Facts change all the time. Smoking has gone from doctor recommended to deadly. We used to think the Earth was the center of the universe and that the brontosaurus was a real dinosaur. In short, what we know about the world is constantly changing. Samuel Arbesman is on the show today to help us understand how this evolution of facts unfolds in a fascinating way that can have a powerful impact on our lives. In this interview Sam and Chris discuss The Half-Life of Facts: Why Everything We Know Has an Expiration Date, as well as his latest book Overcomplicated: Technology at the Limits of Comprehension.