Designing electronics is generally cumbersome and expensive -- or was, until Leah Buechley and her team at MIT developed tools to treat electronics just like paper and pen. In this talk from TEDYouth 2011, Buechley shows some of her charming designs, like a paper piano you can sketch and then play.

Hannah Brencher's mother always wrote her letters. So when she felt herself bottom into depression after college, she did what felt natural -- she wrote love letters and left them for strangers to find. The act has become a global initiative, The World Needs More Love Letters, which rushes handwritten letters to those in need of a boost.

In Western society, bats are often characterized as creepy, even evil. Zoologist Emma Teeling encourages us to rethink common attitudes toward bats, whose unique and fascinating biology gives us insight into our own genetic makeup.

The suits, numbers and colors in a deck of cards correspond to the seasons, moon cycles and calendar. Marco Tempest straps on augmented reality goggles and does a card trick like you've never seen before, weaving a lyrical tale as he deals. (This version fixes a glitch in the original performance, but is otherwise exactly as seen live by the TEDGlobal audience, including the dazzling augmented reality effects.)

Literature has long been fascinated with fostered, adopted and orphaned children, from Moses to Cinderella to Oliver Twist to Harry Potter. So why do many parentless children feel compelled to hide their pasts? Poet and playwright Lemn Sissay tells his own moving story.

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 ... "

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 ... "

Why do teenagers seem so much more impulsive, so much less self-aware than grown-ups? Cognitive neuroscientist Sarah-Jayne Blakemore compares the prefrontal cortex in adolescents to that of adults, to show us how typically "teenage" behavior is caused by the growing and developing brain.

"The world needs you, badly," says legendary biologist E.O. Wilson in his letter to a young scientist. He gives advice collected from a lifetime of experience -- and reminds us that wonder and creativity are the center of the scientific life.

Want to navigate the solar system without having to buy a spacecraft? Jon Nguyen demos NASA JPL's "Eyes on the Solar System" -- free-to-use software for exploring the planets, moons, asteroids, and spacecraft that rotate around our sun in real-time.