Transcript: In the year 584 B.C., on the coast of Asia Minor, two warlike tribes were engaged in a fierce battle: the Medes and the Lydains. As written by the Greek poets, these two cultures were hacking away at each other on the battlefield with burnished swords and shields, when suddenly the sky darkened. The temperature dropped five or ten degrees. Animals started acting strangely, and the warriors, seeing no explanation for the darkening of the Sun, wandered, dazed and confused, from the battlefield. They were ignorant as to the cause of what had surrounded them, but, unbeknownst to them, a man called Thales had used Egyptian eclipse records to predict this eclipse of the sun. Ancient cultures like the Babylonians and the Egyptians made careful observations of the sky. They observed patterns. They had accurate calendars. But they could never answer the fundamental questions that we would ask as scientists: how far away are the objects? What’s their fundamental nature? What are the distances and sizes of the things that you see in the night and daytime sky? They could not answer these questions. The answers first started to come from a Greek group of philosopher-scientists in the 6th century B.C. who lived in the place that is now Greece and Turkey. These philosopher-scientists were able to speculate about the true nature of astronomical objects and the physical nature of the universe for the very first time.