Who discovered that the Earth was round, not flat?

Question

Serious answers only, please!

Answer 1

The Greeks.

Around 330 BC, Aristotle provided observational evidence for the spherical Earth, noting that travelers going south see southern constellations rise higher above the horizon. This is only possible if their horizon is at an angle to northerners' horizon. Thus the Earth's surface cannot be flat. He also noted that the border of the shadow of Earth on the Moon during the partial phase of a lunar eclipse is always circular, no matter how high the Moon is over the horizon. Only a sphere casts a circular shadow in every direction, whereas a circular disk casts an elliptical shadow in most directions.

The Earth's circumference was first determined around 240 BC by Eratosthenes. Eratosthenes knew that in Syene, in Egypt, the Sun was directly overhead at the summer solstice, while he estimated that a shadow cast by the Sun at Alexandria was 1/50th of a circle. He estimated the distance from Syene to Alexandria as 5,000 stades, and estimated the Earth's circumference was 250,000 stades and a degree was 700 stades (implying a circumference of 252,000 stades). Eratosthenes used rough estimates and round numbers, but depending on the length of the stadion, his result is within a margin of between 2% and 20% of the actual circumference, 40,008 kilometres.

Answer 2

The ancient Greeks. Pythagoras taught others that it was round, but his reasoning was not based on scientific fact. He, and others, thought that a sphere was the perfect shape and that the gods would have made the earth the perfect shape. This was in about 500bc.

Then by about 300 BC, Aristotle used simple observations to argue that the earth was round. He used the curved shape of the earth's shadow on the moon during a lunar eclipse as an example. He also said that the fact that you could see different stars/constellations as you moved south meant that the stars were behind the horizon created by the round surface of the earth.

Answer 3

It was of course the ancient Greeks who "espoused" the idea, but they were just based on theories on observations about the skies and the heavens.

The first ever who got to actually experience that the earth is round is Ferdinand Magellan, a Portuguese who was commissioned by the Spanish to travel for conquest. He was able to go around the world through the Pacific Ocean to the Spice Islands, before being killed in the Philippines.

Answer 4

Yajnavalkya (c. 9th–8th century BCE) recognized that the Earth is spherical in his astronomical text Shatapatha Brahmana. This assertion was proven by the expidition of Fernando or Hernando de Magallanes); (Spring 1480 – April 27, 1521) This was the first known successful attempt to circumnavigate the Earth.

Answer 5

I believe the ancient Egyptians knew that the earth was round. Earlier civilizations may have known it, but not written it down. Pythagoras is credited with making it a popular notion.

These sites are interesting and discuss the issue.

Answer 6

I'm sure there is no definitive answer to that. Yes, it was possibly Galileo or Copernicus. Of course it was Columbus who set out to prove it by sailing west to find a new passage to the east, but he ended up discovering the new world (America) instead.

Answer 7

I believe the ancient Egyptians knew that the earth was round. Earlier civilizations may have known it, but not written it down. Pythagoras is credited with making it a popular notion.

Answer 8

I can't find the name of the person, but it was possibly a Greek mathematician who's experiments in the second century BC that first tried to measure the Earth came up with the theory.

Answer 9

Copernicus

Answer 10

It was a greek (whose name escapes me) who not only knew the earth was round, but made a very good guess as to its circumference, getting it to about 22,000