Sarah Parcak hoped the power of the crowd could help accelerate archaeological discovery. See how 90-year-old Doris Mae Jones heard her call -- and jumped in to search more than 50,000 tiles in Expedition Peru. With cat assistants.

Jamie Oliver crystallized his vision for a food revolution in his TED Talk. At the Charlton Manor Primary School in London, head teacher Timothy Baker is putting his idea into action by offering not just food education but education centered on food.

With the Charter for Compassion, Karen Armstrong challenged the world to bring the Golden Rule to the center of life. Learn about how her vision inspired Greg Fischer -- the mayor of Louisville, Kentucky -- to lead the city in fascinating new directions.

JR launched the participatory art project INSIDE OUT to highlight our shared humanity. Travel with a group of people who packed up their lives and got on the INSIDE OUT bus, crossing the United States to capture portraits of undocumented people and those that support them.

Raj Panjabi has a bold idea: to recruit and train an army of community health workers to bring medical care to the billion people around the world who lack access to it. See how technology is transforming things for health workers like Serena and Prince -- and how TED's just-launched initiative, the Audacious Project, is amplifying their impact. Learn more at AudaciousProject.org.