When did the earth officially become round instead of flat?

Answer 1

The year 240 BC with Eratosthenes calculated the circumference of the earth.

The Greeks determined the Earth was round This and a lot of other information was lost to science in the Dark Ages.

Aristotle (384 BC - 322 BC) observed the earth was round, but it took Eratosthenes (276 BC - 194 BC) to prove it.

True the Earth has held its current shape for all of mankind's history, but it wasn't until the Greeks determined the size that we knew for sure it was round and why. Of course you can't convince the Flat Earth Society: http://www.alaska.net/~clund/e_djublonskopf/Flatearthsociety.htm that the Earth is round.

The discover of the New World by the Vikings and Christopher Columbus didn't prove the world was round, only that it was larger. The voyage of Ferdinand Magellan commanded the first voyage to travel all the way around the Earth. He was killed by natives in the Pacific so he never returned to England to receive the credit for his work, but it was his idea and he provided the first eye witness account that the earth was round (or at least his crew did).

Incidentally the earth is more pear shaped, it isn't really round. This is due to a non-uniform distribution of the earth's surface.

Answer 2

It has been known since antiquity that the earth is round; it casts a round shadow on the moon during a lunar eclipse.

Answer 3

Columbus discovered the New World but thought he was in Indonesia, Amerigo Vespucci was the one who realized that it was not Indonesia, thus why the continents are not North Columbia and South Columbia.

When Magellan circumnavigated the world between 1519-1522 it was official.

Answer 4

It was always round

Answer 5

it was never flat it has always been round

Answer 6

when coumbus didn't fall off the end in 1492