Abu Ali al-Hasan ibn al-Hasan ibn al-Haytham (965 in Basra – c. 1040 in Cairo) was a prominent scientist and polymath from the ‘Golden Age’ of Muslim civilization. He is commonly referred to as Ibn al-Haytham, and sometimes as al-Basri, after his birthplace in the city of Basra. He is also known by his Latinized name of Alhzen or Alhacen.
Ibn al-Haytham made significant contributions to the principles of optics, as well as to physics, astronomy, mathematics, ophthalmology, philosophy, visual perception, and to the scientific method. He was also nicknamed Ptolemaeus Secundus ("Ptolemy the Second") or simply "The Physicist" in medieval Europe. Ibn al-Haytham wrote insightful commentaries on works by Aristotle, Ptolemy, and the Greek mathematician Euclid.
Born circa 965, in Basra, Iraq, he lived mainly in Cairo, Egypt, dying there at age 76. Over-confident about practical application of his mathematical knowledge, he assumed that he could regulate the floods of the Nile.
After being ordered by al-Hakim bi-Amr Allah, the sixth ruler of the Fatimid caliphate, to carry out this operation, he quickly perceived the impossibility of what he was attempting to do, and retired from engineering. Fearing for his life, he feigned madness and was placed under house arrest, during and after which he devoted himself to his scientific work until his death.
A crater on the moon is named in his honor, as is the asteroid 59239 Alhazen.