Alan Alda has issued this year’s challenge to the world’s top scientists: What is sound? In an action-packed hour of interactive demonstrations, Alan and a team of communication experts invite the audience to explore what we hear, how we hear, and what that means for different species.

What we touch. What we smell. What we feel. They’re all part of our reality. But what if life as we know it reflects only one side of the full story? Some of the world’s leading physicists think that this may be the case.

Paralyzed patients are starting to walk with the aid of exoskeletons and doctors are testing artificial retinas in the blind thanks to neuroprosthetics: surgical brain implants that restore some function …

Humans work together on enormous scales to build complex tools as large as cities and create social networks that span the globe. What is the key to our success? This …

The mechanism of collapsing stars falls short of explaining the existence of supermassive black holes—giants that weigh millions or even billions of times the mass of the Sun. Astrophysicist Priya …

This video is part of our Brilliant Breakthroughs series: our new 20-episode mini-series exploring the “Eureka!” moments and proud accomplishments of the greatest scientific minds of our time. Join us …