Muslim Scientists – Historyofislam

Thabit Ibn Qurra Ibn Marwan al-Sabi al-Harrani was born in the year 836 C.E. at Harran (present Turkey). As the name indicates he was basically a member of the Sabian sect, but the great Muslim mathematician Muhammad Ibn Musa Ibn Shakir, impressed by his knowledge of languages, and realising his potential for a scientific career, selected him to join the scientific group at Baghdad that was being patronised by the Abbasid Caliphs. There, he studied under the famous Banu Musa brothers. It was in this setting that Thabit contributed to several branches of science, notably mathematics, astronomy and mechanics, in addition to translating a large number of works from Greek to Arabic. Later, he was patronised by the Abbasid Caliph al-M’utadid. After a long career of scholarship, Thabit died at Baghdad in 901 C.E.

*Al-Jazira region and its subdivisions (Diyar Bakr, Diyar Mudar, and Diyar Rabi’a) during the Abbasid Caliphate*

Thabit’s major contribution lies in mathematics and astronomy. He was instrumental in extending the concept of traditional geometry to geometrical algebra and proposed several theories that led to the development of non-Euclidean geometry, spherical trigonometry, integral calculus and real numbers. He criticised a number of theorems of Euclid’s elements and proposed important improvements. He applied arithmetical terminology to geometrical quantities, and studied several aspects of conic sections, notably those of parabola and ellipse. A number of his computations aimed at determining the surfaces and volumes of different types of bodies and constitute, in fact, the processes of integral calculus, as developed later.

Thabit ibn Qurra was a native of Harran and a member of the Sabian sect. The Sabian religious sect were star worshippers from Harran often confused with the Mandaeans. Of course being worshipers of the stars meant that there was strong motivation for the study of astronomy and the sect produced many quality astronomers and mathematicians. 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 Thabit ibn Qurra’s native language, but he was fluent in both Greek and Arabic.

Some accounts say that Thabit was a money changer as a young man. This is quite possible but some historians do not agree. Certainly he inherited a large family fortune and must have come from a family of high standing in the community. Muhammad ibn Musa ibn Shakir, who visited Harran, was impressed at Thabit’s knowledge of languages and, realising the young man’s potential, persuaded him to go to Baghdad and take lessons in mathematics from him and his brothers the Banu Musa.

In Baghdad Thabit received mathematical training and also training in medicine, which was common for scholars of that time. He returned to Harran but his liberal philosophies led to a religious court appearance when he had to recant his ‘heresies’. To escape further persecution he left Harran and was appointed court astronomer in Baghdad. There Thabit’s patron was the Caliph, al-Mu’tadid, one of the greatest of the ‘Abbasid caliphs.

At this time there were many patrons who employed talented scientists to translate Greek text into Arabic and Thabit, with his great skills in languages as well as great mathematical skills, translated and revised many of the important Greek works. The two earliest translations of Euclid’s Elements were made by alHajjaj. These are lost except for some fragments. There are, however, numerous manuscript versions of the third translation into Arabic which was made by Hunayn ibn Ishaq and revised by Thabit. Knowledge today of the complex story of the Arabic translations of Euclid’s Elements indicates that all later Arabic versions develop from this revision by Thabit.

*Pages from Thābit’s Arabic translation of Apollonius’ Conics*

In fact many Greek texts survive today only because of this industry in bringing Greek learning to the Arab world. However we must not think that the mathematicians such as Thabit were mere preservers of Greek knowledge. Far from it, Thabit was a brilliant scholar who made many important mathematical discoveries.

Although Thabit contributed to a number of areas the most important of his work was in mathematics where he:-

played an important role in preparing the way for such important mathematical discoveries as the extension of the concept of number to (positive) real numbers, integral calculus, theorems in spherical trigonometry, analytic geometry, and non-euclidean geometry. In astronomy Thabit was one of the first reformers of the Ptolemaic system, and in mechanics he was a founder of statics.

We shall examine in more detail Thabit’s work in these areas, in particular his work in number theory on amicable numbers. Suppose that, in modern notation, S(n) denotes the sum of the aliquot parts of n, that is the sum of its proper quotients. Perfect numbers are those numbers n with S(n) = n while m and n are amicable if S(n) = m, and S(m) = n. In Book on the determination of amicable numbers Thabit claims that Pythagoras began the study of perfect and amicable numbers. This claim, probably first made by Iamblichus in his biography of Pythagoras written in the 3rd century AD where he gave the amicable numbers 220 and 284, is almost certainly false. However Thabit then states quite correctly that although Euclid and Nicomachus studied perfect numbers, and Euclid gave a rule for determining them:-

neither of these authors either mentioned or showed interest in (amicable numbers).

