The fact of the matter

摘要

In physics, there is sometimes life after death. The constant wish of researchers who study the universe at the subatomic level is for bigger and more powerful machines. When this wish is granted by the funding agencies, the existing, smaller machines become redundant. That was the fate of pep, the positron-electron project at SLAC, the Stanford Linear Accelerator Centre, in California. It was overtaken by events, and turned off in 1990.