Aristarchus of Samos

Aristarchus (Greek: Ἀρίσταρχος, Arístarchos; 310 BC – ca. 230 BC) was a Greek astronomer and mathematician, born on the island of Samos, in Greece. He presented the first known heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe. He was influenced by the Pythagorean Philolaus of Croton, but, in contrast to Philolaus, he identified the "central fire" with the Sun, and put the other planets in their correct order of distance around the Sun. His astronomical ideas were often rejected in favor of the geocentric theories of Aristotle and Ptolemy. The heliocentric theory was successfully revived nearly 1800 years later by Copernicus and modified by Johannes Kepler and Isaac Newton.

Vatican has preserved two ancient manuscripts with estimates of the length of the year. The only ancient scientist listed for two different values is Aristarchus. It is now widely suspected that these are among the earliest surviving examples of continued fraction expressions. The most obvious interpretations are precisely computable from the manuscript numbers.