Alī Ibn Khalaf al-Murādī;
(Arabic: أبو جعفر المرادي; 11th century) was an Andalusian mathematician and astronomer who belonged to the scientific circle of Ṣāʿid al- Andalusī.
He was the author of the technological manuscript entitled Kitāb al-asrār fī natā’ij al-afkār (The Book of Secrets in the Results of Thoughts or The Book of Secrets in the Results of Ideas). It was copied and used at the court of Alfonso VI of León and Castile in Christian Spain in the 11th century.
The manuscript provides information about a “Castle and Gazelle Clock” and many other forms of complicated clocks and ingenious devices. Al-Muradi was a contemporary of Abū Ishāq Ibrāhīm al-Zarqālī.
In 2008, the Book of Secrets of al-Muradi has been published in facsimile, translated in English/Italian/French/Arabic and in an electronic edition with all machines interpreted in 3D, by the Italian study center Leonardo3.
He also devised, with help from al-Zarqali, the universal astrolabe. Both al-Muradi and al-Zarqali’s design were included in the Libros del Saber (1227) of Alfonso X of Castile.