Selasa, 17 Agustus 2010

Abu Al-Nasr Al-Farabi

Abū Naṣr al-Fārābī (Arabic: أبو نصر محمد الفارابي‎, Abū Naṣr Muḥammad al-Fārābī; for other recorded variants of his name see below) known in the West as Alpharabius (c. 872 – between 14 December 950 and 12 January 951), was a Muslim[2] polymath and one of the greatest scientists and philosophers of the Islamic world in his time. He was also a cosmologist, logician, musician, psychologist and sociologist.

Biography

The existing variations in the basic accounts of al-Farabi's origins and pedigree indicate that they were not recorded during his lifetime or soon thereafter by anyone with concrete information, but were based on hearsay or guesses (as is the case with other contemporaries of al-Farabi). The sources for his life are scanty which makes the reconstruction of his biography beyond a mere outline nearly impossible. The earliest and more reliable sources, i. e., those composed before the 6th/12th century, that are extant today are so few as to indicate that no one among Fārābī’s successors and their followers, or even unrelated scholars, undertook to write his full biography, a neglect that has to be taken into consideration in assessing his immediate impact. The sources prior to the 6th/12th century consist of: (1) an autobiographical passage by Farabi, preserved by Ibn Abī Uṣaibiʿa. In this passage, Farabi traces the transmission of the instruction of logic and philosophy from antiquity to his days. (2) Reports by Al-Masudi, Ibn al-Nadim and Ibn Hawqal as well as by Said Al-Andalusi (d. 1070), who devoted a biography to him.

When major Arabic biographers decided to write comprehensive entries on Farabi in the 6th-7th/12th-13th centuries, there was very little specific information on hand; this allowed for their acceptance of invented stories about his life which range from benign extrapolation on the basis of some known details to tendentious reconstructions and legends. Most modern biographies of the philosopher present various combinations of elements drawn at will from this concocted material. The sources from the 6th/12th century and later consist essentially of three biographical entries, all other extant reports on Farabi being either dependent on them or even later fabrications: 1) the Syrian tradition represented by Ibn Abī Uṣaibiʿa. 2) The Wafayāt al-aʿyān wa-anbāʾ abnāʾ az-zamān (“Deaths of Eminent Men and History of the Sons of the Epoch”; trans. by Baron de Slane, Ibn Khallikan’s Biographical Dictionary, 1842–74) compiled by Ibn Khallikān. 3) the scanty and legendary Eastern tradition, represented by Ẓahīr-al-Dīn Bayhaqī.

From incidental accounts it is known that he spent significant time in Baghdad with Christian scholars including the cleric Yuhanna ibn Haylan, Yahya ibn Adi, and Abu Ishaq Ibrahim al-Baghdadi. He later spent time in Damascus, Syria and Egypt before returning to Damascus where he died in 950-1.

Name

His name was Abū Naṣr Moḥammad b. Moḥammad Farabi, as all sources, and especially the earliest and most reliable, Al-Masudi, agree. In some manuscripts of Fārābī’s works, which must reflect the reading of their ultimate archetypes from his time, his full name appears as Abū Naṣr Moḥammad b. Moḥammad al-Ṭarḵānī, i.e., the element Ṭarḵān appears in a nisba (family surname or attributive title). Moreover, if the name of Farabi’s grandfather was not known among his contemporaries and immediately succeeding generations, it is all the more surprising to see in the later sources the appearance of yet another name from his pedigree, Awzalaḡ. This appears as the name of the grandfather in Ibn Abī Uṣaibiʿa and of the great-grandfather in Ibn Khallekān. Ibn Abī Uṣaibiʿa is the first source to list this name which, as Ibn Khallekān explicitly specifies later, is so to be pronounced as Awzalaḡ. In modern Turkish scholarship and some other sources, the pronunciation is given as Uzluḡ rather than Awzalaḡ, without any explanation.

Birthplace

His brithplace is contradicted in the classical sources as either Faryāb in Khorasan (in modern Afghanistan) or Fārāb on the Amu Darya (Oxus) in modern Kazakhstan. The older Persian Pārāb (in Hudud ul-'alam) or Fāryāb (also Pāryāb), is a common Persian toponym meaning “lands irrigated by diversion of river water”. By the 13th century, Farab on the Jaxartes was known as Otrār.

Origin

There exist a difference of opinion on the ethnic background of Farabi. According to D. Gutas, "ultimately pointless as the quest for Farabi’s ethnic origins might be, the fact remains that we do not have sufficient evidence to decide the matter. The Cambridge companion to Arabic philosophy also states that "[...] these biographical facts are paltry in the extreme but we must resist the urge to embellish them with fanciful stories, as the medieval biographers did, or engage in idle speculation about al-Farabi’s ethnicity or religious affiliation on the basis of contrived interpretations of his works, as many modern scholars have done [...]"

Iranic origin

An Iranian stamp bearing an illustration of Al-Farabi

Medieval Arab historian Ibn Abī Uṣaibiʿa (died in 1269) - al-Farabi's oldest biographer - mentions in his ʿOyūn (final rescension in 1268) that al-Farabi's father was of Persian descent. Al-Shahrazūrī who lived around 1288 A.D. and has written an early biography also has stated that Farabi hailed from a Persian family. Additionally, Farabi has in a number of his works references and glosses in Persian and Sogdian (and even Greek but, interestingly, no Turkish; see below). Sogdian has been mentioned as his native language and the language of the inhabitants of Farab. Mohammad Javad Mashkoor argues for an Iranian-speaking Central Asian origin but states Farabi was foremost a Muslim and was great due to blessing of the Quran and Prophet Muhammad, and hence is a Muslim scholar belonging to all of humanity and whether he was Turkish, Iranian or Arab is not of importance. A Persian origin has been discussed by other sources as well.

Turkic origin

Al-Farabi's imagined face appeared on the currency of the Republic of Kazakhstan

The oldest known reference to a possible Turkic origin is given by the medieval historian Ibn Khallekān (died in 1282), who in his work Wafayāt (completed in 669/1271) states that Farabi was born in the small village of Wasij near Farab (in what is today Otrar, Kazakhstan) of Turkic parents. Based on this account, some modern scholars state his origin to be Turkic. Others, such as D. Gutas, criticize this, saying that Ibn Khallekān's account is aimed at the earlier historical accounts by Ibn Abī Uṣaibiʿa, and servers the sole purpose to prove a Turkic origin for al-Farabi, for instance by inventing the additional nisba (surname) "al-Turk" (arab. "the Turk") - a nisba Farabi never had. In this regard, Oxford professor C.E. Bosworth notes that "great figures [such] as al-Farabi, al-Biruni, and ibn Sina have been attached by over enthusiastic Turkish scholars to their race".

