Mystery AtlasEratosthenes
Greek scholar and head of the Library of Alexandria who, around 240 BC, calculated Earth's circumference to within a few percent of the true figure using shadow-angle measurements at Alexandria and Syene, establishing the planet's spherical shape long before the modern flat-Earth movement.
In Egypt
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Connected to
How this topic links to the people, places, and ideas around it — drawn from our knowledge graph.
Theories & Explanations
Eratosthenes discovered Spherical Earth Scientific Consensus — His c. 240 BC shadow-angle measurement at Alexandria and Syene established Earth's spherical shape and estimated its circumference.
Places
Eratosthenes is located in Egypt — Worked at the Library of Alexandria.