Codes, Ciphers, and Cartography: Math Goes to War

Codes, Ciphers, and Cartography: Math Goes to War — page 3
NAVIGATION Navigation is the science of planning and following a route For centuries sailors had no way to chart their course other than to use math to figure out their location Tn the third century BCE the Greek mathematician Eratosthenes had the idea of placing an imaginary grid around the Earth The grid had lines running from north to south and from east to west In around 120 BCE a Greek astronomer named Hipparchus used math to plot locations on these lines He used a method modern mathematicians call triangulation Early ships like this Phoenician galley usually stayed close to shore so sailors Could navigate by using landmarks on coast the