In a world without artificial lights, the night sky was ablaze with over a thousand stars, whose patterns illustrated stories people had heard since childhood. Thus, ancient people viewed the sky differently than we do. Skywatching was crucial to daily life, since the motions of the heavens served as timekeeper, calendar, compass, and almanac for planning when to plant and harvest. The perfect regularity of celestial cycles was the only guaranteed aspect of life and inspired a wide range of religious and philosophical views, as different cultures struggled to grasp the unseen forces that govern the cosmos.
This visually rich course is designed to provide a nontechnical description of modern astronomy, including the structure and evolution of planets, stars, galaxies, and the Universe as a whole. It includes almost all of the material in my first two astronomy courses for The Teaching Company, produced in 1998 and 2003, but with a large number of new images, diagrams, and animations. The discoveries reported in the 2003 course are integrated throughout these new lectures, and more recent findings (through mid-2006) are included, as well. Much has happened in astronomy during the past few years; we will discuss the most exciting and important advances.