Building sophisticated educational tools out of cheap parts, Johnny Lee demos his cool Wii Remote hacks, which turn the $40 video game controller into a digital whiteboard, a touchscreen and a head-mounted 3-D viewer.

John La Grou unveils an ingenious new technology that will smarten up the electrical outlets in our homes, using microprocessors and RFID tags. The invention, Safeplug, promises to prevent deadly accidents like house fires -- and to conserve energy.

The world around us is mainly made of two things: nature and the materials that we extract from it. To fight climate change, we need to protect and regenerate nature and transform materials into low- or zero-carbon alternatives. Session 4 of the Countdown Global Launch, hosted by Prajakta Koli and Hannah Stocking, features Thomas Crowther, Ernes...

Terrorists and extremists aren't all naturally violent sociopaths -- they're deliberately recruited and radicalized in a process that doesn't fit into a neat pattern. Erin Marie Saltman discusses the push and pull factors that cause people to join extremist groups and explains innovative ways of preventing and countering radicalization.

John Gerzema says there's an upside to the recent financial crisis -- the opportunity for positive change. In this talk, he identifies four major cultural shifts driving new consumer behavior and shows how businesses are evolving to connect with thoughtful spending.

The world relies on manufacturing, and manufacturing relies on heat — a massive contributor to global carbon emissions, responsible for a quarter of the world's fossil fuel use. Energy entrepreneur John O'Donnell has figured out a better, cleaner way to generate the heat we need to make the stuff we want. Learn how his team turned simple bricks ...

In standard notation, rhythm is indicated on a musical bar line. But there are other ways to visualize rhythm that can be more intuitive. John Varney describes the 'wheel method' of tracing rhythm and uses it to take us on a musical journey around the world. [Directed by TED-Ed, narrated by Addison Anderson].

Some of us learn best in the classroom, and some of us ... well, we don't. But we still love to learn -- we just need to find the way that works for us. In this charming, personal talk, author John Green shares the community of learning that he found in online video.

What can you hear in silence? In this exploration of sound, host of the podcast "Twenty Thousand Hertz" Dallas Taylor tells the story of arguably the most debated musical composition in recent history -- composer John Cage's iconic piece 4'33" -- and invites you to take notice of the soundscape around you. Watch to the end to experience a perfor...

On his first day as president, Joe Biden signed a letter of acceptance that set in motion the 30-day process for the United States to re-join the Paris Agreement on climate. On the day the US returns to the accord, John Kerry, the US Special Envoy for Climate, sits down with Nobel Laureate Al Gore to discuss the make-or-break decade ahead of us....

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...

"The good news is it's now clearly cheaper to save the planet than to ruin it," says engineer and investor John Doerr. "The bad news is: we are fast running out of time." In this conversation with climate policy expert Hal Harvey, the two sustainability leaders discuss why humanity has to act globally, at speed and at scale, to meet the staggeri...

In this funny and inspiring talk, Dan Phillips tours us through a dozen homes he's built in Texas using recycled and reclaimed materials in wildly creative ways. Brilliant, low-tech design details will refresh your own drive to make more with less.

Today, there are thousands of cults around the world. Broadly speaking, a cult is a group or movement with a shared commitment to a usually extreme ideology that's typically embodied in a charismatic leader. But what exactly differentiates cults from other groups – and why do people join them? Janja Lalich describes how cults recruit and manipul...

In June 2022, TED's climate initiative, Countdown, launched its Dilemma Series: events designed to look at some of the "knots" in the climate change space, where diverging positions have stalled progress and solidified into an inability to collaborate across differences. The event focused on the question: Is there a role for carbon credits in th...

As Arctic ice melts, polar bears are being forced on land -- and they're hungry. With the apex predators frequently turning to human junkyards for a snack, northern towns have had to get creative in order to keep both their people and wildlife safe. Biologist and conservationist Alysa McCall shares lessons from the field on how to safely navigat...

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 ...

Many of the jobs that keep the world running — like cleaning bathrooms, picking up trash, caring for the elderly — pay so poorly that workers can barely make ends meet. Nonprofit leader Zeynep Ton is intent on changing that, showing why everyone wins when companies pay their people livable wages and offer opportunities for growth.

"You are constantly becoming a new person," says journalist Shankar Vedantam. In a talk full of beautiful storytelling, he explains the profound impact of something he calls the "illusion of continuity" -- the belief that our future selves will share the same views, perspectives and hopes as our current selves -- and shows how we can more proact...

Scott Rickard set out to engineer the ugliest possible piece of music, devoid of repetition, using a mathematical concept known as the Costas Array. In this surprisingly entertaining talk, he shares the math behind musical beauty ... and its opposite.

From its earliest incarnations, poker has always been a contest of guile, guts, and gambling. The game first emerged around 1800 in the melting pot of New Orleans, and soon spread up the Mississippi, Ohio, and Missouri rivers. So, how did this simple game of the American South skyrocket in popularity? James McManus shares how the card game becam...

Harness the power of frustrated people to shake up the status quo -- just like Pixar did. (Audio only)

"Confidence is the necessary spark before everything that follows," says educator and activist Brittany Packnett Cunningham. In an inspiring talk, she shares three ways to crack the code of confidence -- and her dream for a world where revolutionary confidence helps turn our most ambitious dreams into reality.

Using examples from birdsong, the natural lilt of emphatic language and even a cooking pan lid, singer-songwriter and TED Fellow Meklit Hadero shows how the everyday soundscape, even silence, makes music. "The world is alive with musical expression," she says. "We are already immersed."

Netflix changed the world of entertainment -- first with DVD-by-mail, then with streaming media and then again with sensational original shows like "Orange Is the New Black" and "Stranger Things" -- but not without taking its fair share of risks. In conversation with TED curator Chris Anderson, Netflix co-founder and CEO Reed Hastings discusses ...

With the same humor and humanity he exuded in "An Inconvenient Truth," Al Gore spells out 15 ways that individuals can address climate change immediately, from buying a hybrid to inventing a new, hotter brand name for global warming.

Why do we like an original painting better than a forgery? Psychologist Paul Bloom argues that human beings are essentialists -- that our beliefs about the history of an object change how we experience it, not simply as an illusion, but as a deep feature of what pleasure (and pain) is.

Prosthetics can't replicate the look and feel of lost limbs but they can carry a lot of personality. Designer Scott Summit shows 3D-printed, individually designed prosthetic legs that are unabashedly artificial and completely personal -- from macho to fabulous.

Women's equality won't just happen -- not unless more women are put in positions of power, says Sandi Toksvig. In a disarmingly hilarious talk, Toksvig tells the story of how she helped start a new political party in Britain, the Women's Equality Party, with the express purpose of putting equality on the ballot. Now she hopes people around the w...

Charles Limb performs cochlear implantation, a surgery that treats hearing loss and can restore the ability to hear speech. But as a musician too, Limb thinks about what the implants lack: They don't let you fully experience music yet. (There's a hair-raising example.) At TEDMED, Limb reviews the state of the art and the way forward.