This incredibly accurate science experiment was centuries ahead of its time. | Business Insider

2,000 years ago, Eratosthenes measured Earth’s circumference without satellites or tech! Using shadows, angles, and math, he got shockingly close to modern calculations—long before the world accepted the Earth was round! #storytime #didyouknow #shorts #ancient #history #documentaryshort #earth #worldhistory #mathematics #astronomy #mindblown Read More:https://www.ancient-origins.net/history-important-events/circumference-earth-0015421 | Ancient Origins

Carl Sagan describes how the ancient Greeks knew that the Earth was round. Aristotle used the round shadow of Earth on the moon during eclipses as evidence, while Eratosthenes measured the Earth’s circumference using the differences in shadow angles at two locations in Egypt. | History In Pictures