Throughout humankind's history, we've driven species after species extinct: the passenger pigeon, the Eastern cougar, the dodo ... But now, says Stewart Brand, we have the technology (and the biology) to bring back species that humanity wiped out. So -- should we? Which ones? He asks a big question whose answer is closer than you may think.

Stewart Brand works on the Clock of the Long Now, a timepiece that counts down the next 10,000 years. It's a beautiful project that asks us to think about the far, far future. Here, he discusses a tricky side problem with the Clock: Where can we put it?

Rural villages worldwide are being deserted, as billions of people flock to cities to live in teeming squatter camps and slums. Stewart Brand says this is a good thing. Why? It'll take you 3 minutes to find out.

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.

Stewart Brand is a futurist, counterculturist and visionary with a very wide-ranging mind. In conversation with TED Curator Chris Anderson, Brand discusses ... just about everything: human nature, bringing back the wooly mammoth, geoengineering, rewilding and science as organized skepticism -- plus the story of an acid trip on a San Francisco ro...

Nuclear power: the energy crisis has even die-hard environmentalists reconsidering it. In this first-ever TED debate, Stewart Brand and Mark Z. Jacobson square off over the pros and cons. A discussion that'll make you think -- and might even change your mind.

Facebook's "like" and "share" buttons are seen 22 billion times a day, making them some of the most-viewed design elements ever created. Margaret Gould Stewart, Facebook's director of product design, outlines three rules for design at such a massive scale—one so big that the tiniest of tweaks can cause global outrage, but also so large that the ...

How many of today's headlines will matter in 100 years? 1000? Kirk Citron's "Long News" project collects stories that not only matter today, but will resonate for decades -- even centuries -- to come. At TED2010, he highlights recent headlines with the potential to shape our future.

In this revelatory talk, technologist Kayvon Tehranian explores why NFTs -- digital assets that represent a certificate of ownership on the internet -- are a technological breakthrough. Learn how NFTs are putting power and economic control back into the hands of digital creators -- and pushing forward the internet's next evolution.

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.

John Hunter puts all the problems of the world on a 4'x5' plywood board -- and lets his 4th-graders solve them. At TED2011, he explains how his World Peace Game engages schoolkids, and why the complex lessons it teaches -- spontaneous, and always surprising -- go further than classroom lectures can.

Kindness can go a long way when it comes to reshaping a business. Having saved a fashion company from the brink of bankruptcy, entrepreneur James Rhee shares the value of investing in a culture of compassion at work -- and shows why we should all lead with our hearts.

Every act of communication is, in some way, an act of translation. Writer Chris Bliss talks about the way that great comedy can translate deep truths for a mass audience.