Whether it’s the four bodily humors, the geocentric universe, or the steady state theory, sometimes an old idea has to die before new science can flourish. (Just ask Copernicus.) A new anthology edited by Edge.org’s John Brockman aims to speed that process along by asking scientists and big thinkers which scientific concepts they’d target for extinction. Ira talks with two contributors to This Idea Must Die—theoretical physicist Sean Carroll and quantum mechanic Seth Lloyd— about the ideas they’d like to give a good shove out the door. Read an excerpt from the book here, and vote for which ideas you think should die.