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.

Why are we drawn to symmetry? Because it provides order in a seemingly chaotic world? Because our brains are the product of the very same laws that yield the flower, the snowflake and the solar system?

What do aerobic exercise and memory have in common? According to neuroscientist Wendy Suzuki, more than you think. Her passion for the human brain, memory, and exercise are inspiring people …

Are there limits to the human lifespan? Is it possible to stop the process of aging? On average, humans now live far longer than at any point in our history …

Elaine Fuchs pioneered the field of reverse genetics—studying proteins and learning what they do, and how they do it, in order to identify the genetic disease they cause when they …

Pioneering computer scientist and physicist Stephen Wolfram joins Brian Greene to discuss the interplay between physical law, computation, and artificial intelligence.