Thābit ibn Qurra | |
|---|---|
| Born | 210-211 AH/220-221 AH / 826 or 836 AD |
| Died | Wednesday, 26 Safar, 288 AH / February 19, 901 AD |
| Academic background | |
| Influences | Banu Musa,Archimedes,Apollonius,Nicomachus,Euclid |
| Academic work | |
| Era | Islamic Golden Age |
| Main interests | Mathematics,Mechanics,Astronomy,Astrology,Translation,Number theory |
| Notable ideas |
|
| Influenced | al-Khazini, al-Isfizari,Na'im ibn Musa[1] |
Thābit ibn Qurra (full name:Abū al-Ḥasan Ṯābit ibn Qurra ibn Zahrūn al-Ḥarrānī al-Ṣābiʾ,Arabic:أبو الحسن ثابت بن قرة بن زهرون الحراني الصابئ,Latin:Thebit/Thebith/Tebit;[2] 826 or 836 – February 19, 901),[3] was a scholar known for his work inmathematics,medicine,astronomy, andtranslation. He lived inBaghdad in the second half of the ninth century during the time of theAbbasid Caliphate.
Thābit ibn Qurra made important discoveries inalgebra,geometry, andastronomy. In astronomy, Thābit is considered one of the first reformers of thePtolemaic system, and in mechanics he was a founder ofstatics.[4] Thābit also wrote extensively on medicine and produced philosophical treatises.[5]
Thābit was born inHarran inUpper Mesopotamia, which at the time was part of theDiyar Mudar subdivision of theal-Jazira region of theAbbasid Caliphate. Thābit was an Arab[6] who belonged to theSabians of Harran, a Hellenized Semitic polytheisticastral religion that still existed in ninth-century Harran.[7]
As a youth, Thābit worked as money changer in a marketplace in Harran until meeting Muḥammad ibn Mūsā, the oldest of three mathematicians and astronomers known as theBanū Mūsā. Thābit displayed such exceptional linguistic skills that ibn Mūsā chose him to come to Baghdad to be trained in mathematics, astronomy, and philosophy under the tutelage of the Banū Mūsā. Here, Thābit was introduced to not only a community of scholars but also to those who had significant power and influence in Baghdad.[8][9]
Thābit and his pupils lived in the midst of the most intellectually vibrant, and probably the largest, city of the time,Baghdad. Thābit came to Baghdad in the first place to work for theBanū Mūsā becoming a part of their circle and helping them translate Greek mathematical texts.[10] What is unknown is howBanū Mūsā and Thābit occupied himself with mathematics, astronomy, astrology, magic,mechanics,medicine, andphilosophy. Later in his life, Thābit's patron was the Abbasid Caliphal-Mu'tadid (reigned 892–902), whom he became a court astronomer for.[10] Thābit became the Caliph's personal friend and courtier. Thābit died inBaghdad in 901. His son,Sinan ibn Thabit and grandson,Ibrahim ibn Sinan would also make contributions to the medicine and science.[11] By the end of his life, Thābit had managed to write 150 works on mathematics, astronomy, and medicine.[12] With all the work done by Thābit, most of his work has not lasted time. There are less than a dozen works by him that have survived.[11]
Thābit's native language wasSyriac,[13] which was theMiddle Aramaic variety fromEdessa, and he was fluent in bothMedieval Greek andArabic.[14] He was the author to multiple treaties. Due to him being trilingual, Thābit was able to have a major role during theGraeco-Arabic translation movement.[11] He would also make a school of translation in Baghdad.[12]
Thābit translated from Greek into Arabic works byApollonius of Perga,Archimedes,Euclid andPtolemy. He revised the translation ofEuclid'sElements ofHunayn ibn Ishaq. He also rewrote Ishaq ibn Hunayn's translation of Ptolemy'sAlmagest and translatedPtolemy'sGeography. Thābit's translation of a work by Archimedes which gave a construction of a regularheptagon was discovered in the 20th century, the original having been lost.[15]
Thābit is believed to have been an astronomer of Caliphal-Mu'tadid.[16] Thābit was able to use his mathematical work on the examination ofPtolemaic astronomy.[11] The medievalastronomical theory of thetrepidation of theequinoxes is often attributed to Thābit.[citation needed] But it had already been described byTheon of Alexandria in his comments of theHandy Tables ofPtolemy. According toCopernicus, Thābit determined the length of thesidereal 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 Thābit. Thābit published his observations of theSun.[citation needed] In regards toPtolemy's Planetary Hypotheses, Thābit examined the problems of the motion of the Sun and Moon, and the theory of sundials.[11] When looking at Ptolemy's Hypotheses, Thābit ibn Qurra found theSidereal year which is when looking at the Earth and measuring it against the background of fixed stars, it will have a constant value.[17]
Thābit was also an author and wroteDe Anno Solis. This book contained and recorded facts about the evolution in astronomy in the ninth century.[16] Thābit mentioned in the book that Ptolemy andHipparchus believed that the movement of stars is consistent with the movement commonly found in planets. What Thābit believed is that this idea can be broadened to include the Sun and Moon.[16] With that in mind, he also thought that the solar year should be calculated by looking at the Sun's return to a given star.[16]
Inmathematics, Thābit derived an equation for determiningamicable numbers. His proof of this rule is presented in theTreatise on the Derivation of the Amicable Numbers in an Easy Way.[18] This was done while writing on thetheory of numbers, extending their use to describe the ratios between geometrical quantities, a step which the Greeks did not take. Thābit's work on amicable numbers and number theory helped him to invest more heavily into the Geometrical relations of numbers establishing hisTransversal (geometry) theorem.[12][18]