Life and Education

Al-Farabi spent almost his entire life in Baghdad, capital of Abbasids that ruled the Islamic world.[10] In the auto-biographical passage about the appearance of philosophy preserved by Ibn Abī Uṣaibiʿa, Farabi has stated that he had studied logic with Yūḥannā b. Ḥaylān up to and including Aristotle’s Posterior Analytics, i.e., according to the order of the books studied in the curriculum, Fārābī said that he studied Porphyry’s Eisagoge and Aristotle’s Categories, De Interpretatione, Prior and Posterior Analytics. His teacher, Yūḥannā b. Ḥaylān, was a Christian cleric who abandoned lay interests and engaged in his ecclesiastical duties, as Fārābī reports. His studies of Aristotelian logic with Yūḥannā in all probability took place in Baghdad, where Al-Masudi tells us Yūḥannā died during the caliphate of al-Moqtader (295-320/908-32). He was in Baghdad at least until the end of September 942 as we learn from notes in some manuscripts of his Mabādeʾ ārāʾ ahl al-madīna al-fāżela, he had started to compose the book in Baghdad at that time and then left and went to Syria. He finished the book in Damascus the following year (331), i.e., by September 943). He also lived and taught for some time in Aleppo. Later on Farabi visited Egypt; and complete six sections summarizing the book Mabādeʾ in Egypt in 337/July 948-June 949. He returned from Egypt to Syria. Al-Masudi writing writing barely five years after the fact (955-6, the date of the composition of the Tanbīh), says that he died in Damascus in Rajab 339 (between 14 December 950 and 12 January 951). In Syria, he was supported and glorified by Saif ad-Daula, the Hamdanid ruler of Syria.

Contributions

Farabi made notable contributions to the fields of logic, mathematics, medicine, music, philosophy, psychology,sociology,Educationist,and Musician.

Alchemy

Al-Farabi wrote: The Necessity of the Art of the Elixir

Logic

Though he was mainly an Aristotelian logician, he included a number of non-Aristotelian elements in his works. He discussed the topics of future contingents, the number and relation of the categories, the relation between logic and grammar, and non-Aristotelian forms of inference. He is also credited for categorizing logic into two separate groups, the first being "idea" and the second being "proof".

Al-Farabi also considered the theories of conditional syllogisms and analogical inference, which were part of the Stoic tradition of logic rather than the Aristotelian. Another addition Al-Farabi made to the Aristotelian tradition was his introduction of the concept of poetic syllogism in a commentary on Aristotle's Poetics.

Music and sociology

Farabi wrote books on early Muslim sociology and a notable book on music titled Kitab al-Musiqa (The Book of Music). According to Seyyed Hossein Nasr and Mehdi Aminrazavi: the book of Kitab al-Musiqa is in reality a study of the theory of Persian music of his day although in the West it has been introduced as a book on Arab music. He presents philosophical principles about music, its cosmic qualities and its influences. Al-Farabi's treatise Meanings of the Intellect dealt with music therapy, where he discussed the therapeutic effects of music on the soul.

Philosophy

As a philosopher, Al-Farabi was a founder of his own school of early Islamic philosophy known as "Farabism" or "Alfarabism", though it was later overshadowed by Avicennism. Al-Farabi's school of philosophy "breaks with the philosophy of Plato and Aristotle [... and ...] moves from metaphysics to methodology, a move that anticipates modernity", and "at the level of philosophy, Alfarabi unites theory and practice [... and] in the sphere of the political he liberates practice from theory". His Neoplatonic theology is also more than just metaphysics as rhetoric. In his attempt to think through the nature of a First Cause, Alfarabi discovers the limits of human knowledge".

Al-Farabi had great influence on science and philosophy for several centuries, and was widely regarded to be second only to Aristotle in knowledge (alluded to by his title of "the Second Teacher") in his time. His work, aimed at synthesis of philosophy and Sufism, paved the way for the work of Ibn Sina (Avicenna).

Al-Farabi also wrote a commentary on Aristotle's work, and one of his most notable works is Al-Madina al-Fadila where he theorized an ideal state as in Plato's The Republic.[30] Al-Farabi represented religion as a symbolic rendering of truth, and, like Plato, saw it as the duty of the philosopher to provide guidance to the state. Al-Farabi departed from the Platonic view in that he regarded the ideal state to be ruled by the prophet-imam, instead of the philosopher-king envisaged by Plato. Al-Farabi argued that the ideal state was the city-state of Medina when it was governed by the prophet Muhammad as its head of state, as he was in direct communion with Allah whose law was revealed to him.

Influenced by the writings of Aristotle, in The Ideas of the Citizens of the Virtuous City and other books, Al-Farabi advanced the view that philosophy and revelation are two different modes of approaching the same truth.[citation needed]

Physics

Al-Farabi is also known for his early investigations into the nature of the existence of void in Islamic physics. In thermodynamics, he appears to have carried out the first experiments concerning the existence of vacuum, in which he investigated handheld plungers in water. He concluded that air's volume can expand to fill available space, and he suggested that the concept of perfect vacuum was incoherent.

Psychology

In psychology, al-Farabi's Social Psychology and Model City were the first treatises to deal with social psychology. He stated that "an isolated individual could not achieve all the perfections by himself, without the aid of other individuals." He wrote that it is the "innate disposition of every man to join another human being or other men in the labor he ought to perform." He concluded that in order to "achieve what he can of that perfection, every man needs to stay in the neighborhood of others and associate with them."

Educationist

Farabi was also a professor of diffrent subject as science he also taught Islamic Jurisprudence and alfiqh (principles as basic of islam)logic philosophy it is said that farabi turns wishes into reality

musician

Farabi was also a great musician and had the commond of music logics and myth by a music instrument he turns the happyness to saidness and saidness to happyness,tears to laugh and laugh to tears and unconcious fellings when he was playing that music instrument it is saidthat farbi came tou you but you could not recognise him His On the Cause of Dreams, which appeared as chapter 24 of his Book of Opinions of the people of the Ideal City, was a treatise on dreams, in which he was the first to distinguish between dream interpretation and the nature and causes of dreams.

Philosophical thought

The main influence on al-Farabi's philosophy was the neo-Aristotelian tradition of Alexandria. A prolific writer, he is credited with over one hundred works. Amongst these are a number of prolegomena to philosophy, commentaries on important Aristotelian works (such as the Nicomachean Ethics) as well as his own works. His ideas are marked by their coherency, despite drawing together of many different philosophical disciplines and traditions. Some other significant influences on his work were the planetary model of Ptolemy and elements of Neo-Platonism, particularly metaphysics and practical (or political) philosophy (which bears more resemblance to Plato's Republic than Aristotle's Politics).

Al-Farabi as well as Ibn Sina and Averroes have been recognized as Peripatetics(al-Mashsha’iyun) or rationalists(Estedlaliun) among Muslims. However he tried to gather the ideas of Plato and Aristotle in his book "The gathering of the ideas of the two philosophers".

