The physicist unified two of the four fundamental forces. Steven Weinberg (right) along with his colleague Sheldon Glashow, who also won the 1979 Nobel Prize in Physics. (Image credit: Bettmann / Contributor/Getty) Steven Weinberg, a Nobel-prize winning physicist whose work helped link two of the four fundamental forces, has died at the age of 88, the University of Texas at Austin (UT Austin) announced Saturday (July 24). HIs work was foundational to the Standard Model, the overarching physics theory that describes how subatomic particles behave. His seminal work was a slim, three-page paper published in 1967 in the journal Physical Review Letters and entitled "A Model of Leptons." In it, he predicted how subatomic particles known as W, Z and the famous Higgs boson should behave — years before those particles were detected experimentally, according to a statement from UT Austin.