Re: OT, was Ptolemy in Re: VMs: Traditional Astrology and the Flat Earth

[Bruce Grant <bgrant@xxxxxxxxxxxxx>]

elvogt@xxxxxxxxxxx wrote:

Zitat von Pamela Richards <spirlhelix@xxxxxxxxx>:

tolemy on the Shape of the Earth, from the Almagest,
Book I, Ch. 4.:

                               ...And since the
differences in the hours is found to be proportional
to the distances between the places, one would
reasonably suppose the surface of the earth
spherical...
    

That is pretty cool. How on Earth did he measure that...?

I seem to remember reading somewhere that the Greeks had two other arguments for theEarth being spherical:

1)   that, as a ship sails away in any direction, its hull disappears from view before the sails do

2)  that the edge of the Earth's shadow on the Moon during a lunar eclipse always appears circular (no corners).

Bruce