Immigrants who founded amazing companies

Our emotions influence every aspect of our lives -- how we learn, how we communicate, how we make decisions. Yet they're absent from our digital lives; the devices and apps we interact with have no way of knowing how we feel. Scientist Rana el Kaliouby aims to change that. She demos a powerful new technology that reads your facial expressions and matches them to corresponding emotions. This "emotion engine" has big implications, she says, and could change not just how we interact with machines -- but with each other.

In politics, representation matters -- and that's why we should elect leaders who reflect their country's diversity and embrace its multicultural tapestry, says Sayu Bhojwani. Through her own story of becoming an American citizen, the immigration scholar reveals how her love and dedication to her country turned into a driving force for political change. "We have fought to be here," she says, calling immigrant voices to action. "It's our country, too."

In a funny, rapid-fire 4 minutes, Alexis Ohanian of Reddit tells the real-life fable of one humpback whale's rise to web stardom. The lesson of Mister Splashy Pants is a shoo-in classic for meme-makers and marketers in the Facebook age.

Tan Le's astonishing new computer interface reads its user's brainwaves, making it possible to control virtual objects, and even physical electronics, with mere thoughts (and a little concentration). She demos the headset, and talks about its far-reaching applications.

There's no single formula for a great talk, but there is a secret ingredient that all the best ones have in common. TED curator Chris Anderson shares this secret -- along with four ways to make it work for you. Do you have what it takes to share an idea worth spreading?