Date: April 10th, 2026 11:46 AM Author: deep bright mood plaza
he noticed that the earth’s shadow on the moon always had a curved edge no matter what time of the year it was and reasoned that the only shape that casts a round shadow from every direction is a sphere
Eratosthenes, like most educated Greeks, knew the Earth was round and he calculated its size within 5% by measuring concurrent shadow angles in Egypt and Greece.