al-Biruni

Abu al-Rayhan Muhammad ibn Ahmad al-Biruni al-Khwarazmi was one of the greatest scholars in human history. Born in Khwarazm (modern Uzbekistan), he traveled extensively and produced groundbreaking works in nearly every field of knowledge: astronomy (al-Qanun al-Mas'udi), geography (Kitab al-Hind), history (al-Athar al-Baqiyah), pharmacology (Kitab al-Saydanah), and mathematics. His al-Qanun al-Mas'udi (dedicated to Sultan Mahmud of Ghazni) is an astronomical encyclopedia of the highest order. His Kitab al-Hind is the most important medieval description of Indian civilization and religion. He calculated the circumference of the Earth with remarkable accuracy. He died in Ghazni in 440 AH.