Muslim Scientist & Their Contribution

ABU AL-QASIM AL-ZAHRAWI (936-1013 C.E.)

Abul Qasim Khalaf ibn al-Abbas al-Zahrawi (known in the west as Abulcasis) was born in 936 C.E. in Zahra in the neighbourhood of Cordova. He became one of the most renowned surgeons of the Muslim era and was physician to King Al-Hakam-II of Spain. After a long medical career, rich with significant original contribution, he died in 1013 C.E.
He is best known for his early and original breakthroughs in surgery as well as for his famous Medical Ecyclopaedia called Al-Tasrif, which is composed of thirty volumes covering different aspects of medical science. The more important part of this series comprises three books on surgery, which describe in detail various aspects of surgical treatment as based on the operations performed by him, including cauterization, removal of stone from the bladder, dissection of animals, midwifery, stypics, and surgery of eye, ear and throat. He perfected several delicate operations, including removal of the dead foetus and amputation.
Al-Tasrif was first translated by Gherard of Cremona into Latin in the Middle Ages. It was followed by several other editors in Europe. The book contains numerous diagrams and illustrations of surgical instruments, in use or developed by him, and comprised a part of the medical curriculum in European countries for many centuries. Contrary to the view that the Muslims fought shy of surgery, Al-Zahrawi's Al-Tasrif provided a monumental collection for this branch of applied science.
Al-Zahrawi was the inventor of several surgical instruments, of which three are notable: (i) an instrument for internal examina- tion of the ear, (ii) an instrument for internal inspection of the urethra, and (iii) and instrument for applying or removing foreign bodies from the throat. He specialized in curing disease by cauterization and applied the technique to as many as 50 different operations. In his book Al-Tasrif, Al-Zahrawi has also discussed the preparation of various medicines, in addition to a comprehensive account of surgical treatment in specialized branches, whose modern counterparts are E.N.T., Ophthalmology, etc. In connection with the preparation of medicines, he has also described in detail the application of such techniques as sublimation and decantation. Al-Zahrawi was also an expert in dentistry, and his book contains sketches of various instruments used thereof, in addition to a description of various important dental operations. He discussed the problem of non-aligned or deformed teeth and how to rectify these defects. He developed the technique of preparing artificial teeth and of replacement of defective teeth by these. In medicine, he was the first to describe in detail the unusual disease, haemophelia.
There can be no doubt that Al-Zahrawi influenced the field of medicine and surgery very deeply and the principles laid down by him were recognized as authentic in medical science, especially
surgery, and these continued to influence the medical world for five centuries. According to Dr. Cambell (History of Arab Medicine), his principles of medical science surpassed those of Galen in the European medical curriculum.


YAQUB IBN ISHAQ AL-KINDI (800-873 C.E.)

Abu Yousuf Yaqub Ibn Ishaq al-Kindi was born at Kufa around 800 C.E. His father was an official of Haroon al-Rashid. Al-Kindi was a contemporary of al-Mamun, al-Mu'tasim and al-Mutawakkil and flourished largely at Baghdad. He vas formally employed by Mutawakkil as a calligrapher. On account of his philosophical views, Mutawakkil was annoyed with him and confiscated all his books. These were, however, returned later on. He died in 873 C.E. during the reign of al-M'utamid. Al-Kindi was a philosopher, mathematician, physicist, astronomer, physician, geographer and even an expert in music. It is surprising that he made original contributions to all of these fields. On account of his work he became known as the philosopher of the Arabs.
In mathematics, he wrote four books on the number system and laid the foundation of a large part of modern arithmetic. No doubt the Arabic system of numerals was largely developed by al- Khawarizmi, but al-Kindi also made rich contributions to it. He also contributed to spherical geometry to assist him in astronomical studies.
In chemistry, he opposed the idea that base metals can be converted to precious metals. In contrast to prevailing alchemical views, he was emphatic that chemical reactions cannot bring about the transformation of elements. In physics, he made rich contributions to geometrical optics and wrote a book on it. This book later on provided guidance and inspiration to such eminent scientists as Roger Bacon.
In medicine, his chief contribution comprises the fact that he was the first to systematically determine the doses to be adminis- tered of all the drugs known at his time. This resolved the conflic- ting views prevailing among physicians on the dosage that caused difficulties in writing recipes. Very little was known on the scientific aspects of music in his time. He pointed out that the various notes that combine to produce harmony, have a specific pitch each. Thus, notes with too low or too high a pitch are non-pleatant. The degree of harmony depends on the frequency of notes, etc. He also pointed out the fact that when a sound is produced, it generates waves in the air which strike the ear-drum. His work contains a notation on the determination of pitch. He was a prolific writer, the total number of books written by him was 241, the prominent among which were divided as follows:
Astronomy 16, Arithmetic 11, Geometry 32, Medicine 22
Physics 12, Philosophy 22, Logic 9, Psychology 5, ar,d Music 7.
In addition, various monographs written by him concern tides, astronomical instruments, rocks, precious stones, etc. He was also an early translator of Greek works into Arabic, but this fact has largely been over-shadowed by his numerous original writings. It is unfortunate that most of his books are no longer extant, but those existing speak very high of his standard of scholarship and contribution. He was known as Alkindus in Latin and a large number of his books were translated into Latin by Gherard of Cremona. His books that were translated into Latin during the Middle Ages comprise Risalah dar Tanjim, Ikhtiyarat al-Ayyam, Ilahyat-e-Aristu, al-Mosiqa, Mad-o-Jazr, and Aduiyah Murakkaba.
Al-Kindi's influence on development of science and philosophy was significant in the revival of sciences in that period. In the Middle Ages, Cardano considered him as one of the twelve greatest minds. His works, in fact, lead to further development of various subjects for centuries, notably physics, mathematics, medicine and music.

