The Life and Works of Abu Rayhan Muhammad ibn Ahmad al-Biruni al-Khwarizmi
(363-439 AH / 973-1048 CE)

This document is based on descriptions given in:

A concise biography of Biruni on the Personalities Noble website

A Saudi Aramco World article on Ottoman silver versus silver from the New World
St. Andrews University biographies on Biruni and Abu Nasr Mansur ibn Ali ibn Iraq
An article on the Muslim Heritage website
A Wikipedia article on Biruni
A biographical entry on Biruni, from the Salaam Knowledge website
The astronomy chapter in "A History of Muslim Philosophy", Volume 2 (Ed. Sharif, MM) (1963, Pakistan Philosophical Congress)

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Biography

Biruni was born just before sunrise on 4th September, or at some time on 15th September according to other sources, in 973 CE, in a suburb (birun) of Kath, on the right bank of the great river Oxus, the Capital of the Principality of Khwarizm, corresponding roughly to the later Khanate of Khiva, now Kara-Kalpakskaya in Uzbekistan. The town were he was born is today called Biruni. He died in in the city of Ghazna, now Ghazni in modern-day Afghanistan, where he was also buried. The date of his death is not known exactly, but it is most likely 13th December, 1048 CE, at the ripe old age of 75.

Deeper into his life

The end of the 10th century CE and beginning of the 11th century CE was a period of great unrest in the Islamic world and there were civil wars in the Transoxania and Persia. Khwarizm was at this time a province of the Samanid Empire which ruled from Bukhara. Other states in the region were the Ziyarid state with its capital at Gorgan on the Caspian sea. Further west the Buwayhid dynasty ruled over the area between the Caspian sea and the Persian Gulf, and over Mesopotamia. Another rising power was the Ghaznavid kingdom (Sultanate) whose capital was at Ghazna in Afghanistan. Biruni's home city of Kath was the seat of the last Khwarizmshah, Abu Abdullah Muhammad, a direct descendant of the Khusraws, but the greater part of the Province was governed by the Amir (prince, Emir) Mamun ibn Muhammad from Gurganj, an important city, now Kuhna Urgenj, 100 miles to the northwest, situated on the branch of the Oxus leading to the Caspian.

Little is known about Biruni's family, childhood and first education. He conversed and corresponded with his younger contemporary, the famous philosopher and physician ibn Sina, whose writings were to become widely known in Europe, in contrast with Biruni, whose works seem to have been scarcely known in medieval Europe. He was a colleague of ibn Sina and the historian, philosopher and ethicist ibn Miskawayh, in a university and science centre established by Amir Abul Abbas al-Mamun Khwarazmshah. Sarton characterises Biruni in comparison with ibn Sina as representing "the more adventurous and critical spirit, Ibn Sina the synthetic; Biruni was more of a discoverer and in that respect comes nearer to the modern scientist's ideal; Ibn Sina was essentially an organiser, an encyclopædist, a philosopher." He also communicated with Abul Wafa (whom he certainly met) and Sijjistani ("al-Sijzi"). Two other contemporaries may be mentioned; Ibn Yunus distinguished for his astronomical work in Cairo and Ali Ibn Isa of Baghdad, known in Latin as Jesu Occulist, who wrote an excellent treatise on ophthalmology. It was translated into Latin and was considered the authoritative work on eye diseases in Europe till the middle of the 18th century. Biruni was a careful observer and a leading exponent of the experimental method. He is known to have received education from Abu Sahl Isa ibn Yahya al-Masihi al-Jurjani (Christian physician from Gorgan, a teacher of Avicenna, author of an encyclopædic treatise on medicine, plus other treatises on measles, plague, pulse, etc., died in 999-1000 CE, aged 40, in a dust storm in the deserts of Khwarizmia), Abu al-Hasan ibn Ali al-Jabali and Abu Nasr Mansur ibn Iraq. He studied mathematics and astronomy under Abu Nasr Mansur ibn Iraq, a fellow Khwarizmian, albeit an Amir. In his work on trigonometry Abu Nasr Mansur ibn Iraq discovered the Sine Law:

