Zīj is the generic name applied to Islamic astronomical books that tabulate parameters used for astronomical calculations of the positions of the Sun, Moon, stars, and planets. The name is derived from the
Middle PersianMiddle Persian , indigenously known as "Pârsig" sometimes referred to as Pahlavi or Pehlevi, is the Middle Iranian language/ethnolect of Southwestern Iran that during Sassanid times became a prestige dialect and so came to be spoken in other regions as well. Middle Persian is classified as a...
term
zih or
zīg, meaning cord. The term is believed to refer to the arrangement of threads in weaving, which was transferred to the arrangement of rows and columns in tabulated data. In addition to the term
zīj, some were called by the name
qānūn, derived from the equivalent Greek word, κανών.
Some of the early
zījes tabulated data from Indian planetary theory (known as the Sindhind) and from pre-Islamic
Sassanid PersianThe Sassanid Empire , known to its inhabitants as Ērānshahr and Ērān in Middle Persian and resulting in the New Persian terms Iranshahr and Iran , was the last pre-Islamic Persian Empire, ruled by the Sasanian Dynasty from 224 to 651...
models, but most
zījes presented data based on the Ptolemaic model. A small number of the
zījes adopted their computations reflecting original observations but most only adopted their tables to reflect the use of a different calendar or geographic longitude as the basis for computations. Since most
zījes generally followed earlier theory, their principal contributions reflected improved trigonometrical, computational and observational techniques.
The content of
zījes were initially based on that of the
Handy Tables (known in Arabic as
al-Qānūn) by
EgyptianEgyptian astronomy begins in prehistoric times, in the Predynastic Period. In the 5th millennium BCE, the stone circles at Nabta Playa may have made use of astronomical alignments...
astronomer
PtolemyClaudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
, the
Zij-i Shah compiled in
SassanidThe Sassanid Empire , known to its inhabitants as Ērānshahr and Ērān in Middle Persian and resulting in the New Persian terms Iranshahr and Iran , was the last pre-Islamic Persian Empire, ruled by the Sasanian Dynasty from 224 to 651...
Persia, and the Indian
SiddhantaSiddhanta, a Sanskrit term, roughly translates as the Doctrine or the Tradition. It denotes the established and accepted view of a particular school within Indian philosophy.-Hindu philosophy:...
s by
AryabhataAryabhata was the first in the line of great mathematician-astronomers from the classical age of Indian mathematics and Indian astronomy...
and
BrahmaguptaBrahmagupta was an Indian mathematician and astronomer who wrote many important works on mathematics and astronomy. His best known work is the Brāhmasphuṭasiddhānta , written in 628 in Bhinmal...
. Muslim
zijes, however, were more extensive, and typically included materials on
chronologyChronology is the science of arranging events in their order of occurrence in time, such as the use of a timeline or sequence of events. It is also "the determination of the actual temporal sequence of past events".Chronology is part of periodization...
, geographical
latitudeIn geography, the latitude of a location on the Earth is the angular distance of that location south or north of the Equator. The latitude is an angle, and is usually measured in degrees . The equator has a latitude of 0°, the North pole has a latitude of 90° north , and the South pole has a...
s and
longitudeLongitude is a geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, usually expressed in degrees, minutes and seconds, and denoted by the Greek letter lambda ....
s,
starA star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
tables, trigonometrical functions, functions in
spherical astronomySpherical astronomy or positional astronomy is the branch of astronomy that is used to determine the location of objects on the celestial sphere, as seen at a particular date, time, and location on the Earth. It relies on the mathematical methods of spherical geometry and the measurements of...
, the
equation of timeThe equation of time is the difference between apparent solar time and mean solar time. At any given instant, this difference will be the same for every observer...
, planetary motions, computation of eclipses, tables for first visibility of the
lunar crescentIn astronomical terminology, the new moon is the lunar phase that occurs when the Moon, in its monthly orbital motion around Earth, lies between Earth and the Sun, and is therefore in conjunction with the Sun as seen from Earth...
, astronomical and/or astrological computations, and instructions for astronomical calculations using epicyclic geocentric models. Some
zījes go beyond this traditional content to explain or prove the theory or report the observations from which the tables were computed.
Over 200 different
zījes have been identified that were produced by
Islamic astronomersIslamic astronomy or Arabic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age , and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and...
during the period from the eighth to the fifteenth centuries. The greatest centers of production of
zījes were
BaghdadBaghdad is the capital of Iraq, as well as the coterminous Baghdad Governorate. The population of Baghdad in 2011 is approximately 7,216,040...
under the Abassid
caliphThe Caliph is the head of state in a Caliphate, and the title for the ruler of the Islamic Ummah, an Islamic community ruled by the Shari'ah. It is a transcribed version of the Arabic word which means "successor" or "representative"...
s in the 9th century, the
Maragheh observatoryMaragheh observatory is an astronomical observatory which was established in 1259 CE by Nasir al-Din al-Tusi, an Iranian scientist and astronomer...
in the 13th century, the
SamarkandAlthough a Persian-speaking region, it was not united politically with Iran most of the times between the disintegration of the Seleucid Empire and the Arab conquest . In the 6th century it was within the domain of the Turkic kingdom of the Göktürks.At the start of the 8th century Samarkand came...
observatory in the 15th century, and the Istanbul observatory of Taqi al-Din in the 16th century. Nearly 100 more
zijes were also produced in India between the 16th and 18th centuries. One of the most famous Indian
zijes was the
Zij-i Muhammad Shahi, compiled at
Jai Singh II of AmberMaharaja Sawai Jai Singh was ruler of the kingdom of Amber . He was born at Amber, the capital of the Kachwahas. He became ruler of Amber at the age of 11 after his father Maharaja Bishan Singh died on 31 December 1699...
