Matthew Chalmers in CERN Courier:
Steven Weinberg was 34 when he produced his iconic “Model of Leptons”. The paper marked a moment of clarity in the history of particle physics and gave rise to the electroweak Standard Model, but it was also exceptional in inspiring one of the biggest experimental programmes science has ever seen. Flushing out and measuring its predicted W, Z and Higgs bosons took a multi-billion Swiss-franc effort in Europe that spanned four major projects – Gargamelle, the SPS, LEP and the LHC – and defined CERN’s research programme, keeping experimentalists in gainful employment for at least four decades. Not bad for a theory that, as Weinberg wrote at the time, “has too many arbitrary features for [its] predictions to be taken very seriously”.
Needless to say, Weinberg is delighted to have been able to witness the validation of the Standard Model (SM) over the decades. “I mean, it’s what keeps you going as a theoretical physicist to hope that one of your squiggles will turn out to describe reality,” he says. “I wouldn’t have been surprised or even very chagrined that, although the general idea was right, this particular model didn’t describe nature.”
Today, 50 years after his 1967 insight, Weinberg protests the notion that he is retired. The US has laws against discrimination on the basis of age, he says dryly. “I tell the people here that I plan to retire shortly after I die.” He is currently teaching a course in astrophysics at the University of Texas at Austin, his base for the past 35 years, and has two books and a new cosmology paper in the pipeline. Weinberg spoke to the Courier by phone in September from his home, reflecting on the state of high-energy physics following the Higgs boson discovery and on where the best hopes for new physics might lie. He began by recounting the thought processes that led him to his seminal 1967 work – many of which took place in children’s playgrounds.