From electric vehicles to space travel, Musk has taken on some of the greatest technological challenges of our time. But what transforms him from mad inventor to visionary leader is his ability to convince the world of the viability of his projects, even ideas like a tube-based transit system called the Hyper-loop. His electric-car maker, Tesla Motors, produces a world-class automobile, but so far nothing for the masses—nor an annual profit. Does it matter? No. We’ll wait.