According to Adamson, his work was singularly directed towards the goal of simultaneously reviving and reinventing the Alexandrian philosophical tradition, to which his Christian teacher, Yuhanna bin Haylan belonged. His success should be measured by the honorific title of "the second master" of philosophy (Aristotle being the first), by which he was known. Interestingly, Adamson also says that he does not make any reference to the ideas of either al-Kindi or his contemporary, Abu Bakr al-Razi, which clearly indicates that he did not consider their approach to Philosophy as a correct or viable one.

Works

Metaphysics and cosmology

In contrast to al-Kindi, who considered the subject of metaphysics to be God, al-Farabi believed that it was concerned primarily with being qua being (that is, being in of itself), and this is related to God only to the extent that God is a principal of absolute being. Al-Kindi's view was, however, a common misconception regarding Greek philosophy amongst Muslim intellectuals at the time, and it was for this reason that Avicenna remarked that he did not understand Aristotle's Metaphysics properly until he had read a prolegomenon written by al-Farabi.

Al-Farabi's cosmology is essentially based upon three pillars: Aristotelian metaphysics of causation, highly developed Plotinian emanational cosmology and the Ptolemaic astronomy. In his model, the universe is viewed as a number of concentric circles; the outermost sphere or "first heaven", the sphere of fixed stars, Saturn, Jupiter, Mars, the Sun, Venus, Mercury and finally, the Moon. At the centre of these concentric circles is the sub-lunar realm which contains the material world. Each of these circles represent the domain of the secondary intelligences (symbolized by the celestial bodies themselves), which act as causal intermediaries between the First Cause (in this case, God) and the material world. Furthermore these are said to have emanated from God, who is both their formal and efficient cause. This departs radically from the view of Aristotle, who considered God to be solely a formal cause for the movement of the spheres, but by doing so it renders the model more compatible with the ideas of the theologians.

The process of emanation begins (metaphysically, not temporally) with the First Cause, whose principal activity is self-contemplation. And it is this intellectual activity that underlies its role in the creation of the universe. The First Cause, by thinking of itself, "overflows" and the incorporeal entity of the second intellect "emanates" from it. Like its predecessor, the second intellect also thinks about itself, and thereby brings its celestial sphere (in this case, the sphere of fixed stars) into being, but in addition to this it must also contemplate upon the First Cause, and this causes the "emanation" of the next intellect. The cascade of emanation continues until it reaches the tenth intellect, beneath which is the material world. And as each intellect must contemplate both itself and an increasing number of predecessors, each succeeding level of existence becomes more and more complex. It should be noted that this process is based upon necessity as opposed to will. In other words, God does not have a choice whether or not to create the universe, but by virtue of His own existence, He causes it to be. This view also suggests that the universe is eternal, and both of these points were criticized by al-Ghazzali in his attack on the philosophers

In his discussion of the First Cause (or God), al-Farabi relies heavily on negative theology. He says that it cannot be known by intellectual means, such as dialectical division or definition, because the terms used in these processes to define a thing constitute its substance. Therefore if one was to define the First Cause, each of the terms used would actually constitute a part of its substance and therefore behave as a cause for its existence, which is impossible as the First Cause is uncaused; it exists without being caused. Equally, he says it cannot be known according to genus and differentia, as its substance and existence are different from all others, and therefore it has no category to which it belongs. If this were the case, then it would not be the First Cause, because something would be prior in existence to it, which is also impossible. This would suggest that the more philosophically simple a thing is, the more perfect it is. And based on this observation, Adamson says it is possible to see the entire hierarchy of al-Farabi's cosmology according to classification into genus and species. Each succeeding level in this structure has as its principal qualities multiplicity and deficiency, and it is this ever-increasing complexity that typifies the material world.

Epistemology and eschatology

Human beings are unique in al-Farabi's vision of the universe because they stand between two worlds: the "higher", immaterial world of the celestial intellects and universal intelligibles, and the "lower", material world of generation and decay; they inhabit a physical body, and so belong to the "lower" world, but they also have a rational capacity, which connects them to the "higher" realm. Each level of existence in al-Farabi's cosmology is characterized by its movement towards perfection, which is to become like the First Cause; a perfect intellect. Human perfection (or "happiness"), then, is equated with constant intellection and contemplation.

Al-Farabi divides intellect into four categories: potential, actual, acquired and the Agent. The first three are the different states of the human intellect and the fourth is the Tenth Intellect (the moon) in his emanational cosmology. The potential intellect represents the capacity to think, which is shared by all human beings, and the actual intellect is an intellect engaged in the act of thinking. By thinking, al-Farabi means abstracting universal intelligibles from the sensory forms of objects which have been apprehended and retained in the individual's imagination.

This motion from potentiality to actuality requires the Agent Intellect to act upon the retained sensory forms; just as the Sun illuminates the physical world to allow us to see, the Agent Intellect illuminates the world of intelligibles to allow us to think. This illumination removes all accident (such as time, place, quality) and physicality from them, converting them into primary intelligibles, which are logical principles such as "the whole is greater than the part". The human intellect, by its act of intellection, passes from potentiality to actuality, and as it gradually comprehends these intelligibles, it is identified with them (as according to Aristotle, by knowing something, the intellect becomes like it). Because the Agent Intellect knows all of the intelligibles, this means that when the human intellect knows all of them, it becomes associated with the Agent Intellect's perfection and is known as the acquired Intellect.

While this process seems mechanical, leaving little room for human choice or volition, Reisman says that al-Farabi is committed to human voluntarism. This takes place when man, based on the knowledge he has acquired, decides whether to direct himself towards virtuous or unvirtuous activities, and thereby decides whether or not to seek true happiness. And it is by choosing what is ethical and contemplating about what constitutes the nature of ethics, that the actual intellect can become "like" the active intellect, thereby attaining perfection. It is only by this process that a human soul may survive death, and live on in the afterlife.

According to al-Farabi, the afterlife is not the personal experience commonly conceived of by religious traditions such as Islam and Christianity. Any individual or distinguishing features of the soul are annihilated after the death of the body; only the rational faculty survives (and then, only if it has attained perfection), which becomes one with all other rational souls within the agent intellect and enters a realm of pure intelligence. Henry Corbin compares this eschatology with that of the Ismaili Neo-Platonists, for whom this process initiated the next grand cycle of the universe.However, Deborah Black mentions we have cause to be skeptical as to whether this was the mature and developed view of al-Farabi, as later thinkers such as Ibn Tufayl, Averroes and Ibn Bajjah would assert that he repudiated this view in his commentary on the Nicomachean Ethics, which has been lost to modern experts.

Psychology, the soul and prophetic knowledge

In his treatment of the human soul, al-Farabi draws on a basic Aristotelian outline, which is informed by the commentaries of later Greek thinkers. He says it is composed of four faculties: The appetitive (the desire for, or aversion to an object of sense), the sensitive (the perception by the senses of corporeal substances), the imaginative (the faculty which retains images of sensible objects after they have been perceived, and then separates and combines them for a number of ends), and the rational, which is the faculty of intellection. It is the last of these which is unique to human beings and distinguishes them from plants and animals. It is also the only part of the soul to survive the death of the body. Noticeably absent from these scheme are internal senses, such as common sense, which would be discussed by later philosophers such as Avicenna and Averroes.

