We explore the history of Pi, examine rheumatoid arthritis and seek the science of sleep in this roundup of the British Science Festival. In the news, we hear how to read the history of the solar system on the surface of the moon, and discover a development in quantum computing. Plus, we launch Naked Engineering, stripping off the image of dirty overalls to discover how engineers solve real-world problems. Diana asks if olive oil is healthier than butter in our Question of the Week.