So much for mathematics, astronomy, chemistry, etc. Stupid "ragheads." What the hell do they know, anyway?
"Nasir ad-Din at-Tusi (1201–1274) was among the Arabic astronomers of the late thirteenth century at the observatory of Maragha in Persia who modified Ptolemy's models based on mechanical principles in order to preserve the uniform rotation of spheres. This early Arabic manuscript contains his principal work on the subject, the "Tadhkira fi ilm al-Haya" (Memoir on Astronomy). The figure shown in this detail from a fourteenth-century copy of his manuscript is his ingenious device for generating rectilinear motion along the diameter of the outer circle from two circular motions."
~ The Copernican Revolution; Prentice-Hall, Inc.
READ about it at CBS News.