This week we're talking about fire: in particular, wildfires. How they spread and how we manage them, but also the deeper history of wildfires on our planet and how they've been shaping our world for a long, long time. We speak with Andrew Scott, Emeritus Professor of Geology at Royal Holloway, University of London, about his book "Burning Planet: The Story of Fire Through Time", learning about wildfire on our planet now and in deep history. And we catch up with Caroline Weinberg, interm executive director of the March for Science organization, about this year's march on April 14.