History tells us that humans have always wondered about the natural world. For thousands of years, our ancestors gazed in wonder at the heavens, experimented with plants and medicines, and tried to comprehend their own mortality. But when did “science” actually begin to be its own field, separate from philosophy, astrology, or faith? Beginning with human origins and prehistoric tools, we turn to the astronomical achievements of the Mayans and Aztecs, the advanced science of early China and the Islamic world, and the murky intricacies of alchemy and magic. We end with the Scientific Revolution, when the world-changing ideas of Copernicus, Galileo, Bacon, Harvey, and Newton gave birth to our modern scientific method.