Special attention must be given to al-Farabi's treatment of the soul's imaginative faculty, which is essential to his interpretation of prophethood and prophetic knowledge. In addition to its ability to retain and manipulate sensible images of objects, he gives the imagination the function of imitation. By this he means the capacity to represent an object with an image other than its own. In other words, to imitate "x" is to imagine "x" by associating it with sensible qualities that do not describe its own appearance. This extends the representative ability of the imagination beyond sensible forms and to include temperaments, emotions, desires and even immaterial intelligibles or abstract universals, as happens when, for example, one associates "evil" with "darkness". The prophet, in addition to his own intellectual capacity, has a very strong imaginative faculty, which allows him to receive an overflow of intelligibles from the agent intellect (the tenth intellect in the emanational cosmology). These intelligibles are then associated with symbols and images, which allow him to communicate abstract truths in a way that can be understood by ordinary people. Therefore what makes prophetic knowledge unique is not its content, which is also accessible to philosophers through demonstration and intellection, but rather the form that it is given by the prophet's imagination.

Practical philosophy (ethics and politics)

The practical application of philosophy is a major concern expressed by al-Farabi in many of his works, and while the majority of his philosophical output has been influenced by Aristotelian thought, his practical philosophy is unmistakably based on that of Plato. In a similar manner to Plato's Republic, al-Farabi emphasizes that philosophy is both a theoretical and practical discipline; labeling those philosophers who do not apply their erudition to practical pursuits as "futile philosophers". The ideal society, he says, is one directed towards the realization of "true happiness" (which can be taken to mean philosophical enlightenment) and as such, the ideal philosopher must hone all the necessary arts of rhetoric and poetics to communicate abstract truths to the ordinary people, as well as having achieved enlightenment himself. Al-Farabi compares the philosopher's role in relation to society with a physician in relation to the body; the body's health is affected by the "balance of its humours" just as the city is determined by the moral habits of its people. The philosopher's duty, he says, is to establish a "virtuous" society by healing the souls of the people, establishing justice and guiding them towards "true happiness".

Of course, al-Farabi realizes that such a society is rare and will require a very specific set of historical circumstances in order to be realized, which means very few societies will ever be able to attain this goal. He divides those "vicious" societies, which have fallen short of the ideal "virtuous" society, into three categories: ignorant, wicked and errant. Ignorant societies have, for whatever reason, failed to comprehend the purpose of human existence, and have supplanted the pursuit of happiness for another (inferior) goal, whether this be wealth, sensual gratification or power. It is interesting to note that democratic societies also fall into this category, as they too lack any guiding principle. Both wicked and errant societies have understood the true human end, but they have failed to follow it. The former because they have willfully abandoned it, and the latter because their leaders have deceived and misguided them. Al-Farabi also makes mention of "weeds" in the virtuous society; those people who try to undermine its progress towards the true human end.

Whether or not al-Farabi actually intended to outline a political programme in his writings remains a matter of dispute amongst academics. Henry Corbin, who considers al-Farabi to be a crypto-Shi'ite, says that his ideas should be understood as a "prophetic philosophy" instead of being interpreted politically. On the other hand, Charles Butterworth contends that nowhere in his work does al-Farabi speak of a prophet-legislator or revelation (even the word philosophy is scarcely mentioned), and the main discussion that takes place concerns the positions of "king" and "statesmen". Occupying a middle position is David Reisman, who like Corbin believes that al-Farabi did not want to expound a political doctrine (although he does not go so far to attribute it to Islamic Gnosticism either). He argues that al-Farabi was using different types of society as examples, in the context of an ethical discussion, to show what effect correct or incorrect thinking could have. Lastly, Joshua Parens argues that al-Farabi was slyly asserting that a pan-Islamic society could not be made, by using reason to show how many conditions (such as moral and deliberative virtue) would have to be met, thus leading the reader to conclude that humans are not fit for such a society. Some other authors like Mykhaylo Yakubovych attest that for al-Farabi religion (milla) and philosophy (falsafa) constituted the same praxeological value (i.e. basis for amal al-fadhil - "virtuos deed"), while its epistemological level (ilm - "knowledge") was different.

From Wikipedia, the free encyclopedia

http://en.wikipedia.org/wiki/Al-Farabi

Minggu, 15 Agustus 2010

Abd Al-Malik Ibn Quraib Al-Asmai

Abdul Malik Ibn Quraib Al-Asmai was born in Basrah in 740 C.E. He was a pious Arab and a good student of Arabic poetry. Al-Asmai is considered as the first Muslim scientist who contributed to Zoology, Botany and Animal Husbandry.

His famous writings include Kitab al-Ibil, Kitab al-Khalil, Kitab al- Wuhush, Kitab al-Sha, and Kitab Khalq al-Insan. The last book on human anatomy demonstrates his considerable knowledge and expertise on the subject. Al-Asmai died in 828 C.E.

Al-Asmai's work was very popular among scientists of the ninth and tenth century.

http://www.thereligionislam.com/islamicreformism/muslimscientistsandscholars/abdulmalikibnquraibalasmai.htm

Abu al-Qasim al-Zahrawi

Abu al-Qasim Khalaf ibn al-Abbas Al-Zahrawi (936–1013), (Arabic: أبو القاسم بن خلف بن العباس الزهراوي‎) also known in the West as Abulcasis, was an Andalusian Arab physician, surgeon, chemist, cosmetologist, and scientist. He is considered Islam's greatest medieval surgeon and one of the fathers of modern surgery. His comprehensive medical texts shaped both Islamic and European surgical procedures up until the Renaissance. His greatest contribution to history is the Kitab al-Tasrif, a thirty-volume encyclopedia of medical practices.

Abū al-Qāsim specialized in curing disease by cauterization. He invented several devices used during surgery, for purposes such as inspection of the interior of the urethra, applying and removing foreign bodies from the throat, inspection of the ear, etc.

Biography

Abū al-Qāsim was born in the city of El-Zahra, six miles northwest of Córdoba/Corona, Spain. He was descended from the Ansar Arab tribe who settled earlier in Spain. Few details remain regarding his life, aside from his published work, due to the destruction of El-Zahra during later Castillian-Andalusian conflicts. His name first appears in the writings of Abu Muhammad bin Hazm (993 – 1064), who listed him among the greatest physicians of Moorish Spain. But we have the first detailed biography of al-Zahrawī from al-Ḥumaydī's Jadhwat al-Muqtabis (On Andalusian Savants), completed six decades after al-Zahrawī's death.

He lived most of his life in Córdoba. It is also where he studied, taught and practiced medicine and surgery until shortly before his death in about 1013, two years after the sacking of El-Zahra.

