Yaqub ibn Tariq
Encyclopedia
Yaʿqūb ibn Ṭāriq was an 8th-century Persian
astronomer
and mathematician
who lived in Baghdad
.
An astrological work called Al‐maqālāt (Chapters) is also ascribed to him by an unreliable source.
The Zīj, written around 770, was based on a Sanskrit work, thought to be similar to the Brāhmasphuṭasiddhānta
. This work was brought to the court of al-Mansūr
from Sindh
, reportedly by an Sindhi
astronomer named Kankah.
The Tarkīb al‐aflāk dealt with cosmography, that is, the placement and sizes of the heavenly bodies. Its estimates of the sizes and distances of the heavenly bodies were tabulated in al-Bīrūnī
's work on India; according to him, Yaʿqūb ibn Ṭāriq gave the radius of the Earth as 1,050 farsakhs, the diameter of the Moon and Mercury as 5,000 farsakhs (4.8 Earth radii), and the diameter of the other heavenly bodies (Venus, the Sun, Mars, Jupiter, and Saturn) as 20,000 farsakhs (19.0 Earth radii.)
Persian people
The Persian people are part of the Iranian peoples who speak the modern Persian language and closely akin Iranian dialects and languages. The origin of the ethnic Iranian/Persian peoples are traced to the Ancient Iranian peoples, who were part of the ancient Indo-Iranians and themselves part of...
astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
and mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
who lived in Baghdad
Baghdad
Baghdad is the capital of Iraq, as well as the coterminous Baghdad Governorate. The population of Baghdad in 2011 is approximately 7,216,040...
.
Works
Works ascribed to Yaʿqūb ibn Ṭāriq include:- Zīj maḥlūl fī al‐Sindhind li‐daraja daraja ("Astronomical tables in the Sindhind resolved for each degree"),
- Tarkīb al‐aflāk ("Arrangement of the orbs"),
- Kitāb al‐ʿilal ("Rationales"),
- Taqṭīʿkardajāt al‐jayb ("Distribution of the kardajas of the sine"), and
- Mā irtafaʿa min qaws niṣf al‐nahār ("Elevation along the arc of the meridian").
An astrological work called Al‐maqālāt (Chapters) is also ascribed to him by an unreliable source.
The Zīj, written around 770, was based on a Sanskrit work, thought to be similar to the Brāhmasphuṭasiddhānta
Brahmasphutasiddhanta
The main work of Brahmagupta, Brāhmasphuṭasiddhānta , written c.628, contains ideas including a good understanding of the mathematical role of zero, rules for manipulating both negative and positive numbers, a method for computing square roots, methods of solving linear and some quadratic...
. This work was brought to the court of al-Mansūr
Al-Mansur
Al-Mansur, Almanzor or Abu Ja'far Abdallah ibn Muhammad al-Mansur was the second Abbasid Caliph from 136 AH to 158 AH .-Biography:...
from Sindh
Sindh
Sindh historically referred to as Ba'ab-ul-Islam , is one of the four provinces of Pakistan and historically is home to the Sindhi people. It is also locally known as the "Mehran". Though Muslims form the largest religious group in Sindh, a good number of Christians, Zoroastrians and Hindus can...
, reportedly by an Sindhi
Sindhi
Sindhi may refer to more than one article:*the Sindhis, an ethnic group from the Sindh region in Pakistan.*the Sindhi language, an Indo-Aryan language spoken by the Sindhi people.*a resident of Sindh province of Pakistan.-See also:*Sindhu Kingdom...
astronomer named Kankah.
The Tarkīb al‐aflāk dealt with cosmography, that is, the placement and sizes of the heavenly bodies. Its estimates of the sizes and distances of the heavenly bodies were tabulated in al-Bīrūnī
Al-Biruni
Abū al-Rayḥān Muḥammad ibn Aḥmad al-BīrūnīArabic spelling. . The intermediate form Abū Rayḥān al-Bīrūnī is often used in academic literature...
's work on India; according to him, Yaʿqūb ibn Ṭāriq gave the radius of the Earth as 1,050 farsakhs, the diameter of the Moon and Mercury as 5,000 farsakhs (4.8 Earth radii), and the diameter of the other heavenly bodies (Venus, the Sun, Mars, Jupiter, and Saturn) as 20,000 farsakhs (19.0 Earth radii.)
Further reading
- Plofker, Kim (2007). "Yaʿqūb ibn Ṭāriq". The Biographical Encyclopedia of Astronomers. Ed. Thomas Hockey et al. Springer Science+Business Media, LLC. pp. 1250–1251. .
- Sezgin, FuatFuat SezginFuat Sezgin is an orientalist who specializes in the history of Arabic-Islamic science. He is professor emeritus of the History of Natural Science at Johann Wolfgang Goethe University in Frankfurt, Germany and the founder and honorary director of the Institute of the History of the Arab Islamic...
(1978). Geschichte des arabischen Schrifttums. Vol. 6, Astronomie, pp. 124–127. Leiden: E. J. Brill.