In the United States, two institutions guide teenagers on the journey to adulthood: college and prison. Sociologist Alice Goffman spent six years in a troubled Philadelphia neighborhood and saw first-hand how teenagers of African-American and Latino backgrounds are funneled down the path to prison — sometimes starting with relatively minor infractions. In an impassioned talk she asks, “Why are we offering only handcuffs and jail time?”

At the INK Conference, Arvind Gupta shares simple yet stunning plans for turning trash into seriously entertaining, well-designed toys that kids can build themselves — while learning basic principles of science and design.

In her talk, longtime English teacher Patricia Ryan asks a provocative question: Is the world's focus on English preventing the spread of great ideas in other languages? (For instance: what if Einstein had to pass the TOEFL?) It's a passionate defense of translating and sharing ideas. (Filmed at TEDxDubai.)

With humor and persistence, filmmaker Morgan Spurlock dives into the hidden but influential world of brand marketing, on his quest to make a completely sponsored film about sponsorship. (And yes, onstage naming rights for this talk were sponsored too. By whom and for how much? He'll tell you.)

By leading the Americans in his audience step by step through the thought process, sociologist Sam Richards sets an extraordinary challenge: can they understand — not approve of, but understand — the motivations of an Iraqi insurgent? And by extension, can anyone truly understand and empathize with another? (Filmed at TEDxPSU.)

Artificial intelligence is getting smarter by leaps and bounds — within this century, research suggests, a computer AI could be as "smart" as a human being. And then, says Nick Bostrom, it will overtake us: "Machine intelligence is the last invention that humanity will ever need to make." A philosopher and technologist, Bostrom asks us to think hard about the world we're building right now, driven by thinking machines. Will our smart machines hel...

Fiorenzo Omenetto shares 20+ astonishing new uses for silk, one of nature's most elegant materials — in transmitting light, improving sustainability, adding strength and making medical leaps and bounds. On stage, he shows a few intriguing items made of the versatile stuff.

John Hunter puts all the problems of the world on a 4'x5' plywood board — and lets his 4th-graders solve them. At TED2011, he explains how his World Peace Game engages schoolkids, and why the complex lessons it teaches — spontaneous, and always surprising — go further than classroom lectures can.

Activist Caroline Casey tells the story of her extraordinary life, starting with a revelation (no spoilers). In a talk that challenges perceptions, Casey asks us all to move beyond the limits we may think we have.

Sebastian Thrun helped build Google's amazing driverless car, powered by a very personal quest to save lives and reduce traffic accidents. Jawdropping video shows the DARPA Challenge-winning car motoring through busy city traffic with no one behind the wheel, and dramatic test drive footage from TED2011 demonstrates how fast the thing can really go.

As kids, we all get advice from parents and teachers that seems strange, even confusing. This was crystallized one night for a young Clint Smith, who was playing with water guns in a dark parking lot with his white friends. In a heartfelt piece, the poet paints the scene of his father's furious and fearful response.

Chris Milk uses cutting edge technology to produce astonishing films that delight and enchant. But for Milk, the human story is the driving force behind everything he does. In this short, charming talk, he shows some of his collaborations with musicians including Kanye West and Arcade Fire, and describes his latest, mind-bending experiments with virtual reality. (This talk was part of a session at TED2015 guest-curated by Pop-Up Magazine: popupma...