2007-10-31 13:42:36 · 19 answers · asked by Anonymous in Arts & Humanities ➔ History
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.
2007-10-31 16:39:55 · answer #1 · answered by Its not me Its u 7 · 2⤊ 0⤋
Long before Columbus, it was known that in clear weather, a tall ship slowly disappeared over the horizon from bottom up, as if going over a hill. Eratosthenes (most famous for the "sieve" to find prime numbers) made an estimate of Earth's diameter more than 2,000 years ago. This knowledge was dispute and forgotten at times.
Those who forget geometry are doomed to repeat the mistakes of the past. (misquote of the day)
2007-10-31 20:50:19 · answer #2 · answered by Anonymous · 4⤊ 1⤋
This may be interesting to you; some people still think the earth is flat. Search the Internet for "Flat Earth Society". The evidence of the earth being round was around before Columbus.
2007-10-31 20:54:11 · answer #3 · answered by butch 5 · 0⤊ 4⤋
Not sure who really made the discovery, but it was definitely not columbus, who is always credited with it!
But your main concern is "when?" I do know the ancient greeks were very aware that the earth was round. In fact, Eratosthenes, a Greek Astronomer living in 200 bc, calculated the earth's circumference at ~46,000 km (it is measured ~40,000 km with modern tools and methods -- not bad!!!)
2007-10-31 20:53:57 · answer #4 · answered by Me Me 3 · 2⤊ 1⤋
Columbus didnt sail around the world, he discovered the americas or what he thought to be Asia. They did start having suspicions around then but they where not positive and had no idea how big it was till Ferdinand Magellan made the first trip across the world. Im not sure exactly when but he was born in 1521 so that gives you an aproximate date. If you really want to know exactly when email me and i can find out.
2007-10-31 20:54:13 · answer #5 · answered by Brenno I 2 · 1⤊ 4⤋
Depends on who you mean by "they." The Greeks knew it a thousand years before Columbus. The Chinese knew it at least a hundred years before Columbus. All educated people knew it in Columbus' time, but he was the one who made it well known.
2007-10-31 21:12:26 · answer #6 · answered by TG 7 · 4⤊ 1⤋
the greeks figured out that the earth was round in the 4th century bc.
2007-10-31 21:37:23 · answer #7 · answered by iberius 4 · 0⤊ 0⤋
OMG I just learned this!
Because people back then weren't educated as we are today and so map makers thought it was flat-because like they drew it. So Columbus who was educated knew it was round and was willing to prove it even if it meant to be killed. He found out the North and South Americas.
=] :) =]
2007-10-31 21:40:17 · answer #8 · answered by ? 7 · 0⤊ 3⤋
It was known all the time but not widely publicized until after the middle ages.
2007-10-31 20:46:43 · answer #9 · answered by Anonymous · 1⤊ 2⤋
THIS IS FASCONATING TO STUDY ABOUT, READ THE LINKS BELOW
ps they knew before Columbus
2007-10-31 20:51:06 · answer #10 · answered by Dr. Albert, DDS, (USA) 7 · 0⤊ 1⤋