Thabit ibn Qurra
Encyclopedia
was a mathematician
, physician
, astronomer
and translator of the Islamic Golden Age
.
Ibn Qurra made important discoveries in algebra
, geometry
and astronomy
. In astronomy, Thabit is considered one of the first reformers of the Ptolemaic system, and in mechanics he was a founder of statics
.
(known as Carrhae in antiquity
) in Higher Mesopotamia/Assyria
(in modern day Turkey
). At the invitation of Muhammad bin Musa bin Shakir, one of the Banu Musa
brothers, Thabit went to study in Baghdad
at the House of Wisdom
. He was an ethnic Assyrian
, a native Syriac/Aramaic speaker, and belonged to the Sabians
of Harran, a sect
of Hermeticists
. Other sources credit him to be a Mandaean. In either case, both sects have a great interest in astronomy
, astrology
, and mathematics
(especially in the case of Mandaeans).
The Sabians lived in the vicinity of the main center of the Caliphate until 1258, when the Mongols destroyed their last shrine. During Muslim
rule, they were a protected minority, and around the time of al-Mutawakkil
's reign Harran became a center for philosophical, esoteric, and medical learning. They may have been joined by the descendants of pagan Greek scholars who, not tolerated in the Byzantine Empire, settled in lands that became part of the Abbasid
caliphate
. After 750 AD, some Muslim rulers and scholars became interested in Greek sciences, collecting and having translated many ancient Greek works in the fields of philosophy and mathematics. Although they later became Arabic speakers, in pre-Islamic times, it was common for Sabians to speak Greek.
Thabit and his pupils lived in the midst of the most intellectually vibrant, and probably the largest, city of the time, Baghdad
. He occupied himself with mathematics, astronomy, astrology, magic, mechanics
, medicine
, and philosophy
. Later in his life, Thabit's patron was the Abbasid Caliph al-Mu'tadid
(reigned 892–902). Thabit became the Caliph's personal friend and courtier.
Thabit died in Baghdad
. After him the greatest Sabean name was Abu Abdallah Mohammad ibn Jabir Al-Battani
. Thabit and his grandson Ibrahim ibn Sinan ibn Thabit
studied the curves needed for making sundial
s. Thabit's son Sinan ibn Thabit
was a distinguished physician who was responsible for supervising all the public hospitals of Baghdad. He was a member of the Sabian sect.
, which was the eastern Aramaic
dialect from Edessa
, and he knew Greek well too. He translated from Greek Apollonius
, Archimedes
, Euclid
and Ptolemy
. Thabit had revised the translation of Euclid
's Elements
of Hunayn ibn Ishaq
. He also rewrote Hunayn's translation of Ptolemy's Almagest
and translated Ptolemy
's Geography. Thabit's translation of a work by Archimedes which gave a construction of a regular heptagon was discovered in the 20th century, the original having been lost.
theory of the trepidation
of the equinoxes is often attributed to Thabit. But it had already been described by Theon of Alexandria
in his comments of the Handy Tables of Ptolemy
. According to Copernicus
Thabit determined the length of the sidereal year
as 365 days, 6 hours, 9 minutes and 12 seconds (an error of 2 seconds). Copernicus based his claim on the Latin text attributed to Thabit. Thabit published his observations of the Sun
.
, Thabit discovered an equation for determining the amicable number
s. He also wrote on the theory of numbers
, and extended their use to describe the ratios between geometrical quantities, a step which the Greeks never took.
He is known for having calculated the solution to a chessboard problem
involving an exponential series.
, Thabit rejected the Peripatetic and Aristotelian
notions of a "natural place" for each element
. He instead proposed a theory of motion in which both the upward and downward motions are caused by weight
, and that the order of the universe is a result of two competing attractions
(jadhb): one of these being "between the sublunar and celestial elements", and the other being "between all parts of each element separately".
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....
, physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
, 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 translator of the Islamic Golden Age
Islamic Golden Age
During the Islamic Golden Age philosophers, scientists and engineers of the Islamic world contributed enormously to technology and culture, both by preserving earlier traditions and by adding their own inventions and innovations...
.
Ibn Qurra made important discoveries in algebra
Algebra
Algebra is the branch of mathematics concerning the study of the rules of operations and relations, and the constructions and concepts arising from them, including terms, polynomials, equations and algebraic structures...
, geometry
Geometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....
and astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
. In astronomy, Thabit is considered one of the first reformers of the Ptolemaic system, and in mechanics he was a founder of statics
Statics
Statics is the branch of mechanics concerned with the analysis of loads on physical systems in static equilibrium, that is, in a state where the relative positions of subsystems do not vary over time, or where components and structures are at a constant velocity...