The street in Córdoba where he lived is named in his honor as "Calle Albucasis". On this street he lived in house no. 6, which is preserved today by the Spanish Tourist Board with a bronze plaque (awarded in January 1977) which reads: "This was the house where lived Abul-Qasim."

Works

Abū al-Qāsim was a court physician to the Andalusian caliph Al-Hakam II. He devoted his entire life and genius to the advancement of medicine as a whole and surgery in particular. His best work was the Kitab al-Tasrif. It is a medical encyclopaedia spanning 30 volumes which included sections on surgery, medicine, orthopedics, ophthalmology, pharmacology, and nutrition.

In the 14th century, the French surgeon Guy de Chauliac quoted al-Tasrif over 200 times. Pietro Argallata (d. 1453) described Abū al-Qāsim as "without doubt the chief of all surgeons". In an earlier work, he is credited to be the first to describe ectopic pregnancy in 963, in those days a fatal affliction. Abū al-Qāsim's influence continued for at least five centuries, extending into the Renaissance, evidenced by al-Tasrif's frequent reference by French surgeon Jaques Delechamps (1513-1588).

Page from a 1531 Latin translation by Peter Argellata of El Zahrawi's treatise on surgical and medical instruments.

Kitab al-Tasrif

Abū al-Qāsim's thirty-chapter medical treatise, Kitab al-Tasrif, completed in the year 1000, covered a broad range of medical topics, including dentistry and childbirth, which contained data that had accumulated during a career that spanned almost 50 years of training, teaching and practice. In it he also wrote of the importance of a positive doctor-patient relationship and wrote affectionately of his students, whom he referred to as "my children". He also emphasized the importance of treating patients irrespective of their social status. He encouraged the close observation of individual cases in order to make the most accurate diagnosis and the best possible treatment.

Al-Tasrif was later translated into Latin by Gerard of Cremona in the 12th century, and illustrated. For perhaps five centuries during the European Middle Ages, it was the primary source for European medical knowledge, and served as a reference for doctors and surgeons.

Not always properly credited, Abū Al-Qāsim's al-Tasrif described both what would later became known as "Kocher's method" for treating a dislocated shoulder and "Walcher position" in obstetrics. Al-Tasrif described how to ligature blood vessels almost 600 years before Ambroise Paré, and was the first recorded book to document several dental devices and explain the hereditary nature of haemophilia.

Abū al-Qāsim also described the use of forceps in vaginal deliveries.He introduced his famous collection of over 200 surgical instruments. Many of these instruments were never used before by any previous surgeons. Hamidan, for example, listed at least twenty six innovative surgical instruments that Abulcasis introduced.

His use of catgut for internal stitching is still practised in modern surgery. The catgut appears to be the only natural substance capable of dissolving and is acceptable by the body. Abū al-Qāsim also invented the forceps for extracting a dead fetus, as illustrated in the Al-Tasrif.

The Al-Tasrif (1000) also introduces the use of ligature for the blood control of arteries in lieu of cauterization.The surgical needle was invented and described by Abū al-Qāsim in his Al-Tasrif.

Abū al-Qāsim devised about 200 new surgical instruments such as scalpels, curettes, retractors, spoons, sounds, hooks, rods, and specula.

Liber Servitoris

In pharmacy and pharmacology, Abū al-Qāsim al-Zahrawī pioneered the preparation of medicines by sublimation and distillation. His Liber Servitoris is of particular interest, as it provides the reader with recipes and explains how to prepare the "simples" from which were compounded the complex drugs then generally used.

He was also a contemporary of famous Andalusian chemists such as: Ibn al-Wafid, Maslamah Ibn Ahmad al-Majriti and Artephius.

From Wikipedia, the free encyclopedia.

http://en.wikipedia.org/wiki/Abu_al-Qasim_al-Zahrawi

Al-Mawardi

Abu al-Hasan Ali Ibn Muhammad Ibn Habib al-Mawardi ( أبو الحسن علي بن محمد بن حبيب البصري الماوردي ), known in Latin as Alboacen (972-1058 CE), was an Arab[citation needed] Muslim jurist of the Shafii school; he also made contributions to Qur'anic interpretations, philology, ethics, and literature. He served as judge at several Iraqi districts, including Baghdad, and as an ambassador of the Abbasid caliph to several Muslim states. Al-Mawardi's works on Islamic governance are recognized as classics in the field.

Biography

He was born in Basrah (present-day Iraq) during the year 972 C.E. Here he learnt Fiqh (Islamic Comprehension) from Abu al-Wahid al-Simari before travelling to Baghdad to study. Since both Basrah and Baghdad were homes of the Mu'tazili school of thought (a non-Sunni group) at this time he was influenced by their teachings. His contribution in political science and sociology comprises a number of monumental books, the most famous of which is Al-Ahkam al-Sultaniyya w'al-Wilayat al-Diniyya (The Ordinances of Government). He is also credited with the creation of darura, a doctrine of necessity.

Works

  • Al-Ahkam al-Sultania w'al-Wilayat al-Diniyya (The Ordinances of Government)
  • Qanun al-Wazarah (Laws regarding the Ministers)
  • Kitab Nasihat al-Mulk (The Book of Sincere Advice to Rulers)
  • Kitab Aadab al-Dunya w'al-Din (The Ethics of Religion and of this World)

Contemporaries

  • Caliph Al-Qadir d. 1031
  • Caliph Al-Qa'im d. 1075
  • From Wikipedia, the free encyclopedia
  • http://en.wikipedia.org/wiki/Al-Mawardi

Muhammad ibn Mūsā al-Khwārizmī

Abū ʿAbdallāh Muḥammad ibn Mūsā al-Khwārizmī (Persian/Arabic: أبو عبد الله محمد بن موسى الخوارزمي) (c. 780, Khwārizm– c. 850) was a mathematician, astronomer and geographer, a scholar in the House of Wisdom in Baghdad.

His Kitab al-Jabr wa-l-Muqabala presented the first systematic solution of linear and quadratic equations. He is considered the founder of algebra, a credit he shares with Diophantus. In the twelfth century, Latin translations of his work on the Indian numerals, introduced the decimal positional number system to the Western world. He revised Ptolemy's Geography and wrote on astronomy and astrology.

His contributions had a great impact on language. "Algebra" is derived from al-jabr, one of the two operations he used to solve quadratic equations. Algorism and algorithm stem from Algoritmi, the Latin form of his name. His name is the origin of (Spanish) guarismo and of (Portuguese) algarismo, both meaning digit.

Life

Few details of al-Khwārizmī's life are known with certainty, even his birthplace is unsure. His name may indicate that he came from Khwarezm (Khiva), then in Greater Khorasan, which occupied the eastern part of the Greater Iran, now Xorazm Province in Uzbekistan. Abu Rayhan Biruni calls the people of Khwarizm "a branch of the Persian tree".

