Aristarchus of Samos, the "Copernicus of antiquity" (310-230 BC.) is credited by the Greek mathematician and inventor Archimedes to the hypothesis that the Sun, and not the Earth is the center of planetary motion. At the time, few people believed this hypothesis, though most believed the Earth rotated about its axis. These people rejected Aristarchus' hypothesis because they believed that the appearance of the fixed stars would change in different parts of the Earth's orbit, but Aristarchus thought that the distance of the fixed stars was so great this effect was unnoticeable. Aristarchus wrote a discourse, "On the sizes and distances of the Sun and the Moon." Through a series of observations he discovered the ratios of the Sun's and Moon's distances from the Earth, and the ratio of their sizes compared to the size of the Earth. With the help of Eratosthenes of Cyrene (276-195 BC.), we shall approximate the distances between the Earth, Sun, and Moon.

Archimedes

 
All of Aristarchus' ideas were found in the notes of the Greek mathematician and inventor Archimedes. Archimedes, a very well known Greek mathematician and inventor, who wrote many important works on plane and solid geometry, arithmetic, and mechanics. Archimedes was born in Syracuse, Sicily, and was educated in Egypt. In mathematics, he anticipated many of the discoveries of modern day science, such as calculus, invented 2000 years later by Newton and Leibniz. He also proved the volume of the sphere is two-thirds the volume of a circumscribed cylinder. In mechanics, he defined the principal of the lever, and is known for inventing the compound pulley. Archimedes spent most of his life in and around Sicily where he was born. He did not hold any public office, but he did devote his entire life to research and discoveries. After the capture of Syracuse during the second Punic War, Archimedes was killed by a Roman soldier who found him drawing a mathematical diagram in the sand. That was in 212 BC

The Heliocentric Theory is often accredited to the Greek mathematician Copernicus, even though Aristarchus proposed this theory nearly 2000 years before. Copernicus believed that Ptolemy's theory wasn't accurate and he found it offensive. Heliocentric is derived from the Greek words, helio, meaning sun, and centric meaning center. The theory states that the Earth and all the other planets revolve around the sun.

By Cari, Brianne, Holly