TED-Ed lessons

What's the Best Fuel? (4:40)

Dig into which fuel— gasoline, electric, biofuels, or electrofuels— is both affordable for consumers and sustainable for the planet.

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How Much Electricity do We Need? (5:01)Discover how much electricity humanity uses, and how clean energy sources could help revolutionize our energy supply in the future.

How Much Land Does It Take to Power the World? (4:47)

Explore the sustainability of fossil fuels, nuclear power, and renewable energy and how much space each of these power sources uses.

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YouTube channel 'Reactions' are getting to the bottom of one of the biggest quandaries in science: Why dogs sniff each other’s butts.

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Why sitting is bad for you

Sitting down for brief periods of rest can help us recover from stress or recuperate from exercise. But nowadays, our lifestyles make us sit much more than we move around. Are our bodies built for such a sedentary existence?

How Many Verb Tenses Does English Have?

What are the different verb tenses in English and when should you use them?

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What would society look like if the world's population was only 100 people? In this video, GOOD Magazine uses data to uncover the answer.

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Contraceptives are designed to prevent pregnancy in three basic ways: they either block sperm, disable sperm before they reach the uterus, or suppress ovulation. But is one strategy better than the other? And how does each one work? NWHunter describes the mechanics behind different kinds of contraceptives.

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If you have a tattoo, you’re part of a rich cultural history that dates back at least 8,000 years. Where did this practice of body modification come from, and how has its function changed over time? Addison Anderson tracks the history of getting inked.

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Computers can beat us in board games, transcribe speech, and instantly identify almost any object. But will future robots go further by learning to figure out what we’re feeling? Kostas Karpouzis imagines a future where machines and the people who run them can accurately read our emotional states — and explains how that could allow them to assist us, or manipulate us, at unprecedented scales.

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Self-driving cars are already cruising the streets today. And while these cars will ultimately be safer and cleaner than their manual counterparts, they can’t completely avoid accidents altogether. How should the car be programmed if it encounters an unavoidable accident? Patrick Lin navigates the murky ethics of self-driving cars.

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Do you think sugar is only found in candy? Want to know why your body craves certain foods? Take a look at this video and become aware of the affect that sugar has on your brain!

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How interpreters juggle two languages at onceLanguage is complex, and when abstract or nuanced concepts get lost in translation, the consequences may be catastrophic. Given the complexities of language and cultural exchange, how do these epic miscommunications not happen all the time? Ewandro Magalhaes explains how much of the answer lies with the skill and training of interpreters to overcome language barriers. [Directed by Andrew Foerster, narrated by Addison Anderson].

The language of lyingWe hear anywhere from 10 to 200 lies a day. And although we've spent much of our history coming up with ways to detect these lies by tracking physiological changes in their tellers, these methods have proved unreliable. Is there a more direct approach? Noah Zandan uses some famous examples of lying to illustrate how we might use communications science to analyze the lies themselves. [Directed by Nadav Arbel, narrated by Noah Zandan].

How to practice effectively...for just about anythingMastering any physical skill takes practice. Practice is the repetition of an action with the goal of improvement, and it helps us perform with more ease, speed, and confidence. But what does practice actually do to make us better at things? Annie Bosler and Don Greene explain how practice affects the inner workings of our brains. [Directed by Martina Meštrović, narrated by Addison Anderson, music by Wonder Boy Audio].

Why you shouldn't worry about pooping once a dayYou may have heard that you should be pooping once a day -- but that's a load of crap, says Dr. Jen Gunter. From the enzymes in your mouth to the nutrient-absorbing power of your large intestine, she journeys through the digestive tract to explain why it's okay to poop at your own pace -- and shares the many regulating benefits of a fiber-rich diet. For more on how your body works, tune in weekly to her podcast Body Stuff with Dr. Jen Gunter, from the TED Audio Collective.

Humans should urinate at least four to six times a day, but occasionally, the pressures of modern life force us to clench and hold it in. How bad is this habit, and how long can our bodies withstand it? Heba Shaheed takes us inside the bladder to find out.

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