1. Geocentric Model: Aristotle and his followers believed that the Earth was the center of the universe, with all other celestial bodies revolving around it. This model, known as the geocentric model, was accepted as dogma for over 1,500 years. It hindered progress in understanding the true nature of the solar system because it simply didn't match the observations. While it could predict some celestial movements, it failed to explain others, like retrograde motion of the planets.
2. Perfect Circles: The geocentric model also assumed that all celestial bodies moved in perfect circles, a notion deeply rooted in Greek philosophy. This led to complex and ultimately inaccurate models, as the actual paths of planets are elliptical. The obsession with circular motion prevented astronomers from considering other, more accurate, possibilities.
3. Crystal Spheres: Aristotle proposed the existence of crystalline spheres that carried the celestial bodies around the Earth. This idea, combined with the geocentric model, created a very rigid and unchangeable view of the cosmos. It was extremely difficult to accommodate new observations, such as the discovery of new stars and comets, within this rigid framework.
It wasn't until Nicolaus Copernicus challenged the geocentric model in the 16th century that a paradigm shift occurred in astronomy. His heliocentric model, which placed the Sun at the center of the solar system, paved the way for a much more accurate and complete understanding of the cosmos.
