earth's tilt

In article ,
"Bast" wrote:

snip

Just like Galileo is often credited for claiming the earth went around the
sun.
His research was based on Copernicus's work, and who knows where Copernicus
got the idea.

I attended a lecture a couple of years ago that proposed the Persian
astronomer Qushji (*) as an important influence on Copernicus'
heliocentric theory, based on similarities between their mathematical
treatments & illustrations. The connection would have been made _via_ a
friend of Copernicus' who apparently brought some astronomical treatises
back from Baghdad. There were other important critics of the Ptolemaic
system in the mediaeval Islamic world, notably al-Tusi (1201-74 CE),
some of whose writings had become available to Western scholars by the
XV century.


*) See http://en.wikipedia.org/wiki/Ali_Qushji

--
Odysseus