Episode 3

In this episode Sagan start by addressing the drastic differences between astronomy and astrology. He then goes into the historic divide between the heliocentric and geocentric models of the universe. The most popular geocentric model was proposed by Ptolemy and was the reigning model of the universe until Nicholas Copernicus came along and proposed the heliocentric model. This model was then corroborated by Tycho Brahe’s data and the math of Johannes Kepler. My favorite part of the episode was when Sagan talked about the ancient calendars and how while good in intention they are hardly scientific in nature.