Eratosthenes

Eratosthenes’ measurement of the Earth’s circumference Ελληνικά: Η μέτρηση της περιφέρειας της γης από τον Ερατοσθένη (Photo credit: Wikipedia)

Eratosthenes (276-194 BCE) was an Ancient Greek who apparently was the first to calculate the circumference of the Earth with remarkable accuracy using math that involved measuring the angles of shadows.

He also invented the idea of longitude and latitude, the leap day, and may have calculated the distance from the earth to the sun.

Related articles

• http://en.wikipedia.org/wiki/Eratosthenes
• History of Mathematics (Btelus) (spacezilotes.wordpress.com)