Mind-Benders of Islamic History
An astronomer's numbers Copernicus was still using six centuries later
The astronomer al-Battani, observing from Raqqa around the year 900, measured the length of the solar year and the tilt of the ecliptic with striking precision. When Copernicus published De Revolutionibus in 1543, he cited al-Battani by name more than twenty times, still drawing on observations made over six centuries earlier.
How we know
al-Battani c. 858–929 CE (observations at Raqqa from 877); Copernicus's De Revolutionibus published 1543; al-Battani named ~23 times in it (Britannica; Wikipedia; De Revolutionibus text). 1543 − 929 = 614 years.
One of many fact-checked wonders across eight traditions at The Spring of Wisdom.