"We're not in a clean energy revolution; we're in a clean energy crisis," says climate policy expert Michael Shellenberger. His surprising solution: nuclear. In this passionate talk, he explains why it's time to overcome longstanding fears of the technology, and why he and other environmentalists believe it's past time to embrace nuclear as a viable and desirable source of clean power.

By loading kids with high expectations and micromanaging their lives at every turn, parents aren't actually helping. At least, that's how Julie Lythcott-Haims sees it. With passion and wry humor, the former Dean of Freshmen at Stanford makes the case for parents to stop defining their children's success via grades and test scores. Instead, she says, they should focus on providing the oldest idea of all: unconditional love.

What happens when the way we buy, sell and pay for things changes, perhaps even removing the need for banks or currency exchange bureaus? That's the radical promise of a world powered by cryptocurrencies like Bitcoin and Ethereum. We're not there yet, but in this sparky talk, digital currency researcher Neha Narula describes the collective fiction of money -- and paints a picture of a very different looking future.

At the intersection of medical invention and indigenous culture, pediatric cardiologist Franz Freudenthal mends holes in the hearts of children across the world, using a device born from traditional Bolivian loom weaving. "The most complex problems in our time," he says, "can be solved with simple techniques, if we are able to dream."

What is a concussion? Probably not what you think it is. In this talk from the cutting edge of research, bioengineer (and former football player) David Camarillo shows what really happens during a concussion -- and why standard sports helmets don't prevent it. Here's what the future of concussion prevention looks like.

For the first time in history, the majority of American parents don't think their kids will be better off than they were. This shouldn't be a cause for alarm, says journalist Courtney Martin. Rather, it's an opportunity to define a new approach to work and family that emphasizes community and creativity. "The biggest danger is not failing to achieve the American Dream," she says in a talk that will resonate far beyond the US. "The biggest danger is achieving a dream that you don't actually believe in."

Would you choose to build a house on top of an unfinished foundation? Of course not. Why, then, do we rush students through education when they haven't always grasped the basics? Yes, it's complicated, but educator Sal Khan shares his plan to turn struggling students into scholars by helping them master concepts at their own pace.

Global problems such as terrorism, inequality and political dysfunction aren't easy to solve, but that doesn't mean we should stop trying. In fact, suggests journalist Jonathan Tepperman, we might even want to think riskier. He traveled the world to ask global leaders how they're tackling hard problems -- and unearthed surprisingly hopeful stories that he's distilled into three tools for problem-solving.

"When you talk to strangers, you're making beautiful interruptions into the expected narrative of your daily life -- and theirs," says Kio Stark. In this delightful talk, Stark explores the overlooked benefits of pushing past our default discomfort when it comes to strangers and embracing those fleeting but profoundly beautiful moments of genuine connection.

Why is it so hard to find female superhero merchandise? In this passionate, sparkling talk, media studies scholar (and father of a Star Wars-obsessed daughter) Christopher Bell addresses the alarming lack of female superheroes in the toys and products marketed to kids -- and what it means for how we teach them about the world.