If everything was the exact same color, would we still be able to see? How long does it take to get to space? How many people are asleep right now?

John has launched a new podcast project with Katie Mack! Crash Course Pods: The Universe is a new limited series podcast where Dr. Katie Mack, a theoretical astrophysicist, walks John Green through the history of the entire universe - including the parts that haven’t been written yet.