: In his only surviving work, On the Sizes and Distances of the Sun and Moon , he used geometry to estimate celestial dimensions.
Aristarchus of Samos (c. 310–230 BC) was a pioneering ancient Greek astronomer and mathematician who famously proposed the first known of the universe, placing the Sun at the center. Often called the "Copernicus of antiquity," his radical ideas were formulated nearly 1,800 years before the Copernican Revolution. Key Scientific Contributions aristarchus
: Like Anaxagoras before him, he suspected stars were other suns located at immense distances, explaining the lack of observable stellar parallax. Calculations vs. Reality : In his only surviving work, On the