What did the sky-watchers of the ancient world think about the night sky, and its implications for human existence? Moving on to the great discoveries of Copernicus, Kepler, and Galileo, we will consider the basic science and ask about the deeper significance of these discoveries.
Space today is terrifyingly silent. But it wasn’t always thus: the early universe was filled with a hot plasma in which sound waves could travel. The cosmos was quivering with the aftershocks of the Big Bang.