Why is x the unknown , Terry Moore

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 chimpanzees, Bill Gates on malaria and mosquitoes, Pattie Maes on the Sixth Sense wearable tech, and Lost producer JJ Abrams on the allure of mystery. TED stands for Technology, Entertainment, Design, and TEDTalks cover these topics as well as science, business, development and the arts. Closed captions and translated subtitles in a variety of languages are now available on at If you have questions or comments about this or other TED videos, please go to