Kamal al-Din al-Farisi's explanation of the rainbow
Explicación del arcoíris con una esfera de vidrio
- Date
- c. 1309 · confidence medium
- Place
- Tabriz, East Azerbaijan, Iran
- Credited to
- Kamal al-Din al-Farisi
- People
- 👤 Al-Farisi1265–1319
- Field
- Communication
⚠️ Disputed: the sources disagree.
What was discovered
Using a glass sphere filled with water in a darkened chamber as a model of a raindrop, he showed that the primary bow arises from two refractions and one internal reflection, and the secondary bow from two reflections. It is the first correct explanation of the rainbow.
Theodoric of Freiberg arrived at the same explanation independently and almost simultaneously (c. 1304-1310). Al-Farisi was a pupil of Qutb al-Din al-Shirazi, of the Maragheh school.
What it led to
- Descartes' optics of meteors (1637)
- scale experimental models
- Newton's theory of dispersion