Alī ibn Khalaf () was an Andalusian astronomer who belonged to the scientific circle of Ṣāʿid al- Andalusī.
He devised, with help from al-Zarqali, the universal astrolabe.David A. King, World-maps for finding the direction and distance to Mecca, (Brill, 1999), 330. Both Khalaf and al-Zarqali's design were included in the Libros del Saber (1227) of Alfonso X of Castile.Koenraad Van Cleempoel. "The Migration of Instrumental Knowledge from Flanders to Spain," in: Silent Messengers: The Circulation of Material Objects of Knowledge in the Early Modern Low Countries, Sven Dupré and Christoph Herbert Lüthy (eds.), (Transaction Publishers, 2011), p. 76.
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