Muhammad Ibn Ahmad Abul-Rayhan
Al-Biruni (973-1050AD), from Haran.
His production exceeds 146 titles in more than 20 different disciplines, ranging from astronomy to mathematics, mathematical geography, chronology, mechanics, pharmacology, mineralogy, history, literature, religion, and philosophy.
But the bulk of his work lies in mathematics and related disciplines (96 titles). Only 22 works have survived the ravages of time; and only 13 of these have been published.
His work Chronology (Al-Athar) combines literary and historical sources of medieval sects and nations with the astronomical lore about their calendars, feasts, and astronomical parameters used in their rituals. His (Tahdid, the demarcation of the coordinates of cities) was written so as to determine the Qibla. Biruni also determined the local meridian and the coordinates of any locality.
His al-Qanun Al-Mas'udi is a most extensive astronomical encyclopaedia, slightly short of 1,500 pages. In it he determines the motion of the solar apogee, corrects Ptolemy's findings, and is able to state for the first time that the motion is not identical to that of precession, but comes very close to it. In this book, too, Biruni employs mathematical techniques unknown to his predecessors that involve analysis of instantaneous motion and acceleration, described in terminology that can best be understood if we assume that he had "mathematical functions" in mind.
Six hundred years before Galileo, Al-Biruni discussed the theory of the earth rotating about is own axis. Using the astrolabe and the presence of a mountain near a sea or flat plain, he calculated the earth circumference by solving a highly complex geodesic equation.
With the aid of mathematics, he also enabled the direction of the Qibla to be determined from anywhere in the world. Max Meyerhof observed earlier this century that most of al-Biruni's mathematical works and many other writings have not been published yet.
1 Max Meyerhof: Science and Medicine, in Sir Thomas Arnold and A. Guillaume edition: The Legacy of Islam, first edition; Oxford University Press; 1931; pp 311-55, at p. 332.