Inventor Manu Prakash turns everyday materials into powerful scientific devices, from paper microscopes to a clever new mosquito tracker. From the TED Fellows stage, he demos Paperfuge, a hand-powered centrifuge inspired by a spinning toy that costs 20 cents to make and can do the work of a $1,000 machine, no electricity required.

What do you do when your firmly held beliefs turn out not to be true? When Casey Gerald's religion failed him, he searched for something new to believe in -- in business, in government, in philanthropy -- but found only false saviors. In this moving talk, Gerald urges us all to question our beliefs and embrace uncertainty.

Author, philosopher, prankster and journalist AJ Jacobs talks about the year he spent living biblically -- following the rules in the Bible as literally as possible.

When someone asks you where you're from … do you sometimes not know how to answer? Writer Taiye Selasi speaks on behalf of "multi-local" people, who feel at home in the town where they grew up, the city they live now and maybe another place or two. "How can I come from a country?" she asks. "How can a human being come from a concept?"

Dave Isay opened the first StoryCorps booth in New York’s Grand Central Terminal in 2003 with the intention of creating a quiet place where a person could honor someone who mattered to them by listening to their story. Since then, StoryCorps has evolved into the single largest collection of human voices ever recorded. His TED Prize wish: to grow this digital archive of the collective wisdom of humanity. Hear his vision to take StoryCorps global — and how you can be a part of it by interviewing someone with the StoryCorps app.

In the pitch-black night, stung by jellyfish, choking on salt water, singing to herself, hallucinating … Diana Nyad just kept on swimming. And that's how she finally achieved her lifetime goal as an athlete: an extreme 100-mile swim from Cuba to Florida -- at age 64. Hear her story.

It's a classic underdog tale: David, a young shepherd armed only with a sling, beats Goliath, the mighty warrior. The story has transcended its biblical origins to become a common shorthand for unlikely victory. But, asks Malcolm Gladwell, is that really what the David and Goliath story is about?

Our lives, our cultures, are composed of many overlapping stories. Novelist Chimamanda Adichie tells the story of how she found her authentic cultural voice -- and warns that if we hear only a single story about another person or country, we risk a critical misunderstanding.

When he was a child, George Takei and his family were forced into an internment camp for Japanese-Americans, as a "security" measure during World War II. 70 years later, Takei looks back at how the camp shaped his surprising, personal definition of patriotism and democracy.

What do you want to be when you grow up? Well, if you're not sure you want to do just one thing for the rest of your life, you're not alone. In this illuminating talk, writer and artist Emilie Wapnick describes the kind of people she calls "multipotentialites" -- who have a range of interests and jobs over one lifetime. Are you one?