Kuu

This might not be the right forum for this question but I will ask it here anyway.

I am trying to prove to a friend that in the 15th century Man, including Columbus knew that the world wasn't flat and had known it for a long time.

I am particularly looking for two references which were from Viking sources. Possibly I read them in a saga.

One was of a Viking who said that the Earth must have been bowl-shaped as this would explain the horizon.

The other was a Viking who was talking about the Northern Lights. He said 'I have heard it said they are caused by dragons' breathe but I don't think this is so, I think it is caused by the sun reflecting off the northern ice (he said something like this, he was wrong was his idea was an advancement on dragon's breather). He added that they must have the same sort lights down the south of the world. Though he never stated that the Earth wasn't flat he seemed quite aware that they was land far south of the equator.

I am specifically looking for these, or any other medieval refernces, rather than ancient reference, to the Earth being round.

Sheep in the big city

Viking quotes will not impress your friend. Just because some vikings knew it doesn't make it generally accepted knowledge. Vikings also were in america centuries before columbus and noone else knew it (not even the other vikings).
You can also find quotes from 400 'B.C.' greeks that the earth is a sphere and I think even for a heliocentric solar system (Aristarch?) but what does that prove?
Columbus on the other hand had to have known the earth is round. Why else would he try to reach India going westward? So just find a Columbus-quote mentioning India as his goal. Or even more obvious ask your friend why the Indians are called Indians.

[ September 27, 2002: Message edited by: Sheep in the big city ]</p>

Glory

Look for stuff on the Portuguese Navigators. They were the last word on geography at the time. That was how Colombus got the knowledge he neede for his journey. He apprenticed on as many portuguese ships as he could. Of course, it was the Portuguese who were most vocal in their condemnation of his plan. They had a monopoly on charting and Colombus was trying to destroy that.

Glory

Kuu

The thing I want to prove is not only was it known in Columbus's time that the world wasnt flat but that it was known for hundreds of years before that.

My friend is an intelligent woman so I cannot see why she has such a closed mind about things. She learnt at school that Columbus proved the world was round and she is sticking by that. She says if the knowledge was known in the ancient times it was lost in the Dark Ages.

Mind you she also thinks that there a good possibilty that man did not go to the moon. The evidence is on a website ger son-in-law told her about and when I try to explain how the website is wrong she simply says that what is on the website makes sense.

Walross

Hello Kuu,

I believe I can help. The ancients knew beyond a shadow of a doubt that our planet is spherical. If your friend doesn't believe this, look up Eratosthenes and his very accurate measurement of the circumference of the Earth several hundred years BCE. I hope this helps. Regards,

Walross

Walross

BTW, Kuu, the astronomer Phil Plait has an excellent rebuttal of those who claim that man never walked on the moon. His website is <a href="http://www.badastronomy.com." target="_blank">www.badastronomy.com.</a>

Personally, I cannot stand those who would perpetuate the myth that the moon landings didn't happen. To do so is a disservice to the many people who worked so very hard and risked their very lives to make such an amazing thing happen.

ok...enough ranting for now regards,

Walross

Vorkosigan

There's lots of stuff about that. Andrew DIckson White has a huge list of ancients who thought the world was round on p 97 of his Warfare of Science and Theology, the text is online at II. Search the phrase "ancient germ" and you should be able to find the paragraph where he lists everyone from Bede to Aquinas. Basically everyone with brains in antiquity knew the earth was round.

Of course, the Greeks measured the circumference of the Earth, so your friend is wrong <a href="http://www.physics.gmu.edu/classinfo/astr103/CourseNotes/ECText/ch01_04.htm" target="_blank">by these class notes</a> by a couple of thousand years.

Vorkosigan

Feather

Try also "The Beginnings of Western Science," By a Mr. Lindberg.

A most excellent book covering everything from ancient babylonian science and math up to the beginnings of the Rennaisance.

Vorkosigan

Lindberg is a well-known historian of science

abe smith

YES! Eratosthenes. He got it astonishingly nearly-correct! Way the hell back there B&gt;C&lt;.