David Bourget (Western Ontario)
David Chalmers (ANU, NYU)
Rafael De Clercq
Jack Alan Reynolds
Learn more about PhilPapers
Arabic Sciences and Philosophy 10 (1):7-77 (2000)
Many studies on the astrolabe were written during the period from the ninth to the eleventh century, but very few of them related to projection, i.e., to the geometrical transformation underlying the design of the instrument. Among those that did, the treatise entitled The Art of the Astrolabe, written in the tenth century by Abu Sahl al-Quhi, represents a particulary important phase in the history of geometry. This work recently appeared in a critical edition with translation and commentary by Roshdi Rashed. It contains the earliest known theory of the projection of the sphere, a theory developed in a commentary written by a contemporary mathematician, Ibn Sahl. Following R. Rashed, the present article offers here a thorough mathematical analysis of al-Quhi's treatise and of the commentary by Ibn Sahl. It also presents, with commentary, an account of a contemporary treatise on the projection of the sphere, written by al-[Sdotu]agani. The latter work is concerned with the conical projection of a sphere on a plane, from a point on an axis of the sphere, other than its pole. The author consciously avoids the case of stereographic projection, but he studies all the other cases of conical projection which, if we employ the terms of al-Quhi's theory, are compatible with the movement of the instrument (i.e. the rotation of the sphere around its axis). These three texts provide clear evidence of the emergence, during the second half of the tenth century, of a new field of study, that of projective geometry.
|Keywords||No keywords specified (fix it)|
|Categories||categorize this paper)|
Setup an account with your affiliations in order to access resources via your University's proxy server
Configure custom proxy (use this if your affiliation does not provide a proxy)
|Through your library|
References found in this work BETA
No references found.
Citations of this work BETA
No citations found.
Similar books and articles
Jacqueline Taylor (2011). Gilding and Staining and the Significance of Our Moral Sentiments. Hume Studies 36 (1):89-95.
Roshdi Rashed (2000). Ibn Sahl Et Al-Quhi: Les Projections Addenda & Corrigenda. Arabic Sciences and Philosophy 10 (1):79-100.
Roshdi Rashed (2003). Al-Quhi and Al-Sijzi on the Perfect Compass and the Continuous Drawing of Conic Sections. Arabic Sciences and Philosophy 13 (1):9-43.
Roshdi Rashed (2007). The Celestial Kinematics of Ibn Al-Haytham. Arabic Sciences and Philosophy 17 (1):7-55.
Kieran McGroarty (2006). Plotinus on Eudaimonia: A Commentary on Ennead I. Oxford University Press.
Catherine Eagleton & Matthew Spencer (2006). Copying and Conflation in Geoffrey Chaucer's Treatise on the Astrolabe: A Stemmatic Analysis Using Phylogenetic Software. Studies in History and Philosophy of Science Part A 37 (2):237-268.
Burkhard Stautz (1997). Ein Astrolab aus dem Jahr 1420. NTM International Journal of History and Ethics of Natural Sciences, Technology and Medicine 5 (1):142-159.
P. J. E. Kail (2011). Précis of Projection and Realism in Hume's Philosophy. Hume Studies 36 (1):61-65.
Philippe Abgrall (2002). A Contribution by Al-Quhi to Geometrical Analysis. Arabic Sciences and Philosophy 12 (1):53-89.
Added to index2009-01-28
Total downloads13 ( #136,613 of 1,410,046 )
Recent downloads (6 months)2 ( #107,760 of 1,410,046 )
How can I increase my downloads?