Stuart Brown's research shows play is not just joyful and energizing -- it's deeply involved with human development and intelligence. Through the National Institute for Play, he's working to better understand its significance.
Brian Greene is perhaps the best-known proponent of superstring theory, the idea that minuscule strands of energy vibrating in a higher dimensional space-time create every particle and force in the universe.
Once known for entertaining millions by creating special effects for Hollywood, theme parks and Broadway, Applied Minds cofounder Bran Ferren now solves impossible tech challenges with previously unimaginable inventions.
Britain's former prime minister Gordon Brown played a key role in shaping the G20 nations' response to the world's financial crisis, and was a powerful advocate for a coordinated global response to problems such as climate change, poverty and social justice.