Ibn al-Haytham

Who is Ibn al-Haytham?

Abu Ali al-Hasan ibn al-Haytham, known in the West by the Latinized name Alhazen, was born in Basra, in what is now Iraq, and became one of the most important scientific minds of the medieval Islamic world. He is best known for his monumental Kitab al-Manazir (Book of Optics), which overturned earlier Greek theories of vision by demonstrating, through careful experiment, that sight results from light entering the eye rather than rays emitted from it. His insistence on systematic observation, controlled experiment, and mathematical proof to test hypotheses has led many historians of science to regard him as a founding figure of the modern scientific method. Ibn al-Haytham traveled to Cairo during the Fatimid era, reportedly at the invitation of Caliph al-Hakim to help regulate the flooding of the Nile; when the plan proved impractical, tradition holds he feigned madness to avoid the caliph's wrath and was placed under house arrest, during which he produced much of his major scientific work. His writings on optics, astronomy, and mathematics were translated into Latin and profoundly influenced later European scientists including Kepler and Descartes.

Sources: Ibn al-Haytham, Kitab al-Manazir (Book of Optics), 11th century · Jim Al-Khalili, Pathfinders: The Golden Age of Arabic Science (2010) · Encyclopaedia Britannica, "Ibn al-Haytham"