Abu Ja'far Muhammad ibn Musa Al-Khwarizmi


We know few details of al-Khwarizmi's life. We know he worked at an academy where Greek philosophical and scientific works were translated. He and his colleagues also studied, and wrote on, algebra, geometry, and astronomy. Certainly al-Khwarizmi worked under the patronage of the Caliph. His treatise on algebra, Hisab al-jabr w'al-muqabala, was the most famous and important of all of al-Khwarizmi's works. It is the title of this text that gives us the word "algebra" and, in a sense that we shall investigate more fully below, it is the first book to be written on algebra. In al-Khwarizmi's own words, the purpose of the book is to teach:
what is easiest and most useful in arithmetic, such as men constantly require in cases of inheritance, legacies, partition, lawsuits, and trade, and in all their dealings with one another, or where the measuring of lands, the digging of canals, geometrical computations, and other objects of various sorts and kinds are concerned.
This does not sound like the contents of an algebra text, and indeed only the first part of the book is a discussion of what we would today recognise as algebra. However it is important to realise that the book was intended to be highly practical, and that algebra was introduced to solve real life problems that were part of everyday life in the Islam empire at that time.
After introducing the natural numbers, he discusses the solution of equations. His equations are linear or quadratic and are composed of units (numbers), roots (x) and squares (x2). He first reduces an equation to one of 6 standard forms, using the operations of addition and subtraction, and then shows how to solve these standard types of equations. He uses both algebraic methods of solution and the geometric method of completing the square.
Al-Khwarizmi continues his study of algebra by examining how the laws of arithmetic extend to an arithmetic for his algebraic objects. For example he shows how to multiply out expressions such as (a + bx)(c + dx), although we should emphasise that al-Khwarizmi uses only words to describe his expressions, and no symbols are used.
The next part of al-Khwarizmi's Algebra consists of applications and worked examples. He then goes on to look at rules for finding the area of figures such as the circle, and also finding the volume of solids such as the sphere, cone, and pyramid. This section on mensuration certainly has more in common with Hindu and Hebrew texts than it does with any Greek work. The final part of the book deals with the complicated Islamic rules for inheritance, but require little from the earlier algebra beyond solving linear equations.
Al-Khwarizmi's algebra is regarded as the foundation and cornerstone of the sciences. In a sense, al-Khwarizmi is more entitled to be called "the father of algebra" than Diophantus because al-Khwarizmi is the first to teach algebra in an elementary form and for its own sake, while Diophantus is primarily concerned with the theory of numbers.
Al-Khwarizmi also wrote a treatise on Hindu-Arabic numerals. The work describes the Hindu place-value system of numerals based on 1, 2, 3, 4, 5, 6, 7, 8, 9, and 0. The first use of zero as a place holder in positional base notation was probably due to al-Khwarizmi in this work. He also wrote an important work on astronomy, covering calendars, calculating true positions of the sun, moon and planets, tables of sines and tangents, spherical astronomy, astrological tables, parallax and eclipse calculations, and visibility of the moon. Although his astronomical work is based on that of the Indians, and most of the values from which he constructed his tables came from Hindu astronomers, al-Khwarizmi must have been influenced by Ptolemy's work too. Al-Khwarizmi wrote a major work on geography which give latitudes and longitudes for 2402 localities as a basis for a world map. The book, which is based on Ptolemy's Geography, lists with latitudes and longitudes, cities, mountains, seas, islands, geographical regions, and rivers. The manuscript includes maps which on the whole are more accurate than those of Ptolemy. A number of minor works were written by al-Khwarizmi on topics such as the astrolabe, on which he wrote two works, on the sundial, and on the Jewish calendar. He also wrote a political history containing horoscopes of prominent persons.
ABU AL - WAFA MUHAMMAD AL-BUZJANI


