Sir Anthony Leggett was a giant in the field of quantum physics University of Illinois Urbana-Champaign/L. Brian Stauffer In my first year of graduate school, I briefly shared an office with a quiet, older graduate student. When we finally managed some chit-chat, I learned that he was “working on theory of glasses with Tony”. Two things became clear: cracking the physics of glasses was difficult, and I really ought to have known who Tony was. I met him soon enough. A polite British man in his 70s, he spoke with the cadence of a life-long teacher and an incontrovertible twinkle in his eyes. His full name was Anthony James Leggett: a Nobel laureate, a knight of the British Empire, winner of countless prizes, an expert on the ultracold denizens of the quantum world, and a theorist who co-developed an influential test for probing just where that world might end, a question he pursued for decades.…