Ibn al-Haytham Completes the Book of Optics
- Date
- c. 1021 CE
- Category
- Science, technology & invention
- Region
- Egypt (Fatimid Caliphate), Middle East
- Era
- Post-Classical / Medieval
- Significance
The Arab polymath Ibn al-Haytham (Latinised as Alhazen, c. 965 - c. 1040) composed his seven-volume Kitab al-Manazir (Book of Optics) in Cairo between roughly 1011 and 1021, traditionally during a period of house arrest under the Fatimid caliph al-Hakim.
The treatise overturned the prevailing extramission theory of vision, establishing instead the intromission model in which sight results from light entering the eye, and it laid out systematic accounts of reflection, refraction, the camera obscura, and the anatomy of perception. Crucially, Ibn al-Haytham insisted that hypotheses be tested against controlled, repeatable experiments and mathematical demonstration rather than accepted on the authority of ancient writers, an approach widely regarded as an early articulation of the experimental scientific method. Translated into Latin around the turn of the thirteenth century, the work profoundly shaped European optics and natural philosophy, influencing figures from Roger Bacon and Witelo to Kepler. It remains a landmark in the history of science and earned its author the epithet 'father of modern optics.'
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Empires active in c. 1021 CE
- Abbasid Caliphate750 CE – 1258 CE
- Song Dynasty960 CE – 1279 CE
- Byzantine Empire330 CE – 1453 CE
- Kanem-Bornu Empire700 CE – 1900 CE
- Liao Dynasty (Khitan Empire)916 CE – 1125 CE
- Fatimid Caliphate909 CE – 1171 CE
Related science, technology & invention events
- Al-Biruni Measures the Earth's Radiusc. 1017 CE
- Ibn Sina completes the Canon of Medicinec. 1025 CE
- Bi Sheng invents movable-type printing in Song Chinac. 1040–1048 CE
- Al-Zahrawi completes the Kitab al-Tasrif, foundational surgical encyclopediac. 1000 CE
- Legendary origin of smallpox variolation (inoculation) in East Asiac. 1000 CE
- Wujing Zongyao records the first gunpowder formulas1044 CE
Further reading
The wider story
A Little History of Science
Warm, jargon-free tour of discovery from Babylonian stargazers to the genome.
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