a/sin A = b/sin B = c/sin C
 

Abu Mansur was teaching trigonometry when he first began his association with Biruni whom he taught from about 990 CE. This began an important collaboration which was to go on for many years. Abu Nasr Mansur is perhaps most famous for his collaboration with Biruni. Certainly Abu Nasr Mansur worked on many topics as a result of requests from Biruni and a total of 25 works are known to have been written by him. It is possible that in this list of 25, 2 names of works that have come down to us are different titles for the same work while another title may refer to a fragment of a larger work (in which case there are only 23). 17 works have survived and they show that Abu Nasr Mansur was an extremely able astronomer and mathematician. Of Abu Nasr Mansur's works, 7 are on mathematics, the rest are on astronomy. All the surviving works have been published, most have been translated into at least 1 European language, and this gives some indication of the importance attached to his work. Many of Abu Nasr Mansur's works were dedicated to his student Biruni. In fact Biruni lists 12 works which he says Abu Nasr Mansur dedicated to him.

Biruni studied Arabic, Islamic Law, and several branches of knowledge. He wrote his books in Arabic and his native Persian, though he also mastered Greek, Hebrew, Sanskrit, Syriac, Turkic and possibly Berber. His education clearly bolstered his fresh and original approach, but in any case, he had drive and intellect.

In 995 CE, while Biruni was still in his early twenties, the ancient dynasty of the Khwarizmshahs, the house of Banu Iraq, of whom Abu Nasr Mansur, was an Amir, was overthrown by the Amir Mamun ibn Muhammad of neighbouring Gurganj, who appropriated the title. By this time the Oxus had already destroyed the Citadel of the Capital, and was making further inroads in the city.It is not clear what happened to Abu Nasr Mansur at this stage but certainly his pupil Biruni fled at the outbreak of the civil war. Biruni found refuge at the court of the Samanid King of Bukhara, Sultan Nuh ibn Mansur (who was operated on in 997 CE by the 17 year-old ibn Sina), the overlord of all the regional Amirs. There he met the Ziyarid Amir Shams al-Ma'ali Abu al-Hasan Qabus ibn Washkamir (himself apparently something a poet) who had been temporarily ousted from his own principality. In 998 CE the Sultan restored Qabus to power and Biruni went with him to Jurjan / Gorgan on the southern coast of the Caspian Sea, where he remained for several years, completing his first major work, The Chronology of Ancient Nations, dedicating it to Qabus. Ibn Sina arrived in Jurjan at around the time Qabus was unfortunately murdered.

By 1009 CE, Biruni returned to Khwarizm after several years in Jurjan, and served alongside his old teacher Abu Nasr Mansur, under the patronage of Amir Abul Abbas Mamun ibn Mamun, the last ruler in the Mamunid dynasty. Describing these events later Biruni wrote: "After l had barely settled down for a few years, l was permitted by the Lord of Time to go back home, but l was compelled to participate in worldly affairs, which excited the envy of fools, but which made the wise pity me." Around the same time, 1009 CE, Abu Sahl al-Masihi (one of Biruni's old mentors, as you may recall) and ibn Sina fled Gurganj together, headed towards Persia and away from Ghazna. One gets the impression that ibn Sina and Biruni differed in the political sense of Ghazna versus Gurganj, if only subliminally. It seems unlikely to be the case though, as they were both great men. Note that both Biruni and ibn Sina served Amir Qabus in Jurjan.

The wars in Transoxania were to disrupt scientific work yet again. Sultan Mahmud Ghaznavi was extending his influence from his base in Ghazna and in 1014 CE got his half-brother, Amir of Khwarizm Abul Abbas Mamun, to have his name inserted into the Friday prayers. This was a signal that he wanted an end to Mamun's rule and for the region to come under his control. After Amir Mamun had at least partially agreeded to Mahmud's demands, he was killed by his own army for what they considered to be an act of treachery. Following this Sultan Mahmud marched his army into the region, gained control, and avenged his half-brother's death upon the Khwarizmian court. Members of the Khwarizmian court were carried off to the Sultan's court in Ghazna. Both teacher Abu Nasr Mansur and pupil Biruni joined Sultan Mahmud's court in Ghazna in about 1017 CE, notably along with one other savant, Abul Khair ibn Khammar the physician. Biruni remained in the service of the Ghaznavid court, as apparently did Abu Nasr Mansur. Biruni seems to have found fulfilment in Ghazna, where he was respected for his learning and employed as court astrologer to Sultan Mahmud and his successors.

