Stewart Brand is a futurist, counterculturist and visionary with a very wide-ranging mind. In conversation with TED Curator Chris Anderson, Brand discusses ... just about everything: human nature, bringing back the wooly mammoth, geoengineering, rewilding and science as organized skepticism -- plus the story of an acid trip on a San Francisco rooftop in the '60s that sparked a perspective-shifting idea. "The story we're told is that we're the next meteor," Brand says, but "things are capable of getting better."