These engaging talks explore the systemic issues of the US criminal justice system and how they plague everyday people and society as a whole.

The Electoral College, gerrymandering — and more! These talks answer your questions and simplify the confusing landscape of the US political system. (For more voting information specific to your location, please visit https://www.vote.org)

Fresh thinking on how we can make a health system that works better for everyone.

The beauty of hackers, says cybersecurity expert Keren Elazari, is that they force us to evolve and improve. Yes, some hackers are bad guys, but many are working to fight government corruption and advocate for our rights. By exposing vulnerabilities, they push the Internet to become stronger and healthier, wielding their power to create a better...

For the majority of recorded human history, units like the weight of a grain or the length of a hand weren't exact and varied from place to place. Now, consistent measurements are such an integral part of our daily lives that it's hard to appreciate what a major accomplishment for humanity they've been. Matt Anticole traces the wild history of t...

Imagine we want to build a new space port at one of four recently settled Martian bases, and are holding a vote to choose its location. Of the 100 colonists on Mars, 42 live on West Base, 26 on North Base, 15 on South Base, and 17 on East Base. Assuming that everyone wants the port to be closest to their home base, what is the fairest way to con...

How can we create an education system that works for kids, instead of against them? Watch eight inspiring talks from TED's May 2013 PBS special, given in their entirety.

Want to navigate the solar system without having to buy a spacecraft? Jon Nguyen demos NASA JPL's "Eyes on the Solar System" -- free-to-use software for exploring the planets, moons, asteroids, and spacecraft that rotate around our sun in real-time.

Inside you, a daily battle is being waged and your immune system is at the frontline. Most of the time, you may not even notice it's there, but over the course of your life your immune system will guard you against hundreds of potentially fatal threats. Emma Bryce explores the different components of this system and how, together, they do their ...

Since 2000, the annual number of people convicted of crimes in the United States has stayed steady, but the average number of people in jail each year has shot up. How can that be? The answer lies in the bail system— which isn't doing what it was intended to do. Camilo Ramirez details how the cash bail system disproportionally hurts people in lo...

It's past time to fix the criminal justice system in the US. These talks outline a few steps that need to be taken to get started.

Forget the rest of solar system -- Mars is humanity's next destination. We keep talking about it, but what would it really be like to live there?

At a TEDx event, 11-year-old Birke Baehr presents his take on a major source of our food -- far-away and less-than-picturesque industrial farms. Keeping farms out of sight promotes a rosy, unreal picture of big-box agriculture, he argues, as he outlines the case to green and localize food production.

What if we could better understand the world's biggest challenges simply by looking at a map? Jack Dangermond, a pioneer in geographic information system (GIS) technology that powers the digital maps people around the world use every day, speaks with TED technology curator Simone Ross about how his team is building a geospatial nervous system: a...

Damon Horowitz reviews the enormous new powers that technology gives us: to know more -- and more about each other -- than ever before. Drawing the audience into a philosophical discussion, Horowitz invites us to pay new attention to the basic philosophy -- the ethical principles -- behind the burst of invention remaking our world. Where's the m...

The US health care system assumes many things about patients: that they can take off from work in the middle of the day, speak English, have a working telephone and a steady supply of food. Because of that, it's failing many of those who are most in need, says Mitchell Katz, CEO of the largest public health care system in the US. In this eye-ope...

The land of the free has become a legal minefield, says Philip K. Howard -- especially for teachers and doctors, whose work has been paralyzed by fear of suits. What's the answer? A lawyer himself, Howard has four propositions for simplifying US law.

Every star we see in the sky has at least one planet orbiting it, says astronomer Sara Seager. So what do we know about these exoplanets, and how can we find out more? Seager introduces her favorite set of exoplanets and shows new technology that can help collect information about them -- and even help us look for exoplanets with life.

Pardons, commutations and bankruptcy laws are all tools of forgiveness within the US legal system. Are we using them frequently enough, and with fairness? Law professor Martha Minow outlines how these merciful measures can reinforce racial and economic inequality -- and makes the case for creating a system of restorative justice that focuses on ...

"Most of what we send into outer space never comes back," says astrodynamicist and TED Fellow Moriba Jah. In this forward-thinking talk, Jah describes the space highways orbiting earth and how they're mostly populated by space junk. Learn more about his quest to develop and scale the world's first crowdsourced space traffic monitoring system -- ...

Bill Gross, the founder of Idealab, talks about his life as an inventor, starting with his high-school company selling solar energy plans and kits. Learn here about a groundbreaking system for solar cells -- and some questions we haven't yet solved.

Define students by what they contribute, not what they lack -- especially those with difficult upbringings, says educator Victor Rios. Interweaved with his personal tale of perseverance as an inner-city youth, Rios identifies three straightforward strategies to shift attitudes in education and calls for fellow educators to see "at-risk" students...

How can Africa, a continent that has 54% of the world's communicable diseases but only 2% of the world's doctors, develop a healthcare system that is both efficient and effective? Healthcare consultant Mathieu Lamiuex believes emerging economies could outperform developed nations' healthcare systems by "leapfrogging" over their inefficiencies an...

As a judge with decades of experience presiding over juvenile courts, Wesley Saint Clair repeatedly encountered the same problem -- the fact that the system was designed for punishment instead of rehabilitation or crime reduction. He draws on that experience to explain why the use of restorative practices should be prioritized in the juvenile ju...

(NOTE: Adam Foss is currently under investigation by the Suffolk County District Attorney's office. For more details and TED's response, read "An update on allegations about a TED speaker" below.) When a kid commits a crime, the US justice system has a choice: prosecute to the full extent of the law, or take a step back and ask if saddling young...

Deep in our solar system, a new era of exploration is unfolding. Beneath the thick ice of Europa; in the vapor plumes on Enceladus; and within the methane lakes of Titan, scientists are hunting for extraterrestrial life. These moons are 'ocean worlds'— they contain liquid oceans, which can support the formation of life. Does life exist on ocean ...

Over our lifetimes, our bodies undergo a series of extraordinary metamorphoses: we grow, experience puberty, and many of us reproduce. Behind the scenes, the endocrine system works constantly to orchestrate these changes. Emma Bryce explains how this system regulates everything from your sleep to the rhythm of your beating heart, exerting its in...

From hours-long lines and limited polling locations to confusing and discriminatory registration policies, why is it so hard to vote in the US? Voting rights expert Amber McReynolds offers a proven alternative: a new process, already happening in parts of the country, that could bring accountability, transparency and equity to the outdated and s...

Physicist Freeman Dyson suggests that we start looking for life on the moons of Jupiter and out past Neptune, in the Kuiper belt and the Oort cloud. He talks about what such life would be like -- and how we might find it.

Carrie Nugent is part of a team that uses NASA's NEOWISE telescope to search the skies for and catalog asteroids.