Al-Tabari gave his name as Muhammad ibn Musa al-Khwārizmī al-Majousi al-Katarbali (Arabic: محمد بن موسى الخوارزميّ المجوسـيّ القطربّـليّ). The epithet al-Qutrubbulli could indicate he might instead have come from Qutrubbul (Qatrabbul), a viticulture district near Baghdad. However, Rashed points out that:

There is no need to be an expert on the period or a philologist to see that al-Tabari's second citation should read “Muhammad ibn Mūsa al-Khwārizmī and al-Majūsi al-Qutrubbulli,” and that there are two people (al-Khwārizmī and al-Majūsi al-Qutrubbulli) between whom the letter wa [Arabic ‘و’ for the article ‘and’] has been omitted in an early copy. This would not be worth mentioning if a series of errors concerning the personality of al-Khwārizmī, occasionally even the origins of his knowledge, had not been made. Recently, G. J. Toomer ... with naive confidence constructed an entire fantasy on the error which cannot be denied the merit of amusing the reader.

Regarding al-Khwārizmī's religion, Toomer writes:

Another epithet given to him by al-Ṭabarī, "al-Majūsī," would seem to indicate that he was an adherent of the old Zoroastrian religion. This would still have been possible at that time for a man of Iranian origin, but the pious preface to al-Khwārizmī's Algebra shows that he was an orthodox Muslim, so al-Ṭabarī's epithet could mean no more than that his forebears, and perhaps he in his youth, had been Zoroastrians.

In Ibn al-Nadīm's Kitāb al-Fihrist we find a short biography on al-Khwārizmī, together with a list of the books he wrote. Al-Khwārizmī accomplished most of his work in the period between 813 and 833. After the Islamic conquest of Persia, Baghdad became the centre of scientific studies and trade, and many merchants and scientists from as far as China and India traveled to this city, as did Al-Khwārizmī. He worked in Baghdad as a scholar at the House of Wisdom established by Caliph al-Maʾmūn, where he studied the sciences and mathematics, which included the translation of Greek and Sanskrit scientific manuscripts.

Contributions

Al-Khwārizmī's contributions to mathematics, geography, astronomy, and cartography established the basis for innovation in algebra and trigonometry. His systematic approach to solving linear and quadratic equations led to algebra, a word derived from the title of his 830 book on the subject, "The Compendious Book on Calculation by Completion and Balancing" (al-Kitab al-mukhtasar fi hisab al-jabr wa'l-muqabalaالكتاب المختصر في حساب الجبر والمقابلة).

On the Calculation with Hindu Numerals written about 825, was principally responsible for spreading the Indian system of numeration throughout the Middle East and Europe. It was translated into Latin as Algoritmi de numero Indorum. Al-Khwārizmī, rendered as (Latin) Algoritmi, led to the term "algorithm".

Some of his work was based on Persian and Babylonian astronomy, Indian numbers, and Greek mathematics.

Al-Khwārizmī systematized and corrected Ptolemy's data for Africa and the Middle east. Another major book was Kitab surat al-ard ("The Image of the Earth"; translated as Geography), presenting the coordinates of places based on those in the Geography of Ptolemy but with improved values for the Mediterranean Sea, Asia, and Africa.

He also wrote on mechanical devices like the astrolabe and sundial.

He assisted a project to determine the circumference of the Earth and in making a world map for al-Ma'mun, the caliph, overseeing 70 geographers.

When, in the 12th century, his works spread to Europe through Latin translations, it had a profound impact on the advance of mathematics in Europe. He introduced Arabic numerals into the Latin West, based on a place-value decimal system developed from Indian sources.

Algebra

A page from al-Khwārizmī's Algebra

Al-Kitāb al-mukhtaṣar fī ḥisāb al-jabr wa-l-muqābala (Arabic: الكتاب المختصر في حساب الجبر والمقابلة‎, 'The Compendious Book on Calculation by Completion and Balancing') is a mathematical book written approximately 830 CE. The book was written with the encouragement of the Caliph al-Ma'mun as a popular work on calculation and is replete with examples and applications to a wide range of problems in trade, surveying and legal inheritance. The term algebra is derived from the name of one of the basic operations with equations (al-jabr, meaning completion, or, subtracting a number from both sides of the equation) described in this book. The book was translated in Latin as Liber algebrae et almucabala by Robert of Chester (Segovia, 1145) hence "algebra", and also by Gerard of Cremona. A unique Arabic copy is kept at Oxford and was translated in 1831 by F. Rosen. A Latin translation is kept in Cambridge.

This book is considered the foundational text of modern algebra. It provided an exhaustive account of solving polynomial equations up to the second degree,and introduced the fundamental methods of "reduction" and "balancing", referring to the transposition of subtracted terms to the other side of an equation, that is, the cancellation of like terms on opposite sides of the equation.

Al-Khwārizmī's method of solving linear and quadratic equations worked by first reducing the equation to one of six standard forms (where b and c are positive integers)

  • squares equal roots (ax2 = bx)
  • squares equal number (ax2 = c)
  • roots equal number (bx = c)
  • squares and roots equal number (ax2 + bx = c)
  • squares and number equal roots (ax2 + c = bx)
  • roots and number equal squares (bx + c = ax2)

by dividing out the coefficient of the square and using the two operations al-jabr (Arabic: الجبر‎ “restoring” or “completion”) and al-muqābala ("balancing"). Al-jabr is the process of removing negative units, roots and squares from the equation by adding the same quantity to each side. For example, x2 = 40x − 4x2 is reduced to 5x2 = 40x. Al-muqābala is the process of bringing quantities of the same type to the same side of the equation. For example, x2 + 14 = x + 5 is reduced to x2 + 9 = x.

The above discussion uses modern mathematical notation for the types of problems which the book discusses. However, in al-Khwārizmī's day, most of this notation had not yet been invented, so he used textual descriptions and geometrical diagrams to present problems and their solutions. For example, for one problem he writes, (from an 1831 translation)

"If some one say: "You divide ten into two parts: multiply the one by itself; it will be equal to the other taken eighty-one times." Computation: You say, ten less thing, multiplied by itself, is a hundred plus a square less twenty things, and this is equal to eighty-one things. Separate the twenty things from a hundred and a square, and add them to eighty-one. It will then be a hundred plus a square, which is equal to a hundred and one roots. Halve the roots; the moiety is fifty and a half. Multiply this by itself, it is two thousand five hundred and fifty and a quarter. Subtract from this one hundred; the remainder is two thousand four hundred and fifty and a quarter. Extract the root from this; it is forty-nine and a half. Subtract this from the moiety of the roots, which is fifty and a half. There remains one, and this is one of the two parts."

