Through dramatisation and animated graphics, this programme clearly explains current theories regarding the structure of the Earth, and how the continents came to be in their current positions. It explores the history behind the widely accepted theory of Tectonic Plates, involving Continental Drift and Sea Floor Spreading, and then examines the alternative theory of Global Expansion. Featuring a range of geological evidence, expert opinions and even a trip back in time to visit Galileo Galilei at his home in Florence, this programme looks at how once hotly-disputed ideas can become accepted as scientific fact.