Kathryn Schulz, author of Being Wrong: Adventures in the Margin of Error: “We need to be able to look at the vastness and complexity of the universe and say, ‘Wow, I dunno. Maybe I’m wrong.'”

John Hunter, creator of World Peace Games says,  “I allow them to learn, in a bloodless way, how to do what’s right.”

Legendary film critic Roger Ebert recruited some of his friends to speak for him: Dr. Dean Ornish, John Hunter, and his wife Chaz. “Computer voices are not very sophisticated, but with my computer I can communicate more widely than ever before.”

Photos: TED / James Duncan Davidson