In modern notation this process, with 'x' the "thing" (shay') or "root", is given by the steps,

(10 − x)2 = 81x
x2 + 100 = 101x

Let the roots of the equation be 'p' and 'q'. Then \tfrac{p+q}{2}=50\tfrac{1}{2}, pq = 100 and

\frac{p-q}{2} = \sqrt{\left(\frac{p+q}{2}\right)^2 - pq}=\sqrt{2550\tfrac{1}{4} - 100}=49\tfrac{1}{2}

So a root is given by

x=50\tfrac{1}{2}-49\tfrac{1}{2}=1

Several authors have also published texts under the name of Kitāb al-jabr wa-l-muqābala, including |Abū Ḥanīfa al-Dīnawarī, Abū Kāmil Shujā ibn Aslam, Abū Muḥammad al-ʿAdlī, Abū Yūsuf al-Miṣṣīṣī, 'Abd al-Hamīd ibn Turk, Sind ibn ʿAlī, Sahl ibn Bišr, and Šarafaddīn al-Ṭūsī.

J. J. O'Conner and E. F. Robertson wrote in the MacTutor History of Mathematics archive:

"Perhaps one of the most significant advances made by Arabic mathematics began at this time with the work of al-Khwarizmi, namely the beginnings of algebra. It is important to understand just how significant this new idea was. It was a revolutionary move away from the Greek concept of mathematics which was essentially geometry. Algebra was a unifying theory which allowed rational numbers, irrational numbers, geometrical magnitudes, etc., to all be treated as "algebraic objects". It gave mathematics a whole new development path so much broader in concept to that which had existed before, and provided a vehicle for future development of the subject. Another important aspect of the introduction of algebraic ideas was that it allowed mathematics to be applied to itself in a way which had not happened before."

R. Rashed and Angela Armstrong write:

"Al-Khwarizmi's text can be seen to be distinct not only from the Babylonian tablets, but also from Diophantus' Arithmetica. It no longer concerns a series of problems to be resolved, but an exposition which starts with primitive terms in which the combinations must give all possible prototypes for equations, which henceforward explicitly constitute the true object of study. On the other hand, the idea of an equation for its own sake appears from the beginning and, one could say, in a generic manner, insofar as it does not simply emerge in the course of solving a problem, but is specifically called on to define an infinite class of problems."
Page from a Latin translation, beginning with "Dixit algorizmi"

Arithmetic

Al-Khwārizmī's second major work was on the subject of arithmetic, which survived in a Latin translation but was lost in the original Arabic. The translation was most likely done in the twelfth century by Adelard of Bath, who had also translated the astronomical tables in 1126.

The Latin manuscripts are untitled, but are commonly referred to by the first two words with which they start: Dixit algorizmi ("So said al-Khwārizmī"), or Algoritmi de numero Indorum ("al-Khwārizmī on the Hindu Art of Reckoning"), a name given to the work by Baldassarre Boncompagni in 1857. The original Arabic title was possibly Kitāb al-Jamʿ wa-l-tafrīq bi-ḥisāb al-Hind[21] ("The Book of Addition and Subtraction According to the Hindu Calculation")

Al-Khwarizmi's work on arithmetic was responsible for introducing the Arabic numerals, based on the Hindu-Arabic numeral system developed in Indian mathematics, to the Western world. The term "algorithm" is derived from the algorism, the technique of performing arithmetic with Hindu-Arabic numerals developed by al-Khwarizmi. Both "algorithm" and "algorism" are derived from the Latinized forms of al-Khwarizmi's name, Algoritmi and Algorismi, respectively.

Trigonometry

In trigonometry, al-Khwārizmī (c. 780-850) produced tables for the trigonometric functions of sines and cosine in the Zīj al-Sindhind, alongside the first tables for tangents. He was also an early pioneer in spherical trigonometry, and wrote a treatise on the subject.

Astronomy

Corpus Christi College MS 283

Al-Khwārizmī's Zīj al-Sindhind (Arabic: زيج "astronomical tables of Sind and Hind") is a work consisting of approximately 37 chapters on calendrical and astronomical calculations and 116 tables with calendrical, astronomical and astrological data, as well as a table of sine values. This is the first of many Arabic Zijes based on the Indian astronomical methods known as the sindhind. The work contains tables for the movements of the sun, the moon and the five planets known at the time. This work marked the turning point in Islamic astronomy. Hitherto, Muslim astronomers had adopted a primarily research approach to the field, translating works of others and learning already discovered knowledge. Al-Khwarizmi's work marked the beginning of non-traditional methods of study and calculations.

The original Arabic version (written c. 820) is lost, but a version by the Spanish astronomer Maslamah Ibn Ahmad al-Majriti (c. 1000) has survived in a Latin translation, presumably by Adelard of Bath (January 26, 1126). The four surviving manuscripts of the Latin translation are kept at the Bibliothèque publique (Chartres), the Bibliothèque Mazarine (Paris), the Bibliotheca Nacional (Madrid) and the Bodleian Library (Oxford).

Al-Khwarizmi made several important improvements to the theory and construction of sundials, which he inherited from his Indian and Hellenistic predecessors. He made tables for these instruments which considerably shortened the time needed to make specific calculations. His sundial was universal and could be observed from anywhere on the Earth. From then on, sundials were frequently placed on mosques to determine the time of prayer. The shadow square, an instrument used to determine the linear height of an object, in conjunction with the alidade for angular observations, was also invented by al-Khwārizmī in ninth-century Baghdad.[not in citation given]

The first quadrants and mural instruments were invented by al-Khwarizmi in ninth century Baghdad.[28][not in citation given] The sine quadrant, invented by al-Khwārizmī, was used for astronomical calculations.[29][not in citation given] The first horary quadrant for specific latitudes, was also invented by al-Khwārizmī in Baghdad, then center of the development of quadrants.[29][not in citation given] It was used to determine time (especially the times of prayer) by observations of the Sun or stars.The Quadrans Vetus was a universal horary quadrant, an ingenious mathematical device invented by al-Khwarizmi in the ninth century and later known as the Quadrans Vetus (Old Quadrant) in medieval Europe from the thirteenth century. It could be used for any latitude on Earth and at any time of the year to determine the time in hours from the altitude of the Sun. This was the second most widely used astronomical instrument during the Middle Ages after the astrolabe. One of its main purposes in the Islamic world was to determine the times of Salah.[29][not in citation given]

Geography

Al-Khwārizmī's third major work is his Kitāb ṣūrat al-Arḍ (Arabic: كتاب صورة الأرض "Book on the appearance of the Earth" or "The image of the Earth" translated as Geography), which was finished in 833. It is a revised and completed version of Ptolemy's Geography, consisting of a list of 2402 coordinates of cities and other geographical features following a general introduction.

There is only one surviving copy of Kitāb ṣūrat al-Arḍ, which is kept at the Strasbourg University Library. A Latin translation is kept at the Biblioteca Nacional de España in Madrid. The complete title translates as Book of the appearance of the Earth, with its cities, mountains, seas, all the islands and rivers, written by Abu Ja'far Muhammad ibn Musa al-Khwārizmī, according to the geographical treatise written by Ptolemy the Claudian.

