In November 1986, Australian miners climbed Lunatic Hill and bored 20 meters into the Earth. They were rewarded with a fist-sized, record breaking gemstone, which they named the Hailey's Comet opal. Thanks to a characteristic called...

In 1959, the WHO set out to eradicate smallpox, an ambitious goal that was achieved by 1980. But this goal wouldn't have been possible without coordination on all levels of society. In this episode of Crash Course Outbreak Science, we'll...

There's no shortage of resources to help people change their health behaviors -- but far too often, these resources aren't accessible in underserved communities, says physician Priscilla Pemu. Enter "culturally congruent coaching," a...

Niti Bhan studies business strategy for Africa's informal markets: the small shops and stands, skilled craftspeople and laborers who are the invisible engine that keeps the continent's economy running. It's tempting to think of these...

Creative, sustainable solutions find their home in the thousands of informal neighborhoods across the world. Urban planner Jota Samper believes these often overlooked settlements (also known as slums) should be regarded as hubs of...

In Latin American countries like El Salvador, homicide rates are alarmingly high thanks in large part to a vicious cycle of violence -- people don't have a chance to heal from recurrent individual and collective trauma. With her team at...

We're at a unique moment in history, says UK Prime Minister Gordon Brown: we can use today's interconnectedness to develop our shared global ethic -- and work together to confront the challenges of poverty, security, climate change and...

How did the US immigration debate get to be so divisive? In this informative talk, historian and writer Paul A. Kramer shows how an "insider vs. outsider" framing has come to dominate the way people in the US talk about immigration --...

Deep in the Himalayas, on the border between China and India, lies the Kingdom of Bhutan, which has pledged to remain carbon neutral for all time. In this illuminating talk, Bhutan's Prime Minister Tshering Tobgay shares his country's...

We could realistically see people starting to live and work on the Moon in the next decade -- and how we do it matters, says space policy researcher Jessy Kate Schingler. In this fascinating talk, she discusses the critical issues that...

On remote, rocky North Pacific islands, you may find a cute little bird that just so happens to smell like tangerines.

Entrepreneurs do have to wear a lot of hats, but we need to understand where we fall short and where other people or products could help get the job done. We can’t be an expert in everything or have time to do everything. But some people...

"Confidence is the necessary spark before everything that follows," says educator and activist Brittany Packnett. In an inspiring talk, she shares three ways to crack the code of confidence -- and her dream for a world where...

Sometimes, small things make a huge impact. After studying how bees in urban environments can survive by navigating small land patches, ecologist Amanda Schochet was inspired to build MICRO, a network of portable science museums the size...

The world needs clean power, but decarbonization calls for a massive increase in the mining and extraction of minerals like lithium, graphite and cobalt. Environmental peacemaking expert Olivia Lazard sheds light on the scramble for...

Government deficits have gotten a bad rap, says economist Stephanie Kelton. In this groundbreaking talk, she makes the case to stop looking at government spending as a path towards frightening piles of debt, but rather as a financial...

So we know what life needs here to work, and we've talked a little about what life COULD look like on other planets. But what about plant life? What could plant life look like on other planets? In this episode of Crash Course Kids,...

If insects suddenly morphed into large beings and decided to wage war on us, there's no doubt that humans would lose. There are an estimated 10 quintillion individual insects on earth, outnumbering humans by more than a billion to one....

Seema Bansal forged a path to public education reform for 15,000 schools in Haryana, India, by setting an ambitious goal: by 2020, 80 percent of children should have grade-level knowledge. She's looking to meet this goal by seeking...

In this deceptively casual talk, Charles Leadbeater weaves a tight argument that innovation isn't just for professionals anymore. Passionate amateurs, using new tools, are creating products and paradigms that companies can't.

* Viewer discretion advised. This video includes discussion of mature topics and may be inappropriate for some audiences. Ghanaian economist George Ayittey unleashes a torrent of controlled anger toward corrupt leaders in Africa -- and...

Even when our lives appear fine from the outside, locked within can be a world of quiet suffering, leading some to the decision to end their life. At TEDYou, JD Schramm asks us to break the silence surrounding suicide and suicide...

What do beavers, termites, and prairie dogs have in common? They all change their environments! Last time we talked about how humans change their environments, but humans are animals and all animals change their environments just by...

Every minute, 20 people are newly displaced by climate change, economic crisis and political instability, according to the UNHCR. How can we help them overcome the barriers to starting new lives? TED Resident Muhammed Idris is leading a...