Onstage at TED2012, Peter Diamandis makes a case for optimism -- that we'll invent, innovate and create ways to solve the challenges that loom over us. "I’m not saying we don’t have our set of problems; we surely do. But ultimately, we knock them down.” Peter Diamandis runs the X PRIZE Foundation, which gives rich cash awards to the inventors and engineers who'll get us back to the moon, build a better car and explore the genome. And watch for more prizes to comes