Bill Stone, a maverick cave explorer who has plumbed Earth's deepest abysses, discusses his efforts to mine lunar ice for space fuel and to build an autonomous robot for studying Jupiter's moon Europa.

Deep in our solar system, a new era of exploration is unfolding. Beneath the thick ice of Europa; in the vapor plumes on Enceladus; and within the methane lakes of Titan, scientists are hunting for extraterrestrial life. These moons are 'ocean worlds'— they contain liquid oceans, which can support the formation of life. Does life exist on ocean ...

The James Webb Space Telescope is a miracle of modern science and engineering. With a 21-foot, gold-coated mirror protected by a sunshield that's the size of a tennis court, it's the world's most powerful telescope and humanity's latest attempt to answer questions like: "Where did we come from?" and "Are we alone?" (It also needed to be folded u...

In the year 1066, 7,000 Norman infantry and knights sailed in warships across the English Channel. Their target: England, home to more than a million people. Around the same period of time, other groups of Normans were setting forth all across Europe. Who were these warriors, and how did they leave their mark so far and wide? Mark Robinson share...

Tour the deep dark world of the East German state security agency known as Stasi. Uniquely powerful at spying on its citizens, until the fall of the Berlin Wall in 1989 the Stasi masterminded a system of surveillance and psychological pressure that kept the country under control for decades. Hubertus Knabe studies the Stasi — and was spied on by...

Written language, the hallmark of human civilization, didn't just suddenly appear one day. Thousands of years before the first fully developed writing systems, our ancestors scrawled geometric signs across the walls of the caves they sheltered in. Paleoanthropologist, rock art researcher and TED Senior Fellow Genevieve von Petzinger has studied ...

Pop culture often portrays the Middle Ages as a time of forceful personalities and warring dynasties. In this talk, historian Maria Golubeva explains how institutions — city councils, guilds and courts — had just as much (if not more) influence within society, and harbor important lessons about identity and politics in modern day.

What kind of data is your cell phone company collecting? Malte Spitz wasn't too worried when he asked his operator in Germany to share information stored about him. Multiple unanswered requests and a lawsuit later, Spitz received 35,830 lines of code -- a detailed, nearly minute-by-minute account of half a year of his life.

In 1165, copies of a strange letter began to circulate throughout Europe. It spoke of a fantastical realm, containing the Tower of Babel and the Fountain of Youth— all ruled over by the letter's mysterious author: Prester John. Who was this powerful ruler, and was he even real? Matteo Salvadore shares the legend of a mythical king who impacted t...

Take a graffiti tour through ancient Pompeii with Roman archaeologist Jacqueline DiBiasie-Sammons and discover what 2,000-year-old scribblings from antiquity can teach us about life in modern times. A fascinating reminder of what we leave behind for future generations.

Medieval Europe. Where unbathed, sword-wielding knights ate rotten meat, thought the Earth was flat, defended chastity-belt wearing maidens, and tortured their foes with grisly gadgets. Except... this is more fiction than fact. So, where do all the myths about the Middle Ages come from? And what were they actually like? Stephanie Honchell Smith ...

Steve Keil fights the "serious meme" that has infected his home of Bulgaria -- and calls for a return to play to revitalize the economy, education and society. A sparkling talk with a universal message for people everywhere who are reinventing their workplaces, schools, lives.

Greece has been the poster child for European economic crisis, but former Prime Minister George Papandreou wonders if it's just a preview of what's to come. “Our democracies," he says, "are trapped by systems that are too big to fail, or more accurately, too big to control” -- while "politicians like me have lost the trust of their peoples." How...

It seems the more we know about how democracy works -- through government transparency, better media coverage, even new insights about our brains -- the less we trust democracy itself. Yet it's still, arguably, the best system of government available. As Ivan Krastev says, "What went right is also what went wrong." Can democracy survive?

Can the interests of an individual nation be reconciled with humanity's greater good? Can a patriotic, nationally elected politician really give people in other countries equal consideration? Following his TEDTalk calling for a global ethic, UK Prime Minister Gordon Brown fields questions from TED Curator Chris Anderson.

After the French Revolution erupted in 1789, Europe was thrown into chaos. Neighboring countries' monarchs feared they would share the fate of Louis XVI and attacked the new Republic, while at home, extremism and mistrust between factions led to bloodshed. In the midst of all this conflict, Napoleon emerged. But did he save the revolution, or de...

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 the economy.

Paddy Ashdown believes we are living in a moment in history where power is changing in ways it never has before. In a spellbinding talk he outlines the three major global shifts that he sees coming.

Margrethe Vestager wants to keep European markets competitive -- which is why, on behalf of the EU, she's fined Google $2.8 billion for breaching antitrust rules, asked Apple for $15.3 billion in back taxes and investigated a range of companies, from Gazprom to Fiat, for anti-competitive practices. In an important talk about the state of the glo...

Make a city beautiful, curb corruption. Edi Rama took this deceptively simple path as mayor of Tirana, Albania, where he instilled pride in his citizens by transforming public spaces with colorful designs.

In the German town of Nördlingen in 1593, innkeeper Maria Höll found herself accused of witchcraft. She was arrested for questioning, and denied the charges. She insisted she wasn't a witch through 62 rounds of torture before her accusers finally released her. Other accused witches weren't so "lucky." Why did these witch hunts occur? Brian A. Pa...

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.

In 2013, the world learned that the NSA and its UK equivalent, GCHQ, routinely spied on the German government. Amid the outrage, artists Mathias Jud and Christoph Wachter thought: Well, if they're listening ... let's talk to them. With antennas mounted on the roof of the Swiss Embassy in Berlin's government district, they set up an open network ...

In this gripping talk, litigator and TED Fellow Itamar Mann details the perilous boat migrations of asylum seekers crossing the Mediterranean Sea. With a surplus of evidence gathered by researchers and activists, he explains how lawyers are making progress in prosecuting human rights abuses happening on militarized coasts. On a basic human level...

António Guterres thinks that we can solve the global refugee crisis -- and he offers compelling, surprising reasons why we must try. In conversation with TED's Bruno Giussani, Guterres discusses the historical causes of the current crisis and outlines the mood of the European countries that are trying to screen, shelter and resettle hundreds of ...

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 ...

In May 1940, with the German army ready to occupy Paris, Noor Inayat Khan was faced with a difficult choice: stand on the sidelines or join the Allied forces fighting the Nazis. After witnessing the devastation across Europe, she travelled to England to learn the art of espionage. Shrabani Basu details how a pacifist turned spy helped build the ...

As Asian economies and governments continue to gain power, the West needs to find ways to adapt to the new global order, says author and diplomat Kishore Mahbubani. In an insightful look at international politics, Mahbubani shares a three-part strategy that Western governments can use to recover power and improve relations with the rest of the w...

As the child of an Afghan mother and Pakistani father raised in Norway, Deeyah Khan knows what it's like to be a young person stuck between your community and your country. In this powerful, emotional talk, the filmmaker unearths the rejection and isolation felt by many Muslim kids growing up in the West -- and the deadly consequences of not emb...

A million refugees arrived in Europe this year, says Alexander Betts, and "our response, frankly, has been pathetic." Betts studies forced migration, the impossible choice for families between the camps, urban poverty and dangerous illegal journeys to safety. In this insightful talk, he offers four ways to change the way we treat refugees, so th...