The Circumference

Abstract This chapter begin with an overview of the findings presented in the work regarding the accuracy of Eratosthenes’ calculation of the circumference of the Earth. It shows that Eratosthenes was able to undertake observations of the shadows cast by sundials, and then apply the details of the ratios gleaned from these observations to calculations of the Earth’s circumference, with a very high level of accuracy. Yet, despite how accurate Eratosthenes’ results were, they were not universally accepted at the time, nor for centuries to come.

This chapter concludes with an examination of the influence that his result had on the works of following generations of scholars, astronomers and thinkers, and how it impacted how people saw the world (and their place in it) for the next seventeen centuries. It will also demonstrate how, somewhat ironically, the rejection of Eratosthenes’ accurate result played an important role in one of the most famous feats of the Age of Exploration—a feat which forever changed our understanding of the world.