The search for climate change solutions requires passion, resources and a sense of urgency -- three qualities Bill Gates clearly possesses. Bill has founded a start-up called TerraPower. After extensive computer modelling, the idea showed promise. Its new reactor greatly reduced the chance of human error. Fuelled by depleted uranium, the travelling wave reactor functions like a slow-burning candle and requires refuelling only once every decade. Bill and his team believed they had finally developed the ideal energy source, a reactor that was clean, efficient, and most importantly, safe.

Ever wonder what's happening inside your head? From dreaming to anxiety disorders, discover how your brain works with this illuminating series. The first episode looks at how memory works and examines the way in which the brain stores, processes, and retrains memories. It also looks at the ways in which memory can fail and discusses how memories can warp over time. It talks to neuroscientists and a memory champion who explains her techniques.

The second episode of the series looks at dreams and tries to explain what happens in the brain and body after we go to sleep. It looks at the significance of dreams and what dreams can teach us about ourselves. It talks to neuroscientists who discuss slow-wave sleep and REM (rapid eye movement) sleep during which dreams occur. It looks at the history of dream interpretation and its validity.

The third episode looks at anxiety and explores why it is so common. It talks to neuroscientists who explain the physiological and evolutionary basis of anxiety. Although it can help animals escape predators, anxiety can cause serious problems for human beings. It talks to sufferers of anxiety and examines the different types of anxiety people can feel. It also looks at how social media can cause anxiety.

The final episode of this series looks at what happens to the brain when someone uses psychedelic drugs. It looks at how psychedelic drugs may be useful in dealing with anxiety in cancer survivors and serious depression. It explores the history of psychedelics and examines early medical experimentation with the drug. It also discussed why psychedelics were banned and examines how they affect the brain.

Modern headlines are claiming mindfulness may cure anxiety, depression, and a whole host of other health problems. How can this simple practice of watching your own breath change the way your brain works? And can that change your life? The fourth episode of the series looks at the power of mindfulness and meditation. It examines different kinds on meditation (transcendental, dynamic, and religious) and notes that they are different from mindfulness meditation (Satipatthana). Also it talks to neuroscientists who discuss what happens in the brain during meditation.