Ask AI: A Greek philosopher who computed the circumference of the Earth and who gave the most accurate size during their time.

The Greek philosopher you are referring to is Eratosthenes of Cyrene. Eratosthenes was a mathematician, geographer, poet, astronomer, and music theorist who lived from approximately 276 BC to 194 BC. He is best known for calculating the circumference of the Earth using a method based on the angle of the Sun's rays at different locations on the planet. His calculation was impressively accurate considering the limited technology of the time, with an estimated error of less than 2% compared to the modern value. Eratosthenes' work has had a lasting impact on our understanding of the Earth and contributed significantly to the field of geography.