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Re: Flat Earth



At 23:30 -0500 2/11/02, John S. Denker wrote:

No. Nooooooooo. No.

Thomas Kuhn warned about this. He said scientists love
to think that just because
a) We know it today, and
b) it could have been known 2350 years ago, then
c) it must have been widely known then and at
all times since then.

Then just what did Eratosthenes measure? Or is that an urban myth? I
didn't say that it *could* have been known 2350 years ago, I said it
*was* known 2350 years ago, at least by one man, who was pretty
well-known in his day, so his result probably would have been known,
at least to the educated classes at the time.

It is certainly possible that that information could have been lost
during the first millennium C.E., but if that was the case, the
knowledge had been recovered, again by the educated classes, by the
fifteenth century.

I have read about seafarers in Phoenecian days noting the phenomenon
of ships disappearing over the horizon by going hull down and
inferring from that that the earth was not flat. I doubt that this
lore would have been lost to mariners for over 1000 years, just
because the Phoenecians had disappeared from view. Careful
observation of their surroundings was a valuable survival technique
for the mariners of old. I suspect that lots of ships seen hull down
from the crow's nest gave even the lowly able seaman a pretty good
idea of what the shape of the earth was.

I just did a Google search on Ancient Maps and the first item turned
up was a time line of ancient cartography that showed an awful lot of
spherical mapping going on from about 400 B.C.E. And then I found
this:
<http://www.henry-davis.com/MAPS/Ancient%20Web%20Pages/119D1.html>
which is a Ptolemaic world projection dating from the 13th century.
And this one:
<http://www.brown.edu/Departments/Italian_Studies/dweb/images/maps/decworld/228A.jpg>
which is dated 1321, and looks pretty global to me.

I don't know how popular these particular maps were, but they
certainly are counterexamples to your claim that 14th century maps
pushed flatness. I've spent enough time looking at grainy images of
old maps for one night.

Hugh
--

Hugh Haskell
<mailto://haskell@ncssm.edu>
<mailto://hhaskell@mindspring.com>

(919) 467-7610

Let's face it. People use a Mac because they want to, Windows because they
have to..
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