Willie Smits restores a rainforest. Todd Kuiken: A prosthetic arm that "feels" Svante Pääbo: DNA clues to our inner neanderthal. Robert Full on engineering and evolution. Michael Shermer: The pattern behind self-deception. Lee Smolin on science and democracy. Juan Enriquez wants to grow energy. Jessa Gamble: Our natural sleep cycle. Helen Fisher studies the brain in love. Heather Knight: Silicon-based comedy. George Whitesides: A lab the size of a postage stamp. Dennis Hong: My seven species of robot. Dan Gilbert asks, Why are we happy? Dan Buettner: How to live to be 100+ Dan Ariely on our buggy moral code. Dan Ariely asks, Are we in control of our own decisions?