The author of "The Fault in Our Stars" and "Paper Towns," John Green is a passionate online video maker.

The author of "Investing in Kids," Timothy Bartik studies state and local economies -- and analyzes the benefits of preschool as an economic development program.

Christopher Emdin is a science advocate who uses hip-hop to make better teachers.

Richard Baraniuk founded Connexions -- now called OpenStax -- a free, open-source, global clearinghouse of course materials. Students and educators tap into its vast store of texts on everything from engineering to ornithology to music, adapting the content as they see fit.

Eduardo Briceño is a learner, leader, speaker and writer devoted to enabling a more learning-oriented world.

Open up a whole new world of possibilities and experiences with these talks that show the benefit (and fun!) of learning a new language.

Lara Setrakian is building innovative news platforms that stand ready to engage and explain the complexity of our world.

A self-described average guy who found success doing what he loved, Richard St. John spent more than a decade researching the lessons of success -- and distilling them into 8 words, 3 minutes and one successful book.

Carnegie Mellon professor Randy Pausch motivated thousands of students with his passionate teaching. Millions more around the world found inspiration in his moving "Last Lecture."

Legendary skeptic James Randi devoted his life to debunking frauds and investigating paranormal and pseudoscientific claims.

One of the true luminaries of personal computing, Alan Kay conceived of laptops and graphical interfaces years before they were realized. At XeroxPARC, Apple, HP and Disney, he has developed tools for improving the mind.

Astronaut Dr. Mae Jemison‘s inclusive, audacious journey to improving life here on earth and beyond is paving the way for human interstellar travel.

The founder of the Riverside School in Ahmedabad, Kiran Sethi has launched an initiative to make our cities more child-friendly.

Jack is the CEO of Anatomage, a company specializing on 3D medical technology.

Victor Rios seeks to uncover how to best support the lives of young people who experience poverty, stigma and social exclusion.

Which of the following is risky behavior: a person taking cholesterol medicine with grapefruit juice? Or a person taking Acetaminophen before going out for drinks? Or a person on blood thinners who takes an aspirin? Turns out, all of them are risky. Each has inadvertently created a drug interaction that could lead to serious complications. Célin...

Why, why, why does our education system look so similar to the way it did 50 years ago? Millions of students were failing then, as they are now -- and it’s because we’re clinging to a business model that clearly doesn’t work. Education advocate Geoffrey Canada dares the system to look at the data, think about the customers and make systematic sh...

Patricia Burchat studies the structure and distribution of dark matter and dark energy. These mysterious ingredients can't be measured in conventional ways, yet form a quarter of the mass of our universe.

JK Rowling penned the bestselling Harry Potter page-turners -- a spellbinding, seven-installment fantasy of wizards, warlocks and decidedly British texture that brought her from rags to riches.

Michael Sandel teaches political philosophy at Harvard, exploring the most hotly contested moral and political issues of our time.

Shukla Bose is the founder and head of the Parikrma Humanity Foundation, a nonprofit that runs four extraordinary schools for poor children.

Sam Richards is a sociologist and teacher of the largest race relations course in the US. He argues that empathy is the core of sociology.

BCG's Seema Bansal asks: Can governments actually make a meaningful difference in education? And rapidly? Yes, it turns out.

From a scientist’s perspective, life is one big experiment. These talks demonstrate that science doesn’t just happen -- it takes determination, unwavering curiosity and a big leap into the unknown.

In January 2009, Ray Zahab broke the record for fastest unsupported trek across Antarctica, to raise awareness and money for kids' environmental education. In 2006, he ran across the Sahara to raise awareness of water shortages. (He started running 5 years ago.)

During his 20-year tenure as president of UMBC, Freeman Hrabowski has helped students of all backgrounds pursue degrees in arts, humanities and the sciences.

Young poet, educator and activist Malcolm London performs his stirring poem about life on the front lines of high school. He tells of the "oceans of adolescence" who come to school "but never learn to swim," of "masculinity mimicked by men who grew up with no fathers." Beautiful, lyrical, chilling.

Jonathan Drori commissioned the BBC's very first websites, one highlight in a long career devoted to online culture and educational media -- and understanding how we learn.

Clint Smith's work blends art and activism.

Violinist Robert Gupta joined the LA Philharmonic at the age of 19 -- and maintains a passionate parallel interest in neurobiology and mental health issues. He's a TED Senior Fellow.