.
Biography
Thabit was born in HarranHarran
Harran was a major ancient city in Upper Mesopotamia whose site is near the modern village of Altınbaşak, Turkey, 24 miles southeast of Şanlıurfa...
(known as Carrhae in antiquity
Classical antiquity
Classical antiquity is a broad term for a long period of cultural history centered on the Mediterranean Sea, comprising the interlocking civilizations of ancient Greece and ancient Rome, collectively known as the Greco-Roman world...
) in Higher Mesopotamia/Assyria
Assyria
Assyria was a Semitic Akkadian kingdom, extant as a nation state from the mid–23rd century BC to 608 BC centred on the Upper Tigris river, in northern Mesopotamia , that came to rule regional empires a number of times through history. It was named for its original capital, the ancient city of Assur...
(in modern day Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
). At the invitation of Muhammad bin Musa bin Shakir, one of the Banu Musa
Banu Musa
The Banū Mūsā brothers , namely Abū Jaʿfar Muḥammad ibn Mūsā ibn Shākir , Abū al‐Qāsim Aḥmad ibn Mūsā ibn Shākir and Al-Ḥasan ibn Mūsā ibn Shākir , were three 9th-century Persian scholars of Baghdad who are known for their Book of Ingenious Devices on automata and mechanical devices...
brothers, Thabit went to study 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...
at the House of Wisdom
House of Wisdom
The House of Wisdom was a library and translation institute established in Abbassid-era Baghdad, Iraq. It was a key institution in the Translation Movement and considered to have been a major intellectual centre during the Islamic Golden Age...
. He was an ethnic Assyrian
Assyrian people
The Assyrian people are a distinct ethnic group whose origins lie in ancient Mesopotamia...
, a native Syriac/Aramaic speaker, and belonged to the Sabians
Sabians
The Sabians of Middle Eastern tradition were a monotheistic Abrahamic religious group mentioned three times in the Quran: "the Jews, the Sabians, and the Christians." In the Hadith they are nothing but converts to Islam, while their identity in later Islamic literature became a matter of...
of Harran, a sect
Sect
A sect is a group with distinctive religious, political or philosophical beliefs. Although in past it was mostly used to refer to religious groups, it has since expanded and in modern culture can refer to any organization that breaks away from a larger one to follow a different set of rules and...
of Hermeticists
Hermeticism
Hermeticism or the Western Hermetic Tradition is a set of philosophical and religious beliefs based primarily upon the pseudepigraphical writings attributed to Hermes Trismegistus...
. Other sources credit him to be a Mandaean. In either case, both sects have a great interest in astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
, astrology
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...
, and mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
(especially in the case of Mandaeans).
The Sabians lived in the vicinity of the main center of the Caliphate until 1258, when the Mongols destroyed their last shrine. During Muslim
Muslim
A Muslim, also spelled Moslem, is an adherent of Islam, a monotheistic, Abrahamic religion based on the Quran, which Muslims consider the verbatim word of God as revealed to prophet Muhammad. "Muslim" is the Arabic term for "submitter" .Muslims believe that God is one and incomparable...
rule, they were a protected minority, and around the time of al-Mutawakkil
Al-Mutawakkil
Al-Mutawakkil ʻAlā Allāh Jaʻfar ibn al-Muʻtasim was an Abbasid caliph who reigned in Samarra from 847 until 861...
's reign Harran became a center for philosophical, esoteric, and medical learning. They may have been joined by the descendants of pagan Greek scholars who, not tolerated in the Byzantine Empire, settled in lands that became part of the Abbasid
Abbasid
The Abbasid Caliphate or, more simply, the Abbasids , was the third of the Islamic caliphates. It was ruled by the Abbasid dynasty of caliphs, who built their capital in Baghdad after overthrowing the Umayyad caliphate from all but the al-Andalus region....
caliphate
Caliphate
The term caliphate, "dominion of a caliph " , refers to the first system of government established in Islam and represented the political unity of the Muslim Ummah...
. After 750 AD, some Muslim rulers and scholars became interested in Greek sciences, collecting and having translated many ancient Greek works in the fields of philosophy and mathematics. Although they later became Arabic speakers, in pre-Islamic times, it was common for Sabians to speak Greek.
Thabit and his pupils lived in the midst of the most intellectually vibrant, and probably the largest, city of the time, 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...
. He occupied himself with mathematics, astronomy, astrology, magic, mechanics
Mechanics
Mechanics is the branch of physics concerned with the behavior of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment....
, medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
, and philosophy
Philosophy
Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
. Later in his life, Thabit's patron was the Abbasid Caliph al-Mu'tadid
Al-Mu'tadid
Al-Mu'tadid was the Abbasid Caliph in Baghdad from 892 to 902. As the son and heir of the powerful vizier and virtual regent Al-Muwaffaq , Mu'tadid was already in possession of supreme power even before he was appointed Caliph, and continued as Caliph to ably administer the Government...
(reigned 892–902). Thabit became the Caliph's personal friend and courtier.
Thabit died 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...
. After him the greatest Sabean name was Abu Abdallah Mohammad ibn Jabir Al-Battani
Al-Battani
Abū ʿAbd Allāh Muḥammad ibn Jābir ibn Sinān al-Raqqī al-Ḥarrānī al-Ṣābiʾ al-Battānī was a Muslim astronomer, astrologer, and mathematician...
. Thabit and his grandson Ibrahim ibn Sinan ibn Thabit
Ibrahim ibn Sinan
Ibrahim ibn Sinan ibn Thabit ibn Qurra was a Syriac speaking Mandean from Harran in northern Mesopotamia/Assyria. He was mathematician and astronomer who studied geometry and in particular tangents to circles. He also made advances in the theory of integration...
studied the curves needed for making sundial
Sundial
A sundial is a device that measures time by the position of the Sun. In common designs such as the horizontal sundial, the sun casts a shadow from its style onto a surface marked with lines indicating the hours of the day. The style is the time-telling edge of the gnomon, often a thin rod or a...
s. Thabit's son Sinan ibn Thabit
Sinan ibn Thabit
Sinan ibn Thabit ibn Qurra سنان بن ثابت بن قرة ) was an ethnic Mandean physician and a Sabian who later converted to Islam. He was the son of Thabit ibn Qurra and the father of Ibrahim ibn Sinan.- References :...
was a distinguished physician who was responsible for supervising all the public hospitals of Baghdad. He was a member of the Sabian sect.
Translation
Thabit's native language was SyriacSyriac language
Syriac is a dialect of Middle Aramaic that was once spoken across much of the Fertile Crescent. Having first appeared as a script in the 1st century AD after being spoken as an unwritten language for five centuries, Classical Syriac became a major literary language throughout the Middle East from...
, which was the eastern Aramaic
Aramaic language
Aramaic is a group of languages belonging to the Afroasiatic language phylum. The name of the language is based on the name of Aram, an ancient region in central Syria. Within this family, Aramaic belongs to the Semitic family, and more specifically, is a part of the Northwest Semitic subfamily,...
dialect from Edessa
Edessa, Mesopotamia
Edessa is the Greek name of an Aramaic town in northern Mesopotamia, as refounded by Seleucus I Nicator. For the modern history of the city, see Şanlıurfa.-Names:...
, and he knew Greek well too. He translated from Greek Apollonius
Apollonius of Perga
Apollonius of Perga [Pergaeus] was a Greek geometer and astronomer noted for his writings on conic sections. His innovative methodology and terminology, especially in the field of conics, influenced many later scholars including Ptolemy, Francesco Maurolico, Isaac Newton, and René Descartes...
, Archimedes
Archimedes
Archimedes of Syracuse was a Greek mathematician, physicist, engineer, inventor, and astronomer. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Among his advances in physics are the foundations of hydrostatics, statics and an...
, Euclid
Euclid
Euclid , fl. 300 BC, also known as Euclid of Alexandria, was a Greek mathematician, often referred to as the "Father of Geometry". He was active in Alexandria during the reign of Ptolemy I...
and Ptolemy
Ptolemy
Claudius 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...
. Thabit had revised the translation of Euclid
Euclid
Euclid , fl. 300 BC, also known as Euclid of Alexandria, was a Greek mathematician, often referred to as the "Father of Geometry". He was active in Alexandria during the reign of Ptolemy I...
's Elements
Euclid's Elements
Euclid's Elements is a mathematical and geometric treatise consisting of 13 books written by the Greek mathematician Euclid in Alexandria c. 300 BC. It is a collection of definitions, postulates , propositions , and mathematical proofs of the propositions...
of Hunayn ibn Ishaq
Hunayn ibn Ishaq
Hunayn ibn Ishaq was a famous and influential Assyrian Nestorian Christian scholar, physician, and scientist, known for his work in translating Greek scientific and medical works into Arabic and Syriac during the heyday of the Islamic Abbasid Caliphate.Ḥunayn ibn Isḥaq was the most productive...
. He also rewrote Hunayn's translation of Ptolemy's Almagest
Almagest
The Almagest is a 2nd-century mathematical and astronomical treatise on the apparent motions of the stars and planetary paths. Written in Greek by Claudius Ptolemy, a Roman era scholar of Egypt,...
and translated Ptolemy
Ptolemy
Claudius 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...
