Al-Farghani's Compendium of Astronomy (Alfraganus)
Compendio de astronomía de al-Farghani (Alfraganus)
- Date
- c. 833 · confidence medium
- Place
- Baghdad, Iraq
- Credited to
- Al-Farghani (a native of Fergana)
- Field
- Cosmos & Earth
What was discovered
A manual by the Fergana astronomer describing the Ptolemaic system, the Earth's diameter and planetary distances without heavy mathematics, read in Europe for centuries as «Elementa astronomica». It was a key link in transmitting Greek astronomy into Latin.
The date of the work and the chronology of his life (born in Fergana, died after 861) are approximate. Columbus confused the Arabic mile with the Italian one when using his estimate of the length of a degree.
What it led to
- Latin translations by John of Seville (1135) and Gerard of Cremona
- a source for Dante, Regiomontanus and Christopher Columbus on the size of the Earth
- spread of Aristotelian-Ptolemaic cosmology among university students