Book excerpt: How do plate tectonics work? Learn from the experts in the ALL-NEW LADYBIRD EXPERT SERIES Discover in this accessible and authoritative introduction the fundamental theory of how our dynamic planet works. You'll learn about the make up of the Earth in the past and the present, from monsoon-like currents in our planet's radioactive interior to magnetic force lines and what the planet would look like without water. You will learn about: - Our planet as an active living system - The planetary force field - Fault lines that cross continents - How plates tectonics protects life on Earth - And much more . . . Written by the celebrated geologist, academic and popular science presenter Iain Stewart, Plate Tectonics explores the Earth as a planetary machine and investigates the people and ideas that changed the way we look at the world. Learn about other topics in the Ladybird Experts series including Gravity, Quantum Physics, Climate Change and Evolution. Written by the leading lights and most outstanding communicators in their fields, the Ladybird Expert books provide clear, accessible and authoritative introductions to subjects drawn from science, history and culture. For an adult readership, the Ladybird Expert series is produced in the same iconic small hardback format pioneered by the original Ladybirds. Each beautifully illustrated book features the first new illustrations produced in the original Ladybird style for nearly forty years.