In my first months as a physics journalist nearly a decade ago, I kept running into an inscrutable string of characters: AdS/CFT. Thoroughly intimidated, I decided to just ignore it. But I couldn’t keep my head in the sand for long. I soon learned that those characters are shorthand for a surprising connection between the seemingly inharmonious worlds of gravity and quantum mechanics. And even more bizarrely, this “anti-de Sitter/conformal field theory” correspondence suggests that gravity elimi...