My guest in this week's Book Club podcast is Tom Whipple, science editor of the Times and author of the gripping new book The Battle of the Beams: The secret science of radar that turned the tide of the Second World War. He describes the ingenious technological, psychological and espionage battles that made electromagnetic warfare a decisive – if under-appreciated – contributor to Britain's victory in the air war and, finally, in the Normandy Landings.