We’ve all wondered why we dream, or even why we sleep. We know it’s good for you, but we don’t really know what’s going on in the brain while you’re tucked up under the covers.In the pod this week are New Scientist journalists Rowan Hooper, Valerie Jamieson, Leah Crane and Jess Hamzelou.The team discusses a study that shows sleep functions differently depending on our age, particularly when babies develop into toddlers, and the purpose of sleep shifts from growing and developing their brains, to repairing them. Also on the show - favourite facts about evolution, like how coffee is able to cause epigenetic changes to your DNA. The team also discusses NASA’s plan to land a man and woman on the moon in 2024. Plus: the team explains how water can exist in two liquid forms simultaneously, and celebrates climate hope with China’s recent pledge to reach net-zero carbon emissions.To find out more, subscribe at newscientist.com/podcasts. Our GDPR privacy policy was updated on August 8, 2022. Visit acast.com/privacy for more information.