In the fall of 2011 Peter Norvig taught a class with Sebastian Thrun on artificial intelligence at Stanford attended by 175 students in situ -- and over 100,000 via an interactive webcast. He shares what he learned about teaching to a global classroom.

Many of us have a social media presence -- a virtual personality made up of status updates, tweets and connections, stored in the cloud. Adam Ostrow asks a big question: What happens to that personality after you've died? Could it ... live on?

In the US, the press has a right to publish secret information the public needs to know, protected by the First Amendment. Government surveillance has made it increasingly more dangerous for whistleblowers, the source of virtually every important story about national security since 9/11, to share information. In this concise, informative talk, Freedom of the Press Foundation co-founder and TED Fellow Trevor Timm traces the recent history of government action against individuals who expose crime and injustice and advocates for technology that can help them do it safely and anonymously.

In the US, most kids have a very long summer break, during which they forget an awful lot of what they learned during the school year. This "summer slump" affects kids from low-income neighborhoods most, setting them back almost three months. TED Fellow Karim Abouelnaga has a plan to reverse this learning loss. Learn how he's helping kids improve their chances for a brighter future.

In a fun, exciting talk, teenager Henry Lin looks at something unexpected in the sky: distant galaxy clusters. By studying the properties of the universe's largest pieces, says the Intel Science Fair award winner, we can learn quite a lot about scientific mysteries in our own world and galaxy.

Imagine it's late 1990, and you've just met a nice young man named Tim Berners-Lee, who starts telling you about his proposed system called the World Wide Web. Ian Ritchie was there. And ... he didn't buy it. A short story about information, connectivity and learning from mistakes.

Hooray for technology! It makes everything better for everyone!! Right? Well, no. When a new technology, like ebooks or health trackers, is only available to some people, it has unintended consequences for all of us. Jon Gosier, a TED Fellow and tech investor, calls out the idea of "trickle-down techonomics," and shares powerful examples of how new tech can make things actually worse if it's not equally distributed. As he says, "the real innovation is in finding ways to include everyone."

In this brief talk, Saul Griffith unveils the invention his new company Makani Power has been working on: giant kite turbines that create surprising amounts of clean, renewable energy.

Solar-powered LED lightbulbs could transform the lives of rural Haitians, but as Daniel Schnitzer found, they don't simply sell themselves. At TEDxPittsburgh, he shows how smart health and energy products for the developing world are useless unless the market works too.

Narcissism isn't just a personality type that shows up in advice columns; it's actually a set of traits classified and studied by psychologists. But what causes it? And can narcissists improve on their negative traits? W. Keith Campbell describes the psychology behind the elevated and sometimes detrimental self-involvement of narcissists. [Directed by TOGETHER, narrated by Addison Anderson].