In article <
5a389bb9-035b-47d2...@p41g2000yqm.googlegroups.com>,
>This was when the earth was flat, right? So how thick was it anyway?
>and when do they meet the giant turtle, gamera?
NO. This was not when the earth was flat. The ancient Greeks
knew that a lunar eclipse was caused by the earth's shadow
blocking the sun's light from the moon; and they observed that
whenever there was a lunar eclipse, no matter where the moon was
in relation to the earth, the shadow was always curved. The only
thing that can cast a round shadow from every angle was a sphere.
In the third century B.C., Eratosthenes made a very close
estimate of the actual size of the earth, by sending someone from
Alexandria -- where the shadows cast at the summer solstice were
seven degrees off the vertical -- to Cyene, where the shadows at
the summer solstice were straight up and down. The guy paced off
the distance between Alexandria and Cyene, Eratosthenes did a few
calculations, and announced that the earth was Iforgethowmany
stadia across. Very close to the real figure.
And everybody said "Oh no! The earth CAN'T be that big!"
Dante knew perfectly well that the earth was round. But he
placed the zero meridian at the longitude of Jerusalem, the 90
degree longitude at the Ganges, and the 180 degree longitude at
the Pillars of Hercules, that is, Gibraltar.
You're thinking of Columbus, right? EVERYbody knows that
EVERYbody thought the world was flat until Columbus proved it was
round. Not so.
They were still arguing about the size of the earth. Nobody
wanted to believe that Eratosthenes could've been right. That's
how Columbus was able to convince Isabella that China and
Indonesia, with their rich trading opportunities, was just a
reasonable distance away westward, and Spanish ships could get
there without having to get through the Arabs who owned the
eastward trading routes. I dare say some ignorant people,
including some of his crew, were afraid they'd fall off the edge
of the earth, but actually sailors ought to have been the easiest
to convince that the earth's surface was curved. If you stand at
the port, looking out to sea, waiting for a ship to come in,
you'll see first the top sails, and then the lower sails, and
finally the hull as it comes up over the curve of the earth.
Also, no giant turtles.