The Manga Guide to the Universe

20 Prologue A Tale That Begins onthe Mn

In Ancient Greece, Where the Size of Earth Was

Calculated

The ancient Greeks tried to explain the shape of the universe by using the logical thinking

that permeates modern mathematics and physics. One of their greatest achievements was the

discovery that Earth is a spherical body floating in space. The ancient Greeks were also the

first to calculate the size of Earth.

Eratosthenes (who lived from about 276 BC to 195 BC) was a Greek scholar who was

active in Egypt during the Hellenistic period. He calculated the size of Earth using the fol-

lowing method.

Eratosthenes' Calculation Method

Eratosthenes disc ...