Sultan Mahmud of Ghazna (971-1030 CE) was the ruler of the Ghaznavid Empire from 997 CE until his death. Sultan Mahmud turned the former provincial city of Ghazna into the wealthy capital of an extensive empire which included modern-day Afghanistan, most of Iran and parts of northwest India (now Pakistan). He was also the first ruler to carry the title Sultan, signifying his break from the suzerainity of the Caliph. He originated the "lion and sun" standard, the symbol used on the old flag of Iran, although he himself was a Sunni.

Between about 1017-1030 CE, Biruni accompanied Sultan Mahmud in his journeys to India and thus extensively travelled the land, collecting material for his monumental survey of the history, customs and beliefs of the sub-continent. The "Kitab al-Hind" was his most highly-acclaimed work during his lifetime. In all, Biruni travelled India for about 20 years and learned Hindu philosophy, mathematics, geography and religion from the Pundits. He became, in this respect, the most learned Arab scholar in Indian history and science, and he became fluent in Sanskrit.

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Contributions to learning

Anthropology

Biruni has been described as "the first anthropologist". He wrote detailed comparative studies on the anthropology of peoples, religions and cultures in the Middle East, Mediterranean and South Asia. Biruni's anthropology of religion was only possible for a scholar deeply immersed in the lore of other nations. Biruni has also been praised by several scholars for his Islamic anthropology.

Astrology

Biruni was also an adept astrologer and is reputed to have astonished people by the accuracy of his predictions. His most famous work on astrology, and also one of the best in the art, is offered by Antioch Gate.

Astronomy

Biruni was an outstanding astronomer. He studied the world's configuration and the nature of stars. He wrote that the speed of light is immense as compared with the speed of sound. He described the Milky Way as a collection of countless fragments of the nature of nebulous stars. Biruni described dawn, the solar eclipse and other phenomena. He wrote his own observation of the solar eclipse of 8th April 1019 CE – at Lamghan, a valley surrounded by mountains between the towns of Qandahar and Kabul – and the lunar eclipse of 17th September 1019 CE – at Ghazna and gave precise details of the exact altitude of various well-known stars at the moment of first contact. Biruni also described the Earth's gravitation as "the attraction of all things towards the centre of the Earth."

In 1030 CE, Biruni discussed the Indian heliocentric theories of Aryabhata, Brahmagupta and Varahamihira in his Kitab al-Hind. He noted that the question of heliocentricity was a philosophical rather than a mathematical problem. Abu Said Sinjari, a contemporary of Biruni, suggested the possible heliocentric movement of the Earth around the Sun, which Biruni did not reject. 600 years before Galileo, Biruni discussed the theory of the Earth rotating about is own axis. Although Biruni was one of the first astronomers to suggest the Earth's rotation about its own axis, it is not clear whether he supported a geocentric or heliocentric model. He remarked that if the Earth rotates on its axis and moves around the Sun, it would remain consistent with his astronomical parameters: "rotation of the Earth would in no way invalidate astronomical calculations, for all the astronomical data are as explicable in terms of the one theory as of the other. The problem is thus difficult of solution."

The heliocentric doctrine was not entirely unknown to the Arabs, who believed that the Earth revolved around the sun and that the orbits of the planets were eliptic (al-Battani - "Tamaddun-i Arab", p. 425). It should be noted that Copernicus gave the scientific formulation and detailed working out of the heliocentric theory some 3 centuries later.