Thabit continues..

Since the matter of (amicable numbers) has occurred to my mind, and since I have derived a proof for them, I did not wish to write the rule without proving it perfectly because they have been neglected by (Euclid and Nicomachus). I shall therefore prove it after introducing the necessary lemmas.

After giving nine lemmas Thabit states and proves his theorem: for n > 1, let pn= 3.2n-1 and qn= 9.22n-1-1. If pn-1, pn, and qn are prime numbers, then a = 2npn-1pn and b = 2nqn are amicable numbers while A is abundant and B is deficient. Note that an abundant number n satisfies S(n) > n, and a deficient number n satisfies S(n) < n. Where the authors conjecture how Thabit might have discovered the rule. Hogendijk shows that Thabit was probably the first to discover the pair of amicable numbers 17296, 18416.

Another important aspect of Thabit’s work was his book on the composition of ratios. In this Thabit deals with arithmetical operations applied to ratios of geometrical quantities. The Greeks had dealt with geometric quantities but had not thought of them in the same way as numbers to which the usual rules of arithmetic could be applied.

Thabit generalised Pythagoras’s theorem to an arbitrary triangle (as did Pappus). He also discussed parabolas, angle trisection and magic squares. Thabit’s work on parabolas and paraboliods is of particular importance since it is one of the steps taken towards the discovery of the integral calculus. An important consideration here is whether Thabit was familiar with the methods of Archimedes. Most authors believe that although Thabit was familiar with Archimedes’ results on the quadrature of the parabola, he did not have either of Archimedes’ two treatises on the topic. In fact Thabit effectively computed the integral of x and:-

The computation is based essentially on the application of upper and lower integral sums, and the proof is done by the method of exhaustion: there, for the first time, the segment of integration is divided into unequal parts.

Thabit also wrote on astronomy, writing Concerning the Motion of the Eighth Sphere. He believed (wrongly) that the motion of the equinoxes oscillates. He also published observations of the Sun. In fact eight complete treatises by Thabit on astronomy have survived and the article describes:-

When we consider this body of work in the context of the beginnings of the scientific movement in ninth-century Baghdad, we see that Thabit played a very important role in the establishment of astronomy as an exact science (method, topics and program), which developed along three lines: the theorisation of the relation between observation and theory, the ‘mathematisation’ of astronomy, and the focus on the conflicting relationship between ‘mathematical’ astronomy and ‘physical’ astronomy.

An important work Kitab fi’l-qarastun (The book on the beam balance) by Thabit is on mechanics. It was translated into Latin by Gherard of Cremona and became a popular work on mechanics. In this work Thabit proves the principle of equilibrium of levers. He demonstrates that two equal loads, balancing a third, can be replaced by their sum placed at a point halfway between the two without destroying the equilibrium. After giving a generalisation Thabit then considers the case of equally distributed continuous loads and finds the conditions for the equilibrium of a heavy beam. Of course Archimedes considered a theory of centres of gravity, but Thabit’s work is not based on Archimedes’ theory.

Finally we should comment on Thabit’s work on philosophy and other topics. Thabit had a student Abu Musa Isa ibn Usayyid who was a Christian from Iraq. Ibn Usayyid asked various questions of his teacher Thabit and a manuscript exists of the answers given by Thabit. Thabit’s concept of number follows that of Plato and he argues that numbers exist, whether someone knows them or not, and they are separate from numerable things. In other respects Thabit is critical of the ideas of Plato and Aristotle, particularly regarding motion. It would seem that here his ideas are based on an acceptance of using arguments concerning motion in his geometrical arguments.

Thabit also wrote:-

logic, psychology, ethics, the classification of sciences, the grammar of the Syriac language, politics, the symbolism of Plato’s Republic … religion and the customs of the Sabians.

His son, Sinan ibn Thabit, and his grandson Ibrahim ibn Sinan ibn Thabit, both were eminent scholars who contributed to the development of mathematics. Neither, however, reached the mathematical heights of Thabit.

AbuHanifa al-Dinawari (d. 895 C.E.)

June 19, 2021June 19, 2021 Shahxaibhatti

Abu Hanifa al-Dinawari (d.895 A.D) lived in Andalusia, Muslim Spain. His work has been made known by the German scholar: Silberberg in a thesis in Breslau in 1908, which contains the descriptions of about 400 plants. However, what is described by Silberberg is just a little part of what has survived; just two volumes out of the six.

His work has been made known by the German scholar: Silberberg in a thesis in Breslau in 1908.

