1. Geocentric Model:
- Before Aristarchus, the prevailing belief was that the Earth was the center of the universe, with the Sun and other celestial bodies revolving around it (geocentric model). Aristarchus proposed a heliocentric model, suggesting that the Earth and other planets orbited around the Sun.
2. Earth's Size:
- Eratosthenes accurately calculated the Earth's circumference using trigonometry. His measurement was remarkably close to the actual value and proved that the Earth was much larger than previously believed.
3. Sun's Distance and Size:
- Aristarchus used geometrical methods to estimate the relative distances of the Sun and Moon from the Earth. Although his estimates were not precise due to the lack of advanced instruments, his work laid the groundwork for later astronomers to determine the actual distances more accurately.
4. Moon's Size and Distance:
- Eratosthenes estimated the size and distance of the Moon using observations and calculations. His estimates were reasonably close to the actual values and provided important insights into the nature of the lunar body.
5. Spherical Shape of Earth:
- Both Aristarchus and Eratosthenes contributed to the growing understanding of the Earth's spherical shape. They used observations and mathematical reasoning to support the concept of a spherical Earth, challenging the flat Earth belief that was prevalent at the time.
6. Celestial Distances and Sizes:
- Aristarchus attempted to determine the relative distances and sizes of the Sun and Moon compared to the Earth. While his estimates were not accurate due to the limitations of ancient technology, his approach showed that celestial bodies were much farther away and larger than previously thought.
Overall, the discoveries of Aristarchus and Eratosthenes challenged and disproved some of the prevailing beliefs about the Earth's position in the universe, its size, and the relative distances and sizes of celestial bodies. Their contributions laid the foundation for further advancements in astronomy and our understanding of the cosmos.