Work · Philosophy in the Islamic World
Book of Optics
Seven books on vision: light and colour radiate from every point of an object in all directions, and the eye sees by receiving them; Ibn al-Haytham supports this with experiments, treats reflection and refraction, and analyses the inferences by which the mind recognises what it sees. Translated into Latin around 1200 as De aspectibus.
Introduction
Ibn al-Haytham wrote the “Book of Optics” (Kitāb al-manāẓir) in Cairo, probably between about 1028 and 1038, in seven books. The first three set out his theory of vision: light and colour radiate from every point of a visible object, the eye receives the rays that fall perpendicularly on it, and perception involves recognition, comparison and inference by the mind, which he analyses in detail together with errors of sight. Books four to seven treat reflection from plane and curved mirrors, including the problem of finding the point of reflection that later bore his name, and refraction. Throughout, claims are tested by experiments with specially built apparatus. Translated into Latin around 1200 as De aspectibus or Perspectiva, the work shaped medieval optics through Roger Bacon, John Pecham and Witelo; Friedrich Risner printed it in Basel in 1572, and Kepler’s optics took it as a starting point. A. I. Sabra edited and translated books one to three (1983, 1989).
More works by Ibn al-Haytham (Alhazen)
- c. 1028Doubts concerning Ptolemy
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