R. Hahn · Public domain

Barry Barish spent decades as a leading experimental physicist on the hunt for gravitational waves, building the sensitivity into LIGO that finally let it detect the ripples in spacetime Einstein had predicted a century earlier. He shared the 2017 Nobel Prize in Physics with Rainer Weiss and Kip Thorne for it. 'I didn't know if I would succeed,' he said afterward. 'I was afraid I would fail, but because I tried, I had a breakthrough.'