Child prodigy Adora Svitak says the world needs "childish" thinking: bold ideas, wild creativity and especially optimism. Kids' big dreams deserve high expectations, she says, starting with grownups' willingness to learn from children as much as to teach.

Fifteen-year-old Tavi Gevinson had a hard time finding strong female, teenage role models — so she built a space where they could find each other. At TEDxTeen, she illustrates how the conversations on sites like Rookie, her wildly popular web magazine for and by teen girls, are putting a new, unapologetically uncertain and richly complex face on modern feminism.

What do science and play have in common? Neuroscientist Beau Lotto thinks all people (kids included) should participate in science and, through the process of discovery, change perceptions. He's seconded by 12-year-old Amy O'Toole, who, along with 25 of her classmates, published the first peer-reviewed article by schoolchildren, about the Blackawton bees project. It starts: "Once upon a time ... "

In the Maasai community where Richard Turere lives with his family, cattle are all-important. But lion attacks were growing more frequent. In this short, inspiring talk, the young inventor shares the solar-powered solution he designed to safely scare the lions away.

Over 85 percent of all pancreatic cancers are diagnosed late, when someone has less than two percent chance of survival. How could this be? Jack Andraka talks about how he developed a promising early detection test for pancreatic cancer that's super cheap, effective and non-invasive — all before his 16th birthday.