For Alan Barr, it started during the covid-19 lockdowns. “I had a bit more time. I could sit and think,” he says.

He had enjoyed being part of the success at CERN’s Large Hadron Collider (LHC) near Geneva, Switzerland — the particle collider that discovered the Higgs boson. But now, he wondered, were they missing a trick? “I had spent long hours screwing bits of it together. And I thought, ‘Well, we’ve built this beautiful piece of apparatus, but maybe we could be doing more with it,’ ” he says.