's Geography. Thabit's translation of a work by Archimedes which gave a construction of a regular heptagon was discovered in the 20th century, the original having been lost.
Astronomy
The medieval astronomicalIslamic astronomy
Islamic 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...
theory of the trepidation
Trepidation
According to a medieval theory of astronomy, trepidation is oscillation in the precession of the equinoxes. The theory was popular from the 9th to the 16th centuries....
of the equinoxes is often attributed to Thabit. But it had already been described by Theon of Alexandria
Theon of Alexandria
Theon was a Greek scholar and mathematician who lived in Alexandria, Egypt. He edited and arranged Euclid's Elements and Ptolemy's Handy Tables, as well as writing various commentaries...
in his comments of the Handy Tables of Ptolemy
Ptolemy
Claudius 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...
. According to Copernicus
Nicolaus Copernicus
Nicolaus Copernicus was a Renaissance astronomer and the first person to formulate a comprehensive heliocentric cosmology which displaced the Earth from the center of the universe....
Thabit determined the length of the sidereal year
Sidereal year
A sidereal year is the time taken by the Earth to orbit the Sun once with respect to the fixed stars. Hence it is also the time taken for the Sun to return to the same position with respect to the fixed stars after apparently travelling once around the ecliptic. It was equal to at noon 1 January...
as 365 days, 6 hours, 9 minutes and 12 seconds (an error of 2 seconds). Copernicus based his claim on the Latin text attributed to Thabit. Thabit published his observations of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
.
Mathematics
In mathematicsIslamic mathematics
In the history of mathematics, mathematics in medieval Islam, often termed Islamic mathematics or Arabic mathematics, covers the body of mathematics preserved and developed under the Islamic civilization between circa 622 and 1600...
, Thabit discovered an equation for determining the amicable number
Amicable number
Amicable numbers are two different numbers so related that the sum of the proper divisors of each is equal to the other number. A pair of amicable numbers constitutes an aliquot sequence of period 2...
s. He also wrote on the theory of numbers
Number theory
Number theory is a branch of pure mathematics devoted primarily to the study of the integers. Number theorists study prime numbers as well...
, and extended their use to describe the ratios between geometrical quantities, a step which the Greeks never took.
He is known for having calculated the solution to a chessboard problem
Mathematical chess problem
Mathematical chess problem is a mathematical problem which is formulated using chessboard or chess pieces. These problems belong to recreational mathematics. The most known problems of this kind are Eight queens puzzle or Knight's Tour problems, which have connection to graph theory and combinatorics...
involving an exponential series.
Physics
In physicsPhysics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
, Thabit rejected the Peripatetic and Aristotelian
Aristotelian physics
Aristotelian Physics the natural sciences, are described in the works of the Greek philosopher Aristotle . In the Physics, Aristotle established general principles of change that govern all natural bodies; both living and inanimate, celestial and terrestrial—including all motion, change in respect...
notions of a "natural place" for each element
Classical element
Many philosophies and worldviews have a set of classical elements believed to reflect the simplest essential parts and principles of which anything consists or upon which the constitution and fundamental powers of anything are based. Most frequently, classical elements refer to ancient beliefs...
. He instead proposed a theory of motion in which both the upward and downward motions are caused by weight
Weight
In science and engineering, the weight of an object is the force on the object due to gravity. Its magnitude , often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus:...
, and that the order of the universe is a result of two competing attractions
Gravitation
Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...
(jadhb): one of these being "between the sublunar and celestial elements", and the other being "between all parts of each element separately".
Works
Only a few of Thabit's works are preserved in their original form.- On the Sector-Figure which deals with Menelaus' theoremMenelaus' theoremMenelaus' theorem, named for Menelaus of Alexandria, is a theorem about triangles in plane geometry. Given a triangle ABC, and a transversal line that crosses BC, AC and AB at points D, E and F respectively, with D, E, and F distinct from A, B and C, thenThis equation uses signed lengths of...
. - On the Composition of Ratios
Further reading
- Francis J. Carmody: The astronomical works of Thābit b. Qurra. 262 pp. Berkeley and Los Angeles: University of California Press, 1960. Reviews: Seyyed Hossein Nasr (1998) in Isis 89 (1) pp. 112-113; Charles Burnett (1998) in Bulletin of the School of Oriental and African Studies, University of London 61 (2) p. 406.
- Churton, Tobias. The Golden Builders: Alchemists, Rosicrucians, and the First Freemasons. Barnes and Noble Publishing, 2006.