Who discovered that the earth is round?

Question

Why did they believe that the earth was flat? What factual evidence did they have that made them believe this?

Answer 1

It is possible that other earlier civilisations knew that the earth is round but ancient Greeks are those for whom we are certain. In fact not only did they know that the earth was round but at least one of them measured the size of earth. It was Eratosthenes from Cyrene (3rd cen. BC), using nothing but shadows, sticks and lots of brains, as Carl Sagan says at Cosmos. His error was only 1.5%!!!
Evidence for the roundness of earth is the circular shadow of the earth upon the moon, the fact that ship disappear at the horizon, the fact that gnomons (vertical sticks) cast different shadows depending on latitude.
As for why people believed it was flat, well, this would be the first impression. The earth seems to be flat. In fact surveyors suppose that the earth is flat when mapping small areas.

Answer 2

This is often credited to Christopher Colombus, but the ancient Greeks were also aware that the Earth is a sphere.

The factual evidence people had to "prove" the Earth is flat was that the ground they walked on, was, well, flat.

People realized that the Earth was round because you dont' have an unobstructed view of faraway places. You can't see China from Europe. If the Earth was flat, you would be able to (assuming there was no fog in the way). The horizen gets in the way when you try to see things really far away, so people knew the Earth is round.

Answer 3

Here's some sites that should help you answer your questions:

"Who knew the Earth was round and when did they know it?

People knew the Earth was round 2500 years ago. They just forgot.

Because Earth-bound observers could only view a small section of the globe at a time, it wasn't possible to tell from direct observation whether the Earth was a flat disk or a sphere. The Greeks were the first to theorize that the Earth was round. Scholars like Pythagoras in 500 BC based their belief on observations about the way the altitudes of stars varied at different places on Earth and how ships appeared on the horizon. As a ship returned to port, first its mast tops, then the sails, and finally its hull gradually came into view. Aristotle, who lived 300 years before Christ, observed that the Earth cast a round shadow on the moon. When a light is shined on a sphere, it casts the same shadow. The Greeks calculated the general size and shape of the Earth. They also created the grid system of latitude and longitude, so that with just two coordinates one can locate any point on the Earth. Greek philosophers also concluded that the Earth could only be a sphere because that, in their opinion, was the 'most perfect' shape."
From the following link, titled "Navigation and Mapping"
* http://octopus.gma.org/space1/nav_map.html

* http://www.timelinescience.org/resource/students/flat/flat.htm

* http://en.wikipedia.org/wiki/Discovery_(observation)

* http://www.phy6.org/stargaze/Scolumb.htm

* http://www.fordham.edu/halsall/mod/1519magellan.html

Answer 4

Scholars knew that the earth was round since ancient times. Not only did they know that it was round, but several ancient scholars calculated the distance around the earth quite accurately. Google "Eratosthenes" for more information about how one ancient scholar figured out the distance around in about the year 300 BC.

I dont think there has been any time in the last 500 years when any educated person thought the Earth was flat.

Columbus did not prove that the world is round. Everyone knew that (except maybe some ignorant peasants). He did have an argument with several people about how far around it was. Columbus thought it was about 18,000 miles around. Everyone else thought it was further. He was wrong, and if American hadnt gotten in the way, his leaky ships would certainly have sunk half way to China. Lucky for him that he ran into the Caribbean islands on his voyage and was saved. Michelangelo and Leonardo had nothing to do with this topic at all. Where do people get this wacky stuff!? Half these answers are pretty good, and half of them are completely wrong! duh!

Answer 5

i do no longer bear in mind the call yet i've got faith a guy from historical Egypt proved that the earth replaced into around or maybe have been given a touch precise estimate of the earth's diameter. It in touch determining the size of particular development's shadows at a particular time on a particular day whilst the solar replaced into at as quickly as above a particular water properly. via geometry, the shadows desperate the angles, the gap between the properly and the two homes (that have been many many miles remote from one yet another). not sure precisely whilst this handed off. The Mayans have been remarkable astronomers and developed a calendar it somewhat is precise interior of ~ 2 seconds a pair thousand years later. of direction the Isaiah did no longer have lots possibility of understanding what the Mayans knew.

Answer 6

The ancient greeks determined that the world was round. They observed that as a ship sailed into the distance that it disappeared from view a little at a time starting with the hull and moving up towards the tip of the mast. They reasoned that for this to occur the world must be round and that as the ship moved over the horizon the curve of the earth obscured the ship a little at a time.

Answer 7

The earliest known globe was constructed by the scholar Crates of Mallus in modern day Turkey around 150 BC.


Anyone who lived by the ocean knew the world wasn't flat, as they could easily observe the horizon and ships appearing on it. The whole "everyone though the world was flat" bit seem to have been invented by teachers (eh they bar used to be lower) and fans of Christopher Columbus who felt the need to claim everyone an idiot, in order to make Columbus seem like a genius.

Answer 8

Look here:
http://www.oceanservice.noaa.gov/education/kits/geodesy/geo02_histr.html

The ancient greeks were the first to discover that the earth is round. They even calculated it's size relatively accurat.
Also since the very beginning of the christian church it has always been the official view of the church that the earth is a sphere. So therefore in the middle ages every educated person knew that of course.

Answer 9

Colombus was the first to decide that the Earth could be round. He then attempted to prove it by sailing around the world to India (hence why Native Americans are also known as Indians).

They believed the Earth was flat because, before this, they had no idea about gravity. If the Earth was round, people would just fall off the bottom. They had no evidence to prove otherwise, so they kept believing this because the Church said it was true, and no one would dare to defy the Church.

Answer 10

well if you look around you youll see everything is 'flat' like walk from asia to europe you wont feel 'rounded' due to gravity but the greeks first questioned why the shipgo down the horizon when sailing or why the shadow of earth is round in lunareclipse all this acocunt made them believe tht earth is round.