's Yantra Mantra observatories. It is notable for employing the use of
telescopicA telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
observations. The last known
zij treatise was the
Zij-i Bahadurkhani, written in 1838 by the Indian astronomer Ghulam Hussain Jaunpuri (1760–1862) and printed in 1855, dedicated to
Bahadur KhanUstad Bahadur Khan was a sarod player.-Early Life & Family:Ustad Bahadur Khan, a Bengali, was born on January 19, 1931 in Shibpur, Comilla, Bangladesh, , and died on October 3, 1989 in Calcutta, India...
. The treatise incorporated the
heliocentricHeliocentrism, or heliocentricism, is the astronomical model in which the Earth and planets revolve around a stationary Sun at the center of the universe. The word comes from the Greek . Historically, heliocentrism was opposed to geocentrism, which placed the Earth at the center...
system into the
Zij tradition.
List of zijes
- Az-Zīj ‛alā Sinī al-‛Arab — by Ibrahim al-Fazari
Abu Ishaq Ibrahim ibn Habib ibn Sulaiman ibn Samura ibn Jundab al-Fazari was an 8th-century Muslim mathematician and astronomer of Persian background....
(d. 777) and Muhammad al-FazariAbu abdallah Muhammad ibn Ibrahim al-Fazari was a Muslim philosopher, mathematician and astronomer. He is not to be confused with his father Ibrāhīm al-Fazārī, also an astronomer and mathematician....
(d. 796/806)
- Az-Zīj al-Mahlul min as-Sindhind li-Darajat Daraja — by Yaqūb ibn Tāriq
Yaʿqūb ibn Ṭāriq was an 8th-century Persian astronomer and mathematician who lived in Baghdad.- Works :Works ascribed to Yaʿqūb ibn Ṭāriq include:...
(d. 796)
- Zīj al-Sindhind — by al-Khwarizmi (c. 780-850)
- Az-Zij as-Sabi — by Muhammad ibn Jābir al-Harrānī al-Battānī (Albatenius) (853-929)
- Zij al-Safa'ih (Tables of the disks of the astrolabe) — by Abū Ja'far al-Khāzin (900-971)
- Book of Fixed Stars
The Book of Fixed Stars is an astronomical text written by Abd al-Rahman al-Sufi around 964. The book was written in Arabic, although the author himself was Persian...
(964) — by Abd al-Rahman al-Sufi (Azophi) (903-986)
- Zij al-Kabir al-Hakimi — by Ibn Yunus
Ibn Yunus was an important Egyptian Muslim astronomer and mathematician, whose works are noted for being ahead of their time, having been based on meticulous calculations and attention to detail.The crater Ibn Yunus on the Moon is named after...
(c. 950-1009)
- Az-Zīj al-Jamī wal-Baligh (The Comprehensive and Mature Tables) — by Kushyar ibn Labban
Abul-Hasan Kūshyār ibn Labbān ibn Bashahri Gilani , also known as Kūshyār Gīlānī , was a Persian mathematician, geographer, and astronomer from Gilan, south of the Caspian Sea, Iran....
(971-1029)
- Almanac of Azarqueil (1088) — by Abū Ishāq Ibrāhīm al-Zarqālī (Azarqueil) (1028–1087)
- 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...
— based on Abū Ishāq Ibrāhīm al-Zarqālī (Azarqueil) (1028–1087)
- Az-Zīj As-Sanjarī (Sinjaric Tables) — by al-Khazini
Abu al-Fath Abd al-Rahman Mansour al-Khāzini or simply Abu al-Fath Khāzini was a Muslim astronomer of Greek ethnicity from Merv, then in the Khorasan province of Persia .-References:...
(fl.Floruit , abbreviated fl. , is a Latin verb meaning "flourished", denoting the period of time during which something was active...
1115-1130)
- Zij-i Ilkhani
Zīj-i Īlkhānī or Ilkhanic Tables is a Zij book with astronomical tables of planetary movements. It was compiled by the Persian astronomer Nasir al-Din al-Tusi in collaboration with his research team of astronomers at the Maragha observatory...
— by Nasīr al-Dīn al-TūsīKhawaja Muḥammad ibn Muḥammad ibn Ḥasan Ṭūsī , better known as Naṣīr al-Dīn al-Ṭūsī , was a Persian polymath and prolific writer: an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed...
(1201–1274)
- Khaqani Zij — by Jamshīd al-Kāshī
Ghiyāth al-Dīn Jamshīd Masʾūd al-Kāshī was a Persian astronomer and mathematician.-Biography:...
(1380–1429)
- Zij-i-Sultani
Zīj-i Sultānī is a Zij astronomical table and star catalogue that was published by Ulugh Beg in 1437. It was the joint product of the work of a group of Muslim astronomers working under the patronage of Ulugh Beg at Samarkand's Ulugh Beg Observatory...
(1437) — by Ulugh BegUlugh Bek was a Timurid ruler as well as an astronomer, mathematician and sultan. His commonly-known name is not truly a personal name, but rather a moniker, which can be loosely translated as "Great Ruler" or "Patriarch Ruler" and was the Turkic equivalent of Timur's Perso-Arabic title Amīr-e...
(1393–1449)
- Unbored Pearl (1579–1580) — by Taqi al-Din Muhammad ibn Ma'ruf (1526–1585)
- Zij-i Muhammad Shahi — by Jai Singh II of Amber
Maharaja Sawai Jai Singh was ruler of the kingdom of Amber . He was born at Amber, the capital of the Kachwahas. He became ruler of Amber at the age of 11 after his father Maharaja Bishan Singh died on 31 December 1699...
(1688–1743)
- Zij-i Bahadurkhani (1838) — by Ghulam Hussain Jaunpuri (1760–1862)
External links