1 174 739

Why the universe seems so strange

Biologist Richard Dawkins makes a case for "thinking the improbable" by looking at how the human frame of reference limits our understanding of the universe.
341 125

George Smoot on the design of the universe

At Serious Play 2008, astrophysicist George Smoot shows stunning new images from deep-space surveys, and prods us to ponder how the cosmos -- with its giant webs of dark matter and mysterious gaping voids -- got built this way.
308 524

Is this our final century?

Speaking as both an astronomer and "a concerned member of the human race," Sir Martin Rees examines our planet and its future from a cosmic perspective. He urges action to prevent dark consequences from our scientific and technological development.
180 348

What went wrong at the LHC

In this short talk from TED U 2009, Brian Cox shares what's new with the CERN supercollider. He covers the repairs now underway and what the future holds for the largest science experiment ever attempted.
168 501

What we can learn from galaxies far, far away

In a fun, exciting talk, teenager Henry Lin looks at something unexpected in the sky: distant galaxy clusters. By studying the properties of the universe's largest pieces, says the Intel Science Fair award winner, we can learn quite a lot about scientific mysteries in our own world and galaxy.
154 005

The discovery that could rewrite physics

On March 17, 2014, a group of physicists announced a thrilling discovery: the “smoking gun” data for the idea of an inflationary universe, a clue to the Big Bang. For non-physicists, what does it mean? TED asked Allan Adams to briefly explain the results, in this improvised talk illustrated by Randall Munroe of xkcd.
142 079

Distant time and the hint of a multiverse

At TEDxCaltech, cosmologist Sean Carroll attacks -- in an entertaining and thought-provoking tour through the nature of time and the universe -- a deceptively simple question: Why does time exist at all? The potential answers point to a surprising view of the nature of the universe, and our place in it.
126 598

How to defend Earth from asteroids

What's six miles wide and can end civilization in an instant? An asteroid -- and there are lots of them out there. With humor and great visuals, Phil Plait enthralls the TEDxBoulder audience with all the ways asteroids can kill, and what we must do to avoid them.
116 380

Let's not use Mars as a backup planet

Stellar astronomer and TED Senior Fellow Lucianne Walkowicz works on NASA's Kepler mission, searching for places in the universe that could support life. So it's worth a listen when she asks us to think carefully about Mars. In this short talk, she suggests that we stop dreaming of Mars as a place that we'll eventually move to when we've messed up Earth, and to start
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107 624

Can technology solve our big problems?

In 1969, Buzz Aldrin’s historical step onto the moon leapt mankind into an era of technological possibility. The awesome power of technology was to be used to solve all of our big problems. Fast forward to present day, and what's happened? Are mobile apps all we have to show for ourselves? Journalist Jason Pontin looks closely at the challenges we face to using
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100 837

How we found hundreds of potential Earth-like planets

Astronomer Dimitar Sasselov and his colleagues search for Earth-like planets that may, someday, help us answer centuries-old questions about the origin and existence of biological life elsewhere (and on Earth). Preliminary results show that they have found 706 "candidates" -- some of which further research may prove to be planets with Earth-like geochemical
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89 012

Roy Gould and Curtis Wong preview the WorldWide Telescope

Educator Roy Gould and researcher Curtis Wong show a sneak preview of Microsoft’s WorldWide Telescope, which compiles images from telescopes and satellites to build a comprehensive, interactive view of our universe.
72 442

This new telescope might show us the beginning of the universe

When and how did the universe begin? A global group of astronomers wants to answer that question by peering as far back in time as a large new telescope will let us see. Wendy Freedman headed the creation of the Giant Magellan Telescope, under construction in South America; at TEDGlobal in Rio, she shares a bold vision of the discoveries about our universe that the
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70 571

Let's look for life in the outer solar system

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.
64 585

Shedding light on dark matter

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.
63 999

The painter and the pendulum

TED visits Tom Shannon in his Manhattan studio for an intimate look at his science-inspired art. An eye-opening, personal conversation with John Hockenberry reveals how nature's forces -- and the onset of Parkinson's tremors -- interact in his life and craft.
56 456

How radio telescopes show us unseen galaxies

Our universe is strange, wonderful and vast, says astronomer Natasha Hurley-Walker. A spaceship can't carry you into its depths (yet) but a radio telescope can. In this mesmerizing talk, Hurley-Walker shows how she probes the mysteries of the universe using special technology that reveals light spectrums we can't see.
45 074

The hunt for a supermassive black hole

With new data from the Keck telescopes, Andrea Ghez shows how state-of-the-art adaptive optics are helping astronomers understand our universe's most mysterious objects: black holes. She shares evidence that a supermassive black hole may be lurking at the center of the Milky Way.
41 968

How spectroscopy could reveal alien life

Garik Israelian is a spectroscopist, studying the spectrum emitted by a star to figure out what it's made of and how it might behave. It's a rare and accessible look at this discipline, which may be coming close to finding a planet friendly to life.
38 416

Could a Saturn moon harbor life?

Carolyn Porco shares exciting new findings from the Cassini spacecraft's recent sweep of one of Saturn's moons, Enceladus. Samples gathered from the moon's icy geysers hint that an ocean under its surface could harbor life.
34 495

A history of the universe in sound

Artist-technologist Honor Harger listens to the weird and wonderful noises of stars and planets and pulsars. In her work, she tracks the radio waves emitted by ancient celestial objects and turns them into sound, including "the oldest song you will ever hear," the sound of cosmic rays left over from the Big Bang.
3 912

Tom Wujec demos the 13th-century astrolabe

Rather than demo another new technology, Tom Wujec reaches back to one of our earliest but most ingenious devices -- the astrolabe. With thousands of uses, from telling time to mapping the night sky, this old tech reminds us that the ancient can be as brilliant as the brand-new.
1 669

Carter Emmart demos a 3D atlas of the universe

For the last 12 years, Carter Emmart has been coordinating the efforts of scientists, artists and programmers to build a complete 3D visualization of our known universe. He demos this stunning tour and explains how it's being shared with facilities around the world.
1 048

3 moons and a planet that could have alien life

Is there life beyond Earth? Join NASA's director of planetary science James Green for a survey of the places in our solar system that are most likely to harbor alien life.

What the discovery of gravitational waves means

More than a billion years ago, two black holes in a distant galaxy locked into a spiral, falling inexorably toward each other, and collided. "All that energy was pumped into the fabric of time and space itself," says theoretical physicist Allan Adams, "making the universe explode in roiling waves of gravity." About 25 years ago, a group of scientists built a giant
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How we'll find life on other planets

Astronomer Aomawa Shields searches for clues that life might exist elsewhere in the universe by examining the atmospheres of distant exoplanets. When she isn't exploring the heavens, the classically trained actor (and TED Fellow) looks for ways to engage young women in the sciences using theater, writing and visual art. "Maybe one day they'll join the ranks of
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The untapped genius that could change science for the better

Jedidah Isler dreamt of becoming an astrophysicist since she was a young girl, but the odds were against her: At that time, only 18 black women in the United States had ever earned a PhD in a physics-related discipline. In this personal talk, she shares the story of how she became the first black woman to earn a PhD in astrophysics from Yale and her deep belief in
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All things are Moleeds

In a presentation that can only be described as epic, comedian Charles Fleischer delivers a hysterical send-up of a time-honored TED theme: the map. Geometry, numbers, charts and stamp art also factor in (somehow), as he weaves together a unique theory of everything called "Moleeds."

Why Earth may someday look like Mars

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.