From satellite-enabled GPS to hi-tech medical procedures – much of today's modern science builds on the work of great thinkers from the past. But while the names Newton, Galileo and Copernicus are well known, just who were the scientists who came before them - in the Golden Age of Islamic Science? Iraqi-born theoretical physicist Jim al-Khalili takes us on a journey of discovery, unravelling the links between the latest scientific developments and the unsung scientific heroes of the past.