Alternate names

Ibn al‐Haytham (often referred to in the literature as Alhazen, the Latin version of al‐Ḥasan) was one of the most important and influential figures in the history of science. He wrote on topics that included logic, ethics, politics, poetry, music, and theology (kalām), and produced summaries of Aristotle and Galen. His extant works are mostly on mathematics, optics, and astronomy. As a young man, Ibn al‐Haytham moved to Egypt from Iraq and was involved in an abortive engineering project in Egypt on regulating the flow of the Nile. The sources do not agree on the details of the story; however, it is clear that after this brief try at government work, Ibn al‐Haytham chose a life of quiet scholarship. He earned his living copying scientific manuscripts, and carried out extensive research and correspondence in philosophy and the sciences. In his youth Ibn al‐Haytham inquired into the different religions and came to the conclusion that the truth is one. This fundamental insight of gaining favor with God by seeking knowledge of the truth underlies some of his most important scientific activity. Specifically with regard to astronomy, Ibn al‐Haytham was troubled by inconsistencies in the treatment of problems of interest to astronomy and two other disciplines, natural philosophy and optics. His most repercussive writings critically examine the issues and propose solutions. At least since Aristotle, it has been taken for a fact that the motions of the celestial bodies are uniform and circular, and that the stars are embedded within a set of concentric spheres. However, astronomy had progresse