In his expose on the earth, Al-Dinawari describes a variety of soils, explaining which is good for planting, its properties and qualities. Al-Dinawari also describes plant evolution from its birth to its death, including the phases of growth and production of flower and fruit. He then covers various crops including: cereals, vineyards and date palms. Relying on his predecessors, he also explains trees, mountains, plains, deserts, aromatic plants, woods, plants used in dyes, honey, bees

Al-Dinawari also describes plant evolution from its birth to its death.

Al-Dinawari also devoted one chapter to the classification of plants (tajnis al-nabat) which he mentions in one of the volumes that have survived, but the work itself on the subject has also been lost. Al-Dinawari’s Book of plants also covers various other subjects such as astronomy and meteorology.

Muslim Scientists

Jabir Ibn Haiyan (Died 803 C.E.)

June 13, 2021 Shahxaibhatti

Jabir Ibn Haiyan, the alchemist Geber of the Middle Ages, is generally known as the father of chemistry. Abu Musa Jabir Ibn Hayyan, sometimes called al-Harrani and al-Sufi, was the son of the druggist (Attar). The precise date of his birth is the subject of some discussion, but it is established that he practised medicine and alchemy in Kufa around 776 C.E. He is reported to have studied under Imam Ja’far Sadiq and the Ummayed prince Khalid Ibn Yazid. In his early days, he practised medicine and was under the patronage of the Barmaki Vizir during the Abbssid Caliphate of Haroon al-Rashid. He shared some of the effects of the downfall of the Barmakis and was placed under house arrest in Kufa, where he died in 803 C.E. Jabir’s major contribution was in the field of chemistry. He introduced experimental investigation into alchemy, which rapidly changed its character into modern chemistry. On the ruins of his well-known laboratory remained after centuries, but his fame rests on over 100 monumental treatises, of which 22 relate to chemistry and alchemy. His contribution of fundamental importance to chemistry includes perfection of scientific techniques such as crystalization, distillation, calcination, sublimation and evaporation and development of several instruments for the same. The fact of early development of chemistry as a distinct branch of science by the Arabs, instead of the earlier vague ideas, is well-established and the very name chemistry is derived from the Arabic word al-Kimya, which was studied and developed extensively by the Muslim scientists. Perhaps Jabir’s major practical achievement was the discovery of mineral and others acids, which he prepared for the first time in his alembic (Anbique). Apart from several contributions of basic nature to alchemy, involving largely the preparation of new compounds and development of chemical methods, he also developed a number of applied chemical processes, thus becoming a pioneer in the field of applied science. His achievements in this field include preparation of various metals, development of steel, dyeing of cloth and tanning of leather, varnishing of water-proof cloth, use of manganese dioxide in glass-making, prevention of rusting, letterring in gold, identification of paints, greases, etc. During the course of these practical endeavours, he also developed aqua regia to dissolve gold. The alembic is his great invention, which made easy and systematic the process of distillation. Jabir laid great stress on experimentation and accuracy in his work. Based on their properties, he has described three distinct types of substances. First, spirits i.e. those which vaporise on heating, like camphor, arsenic and ammonium chloride; secondly, metals, for example, gold, silver, lead, copper, iron, and thirdly, the category of compounds which can be converted into powders. He thus paved the way for such later ical reactions, definite quantities of various substances are involved and thus can be said to have paved the way for the law of constant proportions. A large number of books are included in his corpus. Apart from chemistry, he also contributed to other sciences such as medicine and astronomy. His books on chemistry, including his Kitab-al-Kimya, and Kitab al-Sab’een were translated into Latin and various European languages. These translations were popular in Europe for several centuries and have influenced the evolution of modern chemistry. Several technical terms devised by Jabir, such as alkali, are today found in various European languages and have become part of scientific vocabulary. Only a few of his books have been edited and published, while several others preserved in Arabic have yet to be annotated and published. Doubts have been expressed as to whether all the voluminous work included in the corpus is his own contribution or it contains later commentaries/additions by his followers. According to Sarton, the true worth of his work would only be known when all his books have been edited and published. His religious views and philosophical concepts embodied in the corpus have been criticised but, apart from the question of their authenticity, it is to be emphasised that the major contribution of Jabir lies in the field of chemistry and not in religion. His various breakthroughs e.g., preparation of acids for the first time, notably nitric, hydrochloric, citric and tartaric acids, and emphasis on systematic experimentation are outstanding and it is on the basis of such work that he can justly be regarded as the father of modern chemistry. In the words of Max Mayerhaff, the development of chemistry in Europe can be traced directly to Jabir Ibn Haiyan.

Tag: Muslim Scientists

Thabit Ibn Qurra (836-901 C.E.