The book opens with the list of latitudes and longitudes, in order of "weather zones", that is to say in blocks of latitudes and, in each weather zone, by order of longitude. As Paul Gallez points out, this excellent system allows us to deduce many latitudes and longitudes where the only document in our possession is in such a bad condition as to make it practically illegible.

Neither the Arabic copy nor the Latin translation include the map of the world itself, however Hubert Daunicht was able to reconstruct the missing map from the list of coordinates. Daunicht read the latitudes and longitudes of the coastal points in the manuscript, or deduces them from the context where they were not legible. He transferred the points onto graph paper and connected them with straight lines, obtaining an approximation of the coastline as it was on the original map. He then does the same for the rivers and towns.

Al-Khwārizmī corrected Ptolemy's gross overestimate for the length of the Mediterranean Sea] (from the Canary Islands to the eastern shores of the Mediterranean); Ptolemy overestimated it at 63 degrees of longitude, while al-Khwarizmi almost correctly estimated it at nearly 50 degrees of longitude. He "also depicted the Atlantic and Indian Oceans as open bodies of water, not land-locked seas as Ptolemy had done." Al-Khwarizmi thus set the Prime Meridian of the Old World at the eastern shore of the Mediterranean, 10–13 degrees to the east of Alexandria (the prime meridian previously set by Ptolemy) and 70 degrees to the west of Baghdad. Most medieval Muslim geographers continued to use al-Khwarizmi's prime meridian.

Jewish calendar

Al-Khwārizmī wrote several other works including a treatise on the Hebrew calendar (Risāla fi istikhrāj taʾrīkh al-yahūd "Extraction of the Jewish Era"). It describes the 19-year intercalation cycle, the rules for determining on what day of the week the first day of the month Tishrī shall fall; calculates the interval between the Jewish era (creation of Adam) and the Seleucid era; and gives rules for determining the mean longitude of the sun and the moon using the Jewish calendar. Similar material is found in the works of al-Bīrūnī and Maimonides.

Other works

Several Arabic manuscripts in Berlin, Istanbul, Tashkent, Cairo and Paris contain further material that surely or with some probability comes from al-Khwārizmī. The Istanbul manuscript contains a paper on sundials, which is mentioned in the Fihirst. Other papers, such as one on the determination of the direction of Mecca, are on the spherical astronomy.

Two texts deserve special interest on the morning width (Maʿrifat saʿat al-mashriq fī kull balad) and the determination of the azimuth from a height (Maʿrifat al-samt min qibal al-irtifāʿ).

He also wrote two books on using and constructing astrolabes. Ibn al-Nadim in his Kitab al-Fihrist (an index of Arabic books) also mentions Kitāb ar-Ruḵāma(t) (the book on sundials) and Kitab al-Tarikh (the book of history) but the two have been lost.

The shaping of our mathematics can be attributed to Al-Khwarizmi, the chief librarian of the observatory, research center and library called the House of Wisdom in Baghdad. His treatise, "Hisab al-jabr w'al-muqabala" (Calculation by Restoration and Reduction), which covers linear and quadratic equations, solved trade imbalances, inheritance questions and problems arising from land surveyance and allocation. In passing, he also introduced into common usage our present numerical system, which replaced the old, cumbersome Roman one.

From Wikipedia, the free encyclopedia

http://en.wikipedia.org/wiki/Muhammad_ibn_Musa_al-Khwarizm

Muhammad ibn Jābir al-Harrānī al-Battānī


Al-Battānī (850-926)

Abu Abdallah Muhammad ibn Jabir ibn Sinan ar-Raqqi al-Harrani as-Sabi al-Batani (Arabic محمد بن جابر بن سنان البتاني `Abū `Abd Allāh Muḥammad ibn Jābir ibn Sinān ar-Raqqī al-Ḥarrānī aṣ-Ṣābi` al-Battānī c. 858, Harran – 929, Qasr al-Jiss, near Samarra) Latinized as Albategnius, Albategni or Albatenius was an Arab[1] astronomer, astrologer, and mathematician, born in Harran near Urfa, which is now in Turkey. His epithet as-Sabi suggests that among his ancestry were members of the Sabian sect; however, his full name affirms that he was Muslim.

Astronomy

One of his best-known achievements in astronomy was the determination of the solar year as being 365 days, 5 hours, 46 minutes and 24 seconds.

His work, the Zij influenced great European astronomers like Tycho Brahe, Johannes Kepler, etc. Nicholas Copernicus repeated what Al-Battani wrote nearly 700 years before him as the Zij was translated into Latin thrice.

The modern world has paid him homage and named a region of the moon Albategnius after him.

Al Battani worked in Syria, at ar-Raqqah and at Damascus, where he died. He was able to correct some of Ptolemy's results and compiled new tables of the Sun and Moon, long accepted as authoritative, discovered the movement of the Sun's apogee, treated the division of the celestial sphere, and introduced, probably independently of the 5th century Indian astronomer Aryabhata, the use of sines in calculation, and partially that of tangents, forming the basis of modern trigonometry. He also calculated the values for the precession of the equinoxes (54.5" per year, or 1° in 66 years) and the inclination of Earth's axis (23° 35'). He used a uniform rate for precession in his tables, choosing not to adopt the theory of trepidation attributed to his colleague Thabit ibn Qurra.

His most important work is his zij, or set of astronomical tables, known as al-Zīj al-Sābī with 57 chapters, which by way of Latin translation as De Motu Stellarum by Plato Tiburtinus (Plato of Tivoli) in 1116 (printed 1537 by Melanchthon, annotated by Regiomontanus), had great influence on European astronomy. The zij is based on Ptolemy's theory, showing little Indian influence.A reprint appeared at Bologna in 1645. Plato's original manuscript is preserved at the Vatican; and the Escorial Library possesses in manuscript a treatise by Al Battani on astronomical chronology.

During his observations for his improved tables of the Sun and the Moon, he discovered that the direction of the Sun's eccentric was changing.[4] His times for the new moon, lengths for the solar year and sidereal year, prediction of eclipses, and work on the phenomenon of parallax, carried astronomers "to the verge of relativity and the space age."

Copernicus mentioned his indebtedness to Al-Battani and quoted him, in the book that initiated the Copernican Revolution, the De Revolutionibus Orbium Coelestium.

Mathematics

In mathematics, Battānī produced a number of trigonometrical relationships:

\tan a = \frac{\sin a}{\cos a}
\sec a = \sqrt{1 + \tan^2 a }

He also solved the equation sin x = a cos x discovering the formula:

\sin x = \frac{a}{\sqrt{1 + a^2}}

He also gives other trigonometric formulae, such as:

b \sin (A) = a \sin (90^\circ - A)

He also used al-Marwazi's idea of tangents ("shadows") to develop equations for calculating tangents and cotangents, compiling tables of them. He also discovered the reciprocal functions of secant and cosecant, and produced the first table of cosecants, which he referred to as a "table of shadows" (in reference to the shadow of a gnomon), for each degree from 1° to 90°.

Honors