TED-Ed

Loki has challenged you to a winner-take-all game to end Ragnarok. Can you beat him and win the right to rule the new world?--Ragnarok has been raging for far too long; many gods and heroes have fallen, and the rest can barely stand. Loki, his bright eyes dimmed by exhaustion, asks to meet. He proposes that you and he settle the conflict with a game atop a sacred table engraved with your names. Ca...

View full lesson: http://ed.ted.com/lessons/losing-everything-david-hoffmanNine days before TED2008, filmmaker David Hoffman lost almost everything he owned in a fire that destroyed his home, office and 30 years of passionate collecting. He looks back at a life that's been wiped clean in an instant -- and looks forward. Talk by David Hoffman. Learn more about your ad choices. Visit megaphone.fm/ad...

Dig into the tale of Princess Savitri and her one true love, Satyavan, and the tragic prophecy that entwined their fates forever.--Princess Savitri was benevolent, brilliant, and bright. Her grace was known throughout the land, and many princes and merchants flocked to her family’s palace to seek her hand in marriage. But upon witnessing her blinding splendor in person, the men lost their nerve. U...

Explore how pulling an all-nighter can impact your cognitive function, and find out what happens to your brain when you don't sleep.--You’re just one history final away from a relaxing spring break. But you still have so much to study! You decide to follow in the footsteps of many students before you, and pull an all-nighter. So, what happens to your brain when you stay up all night? And does cram...

Puzzle through the ethical dilemma where two ships are in distress but you can only save one, and decide: which do you choose?--You are the captain of an interstellar cargo transport headed to port when you receive two distress calls. The first is from a labor ship, whose passengers are running out of oxygen. The other from a luxury space cruiser which has lost a thruster, sending them careening i...

View full lesson: http://ed.ted.com/lessons/your-genes-are-not-your-fate-dean-ornishDean Ornish shares new research that shows how adopting healthy lifestyle habits can affect a person at a genetic level. For instance, he says, when you live healthier, eat better, exercise, and love more, your brain cells actually increase. Talk by Dean Ornish. Learn more about your ad choices. Visit megaphone.fm/...

Explore how the Right to Repair movement is pushing back against companies which don’t want consumers fixing their products.--Today, some companies are working hard to prevent consumers from repairing products on their own. In many cases, repair can only be done by the original manufacturer, if at all. With limited repair options available, we end up buying new and throwing more items out. So, how...

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. (Filmed at TEDxBoulder.)Talk by Phil Plait. Learn more about your ad choices. Visit megaphone.fm/adchoices

View full lesson: http://ed.ted.com/lessons/is-light-a-particle-or-a-wave-colm-kelleherCan we accurately describe light as exclusively a wave or just a particle? Are the two mutually exclusive? In this third part of his series on light and color, Colm Kelleher discusses wave-particle duality and its relationship to how we see light and, therefore, color. Lesson by Colm Kelleher, animation by Nelso...

Explore the phenomenon known as peat fires, smoldering fires that burn underground and can continue for months or even years.--In 1997, a fire began in Indonesia that would rage for almost a year. Despite being one of the largest fires in recorded history, for months at a time it burned without a flame. This might sound like a uniquely freaky fire, but it’s actually one of many. So, is it possible...

View full lesson: http://ed.ted.com/lessons/vermicomposting-how-worms-can-reduce-our-waste-matthew-rossNearly one third of our food ends up in the trash can. There is hope, however, in the form of worms, which naturally convert organic waste into fertilizer. Matthew Ross details the steps we can all take to vermicompost at home -- and why it makes good business sense to do so. Lesson by Matthew Ro...

View full lesson: http://ed.ted.com/lessons/the-bottom-billion-paul-collierAround the world right now, one billion people are trapped in poor or failing countries. How can we help them? Economist Paul Collier lays out a bold, compassionate plan for closing the gap between rich and poor. Talk by Paul Collier. Learn more about your ad choices. Visit megaphone.fm/adchoices

How can you make your voice heard in a noisy world? The key is public speaking and presentation literacy, and we can help: http://bit.ly/TMCPSApp--Storytelling is an ancient art; as humans developed language and culture, we learned to share our stories, thoughts, and dreams. And that storytelling evolved into public speaking, and our audience— thanks to the internet— is the whole world, not just a...

