In 132 CE, Zhang Heng presented his latest invention: a large vase he claimed could tell them whenever an earthquake occurred for hundreds of miles. Today, we no longer rely on pots as warning systems, but earthquakes still offer challenges to those trying to track them. Why are earthquakes so hard to anticipate, and how could we get better at predicting them? Jean-Baptiste P. Koehl investigates. [Directed by Cabong Studios, narrated by Addison Anderson, music by Matheus Wittmann].

In a talk that's by turns heartbreaking and hilarious, writer and podcaster Nora McInerny shares her hard-earned wisdom about life and death. Her candid approach to something that will, let's face it, affect us all, is as liberating as it is gut-wrenching. Most powerfully, she encourages us to shift how we approach grief. "A grieving person is going to laugh again and smile again," she says. "They're going to move forward. But that doesn't mean that they've moved on."

Keith Kirkland is developing wearable tech that communicates information using only the sense of touch. He's trying to figure out: What gestures and vibration patterns could intuitively communicate ideas like "stop" or "go"? Check out his team's first product, a navigation device for the blind and visually impaired, and learn more about the entirely new "haptic language" he's creating to power it.

Why do teenagers sometimes make outrageous, risky choices? Do they suddenly become reckless, or are they just going through a natural phase? To find out, Kashfia Rahman -- winner of the Intel International Science and Engineering Fair (and a Harvard freshman) -- designed and conducted an experiment to test how high school students respond to and get used to risk, and how it changes their still-developing brains. What she discovered about risk and decision-making could change how we think about why teens do what they do.

Around the world there are more than 600 plant species that supplement a regular diet of sunlight, water and soil with insects, frogs and even rats. Flies, tadpoles and beetles fall prey to the remarkable, predatory antics of carnivorous plants. What exactly are carnivorous plants and how do they trap their prey? Kenny Coogan dives into the world of these flesh-eating tricksters. [Directed by Lisa LaBracio, narrated by Addison Anderson, music by Jarrett Farkas].

At 16, Rana Abdelhamid started teaching self-defense to women and girls in her neighborhood. Almost 10 years later, these community classes have grown into Malikah: a global grassroots network creating safety, power and solidarity for all women. How did she do it? Abdelhamid shares three ingredients for building a movement from the ground up.

Kakenya Ntaiya turned her dream of getting an education into a movement to empower vulnerable girls and bring an end to harmful traditional practices in Kenya. Meet two students at the Kakenya Center for Excellence, a school where girls can live and study safely -- and uplift their community along the way. "When you empower a girl, you transform a community," Ntaiya says.

Robot brains are getting smarter and smarter, but their bodies are often still clunky and unwieldy. Mechanical engineer Christoph Keplinger is designing a new generation of soft, agile robot inspired by a masterpiece of evolution: biological muscle. See these "artificial muscles" expand and contract like the real thing and reach superhuman speeds -- and learn how they could power prosthetics that are stronger and more efficient than human limbs.

In an unmissable talk, journalist Carole Cadwalladr digs into one of the most perplexing events in recent times: the UK's super-close 2016 vote to leave the European Union. Tracking the result to a barrage of misleading Facebook ads targeted at vulnerable Brexit swing voters -- and linking the same players and tactics to the 2016 US presidential election -- Cadwalladr calls out the "gods of Silicon Valley" for being on the wrong side of history and asks: Are free and fair elections a thing of the past?

Can Twitter be saved? In a wide-ranging conversation with TED's Chris Anderson and Whitney Pennington Rodgers, Twitter CEO Jack Dorsey discusses the future of the platform -- acknowledging problems with harassment and moderation and proposing some fundamental changes that he hopes will encourage healthy, respectful conversations. "Are we actually delivering something that people value every single day?" Dorsey asks.