Terry Moore: Why is x the unknown

Why is x the symbol for an unknown In this short and funny talk, Terry Moore gives the surprising answer. TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world s leading thinkers and doers give the talk of their lives in 18 minutes. Featured speakers have included Al Gore on climate change, Philippe Starck on design, Jill Bolte Taylor on observing her own stroke, Nicholas Negroponte on One Laptop per Child, Jane Goodall on