April 30th, 2015
Episode 455 of 550 episodes
The Earth's inner core is an extremely dense, solid ball of iron and nickel, while the outer core is a flowing liquid. Life on Earth is possible thanks to the magnetic fields produced by the core which protect the Earth from dangerous cosmic rays from space. The precise structure of the core and its properties have fascinated scientists since the Renaissance. Recent research shows the picture is even more complex than we might have imagined, with suggestions that the core is spinning at a different speed from the surface. Melvyn Bragg is joined by Stephen Blundell, Professor of Physics and Fellow of Mansfield College at the University of Oxford; Arwen Deuss, Associate Professor in Seismology at Utrecht University and Simon Redfern, Professor of Mineral Physics at the University of Cambridge.