| From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, p. 549 |
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Ibn al‐Aʿlam: ʿAlī ibn
al‐Ḥusayn Abū
al‐Qāsim al‐ʿAlawī al‐Sharīf al‐Ḥusaynī
Josep Casulleras
Died possibly Baghdad,
(Iraq), 985
Ibn
al‐Aʿlam
composed a zīj (astronomical handbook with tables) that later
influenced astronomy in Iraq and Iran, especially Naṣīr
al‐Dīn al‐Ṭūsī's īlkhānī
Zīj (13th century), and in Byzantium. He was also reported to have
practiced astrology under the patronage of the Būyid ruler of Baghdad
ʿAḍud
al‐Dawla (978–983) and to have cultivated musical theory. Very little
is known about Ibn al‐Aʿlam's
life and work. His zīj, unfortunately lost, is only known by later
references in other astronomical works. One of the names given to this work,
al‐Zīj al‐ʿAḍudī, derives from the name
of his patron. It was also known as al‐Zīj al‐Sharīf,
from the name of the author, and al‐Zīj al‐Baghdādī,
which either refers to his place of residence or may indicate that the original
tables were based on the prime meridian of Baghdad.
Ibn
al‐Aʿlam's
work attracted significant interest, mainly because of the observations attributed
to him; the values from his zīj are reported in several sources
in Arabic, Persian, and Greek. Recent analyses of the quoted planetary parameters
for epoch positions, mean motions, and equations indicate that Ibn al‐Aʿlam's
planetary tables were formed on the basis of a review and consolidation of
earlier observations rather than by his own observations. There is, though,
no information available on other materials typically found in this kind of
work, such as tables for calendars, geographical coordinates, fixed stars,
or trigonometric and spherical functions.
Regarding the influence of the work, Greek sources mention Ibn al‐Aʿlam
under the name of Alim; there is evidence for the existence of a Byzantine
version of his tables, adapted to the Byzantine calendar and, probably, to
the meridian of Constantinople, made by the year 1032 and used one century
later for casting a pair of horoscopes for the years 1153 and 1162. A number
of Persian and Arabic sources reveal that Ibn al‐Aʿlam's tables were being used from his own
time until the 14th century. In al‐Zīj al‐Ḥākimī, the Egyptian astronomer
Ibn Yūnus (circa 990) stated
that Ibn al‐Aʿlam
made observations with instruments constructed by him, and he took the motion
of the mean Sun and the rate of precession from Ibn al‐Aʿlam's
tables. The Persian astronomer Shams al‐Munajjim
Muḥammad ibn ʿAlī
al‐Wābkanawī reported in his zīj
(circa 1320) that in the Zīj‐i īlkhānī,
the group of astronomers working at the Marāgha Observatory under Ṭūsī did not apply their own observations, but used the mean
motions of Ibn al‐Aʿlam.
Indeed, an analysis of the Zīj‐i īlkhānī
shows that the underlying parameters used for the solar, lunar, and planetary
tables were all taken from Ibn al‐Aʿlam and Ibn Yūnus. Finally, the Persian
Zīj‐i Ashrafī, written circa 1310 by Sayf‐i
Munajjim Muḥammad ibn
Abī ʿAbd Allāh Sanjar
al‐Kāmilī, preserves the values of Ibn al‐Aʿlam
for the radices, the equations, and the apogees.
Selected References
Kennedy, E. S. (1956). “A Survey of Islamic Astronomical Tables.”
Transactions of the American Philosophical Society, n.s., 46, pt. 2:
121–177. (Reprint, Philadelphia: American Philosophical Society, 1989.)
——— (1977). “The Astronomical
Tables of Ibn al‐Aʿlam.”
Journal for the History of Arabic Science 1: 13–23.
King, D. A. and J. Samsó (2001). With a contribution by B. R.
Goldstein. “Astronomical Handbooks and Tables from the Islamic World (750–1900):
An Interim Report.” Suhyal 2: 9–105.
Mercier, Raymond (1989).
“The Parameters of the Zīj of Ibn al‐Aʿlam.” Archives internationales d'histoire
des sciences 39: 22–50.
Sayılı, Aydın (1960). The Observatory in Islam.
Ankara: Turkish Historical Society, pp. 107–109.
Sezgin, Fuat Geschichte des arabischen Schrifttums. Vol.
5, Mathematik (1974): 309; Vol. 6, Astronomie (1978): 215–216,
293–294. Leiden: E. J. Brill.
Tihon,
Anne (1989). “Sur l'identité de l'astronome Alim.” Archives internationales
d'histoire des sciences 39: 3–21. (Reprinted in Tihon,
Études d'astronomie byzantine, IV. Aldershot: Variorum, 1994.)