A little known astronomer in the late Islamic period. A study of Qasim ali al-Qayini's manuscripts

Abstract

It is widely believed that the advance of science in the Islamic world after the mid-fifteenth century A.D. suffered a decline. For the purpose of examining this belief, a manuscript by Qasim ali al-Qayini (ca. A.D.1685) was chosen based on previous works which considered it a valuable source on the history of optics that had not been studied before. After studying his major optical manuscript, titled Manazir wa Maraya, it was found very interesting that the majority of al-Qayini's propositions relating to natural phenomena were not merely geometrical definitions, but that the proofs related to astronomy. As an example, in one case, which had not been explained in previous astronomical and optical manuscripts, al-Qayini tried, despite lacking a vigorous proof, to show how a special point in a room could be lit up by sunlight throughout the year. His particular interest in astronomy led us to a general study of his other works, and it is worth noting that out of the nineteen works that have been attributed to him, eleven are devoted to astronomy and have not been thoroughly studied. Much more research is required on his astronomical manuscripts in order to obtain a better understanding of this author, the century in which he lived and the general state of science in the late Islamic period. After all, given the many as-yet unstudied manuscripts that still exist, maybe this decline was not as rapid as has previously been assumed.