Ibn Al-Haytham, made major contributions to the fields of optics, mathematics, and physics. Born in Basra, Iraq, in 354 AH (965 CE) Al-Haytham rose in prominence as an acclaimed scientist before being invited by the Fatimid Caliph to Cairo, Egypt where he spent the remainder of his days.
In his book “Kitab al-Manazir (The Book of Optics)”, he refuted the emission theory of light which was proposed by Greek philosophers Ptolemy and Euclid. This theory argued that rays of light are emitted from our eyes and thus allow us to see. Al-Haytham argued the opposite, which is now the accepted model, that vision occurs by light entering our eyes.
He was also a major proponent for the use of the scientific method, scientific skepticism, and empiricism, which are the foundations of modern science today. In his own words, “The duty of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and … attack it from every side. He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency.”
Al-Haytham left a lasting legacy in the field of physics and his work was widely read in Europe during the renaissance and had an influence on the likes of Johannes Kepler, Francis Bacon, Leonardo Da Vinci, Galileo Galilei and René Descartes. In the words of Matthias Schramm, a professor of historical science at the University of Tübingen and associate editor of Historia Mathematica, who also spent a year studying Arabic at the University of Oxford, “Through a closer examination of Ibn al-Haytham’s conceptions of mathematical models and of the role they play in his theory of sense perception, it becomes evident that he was the true founder of physics in the modern sense of the word; in fact he anticipated by six centuries the fertile ideas that were to mark the beginning of this new branch of science.”