Sugar pills, injections of nothing -- studies show that, more often than you'd expect, placebos really work. At TEDMED, magician Eric Mead does a trick to prove that, even when you know something's not real, you can still react as powerfully as if it is. (Warning: This talk is not suitable for viewers who are disturbed by needles or blood.)

When disaster strikes, who's first on the scene? More and more, it’s a robot. In her lab, Robin Murphy builds robots that fly, tunnel, swim and crawl through disaster scenes, helping firefighters and rescue workers save more lives safely -- and help communities return to normal up to three years faster.

Explorer Ben Saunders wants you to go outside! Not because it’s always pleasant and happy, but because that’s where the meat of life is, “the juice that we can suck out of our hours and days.” Saunders’ next outdoor excursion? To try to be the first in the world to walk from the coast of Antarctica to the South Pole and back again.

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.

Bjørn Otto Sverdrup leads the Oil and Gas Climate Initiative (OGCI), which gathers the CEOs of twelve of the world's largest oil and gas companies around an ambitious goal: to get one of the sectors contributing most to climate change to drastically lower their own carbon emissions. He describes a possible path for the industry to pivot to net-z...

The sounds of the rainforest include: the chirps of birds, the buzz of cicadas, the banter of gibbons. But in the background is the almost-always present sound of a chainsaw, from illegal loggers. Engineer Topher White shares a simple, scalable way to stop this brutal deforestation — that starts with your old cell phone.

Gregory Heyworth is a textual scientist; he and his lab work on new ways to read ancient manuscripts and maps using spectral imaging technology. In this fascinating talk, watch as Heyworth shines a light on lost history, deciphering texts that haven't been read in thousands of years. How could these lost classics rewrite what we know about the p...

What shapes our perceptions (and misperceptions) about science? In an eye-opening talk, meteorologist J. Marshall Shepherd explains how confirmation bias, the Dunning-Kruger effect and cognitive dissonance impact what we think we know -- and shares ideas for how we can replace them with something much more powerful: knowledge.

Ocean expert Nancy Rabalais tracks the ominously named "dead zone" in the Gulf of Mexico -- where there isn't enough oxygen in the water to support life. The Gulf has the second largest dead zone in the world; on top of killing fish and crustaceans, it's also killing fisheries in these waters. Rabalais tells us about what's causing it -- and how...

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."

Our oceans are unexplored and undersampled -- today, we still know more about other planets than our own. How can we get to a better understanding of this vast, important ecosystem? Explorer Sebastien de Halleux shares how a new fleet of wind- and solar-powered drones is collecting data at sea in unprecedented detail, revealing insights into thi...

Top climate scientist James Hansen tells the story of his involvement in the science of and debate over global climate change. In doing so he outlines the overwhelming evidence that change is happening and why that makes him deeply worried about the future.

Today nine nations collectively control more than 15,000 nuclear weapons, each hundreds of times more powerful than those dropped on Hiroshima and Nagasaki. We don't need more nuclear weapons; we need a new generation to face the unfinished challenge of disarmament started decades ago. Nuclear reformer Erika Gregory calls on today's rising leade...

Every minute, 400 pounds of hydrogen and almost 7 pounds of helium escape from Earth's atmosphere into outer space. Astrophysicist Anjali Tripathi studies the phenomenon of atmospheric escape, and in this fascinating and accessible talk, she considers how this process might one day (a few billion years from now) turn our blue planet red.

Planetary scientist Joel Levine shows some intriguing -- and puzzling -- new discoveries about Mars: craters full of ice, traces of ancient oceans, and compelling hints at the presence, sometime in the past, of life. He makes the case for going back to Mars to find out more.

Ask any deep space navigator like Jill Seubert what makes steering a spacecraft difficult, and they'll tell you it's all about the timing; a split-second can decide a mission's success or failure. So what do you do when a spacecraft is bad at telling time? You get it a clock -- an atomic clock, to be precise. Let Seubert whisk you away with the ...

As a child growing up in North Korea, Hyeonseo Lee thought her country was "the best on the planet." It wasn't until the famine of the 90s that she began to wonder. She escaped the country at 14, to begin a life in hiding, as a refugee in China. Hers is a harrowing, personal tale of survival and hope -- and a powerful reminder of those who face ...

All our manufacturing currently takes place on Earth and, as a result, all its harmful byproducts and wasteful processes end up wreaking Earthbound havoc. In this forward-thinking talk, James Orsulak argues that the fix is to move manufacturing operations off-planet, using automated labor to mine resources and perform all those ecosystem-destabi...

By the end of this talk, there will be 864 more hours of video on YouTube and 2.5 million more photos on Facebook and Instagram. So how do we sort through the deluge? At the TEDSalon in London, Markham Nolan shares the investigative techniques he and his team use to verify information in real-time, to let you know if that Statue of Liberty image...

What are our forests really made of? From the air, ecologist Greg Asner uses a spectrometer and high-powered lasers to map nature in meticulous kaleidoscopic 3D detail -- what he calls "a very high-tech accounting system" of carbon. In this fascinating talk, Asner gives a clear message: To save our ecosystems, we need more data, gathered in new ...

Botanist Corneille Ewango talks about his work at the Okapi Faunal Reserve in the Congo Basin -- and his heroic work protecting it from poachers, miners and raging civil wars.

Roughly 85 percent of mass in the universe is "dark matter" -- mysterious material that can't be directly observed but has an immense influence on the cosmos. What exactly is this strange stuff, and what does it have to do with our existence? Astrophysicist Risa Wechsler explores why dark matter may be the key to understanding how the universe f...

Leadership doesn't have a user's manual, but Fields Wicker-Miurin says stories of remarkable, local leaders are the next best thing. At a TED salon in London, she shares three.

China is the world's biggest polluter -- and now one of its largest producers of clean energy. Which way will China go in the future, and how will it affect the global environment? Data scientist Angel Hsu describes how the most populous country on earth is creating a future based on alternative energy -- and facing up to the environmental catas...

What does the world look like when you map it using data? Social geographer Danny Dorling invites us to see the world anew, with his captivating and insightful maps that show Earth as it truly is -- a connected, ever-changing and fascinating place in which we all belong. You'll never look at a map the same way again.

Physicist Patricia Burchat sheds light on two basic ingredients of our universe: dark matter and dark energy. Comprising 96% of the universe between them, they can't be directly measured, but their influence is immense.

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.

Physicist Freeman Dyson suggests that we start looking for life on the moons of Jupiter and out past Neptune, in the Kuiper belt and the Oort cloud. He talks about what such life would be like -- and how we might find it.

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.

As we recklessly warm the planet by pumping greenhouse gases into the atmosphere, some industrial emissions also produce particles that reflect sunshine back into space, putting a check on global warming that we're only starting to understand. Climate activist Kelly Wanser asks: Can we engineer ways to harness this effect and further reduce warm...