One of the companies you couldn’t ignore this year was NVIDIA, so we’re re-airing a conversation Oz had with Stephen Witt, a frequent contributor to The New Yorker and author of The Thinking Machine: Jensen Huang, NVIDIA, and the World’s Most Coveted Microchip. They discuss what’s made NVIDIA the most valuable chip company in the world, how a single piece of hardware changed the world forever, and why data centers are shrouded in so much secrecy.