A brief history of behavioural economics by Richard Thaler. Real-time pose estimation! In the browser! What makes a tree a tree? Recent fossil discoveries challenge ideas about Earth's start. The long-awaited data release from the Gaia space observatory has spurred a torrent of discoveries about the history and nature of our galaxy. Some machine learning algorithms turn out to be surprisingly good at predicting chaotic dynamic systems. Neural networks, faced with a navigation challenge, spontaneously evolved “grid cells”. More photos from NASA's IceBridge expedition to the Antarctic. Lisa Randall answers the question: What is dark matter? Freeman Dyson reviews Scale by Geoffrey West. Everything is a machine. Ray Dalio is the best student Deleuze never had. Photographer Naoya Hatakeyama discusses his work. The Triumph of Philanthropy. And more.