Abul Wafa Muhammad Ibn Muhammad Ibn Yahya Ibn Ismail al-Buzjani was born in Buzjan, Nishapur in 940 C.E. He flourished as a great mathematician and astronomer at Baghdad and died in 997/998 C.E. He learnt mathematics in Baghdad. In 959 C.E. he migrated to Iraq and lived there till his death.
Abul Wafa's main contribution lies in several branches of mathematics, especially geometry and trigonometry. In geometry his contribution comprises solution of geometrical problems with opening of the compass; construction of a square equivalent to other squares; regular polyhedra; construction of regular hectagon taking for its side half the side of the equilateral triangle inscribed in the same circle; constructions of parabola by points and geometrical solution of the equations: x4 = a and x4 + ax3 = b
Abul Wafa's contribution to the development of trigonometry was extensive. He was the first to show the generality of the sine theorem relative to spherical triangles. He developed a new method of constructing sine tables, the value of sin 30' being correct to the eighth decimal place. He also developed relations for sine (a+b) and the formula:
2 sin2 (a/2) = 1 - cos a , an
sin a = 2 sin (a/2) cos (a/2)
In addition, he made a special study of the tangent and calculated a table of tangents. He introduced the secant and cosecant for the first time, knew the relations between the trigonometric lines, which are now used to define them, and undertook extensive studies on conics. Apart from being a mathematician, Abul Wafa also contributed to astronomy. In this field he discussed different movernents of the moon, and discovered 'variation'. He was also one of the last Arabic translators and commentators of Greek works.
He wrote a large number of books on mathematics and other subjects, most of which have been lost or exist in modified forms. His contribution includes Kitab 'Ilm al-Hisab, a practical book of arithmetic, al-Kitab al-Kamil (the Complete Book), Kitab al-Handsa (Applied Geometry). Apart from this, he wrote rich commentaries on Euclid, Diophantos and al-Khawarizmi, but all of these have been lost. His books now extant include Kitab 'Ilm al-Hisab, Kitab al- Handsa and Kitab al-Kamil. His astronomical knowledge on the movements of the moon has been criticized in that, in the case of 'variation' the third inequality of the moon as he discussed was the second part of the 'evection'. But, according to Sedat, what he discovered was the same that was discovered by Tycho Brache six centuries later. Nonetheless, his contribution to trigonometry was extremely significant in that he
developed the knowledge on the tangent and introduced the secant and cosecant for the first time; in fact a sizeable part of today's trigonometry can be traced back to him.

Abu 'Ali al-Hasan ibn al-Haytham

The Arab physicist, astronomer, and mathematician Abu 'Ali al-Hasan ibn al-Haytham (ca. 966-1039), or Alhazen, established the theory of vision that prevailed till the 17th century. He also defended a theory of the physical reality of Ptolemy's planetary models.
Al-Hasan was born at Basra in southern Iraq, where he must have received all his education. He gained sufficient fame for his knowledge of physics in his youth that he was called to Egypt by the Fatimid ruler al-Hakim to attempt to regulate the flow of the Nile. Failing in this effort, he was disgraced and established himself as a copyist of mathematical manuscripts; there still exists in Istanbul a manuscript of the Banu Musa's version of Apollonius's Conics copied by him in 1024. He continued to practice the scribal art in Cairo for the remainder of his life.
He did not cease to pursue his scientific studies, however, and published a large number of highly original works. He produced two catalogs of his own work, which are preserved by Ibn abi Usaybia. The first of these, compiled in 1027, comprises 25 books on mathematics and 44 on physics and metaphysics, including On the Structure of the World. The second, supplementary catalog was complied in 1028.
Work in Astronomy
The primary interest of al-Hasan was the explanation of phenomena by both mathematical and physical hypotheses. His interest in astronomy was motivated by the discrepancy between the Aristotelian physical and mechanistic model of the celestial spheres and the Ptolemaic mathematical model. On the Structure of the World, of which only the Latin translation has been published, describes the Aristotelian sublunar world of four elements and the Ptolemaic celestial spheres in all their complexity (his only change is to accept the theory that the solar apogee is fixed with respect to the fixed stars) as if they were material. He inserts a discussion of the perception of lunar and solar eclipses based on the assumption that the moon and sun are solid physical bodies. This problem al-Hasan takes up again in On the Light of the Moon, in which he refutes the ancient theory that the moon reflects the sun's light like a mirror.

ABIR IBN HAIYAN (Died 803 C.E.)
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 classification as metals, non-metals and volatile substances.
Although known as an alchemist, he did not seem to have seriously pursued the preparation of noble metals as an alchemist; instead he devoted his effort to the development of basic chemical methods and study of mechanisms of chemical reactions in themselves and thus helped evolve chemistry as a science from the legends of alchemy. He emphasised that, in chemical reactions, definite quantities of various substances are involved and thus can be said to have paved the way for the law of constant proportions.