Learn more at https://brilliant.org/TedEd--A spy presses a button on their suit and blinks out of sight. A wizard wraps himself in a cloak and disappears. A star pilot flicks a switch, and their ship vanishes into space. Invisibility is one of the most tantalizing powers in fiction, spanning all kinds of stories. But could this fantasy ever become a reality? Max G. Levy digs into the technologies...

Dig into the engineering of the Hoover Dam, a concrete arch-gravity dam on the Colorado River that supplies water to the US southwest.--In the early 20th century, the US had expanded from coast to coast, but many cities in the southwest still lacked reliable water sources. The Colorado River's erratic flow and frequent floods made it unreliable for agriculture, and the region’s growing cities need...

View full lesson: http://ed.ted.com/lessons/write-your-story-change-history-brad-meltzerThe idea that youth is wasted on the young? Wrong. Martin Luther King, Jr. and the creators of Superman were all under 30 when they wrote themselves into history. In this inspirational TEDYouth 2011 Talk, Brad Meltzer encourages us to dream big, work hard, and stay humble. Talk by Brad Meltzer. Learn more about...

Dig into what causes your stress response to be triggered, and how you can best train your mind and body to deal with stress.--An upcoming project deadline, a fight with a family member, or even an embarrassing moment can easily trigger our body’s stress response. While we can’t always control what life throws at us, there are ways to better prepare for stressful events we may experience. So, how...

Charlie Todd causes bizarre, hilarious, and unexpected public scenes: Seventy synchronized dancers in storefront windows, "ghostbusters" running through the New York Public Library, and the annual no-pants subway ride. In his talk, he shows how his group, Improv Everywhere, uses these scenes to bring people together. (Filmed at TEDxBloomington.)Talk by Charlie Todd. Learn more about your ad choice...

Teaching is both a science and an art, and many teachers around the world spend endless hours perfecting their professional practice. At TEDActive 2013, a few teachers from the United States offer some tricks of the trade they've learned (and continue to hone) along the way. Learn more about your ad choices. Visit megaphone.fm/adchoices

View full lesson: http://ed.ted.com/lessons/can-we-domesticate-germs-paul-ewaldEvolutionary biologist Paul Ewald drags us into the sewer to discuss germs. Why are some more harmful than others? How could we make the harmful ones benign? Searching for answers, he examines a disgusting, fascinating case: diarrhea. Talk by Paul Ewald. Learn more about your ad choices. Visit megaphone.fm/adchoices

Dig into the Chinese myth of Lady Meng Jiang, and how her grief over the death of her husband brought down the Great Wall.--Long ago, an emperor decided to build a great wall to protect his new empire and ensure his power. He ordered men across China to leave their homes and submit to the grueling labor required for its construction. As years passed and the wall grew, few returned home. But one wo...

View full lesson: http://ed.ted.com/lessons/how-to-defeat-a-dragon-with-math-garth-sundemHaving trouble remembering the order of operations? Let's raise the stakes a little bit. What if the future of your (theoretical) kingdom depended on it? Garth Sundem creates a world in which PEMDAS is the hero but only heroic when in the proper order. Lesson by Garth Sundem, animation by Mark Phillips. Learn...

Discover how scientists developed atomic clocks, which use the vibrations of atoms to measure and maintain a globally consistent time. --In 1967, researchers gathered to answer a long-running scientific question: just how long is a second? It might seem obvious at first. A second is the tick of a clock, the swing of a pendulum, the time it takes to count to one. But how precise are those measureme...

Dig into the animal kingdom’s capacity for generosity, and find out how cooperation between animals may contribute to their survival.--Charles Darwin introduced the notion of “survival of the fittest,” where the fittest animals are those who can survive long enough to produce healthy offspring. The fittest animal can also be the most stealthy, resourceful, or even the most cooperative. So what exa...

Discover what factors helped Leonardo da Vinci’s “Mona Lisa” become the world’s most famous painting.--More than 500 years after its creation, Leonardo da Vinci’s “Mona Lisa” is arguably the world’s most famous painting. Many scholars consider it an outstanding work of Renaissance art— but history is full of great paintings. So, how did this particular portrait skyrocket to unprecedented fame? Noa...