Eratosthenes Calculates the Diameter of the Earth (c. 240 BCE)

240 BCE · İskenderiye · cultural

Eratosthenes, chief librarian of the Library of Alexandria, calculated the circumference of the Earth as 40,074 km from the difference in the sun's angle between Alexandria and Syene (the true figure is 40,075 km — an error of 0.001%).

| One of the most astonishing achievements of ancient science; the modern Eratosthenes experiment is a staple of schools.

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Frequently asked questions

What was Eratosthenes Calculates the Diameter of the Earth (c. 240 BCE)?
Eratosthenes, chief librarian of the Library of Alexandria, calculated the circumference of the Earth as 40,074 km from the difference in the sun's angle between Alexandria and Syene (the true figure is 40,075 km — an error of 0.001%).
When did Eratosthenes Calculates the Diameter of the Earth (c. 240 BCE) happen?
240 BCE
Where did Eratosthenes Calculates the Diameter of the Earth (c. 240 BCE) take place?
İskenderiye