Given a range of integers from 0 to 100, what would the whole number closest to 2/3 of the average of all numbers guessed be? For example, if the average of all guesses is 60, the correct guess will be 40. The game is played under conditions known to game theorists as "common knowledge:" every player has the same information— they also know that...

The word "mole" suggests a small, furry burrowing animal to many. But in this lesson, we look at the concept of the mole in chemistry. Learn the incredible magnitude of the mole-- and how something so big can help us calculate the tiniest particles in the world. [Directed by Barbara Benas, narrated by Daniel Dulek].

Before he turned physics upside down, a young Albert Einstein supposedly showed off his genius by devising a complex riddle involving a stolen exotic fish and a long list of suspects. Can you resist tackling a brain teaser written by one of the smartest people in history? Dan Van der Vieren shows how. [Directed by Artrake Studio, narrated by Add...

Often people make decisions that are not "rational" from a purely economical point of view — meaning that they don't necessarily lead to the best result. Why is that? Are we just bad at dealing with numbers and odds? Or is there a psychological mechanism behind it? Sara Garofalo explains heuristics, problem-solving approaches based on previous e...

Bruce Bueno de Mesquita uses mathematical analysis to predict (very often correctly) such messy human events as war, political power shifts, Intifada ... After a crisp explanation of how he does it, he offers three predictions on the future of Iran.

Mathematician Steven Strogatz shows how flocks of creatures (like birds, fireflies and fish) manage to synchronize and act as a unit -- when no one's giving orders. The powerful tendency extends into the realm of objects, too.

On their 20th birthday, identical twin astronauts volunteer for an experiment. Terra will remain on Earth, while Stella will board a spaceship. Stella's ship will travel to visit a star that is 10 light-years away, then return to Earth. As they prepare to part ways, the twins wonder what will happen when they're reunited. Who will be older? Ambe...

If you were in the marching band, jazz ensemble or choir, music is a part of you — whether you still play or not. Let these talks tap into that.

In 2016, at age 13, Anushka Naiknaware was the youngest winner of the Google Science Fair, with her invention of a clever new bandage that tells caregivers when it needs to be changed.

This is episode 9 of our animated series "Think Like A Coder." This 10-episode narrative follows a girl, Ethic, and her robot companion, Hedge, as they attempt to save the world. The two embark on a quest to collect three artifacts and must solve their way through a series of programming puzzles. [Directed by Kozmonot Animation Studio, narrated ...

Could there be intelligent life on other planets? This question has piqued imagination and curiosity for decades. Explore the answer with the Drake Equation -- a mathematical formula that calculates the possibility of undiscovered life. [Directed by Jeremiah Dickey, narrated by Jill Tarter].

Your research team has found a prehistoric virus preserved in the permafrost and isolated it for study. After a late night working, you're just closing up the lab when a sudden earthquake hits and breaks all the sample vials. Will you be able to destroy the virus before the vents open and unleash a deadly airborne plague? Lisa Winer shows how. [...

Inspired by cell division, Michael Hansmeyer writes algorithms that design outrageously fascinating shapes and forms with millions of facets. No person could draft them by hand, but they're buildable -- and they could revolutionize the way we think of architectural form.

Statistics are persuasive. So much so that people, organizations, and whole countries base some of their most important decisions on organized data. But any set of statistics might have something lurking inside it that can turn the results completely upside down. Mark Liddell investigates Simpson's paradox. [Directed by Mike Foster and Tom Sande...

This is episode 6 of our animated series "Think Like A Coder." This 10-episode narrative follows a girl, Ethic, and her robot companion, Hedge, as they attempt to save the world. The two embark on a quest to collect three artifacts and must solve their way through a series of programming puzzles. [Directed by Kozmonot Animation Studio, narrated ...

Whether you love to swim, run, ski, shoot hoops or play cricket, these talks will make you wish you had a foam finger to hoist in the air.

¡Ideas en nuestro idioma! TED Talks in Spanish, with subtitles in English and other languages.

Reuben Margolin's moving sculptures combine the logic of math with the sensuousness of nature.

At the University of Pennsylvania, Angela Lee Duckworth studies intangible concepts such as self-control and grit to determine how they might predict both academic and professional success.

It's an incredible discovery: an abandoned alien space station filled with precursor technology. Now every species in the galaxy is in a mad dash to get there first, but you've got a problem. Your ship can't hold enough fuel to get you there unless you vent caches of it into space at precise points and then come back for the fuel later. Can you ...

Accepting his 2008 TED Prize, physicist Neil Turok speaks out for talented young Africans starved of opportunity: by unlocking and nurturing the continent's creative potential, we can create a change in Africa's future.

At Pixar, Danielle Feinberg delights in bending the rules of light to her every whim.

Michael Moschen puts on a quietly mesmerizing show of juggling. Don't think juggling is an art? You might just change your mind after watching Moschen in motion.

In keeping with the theme of TED2008, professor Stephen Hawking asks some Big Questions about our universe -- How did the universe begin? How did life begin? Are we alone? -- and discusses how we might go about answering them.

Why can we find geometric shapes in the night sky? How can we know that at least two people in London have exactly the same number of hairs on their head? And why can patterns be found in just about any text — even Vanilla Ice lyrics? PatrickJMT describes the Ramsey theory, which states that given enough elements in a set or structure, some inte...

At the 2008 EG conference, famed puzzle designer Scott Kim takes us inside the puzzle-maker's frame of mind. Sampling his career's work, he introduces a few of the most popular types, and shares the fascinations that inspired some of his best.

As a wildfire rages through the grasslands, three lions and three wildebeest flee for their lives. To escape the inferno, they must cross over to the left bank of a crocodile-infested river. Can you help them figure out how to get across on the one raft available without losing any lives? Lisa Winer shows how. [Directed by Artrake Studio, narrat...

This is episode 8 of our animated series "Think Like A Coder." This 10-episode narrative follows a girl, Ethic, and her robot companion, Hedge, as they attempt to save the world. The two embark on a quest to collect three artifacts and must solve their way through a series of programming puzzles. [Directed by Kozmonot Animation Studio, narrated ...

Dive into the unexplored universe beneath the waves: the beautiful, fragile (and sometimes terrifying) world of the ocean.

When they're used well, graphs can help us intuitively grasp complex data. But as visual software has enabled more usage of graphs throughout all media, it has also made them easier to use in a careless or dishonest way — and as it turns out, there are plenty of ways graphs can mislead and outright manipulate. Lea Gaslowitz shares some things to...