In 1031 CE, Biruni completed his extensive astronomical encyclopædia Kitab al-Qanun al-Masudi (Latinised as Canon Masudicus), in which he recorded his astronomical findings and formulated astronomical tables. The book introduces the mathematical technique of analysing the acceleration of the planets, and has primacy in stating that the motions of the solar apogee and the precession are not identical. Biruni also discovered that the distance between the Earth and the Sun is larger than Ptolemy's estimate, on the basis that Ptolemy disregarded the annual solar eclipses.

Biruni also invented a few astronomical instruments. He invented and wrote the earliest treatises on the planisphere and the orthographical astrolabe, as well as the armillary sphere, and was able to mathematically determine the direction of the Qibla from any place in the world.

Biology

His investigations included descriptions of unusual phenomena such as Siamese twins. He observed that flowers have 3,4,5,6, or 18 petals, but never 7 or 9.

Cartography

By the age of 22, Biruni had written several short works, including a study of map projections, which included a methodology for projecting a hemisphere on a plane.

Chemistry

The Arab traveller Elias ibn Hanna, reported on silver extraction in Bolivia:

"After the ore is pulverized, they take 50 quintals [about 2.5 tonnes] of it and pile it up on a heap and mix it with water... then they add as much quicksilver as is necessary, mix it with water and stir it with trowels a number of times. If it requires more quicksilver, they add it until the proportions are right.... When it is 'cooked' and completely amalgamated, so that it gleams when spread on a shard, they put it in a trough and let water flow over it and mix it well. The silver and the quicksilver adhere to the bottom and the water washes away the dust. After they finish washing the mixture, they close the trough and drain out the water and clean it. Then they remove the silver and quicksilver, which have amalgamated. They put the mixture in bags of sackcloth and hang them up, placing cow-hide boxes underneath. The quicksilver runs out of the bags and falls into the hide boxes. The pure silver keeps the shape of the bags, like molded cones of sugar."

The amalgamation technique for extracting silver had been used in Islamic lands for centuries in refining not only silver but also gold. Biruni, writing around 1000 CE, describes an amalgamation process very similar to the one Elias ibn Hanna reported almost 700 years later: "After pounding the gold ore or milling it, it is washed out of its stones, and the gold and mercury are combined and then squeezed in a piece of leather until mercury exudes from the pores of the leather." Quite possibly the Spanish "inventor" of the process, Pedro Fernández de Velasco, learned it from Muslim miners in Andalusia or North Africa.

Chronology

By the age of 27, Biruni had written a book called Chronology which referred to other works he had completed (now lost) that included 1 book about the astrolabe, 1 about the decimal system, 4 about astrology, and 2 about history.

Geodesy and Geography

Biruni made a number of contributions to the Earth sciences. In particular, he is regarded as the "father of geodesy" for his important contributions to the field of geodesy, along with his significant contributions to geography.

At the age of 17, Biruni calculated the latitude of Kath, Khwarizm, using the maximum altitude of the Sun. He discovered 7 ways of finding the direction of the north and south, and discovered mathematical techniques to determine exactly the beginning of the season. He elaborated a method to calculate the Earth’s diameter - Using the astrolabe and the presence of a mountain near a sea or flat plain, he calculated the Earth's circumference by solving a highly complex geodesic equation, arriving at a figure close to modern values of the Earth's circumference. His estimate of 6,339.9 km for the Earth radius was only 16.8 km less than the modern value of 6,356.7 km.. This method is known in the modern world as the "al-Biruni Law",

His Masudic Canon contains a table giving the coordinates of six hundred places, almost all of which he had direct knowledge.

Geology

Among his writings on geology, Biruni wrote the following on the geology of India: "But if you see the soil of India with your own eyes and meditate on its nature, if you consider the rounded stones found in the Earth however deeply you dig, stones that are huge near the mountains and where the rivers have a violent current: stones that are of smaller size at a greater distance from the mountains and where the streams flow more slowly: stones that appear pulverised in the shape of sand where the streams begin to stagnate near their mouths and near the sea - if you consider all this you can scarcely help thinking that India was once a sea, which by degrees has been filled up by the alluvium of the streams."

