Weinberg, Steven (1933– )

US physicist who, together with Abdus Salam, was awarded the Nobel Prize for Physics in 1979 for demonstrating in 1967 that the weak nuclear force and the electromagnetic force (two of the fundamental forces of nature) are variations of a single underlying force, now called the electroweak force, and for the prediction of the existence of the weak neutral current.

Weinberg and Salam's theory involved the prediction of a new interaction, the neutral current (discovered in 1973), which required the presence of a fourth, ‘charmed’ quark.