The US consumes 25% of the world's oil -- but as energy tycoon T. Boone Pickens points out onstage, the country has no energy policy to prepare for the inevitable. Is alternative energy our bridge to an oil-free future? After losing $150 million investing in wind energy, Pickens suggests it isn't, not yet. What might get us there? Natural gas. A...

With vibrant video clips captured by submarines, David Gallo takes us to some of Earth's darkest, most violent, toxic and beautiful habitats, the valleys and volcanic ridges of the oceans' depths, where life is bizarre, resilient and shockingly abundant.

When two bodies wearing identical wetsuits washed ashore in Norway and the Netherlands, journalist Anders Fjellberg and photographer Tomm Christiansen started a search to answer the question: who were these people? What they found and reported in Norway's "Dagbladet" is that everybody has a name, everybody has a story and everybody is someone.

The man who helped usher in the environmental movement in the 1960s and '70s has been rethinking his positions on cities, nuclear power, genetic modification and geo-engineering. This talk at the US State Department is a foretaste of his major new book, sure to provoke widespread debate.

Economics writer Tim Harford studies complex systems -- and finds a surprising link among the successful ones: they were built through trial and error. In this sparkling talk from TEDGlobal 2011, he asks us to embrace our randomness and start making better mistakes.

Mycologist Paul Stamets lists 6 ways the mycelium fungus can help save the universe: cleaning polluted soil, making insecticides, treating smallpox and even flu viruses.

What if you knew what your coworkers really thought about you and what they were really like? Ray Dalio makes the business case for using radical transparency and algorithmic decision-making to create an idea meritocracy where people can speak up and say what they really think -- even calling out the boss is fair game. Learn more about how these...

We need a more considered approach to using social media for social justice, says writer and activist Ione Wells. After she was the victim of an assault in London, Wells published a letter to her attacker in a student newspaper that went viral and sparked the #NotGuilty campaign against sexual violence and victim-blaming. In this moving talk, sh...

Are we born to be optimistic, rather than realistic? Tali Sharot shares new research that suggests our brains are wired to look on the bright side -- and how that can be both dangerous and beneficial.

Legendary skeptic James Randi takes a fatal dose of homeopathic sleeping pills onstage, kicking off a searing 18-minute indictment of irrational beliefs. He throws out a challenge to the world's psychics: Prove what you do is real, and I'll give you a million dollars. (No takers yet.)

In this eye-opening talk, conservationist Ocean Ramsey explains why sharks -- highly intelligent marvels of evolution -- are actually an essential part of the ocean's ecosystem.

Have you wondered why politicians aren't what they used to be, why governments seem unable to solve real problems? Economist Yanis Varoufakis, the former Minister of Finance for Greece, says that it's because you can be in politics today but not be in power -- because real power now belongs to those who control the economy. He believes that the ...

The treatment of HIV has significantly advanced over the past three decades -- why hasn't our perception of people with the disease advanced along with it? After being diagnosed with HIV, Arik Hartmann chose to live transparently, being open about his status, in an effort to educate people. In this candid, personal talk, he shares what it's like...

You've heard about slow food. Now here's slow ... TV? In this very funny talk, Norwegian television producer Thomas Hellum shares how he and his team began to broadcast long, boring events, often live -- and found a rapt audience. Shows include a 7-hour train journey, an 18-hour fishing expedition and a 5.5-day ferry voyage along the coast of No...

As we reboot the world's economy, Geoff Mulgan poses a question: Instead of sending bailout money to doomed old industries, why not use stimulus funds to bootstrap some new, socially responsible companies -- and make the world a little bit better?

How do you define "nature?" If we define it as that which is untouched by humans, then we won't have any left, says environmental writer Emma Marris. She urges us to consider a new definition of nature -- one that includes not only pristine wilderness but also the untended patches of plants growing in urban spaces -- and encourages us to bring o...

Josette Sheeran, the head of the UN's World Food Program, talks about why, in a world with enough food for everyone, people still go hungry, still die of starvation, still use food as a weapon of war. Her vision: "Food is one issue that cannot be solved person by person. We have to stand together."

Can two countries at war dare to empathize with one another? Step by methodical step, sociologist Sam Richards gives his audience an extraordinary challenge: to allow a group of (mainly) Americans to understand -- not approve of, but understand -- the motivations of an Iraqi insurgent. A powerful talk.

Facebook COO Sheryl Sandberg looks at why a smaller percentage of women than men reach the top of their professions -- and offers 3 powerful pieces of advice to women aiming for the C-suite.

Rich scientific evidence comes from the history of life on Earth -- we just have to ask the right questions to find it. Whether it's figuring out the cause of the dodo bird's extinction or the bite force of a Tyrannosaurus rex, paleontologist Michael Benton shares some offbeat quandaries from the past, present and future.

From rockets to stock markets, many of humanity's most thrilling creations are powered by math. So why do kids lose interest in it? Conrad Wolfram says the part of math we teach -- calculation by hand -- isn't just tedious, it's mostly irrelevant to real mathematics and the real world. He presents his radical idea: teaching kids math through com...

When the dotcom bubble burst, hotelier Chip Conley went in search of a business model based on happiness. In an old friendship with an employee and in the wisdom of a Buddhist king, he learned that success comes from what you count.

David Logan talks about the five kinds of tribes that humans naturally form -- in schools, workplaces, even the driver's license bureau. By understanding our shared tribal tendencies, we can help lead each other to become better individuals.

Women and girls are conditioned to believe success is "a seat at the table." Creator, actress and author Lilly Singh thinks we need to build a better table. In this hilarious, incisive talk, Singh traces the arc of her career from up-and-coming YouTuber to history-making late-night talk show host, offering four ways to build a more inclusive soc...

"Ebola threatens everything that makes us human," says Bruce Aylward of the World Health Organization. And when the Ebola epidemic exploded in 2014, it caused a worldwide panic. But humanity can beat Ebola -- and Aylward shows four strategies that show how we are succeeding. The fight against Ebola is not yet won, he says, but it can be.

If an asteroid were headed for Earth, we'd all band together and figure out how to stop it, just like in the movies, right? And yet, when faced with major, data-supported, end-of-the-world problems in real life, too often we retreat into partisan shouting and stalemate. Jonathan Haidt shows us a few of the very real asteroids headed our way -- s...

Sir Ken Robinson makes an entertaining and profoundly moving case for creating an education system that nurtures (rather than undermines) creativity.

Ngozi Okonjo-Iweala, the former finance minister of Nigeria, sums up four days of intense discussion on aid versus trade on the closing day of TEDGlobal 2007, and shares a personal story explaining her own commitment to this cause.

"What would you attempt to do if you knew you could not fail?" asks Regina Dugan, then director of DARPA, the Defense Advanced Research Projects Agency. In this breathtaking talk she describes some of the extraordinary projects -- a robotic hummingbird, a prosthetic arm controlled by thought, and, well, the internet -- that her agency has create...

How can we fit more people into cities without overcrowding? Kent Larson shows off folding cars, quick-change apartments and other innovations that could make the city of the future work a lot like a small village of the past.