Eratosthenes of Cyrene
Eratosthenes of Cyrene was the Chief Librarian of Alexandria and one of the most wide-ranging scholars of antiquity. He calculated the circumference of the Earth to within 2 percent, estimated the axial tilt and distance to the Sun, produced the most accurate map of the known world to date, coined the word 'geography,' and devised the prime number sieve bearing his name.
- Lived: 276 BCE – 194 BCE
- Nationality: greek
- Roles: scientist, geographer, mathematician, librarian
