Ibn al-Haythan was one of the great scientists of the world who made a remarkable contribution to physics, mathematics and astronomy. His Kitab al-manazir was the first comprehensive book on optics and light, and a masterpiece of physics.
He was first to give a correct description of vision. He improved the planetary model with his theory of solid spheres against the ancient view of imaginary circles of orbits for planets and discovered the laws of reflection and refraction of light.
Abu Ali al-Hasan Ibn al-Haytham was born in Basrah, Iraq, in about 354 AH/956 CE completing his education at Basrah; he worked in a government office, but he was not satisfied with his job and continued his studies.
He prepared a major project to construct three dams and reservoir on the Nile at Cairo. This had three objectives to save Cairo from the annual flooding, to store water, and to increase the agricultural produce by using the stored water throughout the year. The project was shelved due to some reasons, may be high cost and the uncertainty about success.
Sometimes ago, the United Nations revived the project and built the Aswan Dam on the Nile near Cairo at a huge cost. In his last years, al-Haytham took residence near the mosque and university of al-Azhar, and dedicated himself to scientific research, experiment and writing. He was a very pious person and lived a very modest life in the meagre earning. He made a copyist of scientific books. He died in Cairo in 430 AH/1039 CE.
Ibn al-Haytham may be rated among the ten greatest scientists of Islam. He wrote more than 100 books on theology, poetry, metaphysics, politics, ethics, logic, music, physics, politics, astronomy and mathematics. More than fifty of his books are extent including Kitab al-manazir, Maqala fi al-alam and Maqala fi dhaw al-qamar
He was the first scientist to give a correct description of vision. He refuted the 700-year old Greek view that eyes emit light making the object visible to the eye, He stated that it is the light from the object which reaches the eye to create the image of the object in the eye.
Concerning light, an object is self-luminous, illuminated by light from the object, opaque, translucent and refraction. He stated that light takes time to travel; its intensity gets reduced as it travels; it travels faster in the rarer medium than in denser one, etc. Mathematicians since Euclid have been struggling to prove his twelfth axiom (of straight lines).
One of the important mathematical achievements of Ibn al-Haytham was the discovery of a simple substitute for the complicated Education method and two straight lines that intersect one another cannot be parallel to the same line. Interestingly this was attributed to the English mathematician Player who came 800 years after Ibn al-Haytham
His works have been translated into Latin, German, Italian, Spanish, Hebrew, Russian and English from the thirteenth century onwards. A large number of European scientists like Roger Bacon, Johannes Kepler, Newton, Fermat, Descartes, Witelo, Snell and others either adopted his ideas or were greatly influenced by him.