Question

how megallean proved that earth is round

Answer 1

so here is your answer...
Magellan didn’t prove the earth was round. It had been known by all educated people in Europe that the Earth was approximately spherical for about 1,500 to 2,000 years before Magellan was born. Magellan no more proved the Earth was round than Richard the Lionheart proved that 1 + 1 = 2. It was a known and accepted fact from long before his birth.

Magellan undertook a circumnavigation, but died during the voyage. As the expedition plotted its path using basic celestial navigation, as available at the time, it became clear that they had, in fact, sailed right around the planet from east to west, crossing every meridian on the way.

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