User:Hygiea10/Thābit ibn Qurra

Biography
Thābit was born in Harran in Upper Mesopotamia, which at the time was part of the Diyar Mudar subdivision of the al-Jazira region of the Abbasid Caliphate. Thābit belonged to the Sabians of Harran, a Hellenized Semitic polytheistic astral religion that still existed in ninth-century Harran.

'''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 the Banū 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. '''

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 the Banū Mūsā becoming a part of their circle and helping them translate Greek mathematical texts. What is unknown is how Banū Mūsā and Thābit occupied himself with mathematics, astronomy, astrology, magic, mechanics, medicine, and philosophy. Later in his life, Thābit's patron was the Abbasid Caliph al-Mu'tadid (reigned 892&#x2013;902), whom he became a court astronomer for. Thābit became the Caliph's personal friend and courtier. Thābit died in Baghdad in 901. His son, Sinan ibn Thabit and grandson, Ibrahim ibn Sinan would also make contributions to the medicine and science. By the end of his life, Thābit had managed to write 150 works on mathematics, astronomy, and medicine.

Mathematics
In mathematics, Thābit derived an equation for determining amicable numbers. His proof of this rule is presented in the Treatise on the Derivation of the Amicable Numbers in an Easy Way. This was done while writing on the theory 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 his Transversal (geometry) theorem.

He is known for having calculated the solution to a chessboard problem involving an exponential series.

He computed the volume of the paraboloid.

He also described a generalization of Pythagoras' theorem. He was able to provide proof of the theorem through dissection. Thābit's contributions included proof of the Pythagoras' theorem and Euclid's fifth postulate. In regards to the Pythagorean Theorem, Thābit used a method reduction and composition to find proof. In regards to Euclid postulates, Thābit believed that geometry should be based on motion and more generally, physics. With that in mind, his argument was that geometry was tied with the equality and differences of magnitudes of such things like lines and angles. He would also write commentary for Archimedes's Liber Assumpta.

Physics
In physics, Thābit 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". and in mechanics he was a founder of statics. In addition, Thābit's Liber Karatonis contained proof of the law of the lever. This work was the result of combining Aristotelian and Archimedean ideas of dynamics and mechanics.

One of Qurra's most important pieces of text is his work with the Kitab fi 'l-qarastun. This text consists of Arabic mechanical tradition. Another piece of important text is Kitab fi sifat alqazn, 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.

Medicine
'''Thābit was well known as a physician and produced substantial number of medical treatises and commentaries. His works included general reference books such as al-Dhakhira fī ilm al-tibb (“A Treasurey of Medicine”), Kitāb al-Rawda fi l–tibb (“Book of the Garden of Medicine”), and al-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 of Galen and others, including such works as De plantis ("On Plants"), part of the Corpus Aristotelicum. '''

'One account of Thābit's work as a physician is given in Ibn al-Qiftī's Ta’rikh al-hukamā'', where Thābit is credited with healing a butcher who was presumed to be certain to die. '''

Works
Only a few of Thābit's works are preserved in their original form.

Additional works by Thābit include:
 * On the Sector-Figure which deals with Menelaus' theorem.
 * On the Composition of Ratios
 * Kitab fi 'l-qarastun (Book of the Steelyard)
 * Kitab fi sifat alwazn (Book on the Description of Weight) - Short text on equal-armed balance


 * Kitāb al-Mafrūdāt (Book of Data)
 * Maqāla fīistikhrāj al-a‘dād al-mutahābba bi–suhūlat al-maslak ilā dhālika (Book on the Determination of Amicable Numbers)
 * Kitāb fi Misāhat qat‘ almakhrūt alladhī yusammaā al-mukāfi’ (Book on the Measurement of the Conic Section Called Parabolic)
 * Kitāb fī Sanat al-shams (Book on the Solar Year)
 * Qawl fi’l–Sabab alladhī ju‘ilat lahu miyāh al-bahr māliha (Discourse on the Reason Why Seawater Is Salted)
 * al-Dhakhira fī ilm al-tibb (A Treasury of Medicine)
 * Kitāb fi ‘ilm al-‘ayn . . . (Book on the Science of the Eye…)
 * Kitāb fi’l–jadarī wa’l–hasbā (Book on Smallpox and Measles)
 * Masā’il su’ila ’anhā Thābit ibn Qurra al-Harrānī (Questions Posed to Thābit. . .)