Eratosthenes of Cyrene (276-194 BC) was a Greek mathematician, geographer, poet, astronomer, and music theorist. He was the chief librarian at the Library of Alexandria. He invented the discipline of geography, including the terminology used today, and was the first person to calculate the circumference of the Earth, the tilt of the Earth's axis, and the first map of the world incorporating parallels and meridians. He was called “father of geography,” and was also a friend of Archimedes.
Eratosthenes yearned to understand the complexities of the entire world, so critics scorned Eratosthenes, calling him “Beta” because he always came in second in his endeavors, but his devotees nicknamed him “Pentathlos,” for proving himself to be knowledgeable in every area of learning.