Astronomy in the Service of Islam

Based on a wide variety of previously unstudied sources, these articles explain how science was applied to three aspects of Islamic ritual in the Middle Ages: the regulation of the lunar calendar; the organisation of the times of the five daily prayers; and the determination of the sacred direction (qibla) towards the Kaaba in Mecca. Simple procedures of folk astronomy were used by the scholars of religious law who determined popular practice; more complicated mathematical methods were provided by the scientists - and this proved a powerful incentive for the development of scientific analysis and research. Some of these procedures were to have far-reaching consequences. For example, the astronomical alignment of the Kaaba - known to various medieval writers, but long forgotten - led to the adoption of similar alignments for the qibla, and the final articles show how these were calculated, whether from astronomical observation or geographical computation, and their impact on the orientation of religious and secular architecture across the Islamic world. C'est A partir d'une grande diversite de sources inexplorees que ces articles expliquent comment la science avait ete appliquee a trois aspects du rituel islamique au Moyen Age: la regulation du calendrier lunaire; l'organisation des heures assignees aux cinq prieres quotidiennes; et l'etablissement de la direction sacree (qibla) vers la Kaaba de la Mecque. Des procedes simples d'astronomie populaire etaient utilises par les erudits en droit religieux qui decidaient de la pratique populaire; des methodes mathematiques plus complexes etaient offertes par les hommes de science - ce qui, en effet, s'avera A?tre une motivation puissante dans le developpement de l'analyse et de la recherche scientifique. Certains de ces procedes eurent des consequences d'une grande portee par la suite. L'alignement astronomique de la Kaaba - pour ne reprendre qu'un exemple connu