Biruni contributed to the geological study of eruptions and metallurgy. He explained the working of natural springs and artesian wells by the hydrostatic principle of communicating vessels.

History

In his Kitab fi Tahqiq ma l'il-Hind (Researches on India), he did not not record political and military history in any detail, but wrote more on India's cultural, scientific, social and religious history. He also discussed more on his idea of history in another work, The Chronology of the Ancient Nations.

Mathematics

He made significant contributions to mathematics, especially in the fields of theoretical and practical arithmetic, summation of series, combinatorial analysis, the rule of 3, irrational numbers, ratio theory, algebraic definitions, method of solving algebraic equations, geometry, and the development of Archimedes' theorems. He gave a clear account of Hindu numerals, elaborating the principle of position. He broke ground in the study of the angles and trigonometry. He worked on shadows and chords of circles, and he developed a method for the trisection of an angle and other problems which cannot be solved by rule and compass alone. He introduced the idea of "function," which, since the time of Leibniz (17th century CE), has become the most important concept in modern mathematics.

The extent of Arabic knowledge in the 11th century CE can be gauged from the fact that Biruni was able to give the correct value of 16¹⁶-1 = 18,44,6,744,073,709,551,619, through summation of a geometric progression apropos of the chess game.

Physics

Biruni measured the specific gravities of 18 gemstones, and discovered that there is a correlation between the specific gravity of an object and the volume of water it displaces. During his experiments, he invented the conical measure in order to find the ratio between the weight of a substance in air and the weight of water displaced, and to accurately measure the specific weights of the gemstones and their corresponding metals, which are very close to modern measurements. He also introduced the method of checking tests during experiments, measured the weights of various liquids, and recorded the differences in weight between fresh water and salt water, and between hot water and cold water. He described the ratios between the densities of gold, mercury, lead, silver, bronze, copper, brass, iron, and tin. Biruni displayed the results as combinations of integers and numbers of the form 1/n, n = 2, 3, 4, ... , 10.

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Bibliography (partial) of Biruni

Biruni was a prolific author. One estimate [Kennedy, ES - Biography in Dictionary of Scientific Biography (New York 1970-1990)] attributes to Biruni's hand 146 works with a total of about 13,000 folios (a folio contains about the same amount as a printed page from a modern book), most of which were mentioned in his treatise known as "Al Fahrass". Alas, only about 1/7th of his works have survived. Only 22 works have survived the ravages of time; and only 13 of these have been published.

Biruni wrote 27 works on India and on different areas of the Indian sciences. He translated a number of books from Sanskrit into Arabic and translated Ptolemy's Almagest into Sanskrit. However, the bulk of his work lies in mathematics and related disciplines (96 titles). Biruni's works cover essentially the whole of science at his time.

A quick list of some of his best-known works follows:

- Kitab / Tarikh al-Hind (Book of India) - a massive work covering many different aspects of the country. Biruni describes the life, religions, languages, cultures, caste system, marriage customs and philosophy of India. He then studies the Indian systems of writing and numbers before going on to examine the geography of the country. The book also examines Indian astronomy, astrology and the calendar. In his book he mentions 2 Sanskrit works, the Patanjal / Patanjali's Yogasutra (dealing with after-death accounts of the migration of the spirit) and Sakaya (dealing with the creation of things and their types), that he translated into Arabic. Sultan Mahmud Ghaznavi, to whom the Indica would probably have been dedicated, died (421 H / 1030 CE) before the work was actually finished, so there was no dedication to Biruni's patron. Abul Fazl’s book "Ain-i Akbari", written six centuries later during the reign of Akbar, was influenced by Biruni's "Kitab al-Hind". Sachau's English translation was printed in London in 1887.

