All over the globe, in every field, scientists have used experimental methods to explore and verify theories ranging from evolution to general relativity. Beginning with the Ancients, through the pioneers of the Scientific Revolution, to the remarkable and increasingly specialized scientists of the modern era, they have inspired legions of followers, generated wonder and fear alike, and many have made discoveries that changed the course of history. This is a guide, in bite-sized chunks, to the life and work of more than 100 of the world's greatest scientists.