The GeV accelerators of the 1950's and 1960's created a dizzying number of previously unknown nuclear particles rarely found in nature. They could do this because, as the famous German-American physicist Albert Einstein demonstrated in his equation E = mc², matter and energy are equivalent. Under the right conditions, matter can be converted into energy, and energy turned into matter. When two particles are accelerated in opposite directions to an energy of many GeV and then crashed together, the combined energy of the collision condenses into a swarm of particles that flash into momentary existence and then decay into other kinds of particles. The only visible remnant of a collision is an array of swirling lines captured with a camera or other recording device, tracing the myriad paths of the various particles.
By the 1960's, the number of particles created by the collisions was becoming bewildering. Surely, in their number and variety, the particles could not all be fundamental building blocks of matter. Physicists were desperate for a theory that would impose order on the apparent chaos of the subatomic world.