How does lightning strike? Should we worry about radiation from mobile phone masts? Do our TV sets give off any radiation? Why do we see the Northern Lights? We tackle these questions in this weeks show as well as reveal how a gyroscope works, why some batteries last longer than others and if the earths core uses oil as a coolant. Plus, we compare the energy consumption of electric and internal combustion engine cars! Like this podcast? Please help us by supporting the Naked Scientists