The author of Sapiens has a knack for finding the profound in the obvious. He tells Steve why money is fiction, traffic can be mind-blowing, and politicians have a right to say stupid things in private.  

When she's not rescuing chickens from coyotes, Susan Athey uses economics to address real-world challenges — from online ad auctions to carbon capture technology.

Khan Academy founder Sal Khan returns to share his vision for a new way to learn — and the conversation inspires Steve to make a big announcement.

Astronomer Jill Tarter spent her career searching for extraterrestrial intelligence. She explains what civilizations from other planets could teach us about our own future.

Game theorist Barry Nalebuff explains how he used basic economics to build Honest Tea into a multimillion-dollar business, and shares his innovative approach to negotiation. 

David Keith has spent his career studying ways to reflect sunlight away from the earth. It could reduce the risks of climate change — but it won’t save us.  

Billionaire John Arnold is figuring out how to do as much good as he can with his wealth. It takes hard work, risk tolerance, and a lot of spending.

Many of us hate to think about future crises. Game designer Jane McGonigal wants to make it fun. 

Jane McGonigal designed a game to help herself recover from a traumatic brain injury — and she thinks playing games can help us all lead our best lives.

Seth Stephens-Davidowitz combs through mountains of information to find advice for everyday life.