Eratosthenes

ancient greece · math · earth · library

Measured Earth's Size. Eratosthenes used shadows and math to calculate how wide Earth is around. His answer was almost perfectly correct, even though he did it over 2,000 years ago without any modern tools.

Head Librarian Genius. He ran the Library of Alexandria, the most famous library in the ancient world. He was in charge of collecting and organizing hundreds of thousands of scrolls and texts.

Invented Geography. Eratosthenes created the word 'geography' and basically started the whole field of studying maps and Earth. Before him, people didn't really have a science for understanding the world's lands and distances.

Master of Everything. This man was incredible at math, poetry, astronomy, music, and philosophy all at once. He was the kind of person who could study almost any subject and become really good at it.

Starred the Skies. Eratosthenes was also an astronomer who studied stars and the universe. He made maps of the sky and helped people understand the heavens above.