Carlo Rubbia, an Italian physicist, proposes and leads at CERN an experiment of enormous technical ambition to directly detect the W and Z bosons, the particles mediating the weak nuclear force whose existence and exact mass had been theoretically predicted fifteen years earlier by the electroweak theory of Glashow, Salam, and Weinberg. Simon van der Meer, a Dutch engineer also at CERN, develops the "stochastic cooling" technique needed to compress and concentrate antiproton beams — particles very difficult to produce in sufficient quantity — to a density enabling high-energy collisions with protons, a technique without which Rubbia's experiment would have been unfeasible. In January 1983, the experiment detects the W boson with a mass approximately 80 times that of the proton; months later, in May of the same year, the Z boson is also detected, with a mass close to 91 times that of the proton. Both masses match with extraordinary precision the predictions made by electroweak theory a decade and a half earlier, constituting one of the most spectacular and rapid experimental confirmations — barely a year between the experiment's final design and the Nobel — in all of 20th-century particle physics, and decisively validating the standard model as the correct description of nature's fundamental forces.