Salam and Steven Weinberg developed a theory relating the electromagnetic and weak forces at about the same time, in 1967-1968. The theory was a major accomplishment since it was the first successful attempt to show the commonality between two of the four basic forces of nature: gravity, electromagnetism, and the strong and the weak forces. The goal of showing how all four of these forces are really different manifestations of a single fundamental force has been a long-term objective of many physicists. For their development of the electroweak theory, Salam and Weinberg shared the 1979 Nobel Prize for physics with Sheldon Glashow, who expanded upon and generalized the Salem-Weinberg theory.

As with any good theory, the Salam-Weinberg theory included predictions that allowed it to be tested experimentally. One of these predictions was the existence of an interaction called a neutral current. A neutral current is one in which no...