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...

Transcript: Thales was a philosopher who lived in the 6th century B.C. in Miletus, in what is now Turkey. No written work by Thales survives, but we know that he kept accurate eclipse records and he speculated about astronomy. He decided that the source of all things was one thing, and that...

Transcript: The apparent motions of the stars in the night sky depend on your position on the Earth’s surface. At a northern temperate latitude, the stars rise in the east and set in the west, and they travel on slanting paths across the sky. The north celestial pole sits in the northern sky...