By the 16th Century, most Europeans had a Geocentric worldview. The geocentric theory is an ancient theory that places the Earth at the center of the universe, and the stars, including the Sun, revolving around the Earth (geo: Earth, centrism: grouped or center).
Adherence to the geocentric model was largely due to several important observations. First of all, if the Earth was able to move, then one should be able to observe the displacement of the fixed stars due to the stellar parallax. In short, if the Earth moved, the shapes of the constellations would change considerably over the course of a year. Because the stars were really much further away from what the Greek astronomers postulated (making the movement extremely subtle), the stellar parallax was not detected until the 19th century.
