} Abu Muhammad Abd al-Haqq al‐Ghafiqi al‐Ishbili (), also known as Ibn al‐Hāʾim (fl. was a medieval Muslim astronomer and

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

from

Seville Seville ( ; , ) is the capital and largest city of the Spain, Spanish autonomous communities of Spain, autonomous community of Andalusia and the province of Seville. It is situated on the lower reaches of the Guadalquivir, River Guadalquivir, ...

. He is known to modern scholars for his (1204/5), which was had a great influence on the development of

Islamic astronomy Medieval Islamic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age (9th–13th centuries), and mostly written in the Arabic language. These developments mostly took place in th ...

and which has provided important information on astronomers from

Al-Andalus Al-Andalus () was the Muslim-ruled area of the Iberian Peninsula. The name refers to the different Muslim states that controlled these territories at various times between 711 and 1492. At its greatest geographical extent, it occupied most o ...

, including the instrument maker and

astrologer Astrology is a range of Divination, divinatory practices, recognized as pseudoscientific since the 18th century, that propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions ...

Al-Zarqali Abū Isḥāq Ibrāhīm ibn Yaḥyā al-Naqqāsh al-Zarqālī al-Tujibi (); also known as Al-Zarkali or Ibn Zarqala (1029–1100), was an Arab maker of astronomical instruments and an astrologer from the western part of the Islamic world. ...

Life

Ibn al‐Hāʾim originated from

. As a student, he learnt mathematics using the works of the scholars

Al-Jayyani Abū ʿAbd Allāh Muḥammad ibn Muʿādh al-Jayyānī (; 989, Cordova, Al-Andalus – 1079, Jaén, Al-Andalus) was an Arab mathematician, Islamic scholar, and Qadi from Al-Andalus (in present-day Spain). Al-Jayyānī wrote important commentari ...

and

Jabir ibn Aflah Abū Muḥammad Jābir ibn Aflaḥ (, ; 1100–1150) was an Arab Muslim astronomer and mathematician from Seville, who was active in 12th century al-Andalus. His work ''Iṣlāḥ al-Majisṭi'' (Correction of the ''Almagest'') influenced Islam ...

. He probably worked in North Africa, at a time when the

Almohad Caliphate The Almohad Caliphate (; or or from ) or Almohad Empire was a North African Berbers, Berber Muslim empire founded in the 12th century. At its height, it controlled much of the Iberian Peninsula (Al-Andalus) and North Africa (the Maghreb). Th ...

ruled the region. Ibn al‐Hāʾim became proficient at mathematics and was familiar with the trigonometrical concepts introduced into al‐Andalus by the scholar Ibn Mu'adh al-Jayyani in the 11th century and developed during the next century by the astronomer and mathematician Jābir ibn Aflaḥ.

In 1204/5 Ibn al‐Hāʾim wrote ("''The Perfect Handbook on Mathematical Astronomy''"), a
treatise A treatise is a Formality, formal and systematic written discourse on some subject concerned with investigating or exposing the main principles of the subject and its conclusions."mwod:treatise, Treatise." Merriam-Webster Online Dictionary. Acc ...
that consisted of an introduction and seven books. A in all but name, the information it contains does not include any numerical tables. It was considered exceptionally complete and accurate by Islamic medieval astronomers, and he had a great influence on the development of astronomy in the
Maghreb The Maghreb (; ), also known as the Arab Maghreb () and Northwest Africa, is the western part of the Arab world. The region comprises western and central North Africa, including Algeria, Libya, Mauritania, Morocco, and Tunisia. The Maghreb al ...
. The work has provided modern historians with important information on earlier astronomers in al‐Andalus. It gives historical data on the life and works of the instrument maker and
astrologer Astrology is a range of Divination, divinatory practices, recognized as pseudoscientific since the 18th century, that propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions ...

Al-Zarqali Abū Isḥāq Ibrāhīm ibn Yaḥyā al-Naqqāsh al-Zarqālī al-Tujibi (); also known as Al-Zarkali or Ibn Zarqala (1029–1100), was an Arab maker of astronomical instruments and an astrologer from the western part of the Islamic world. ...
and the creation of the ''
Tables of Toledo The ''Toledan Tables'', or ''Tables of Toledo'', were astronomical tables which were used to predict the movements of the Sun, Moon and planets relative to the fixed stars. They were a collection of mathematical tables that describe different asp ...
'' by astronomers in
Toledo Toledo most commonly refers to: * Toledo, Spain, a city in Spain * Province of Toledo, Spain * Toledo, Ohio, a city in the United States Toledo may also refer to: Places Belize * Toledo District * Toledo Settlement Bolivia * Toledo, Or ...
patronized by the
Said Al-Andalusi Ṣāʿid al-Andalusī (), in full Abū al-Qāsim Ṣāʿid ibn Abū al-Walīd Aḥmad ibn Abd al-Raḥmān ibn Muḥammad ibn Ṣāʿid ibn ʿUthmān al-Taghlibi al-Qūrtūbi () (1029July 6, 1070 AD; 4206 Shawwal, 462 AH), was an Arab qadi of ...
. Ibn al‐Hāʾim further extended Al-Zarqali's theories on the
oscillation Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...
of the
obliquity of the ecliptic In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orbital ...
, presented
spherical trigonometrical Spherical trigonometry is the branch of spherical geometry that deals with the metrical relationships between the sides and angles of spherical triangles, traditionally expressed using trigonometric functions. On the sphere, geodesics are grea ...
formulae, gives a
longitude Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lett ...
of the solar apogee of 85° 49′ and further confirmed the works of Al-Zarqali. The work also deals with the computation of the Moon's longitude and latitude, attempting to correct
Ptolemy Claudius Ptolemy (; , ; ; – 160s/170s AD) was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which were important to later Byzantine science, Byzant ...
's theory. A copy of the
manuscript A manuscript (abbreviated MS for singular and MSS for plural) was, traditionally, any document written by hand or typewritten, as opposed to mechanically printed or reproduced in some indirect or automated way. More recently, the term has ...
is held at the
Bodleian Library The Bodleian Library () is the main research library of the University of Oxford. Founded in 1602 by Sir Thomas Bodley, it is one of the oldest libraries in Europe. With over 13 million printed items, it is the second-largest library in ...
at
Oxford Oxford () is a City status in the United Kingdom, cathedral city and non-metropolitan district in Oxfordshire, England, of which it is the county town. The city is home to the University of Oxford, the List of oldest universities in continuou ...
, UK.

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Life

Notes

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Further reading