TED-Ed

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...

View full lesson: http://ed.ted.com/lessons/questioning-the-universe-stephen-hawkingIn 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. Talk by Stephen Hawking. Learn more about your ad choices. Visit megaphone.fm/adchoices

Explore how to build healthy habits when it comes to making, growing, and maintaining friendships.--Friendships can change how we see and move through the world. They can boost our academic performance, help us deal with setbacks, and even improve our health. And the relationships we form in adolescence can shape our beliefs, values, and emotional growth. But making and maintaining friends isn’t a...

How do we search for alien life if it's nothing like the life that we know? Christoph Adami shows how he uses his research into artificial life -- self-replicating computer programs -- to find a signature, a 'biomarker,' that is free of our preconceptions of what life is. (Filmed at TEDxUIUC.)Talk by Christoph Adami. Learn more about your ad choices. Visit megaphone.fm/adchoices

View full lesson: http://ed.ted.com/lessons/what-aristotle-and-joshua-bell-can-teach-us-about-persuasion-conor-neill Imagine you are one of the world's greatest violin players, and you decide to conduct an experiment: play inside a subway station and see if anyone stops to appreciate when you are stripped of a concert hall and name recognition. Joshua Bell did this, and Conor Neill channels Aristo...

Discover the benefits of walking, and how this simple exercise can positively impact the health of your body and brain.--For years, Jean Béliveau walked from country to country, with the goal of circumnavigating the globe on foot. While few people have the time or desire to walk such extreme lengths, research shows that adding even a modest amount of walking to your daily routine can dramatically...

View full lesson: http://ed.ted.com/lessons/is-there-a-center-of-the-universe-marjee-chmiel-and-trevor-owensIt's been a long road to the discovery that Earth is not the center of the Solar System, the Milky Way, or the universe; great thinkers from Aristotle to Bruno have grappled with it for millennia. But if we aren't at the center of the universe, what is? Marjee Chmiel and Trevor Owens discuss...

View full lesson: http://ed.ted.com/lessons/how-to-find-the-true-face-of-leonardo-siegfried-woldhekMona Lisa is one of the best-known faces on the planet. But would you recognize an image of Leonardo da Vinci? Illustrator Siegfried Woldhek uses some thoughtful image-analysis techniques to find what he believes is the true face of Leonardo. Talk by Siegfried Woldhek. Learn more about your ad choice...

View full lesson: http://ed.ted.com/lessons/detention-or-eco-club-choosing-your-future-juan-martinezGrowing up surrounded by gangs in South Central Los Angeles, Juan Martinez wasn't exposed to the great outdoors. One day in high school, he was given the life-changing choice between detention or Eco Club. He chose nature and has since devoted his life to getting kids back to the outdoors as a Natio...

Ada imagines how society would change if governments paid living organ donors. Should we receive compensation for our organs?--This is episode 2 of the animated series, “Ada.” This 5-episode narrative follows the young library assistant Ada as she juggles two worlds: her daily mundane reality and the future she vividly imagines for all humanity. Traveling through her visions of potential futures,...

Follow Chu Hong, a Chinese martial artist in training, as he practices his skills and competes in an archery tournament.--The year is 1030 CE. Chu Hong's best friend, Liang Gao, tells him that the local magistrate has been spotted holding a surprise archery competition in a nearby town and will arrive at their village soon. This is Hong’s chance to showcase his talents in martial arts— and secure...

Explore the early days of the Ottoman Empire, as shrewd political rulers grew the principality into an intercontinental empire. --In the late 13th century, Osman I established a small principality sandwiched between a crumbling Byzantine Empire and a weakened Sultanate of the Seljuk of Rum, in what is now Turkey. In just a few generations, this territory had outmaneuvered more powerful neighbors t...

View full lesson: http://ed.ted.com/lessons/behind-the-great-firewall-of-china-michael-antiMichael Anti (aka Jing Zhao) has been blogging from China for 12 years. Despite the control the central government has over the Internet -- "All the servers are in Beijing" -- he says that hundreds of millions of microbloggers are in fact creating the first national public sphere in the country's history, an...

View full lesson: http://ed.ted.com/lessons/a-plant-s-eye-view-michael-pollanWhat if human consciousness isn't the end-all be-all of Darwinism? What if we are all just pawns in corn's clever strategy game to rule the Earth? Author Michael Pollan asks us to see the world from a plant's-eye view. Talk by Michael Pollan. Learn more about your ad choices. Visit megaphone.fm/adchoices

Dig into the history of arsenic dating back to ancient civilizations, and find out why this element is known as the king of poisons.--No substance has been as constant an ally to insidious scheming as arsenic, the so-called “king of poisons.” In its chemically pure form, it isn’t much of a threat because our bodies don’t absorb it well; it’s when arsenic combines with other elements that things ge...

View full lesson: http://ed.ted.com/lessons/conserving-our-spectacular-vulnerable-coral-reefs-joshua-drewHow do coral reef conservationists balance the environmental needs of the reefs with locals who need the reefs to survive? Joshua Drew draws on the islands of Fiji and their exemplary system of protection, called "connectivity," which also keep the needs of fishermen in mind. Lesson by Joshua D...

Dig into the tragic myth of Tristan and Princess Isolde, and how they fall in love despite her being promised to another.--After witnessing a bird carrying a single golden hair, King Mark of Cornwall declared his future bride must have equally radiant locks. The only royal matching this description was Princess Isolde of Ireland. So the king sent Tristan, his bravest knight, to extend an olive bra...

Download a free audiobook version of “Where the Crawdads Sing“ and support TED-Ed's nonprofit mission: https://www.audible.com/ted-ed--Odin, the king of Asgard, was plagued by nightmares. Three fearsome figures haunted his dreams: a massive, writhing shadow; a shambling, rotting corpse; and worst of all, a monstrous beast with a deadly bite. Though their true forms were unknown to him, he could te...

View full lesson: http://ed.ted.com/lessons/how-photography-connects-us-david-griffinThe photo director for National Geographic David Griffin knows the power of photography to connect us to our world. In a Talk filled with glorious images, he discusses how we all use photos to tell our stories. Talk by David Griffin. Learn more about your ad choices. Visit megaphone.fm/adchoices