Can we rebuild our broken suburbs? Ellen Dunham-Jones shares a vision of dying malls rehabilitated, dead "big box" stores re-inhabited, and endless parking lots transformed into thriving wetlands.

When you think of North American cuisine, do Indigenous foods come to mind? Chef Sean Sherman serves up an essential history lesson that explains the absence of Native American culinary traditions across the continent, highlighting why revitalizing Indigenous education sits at the center of a better diet and healthier relationship with the planet.

Child prodigy Adora Svitak says the world needs "childish" thinking: bold ideas, wild creativity and especially optimism. Kids' big dreams deserve high expectations, she says, starting with grownups' willingness to learn from children as much as to teach.

In keeping with the theme of TED2008, professor Stephen Hawking asks some Big Questions about our universe -- How did the universe begin? How did life begin? Are we alone? -- and discusses how we might go about answering them.

Trivia whiz Ken Jennings has made a career as a keeper of facts; he holds the longest winning streak in history on the US quiz show Jeopardy. But in 2011, he played a challenge match against IBM's supercomputer Watson -- and lost. With humor and humility, Jennings tells us how it felt to have a computer literally beat him at his own game, and ma...

Flags are one of the simplest yet most powerful pieces of design ever conceived. They can make us swell with pride, burn with hatred -- and even inspire people to die or kill in their name, says vexillologist Michael Green. Take a brief walk through history as Green explores the symbolic fervor behind flags that unify and divide, inviting us to ...

Economist Yasheng Huang compares China to India, and asks how China's authoritarian rule contributed to its astonishing economic growth -- leading to a big question: Is democracy actually holding India back? Huang's answer may surprise you.

We must face our fears if we want to get the most out of technology -- and we must conquer those fears if we want to get the best out of humanity, says Garry Kasparov. One of the greatest chess players in history, Kasparov lost a memorable match to IBM supercomputer Deep Blue in 1997. Now he shares his vision for a future where intelligent machi...

The progress bar makes waiting more exciting... and mitigates our fear of death. Journalist Daniel Engber explores how it came into existence.

Eduardo Paes is the mayor of Rio de Janeiro, a sprawling, complicated, beautiful city of 6.5 million. He shares four big ideas about leading Rio -- and all cities -- into the future, including bold (and do-able) infrastructure upgrades and how to make a city "smarter."

Seth Godin argues the Internet has ended mass marketing and revived a human social unit from the distant past: tribes. Founded on shared ideas and values, tribes give ordinary people the power to lead and make big change. He urges us to do so.

Cave diver Jill Heinerth explores the hidden underground waterways coursing through our planet. Working with biologists, climatologists and archaeologists, Heinerth unravels the mysteries of the life-forms that inhabit some of the earth's most remote places and helps researchers unlock the history of climate change. In this short talk, take a di...

In this thoughtful talk, David Puttnam asks a big question about the media: Does it have a moral imperative to create informed citizens, to support democracy? His solution for ensuring media responsibility is bold, and you might not agree. But it's certainly a question worth asking.

You can't understand climate change in pieces, says climate scientist Gavin Schmidt. It's the whole, or it's nothing. In this illuminating talk, he explains how he studies the big picture of climate change with mesmerizing models that illustrate the endlessly complex interactions of small-scale environmental events.

Necessity is the mother of invention, right? Well, not always. Steven Johnson shows us how some of the most transformative ideas and technologies, like the computer, didn't emerge out of necessity at all but instead from the strange delight of play. Share this captivating, illustrated exploration of the history of invention. Turns out, you'll fi...

At the center of a galaxy more than 55 million light-years away, there's a supermassive black hole with the mass of several billion suns. And now, for the first time ever, we can see it. Astrophysicist Sheperd Doeleman, head of the Event Horizon Telescope collaboration, speaks with TED's Chris Anderson about the iconic, first-ever image of a bla...

You don't have to be a scientist to help protect the world's oceans, says underwater drone expert and TED Fellow David Lang -- in fact, ordinary citizens have pulled together to save the planet's natural treasures many times in history. Lang asks us to take a lesson from the story of the US National Parks Service, offering a three-point plan for...

At TEDMED, Eric Dishman makes a bold argument: The US health care system is like computing circa 1959, tethered to big, unwieldy central systems: hospitals, doctors, nursing homes. As our aging population booms, it's imperative, he says, to create personal, networked, home-based health care for all.

Nate Silver has data that answers big questions about race in politics. For instance, in the 2008 presidential race, did Obama's skin color actually keep him from getting votes in some parts of the country? Stats and myths collide in this fascinating talk that ends with a remarkable insight.

Bill Gates hopes to solve some of the world's biggest problems using a new kind of philanthropy. In a passionate and, yes, funny 18 minutes, he asks us to consider two big questions and how we might answer them. (And see the Q&A on the TED Blog.)

Emily Parsons-Lord re-creates air from distinct moments in Earth's history -- from the clean, fresh-tasting air of the Carboniferous period to the soda-water air of the Great Dying to the heavy, toxic air of the future we're creating. By turning air into art, she invites us to know the invisible world around us. Breathe in the Earth's past and f...

What happens when you discover a dinosaur? Paleontologist Kenneth Lacovara details his unearthing of Dreadnoughtus -- a 77-million-year-old sauropod that was as tall as a two-story house and as heavy as a jumbo jet -- and considers how amazingly improbable it is that a tiny mammal living in the cracks of the dinosaur world could evolve into a se...

In this uplifting talk, Katherine Fulton sketches the new future of philanthropy -- one where collaboration and innovation allow regular people to do big things, even when money is scarce. Giving five practical examples of crowd-driven philanthropy, she calls for a new generation of citizen leaders.

In 2018, biomolecular archaeologist Ian Barnes' team at the Natural History Museum in London ascertained that Cheddar Man—the oldest near-complete human skeleton discovered in the British Isles—had dark skin and light eyes. Their findings challenged the views that many groups had long held about Britain's racial heritage. In this talk, Barnes de...

Gayla Benefield was just doing her job -- until she uncovered an awful secret about her hometown that meant its mortality rate was 80 times higher than anywhere else in the US. But when she tried to tell people about it, she learned an even more shocking truth: People didn't want to know. In a talk that's part history lesson, part call-to-action...

Rivers are one of nature's most powerful forces -- they bulldoze mountains and carve up the earth, and their courses are constantly moving. Understanding how they form and how they'll change is important for those that call their banks and deltas home. In this visual-packed talk, geoscientist Liz Hajek shows us how rocks deposited by ancient riv...

When Jamie Heywood's brother was diagnosed with ALS, he devoted his life to fighting the disease as well. The Heywood brothers built an ingenious website where people share and track data on their illnesses -- and they discovered that the collective data had enormous power to comfort, explain and predict.

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 contribution to the things that matter -- like health care, education, infrastructure and beyond. "We have the re...

Pushing his body through epic cold-water swims, Lewis Gordon Pugh wants to draw attention to our global climate. He's just back from swimming in a meltwater lake on the slopes of Mount Everest.

Cheyenne Cochrane explores the role that hair texture has played in the history of being black in America -- from the heat straightening products of the post-Civil War era to the thousands of women today who have decided to stop chasing a conventional beauty standard and start embracing their natural hair. "This is about more than a hairstyle," ...