A history of the various manifestations and shifting meaning of the Twentieth Century's single great contribution to mythology: the UFO.Neither a credulous work of conspiracy theory nor a sceptical debunking of belief in 'flying saucers',How UFOs Changed the World explores the origins of UFOs in the build-up to the First World War and how reports of them have changed in tandem with world events, science and culture. The book also explores the overlaps between UFO belief and religion and superstition.