Oenopides

Oenopides of Chios was a Greek astronomer, mathematician and geometer, who lived in the 2nd half of the 5th century BC in Athens.

Oenopides was of the view that the surrounding room for us is not just air, but also from fire. With the help of astronomical observations, he tried to prove several of his ideas. Among other things, he averaged probably the first the obliquity of the ecliptic. He determined the solar year relatively accurate with 365 22/59 days and the moon period to 29.53 days. He called for mathematics, the restriction to simple tools, such as angles and ruler.

The lunar crater Oenopides is named after him.