Unit 1
Humanity and the Cosmos

Astronomy is the oldest science; it is also one of the newest. These statements may seem contradictory, but they give an indication of the importance of astronomy in the development of civilization. The ancients relied on astronomical observations for information about the time to plant and harvest crops. During the great ages of exploration, seafarers used astronomical observations to determine their position on the Earth’s surface. More recently, other physical sciences, especially physics and chemistry, have profoundly affected astronomy. Using the laws of these sciences to assist in interpreting their observations, astronomers have made truly amazing discoveries about the universe we live in.