Astronomer Ibn Hazm

By the 9th century, many Muslim scholars took it for granted that the Earth was a sphere. The proof, said astronomer Ibn Hazm, is that the Sun is always vertical to a particular spot on Earth. It was 500 years before that realisation dawned on Galileo. The calculations of Muslim astronomers were so accurate that in the 9th century they reckoned the Earths circumference to be 40,253.4km less than 200 km out. The scholar al-Idrisi took a globe depicting the world to the court of King Roger of Sicily in 1139.[2]
How Islamic inventors changed the world
A pre-Islamic Byzantine coin Struck 607 - 609 AD. It features the depiction of a crowned emperor Focas holding a globus cruciger (an orb representing the spherical Earth) more than 400 years before the realisation dawned on Ibn Hazm and 532 years before al-Idrisi took a globe to the court of King Roger.