- Athar al-Baqiyah fi al-Qurun al-Khaliyah (Chronology of Ancient Nations and their History) - here, Biruni discusses ancient history and geography. He combined literary and historical sources of mediæval sects and nations with astronomical lore about their calendars, feasts, and astronomical parameters used in their rituals. He discussed the Earth’s rotation on its axis and its flatness. He initiated the rules of geodesy. He made accurate calculations of latitude and longitude (plus other geodetic measurements) and observed the same. He made considerable contributions in the fields of physical and economic geography. Though not his first work, this book represents the summation of Biruni's researches up till that time. This book was translated by Edward Sachau into English and edited in London in 1879. It had apparently been earlier translated into German (edited by Sachau) in 1878. This book is on offer by Antioch Gate. 

- Tafhim li Awa'il Sina'at al-Tanjim (Instruction in the Elements of the Art of Astrology) deals with and summarises Biruni's work on mathematics, geometry, algebra, numerals and astronomy. It was written in a question-answer model and illustrated with forms and figures. It is a question and answer style book in Arabic and Persian. This book is on offer by Antioch Gate.

- Qanun al-Masudi fi al-Hai'a wa al-Nujum (The Masudic Canon) - a most extensive astronomical encyclopædia on astronomy, geography, and engineering, slightly short of 1,500 pages. This 3rd principal work of Biruni's was dedicated to Sultan Masud (son of Sultan Mahmud Ghaznavi), upon whose request it was composed. Biruni was in receipt of a pension which enabled him to devote the rest of his life to his scientific studies and his literary work. Yaqut relates that Sultan Masud sent him an elephant-load of silver coin for the Canon, but Biruni returned it to the Treasury. In the book, Biruni discussed several theorems of trigonometry, astronomy, and solar, lunar and planetary motions, and it contains a collection of 23 observations of equinoxes. It contains 143 parts and discusses several subjects related to astronomy and mathematics. For example, Biruni discussed for the first time the question that the Earth rotates around an axis. A translation of the relevant Arabic passages is as follows: "When a thing falls from a height, it does not coincide with the perpendicular line of its descent but inclines a little, and falls making different angles. When a piece of Earth separates from it and falls, it has two kinds of motions: one is the circular motion which it receives from the rotation of the Earth, and the other is straight which it acquires in falling directly to the centre of the Earth. If it had only the straight motion, it would have fallen to the west of its perpendicular position. But since both of them exist at one and the same time, it falls neither to the west nor in the perpendicular direction, but a little to the east." Biruni also gave the explanation of the rising and setting of the heavenly bodies as being due to the rotation of the Earth, thus pointing to the error in the geocentric conception of the solar system. He determines the motion of the solar apogee, corrects Ptolemy's findings, and is able to state for the first time that the motion is not identical to that of precession, but comes very close to it. In this book, too, Biruni employs mathematical techniques unknown to his predecessors that involve analysis of instantaneous motion and acceleration, described in terminology that can best be understood if we assume that he had "mathematical functions" in mind.

The Masudic Canon was written in 1030 CE after Biruni returned from India. There was a printed edition of this work originating from Hyderabad, India.

- Shadows - one of Biruni's most important texts, which he is thought to have written around 1021 CE. The contents of the work include the Arabic nomenclature of shade and shadows, strange phenomena involving shadows, gnomonics, the history of the tangent and secant functions, applications of the shadow functions to the astrolabe and to other instruments, shadow observations for the solution of various astronomical problems, and the shadow-determined times of Muslim prayers. Shadows is an extremely important source for our knowledge of the history of mathematics, astronomy, and physics. It also contains important ideas such as the idea that acceleration is connected with non-uniform motion, using three rectangular coordinates to define a point in 3-space, and ideas that some see as anticipating the introduction of polar coordinates.

- Tahdid - on the demarcation of the co-ordinates of cities, this book was written so as to determine the Qibla. Biruni also determined the local meridian and the coordinates of any locality.

- Kitab al-Saidana - an extensive materia medica, synthesising Arabic and Indian medicine.

- History of Sultan Mahmud Ghaznavi and his father

- History of Khwarizm

- Kitab al-Jamahir - about geology, mineralogy, and gemology. Here he accurately determined the specific weight of 18 elements and compounds including many metals and precious stones. Biruni survived Sultan Masud and dedicated this work to Sultan Mawdud son of Masud, the successor to the Ghaznavid throne.

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