Thābit described a generalized proof of thePythagorean theorem.[19] He provided a strengthened extension[clarification needed] of Pythagoras' proof which included the knowledge ofEuclid's fifth postulate.[20] This postulate states that the intersection between two straight line segments combine to create two interior angles which are less than 180 degrees. The method of reduction and composition[clarification needed] used by Thābit resulted in a combination and extension[clarification needed] of contemporary and ancient knowledge on this famous proof. Thābit believed that geometry was tied with the equality and differences of magnitudes of lines and angles,[clarification needed] as well as that ideas of motion (and ideas taken from physics more widely) should be integrated in geometry.[21][clarification needed]
The continued work done on geometric relations and the resulting exponential series allowed Thābit to calculate multiple solutions tochessboard problems. This problem was less to do with the game itself, and more to do with the number of solutions or the nature of solutions possible. In Thābit's case, he worked withcombinatorics to work on the permutations needed to win a game of chess.[22]
In addition to Thābit's work onEuclidean geometry there is evidence that he was familiar with the geometry ofArchimedes as well. His work withconic sections and the calculation of a paraboloid shape (cupola) show his proficiency as an Archimedean geometer. This is further embossed[clarification needed] by Thābit's use of theArchimedean property in order to produce a rudimentary approximation of the volume of a paraboloid. The use of uneven sections, while relatively simple, does show a critical understanding of both Euclidean and Archimedean geometry.[23] Thābit was also responsible for a commentary on Archimedes'Liber Assumpta.[24]
Inphysics, Thābit rejected thePeripatetic andAristotelian notions of a "natural place" for eachelement. He instead proposed a theory of motion in which both the upward and downward motions are caused byweight, and that the order of the universe is a result of two competingattractions (jadhb): one of these being "between thesublunar and celestial elements", and the other being "between all parts of each element separately".[25] and in mechanics he was a founder ofstatics.[26] In addition, Thābit'sLiber Karatonis contained proof of the law of the lever. This work was the result of combining Aristotelian and Archimedean ideas of dynamics and mechanics.[12]
One of Qurra's most important pieces of text is his work with theKitab fi 'l-qarastun. This text consists of Arabic mechanical tradition.[27] Another piece of important text isKitab fi sifat alwazn, which discussed concepts of equal-armed balance. Qurra was reportedly one of the first to write about the concept of equal-armed balance or at least to systematize the treatment.
Qurra sought to establish a relationship between forces of motion and the distance traveled by the mobile.[27]
Thābit was well known as a physician and produced a substantial number of medical treatises and commentaries. His works included general reference books such asal-Dhakhira fī ilm al-tibb ("A Treasury of Medicine"),Kitāb al-Rawda fi l–tibb ("Book of the Garden of Medicine"), andal-Kunnash ("Collection"). He also produced specific works on topics such as gallstones; the treatment of diseases such as smallpox, measles, and conditions of the eye; and discussed veterinary medicine and the anatomy of birds. Thābit wrote commentaries on the works ofGalen and others, including such works asOn Plants (attributed toAristotle but likely written by the first-century BC philosopherNicolaus of Damascus).[5]
One account of Thābit's work as a physician is given inIbn al-Qiftī'sTa’rikh al-hukamā, where Thābit is credited with healing a butcher who was presumed to be certain to die.[5]
Only a few of Thābit's works are preserved in their original form.
Additional works by Thābit include:
In his epitome ofal-Qifṭī'sKitāb ikhbār al-'ulamā' bi akhbār al-ḥukamā,al-Zawzanī lists seven religious works in Syriac by Thābit and says that he also wrote in Syriac on music and geometry. According toBar Hebraeus, the 13th-century Syriac historian, Thābit wrote some 150 works in Arabic and 16 in Syriac. He claims to have seen most of the Syriac works himself and lists them. The list of Bar Hebraeus is consistent with that of al-Zawzanī. Most of the works concern pagan religion, but there is a work on music and two on geometry as well as a "book of the chronicle of the ancient Syrian kings, who are Chaldeans" and a "book on the renown of his race and his forefathers, from whom they descend".[30]
The sect, with strong Greek connections, had in earlier times adopted Greek culture, and it was common for members to speak Greek although after the conquest of the Sabians by Islam, they became Arabic speakers. There was another language spoken in southeastern Turkey, namely Syriac, which was based on the East Aramaic dialect of Edessa. This language was Thābit ibn Qurra's native language, but he was fluent in both Greek and Arabic.
{{cite book}}: CS1 maint: publisher location (link){{cite book}}: CS1 maint: location missing publisher (link) Reviews: Seyyed Hossein Nasr (1998) inIsis89 (1) pp.112-113; Charles Burnett (1998) inBulletin of the School of Oriental and African Studies, University of London61 (2) p.406.| Mathematicians |
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