Space-Time, Quantum Mechanics, and the Large Hadron Collider

In physics, the twentieth century started with the twin revolutions of relativity and quantum mechanics. Much of the second half of the century was devoted to the construction of a theoretical structure unifying these radical ideas, confirmed experimentally to exquisite precision over the past three decades. Yet questions remain. The union of quantum mechanics and gravity strongly suggests that space-time is doomed—but what replaces it? The unification of relativity and quantum mechanics predicts violent short-distance quantum fluctuations that make the existence of a macroscopic world wildly implausible, and yet we comfortably live in a huge universe. What tames these violent fluctuations, and why is there a macroscopic universe? A spectacular new experiment—the Large Hadron Collider—is now poised to shed significant light on at least some of these mysteries. In this talk, Nima Arkani-Hamed, Professor in the School of Natural Sciences, describes these ideas and discuss what we can expect to know by 2020.