Ibn al-Haytham and the Book of Optics
Vision is explained correctly, and experiment is made the arbiter of theory.
- When
- Known to
- ± 5 years
- Era
- Post-Classical, Holocene
Writing around 1021, Ibn al-Haytham demonstrates that we see because light enters the eye rather than because rays leave it, works out reflection and refraction, describes the camera obscura, and — most importantly — insists that claims be tested by controlled experiment and that the seeker after truth should distrust his own conclusions. Many historians treat him as the first recognisable practitioner of the scientific method.