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The Persian astronomer Nasir al-Din al-Tusi spent over two decades among the Nizari Ismailis, including time at Alamut, then entered the Mongol conqueror Hülegü's service in 1256. With Mongol support he founded a great observatory at Maragha, in north-western Iran, in 1259.

Nasir al-Din al-Tusi

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The story behind the card

Nasir al-Din al-Tusi (1201–1274), born in Tus in north-eastern Iran, was an astronomer, mathematician and philosopher. Among the Nizaris he wrote the Nasirean Ethics (1235), a widely read book on moral philosophy, and in 1247 described what is now called the 'Tusi couple': a small circle rolling inside one twice its size, which turns circular motion into a straight line. Historians still debate how freely he stayed there. At Maragha he gathered scholars, instruments and a large library, and produced new astronomical tables. A device like the Tusi couple later appears in Copernicus's work; how it reached him is not known.

Türkçe oku
İranlı gökbilimci Nasîrüddin Tûsî, aralarında Alamut'un da bulunduğu Nizari İsmaili kalelerinde yirmi yılı aşkın süre yaşadı; 1256'da Moğol fatihi Hülagü'nün hizmetine girdi. Moğolların desteğiyle 1259'da kuzeybatı İran'daki Meraga'da büyük bir rasathane kurdu.

Nasîrüddin Tûsî (1201–1274), İran'ın kuzeydoğusundaki Tus'ta doğmuş bir gökbilimci, matematikçi ve filozoftu. Nizarilerin yanındayken ahlak felsefesi üzerine çok okunan Ahlâk-ı Nâsırî'yi (1235) yazdı; 1247'de de bugün “Tûsî çifti” denen düzeneği tanımladı: İki katı büyüklükteki bir çemberin içinde yuvarlanan küçük bir çember, dairesel hareketi doğrusal harekete çevirir. Orada ne kadar kendi isteğiyle kaldığı hâlâ tartışılıyor. Meraga'da bilginleri, aletleri ve büyük bir kütüphaneyi bir araya getirdi, yeni gökbilim cetvelleri hazırladı. Tûsî çiftine benzeyen bir düzenek sonradan Kopernik'in eserinde de görülür; ona nasıl ulaştığı ise bilinmiyor.

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