Ali Qushji

Key Accomplishments

• Argued for the independence of astronomy from Aristotelian philosophy on empirical grounds
• Provided empirical arguments for the possibility of the Earth's rotation
• Worked at the Ulugh Beg Observatory and helped produce the Zij-i Sultani star catalogue
• Reformed the Ottoman madrasa system and introduced Timurid scientific traditions to Istanbul

The Full Story

Born in Samarkand, Ali Qushji was the son of the royal falconer (qushji means "falconer") at the court of Ulugh Beg. He studied mathematics and astronomy under Ulugh Beg himself and under the mathematician Qadi Zada al-Rumi at the great Samarkand observatory. After Ulugh Beg's assassination in 1449, Ali Qushji spent time in Iran before being invited to Istanbul by Sultan Mehmed II.

His most important intellectual contribution was his argument that astronomy should be an independent empirical science, freed from the constraints of Aristotelian natural philosophy. In his Concerning the Supposed Dependence of Astronomy upon Philosophy, he argued that the question of the Earth's rotation should be settled by observation and mathematical reasoning, not by philosophical axioms about the nature of elements. He provided empirical arguments supporting the possibility of the Earth's rotation, anticipating some of the reasoning later used by Copernicus.

In Istanbul, Ali Qushji was appointed to the Ayasofya madrasa and became a central figure in Ottoman scientific and educational reform. He helped reorganize the madrasa system and introduced Timurid mathematical and astronomical traditions into Ottoman scholarship. His textbooks on mathematics and astronomy were used in Ottoman madrasas for centuries. Some scholars have suggested that his work may have influenced Copernicus through intermediary channels, though direct transmission remains debated.

Places

Connected Figures

Sources

• [1]Ragep, F.J. "Ali Qushji and Regiomontanus: Eccentric Transformations and Copernican Revolutions." Journal for the History of Astronomy, 2005.
• [2]Ihsanoglu, Ekmeleddin. "Ali Kushji." Biographical Encyclopedia of Astronomers, Springer, 2007.
• [3]Saliba, George. Islamic Science and the Making of the European Renaissance. MIT Press, 2007.