MOHAMMAD BIN MUSA AL-KHAWARIZMI

(Died 840 A.D.)

Abu Abdullah Mohammad Ibn Musa al-Khawarizmi was bornat Khawarizm (Khev a), south of Aral sea. Very little is known abouthis early life, except for the fact that his parents had migrated to aplace south of Baghdad. The exact dates of his birth and death arealso not known, but it is established that he flourished under Al-Mamu n at Baghdad through 813-833 and probably died around840 A.D.

Khawarizmi was a mathematician, astronomer and geographer.He was perhaps one of the greatest mathematicians who ever lived,as, in fact, he was the founder of several branches and basic co nceptsof mathematics. In the words of Phillip Hitti, he influencedmathematical thought to a greater extent than any other mediaevalwriter. His work on algebra was outstanding, as he not only initiatedthe subject in a systematic form but he also developed it to theextent of giving analytical solutions of linear and quadraticequations, which established him as the founder of Algebra. Thevery name Algebra has been derived from his famous book Al-Jabrwa-al-Muqabilah. His arithmetic synthesised Greek an d Hinduknowledge and also contained his own contribution of fundamentalimportance to mathematics and science. Thus, he explained the useof zero, a numeral of fundamental importance developed by theArabs. Similarly, he developed the decimal system so that the overallsystem of numerals, 'algorithm' or 'algorizm' is named after him.In addition to introducting the Indian system of numerals (nowgenerally known as Arabic numerals), he developed at length severalarithmetical procedures, including operations on f ractions. It wasthrough his work that the system of numerals was first introduced toArabs and later to Europe, through its translations in Europeanlanguages. He developed in detail trigonometric tables containing thesine functions, which were probably ext rapolated to tangentfunctions by Maslama. He also perfected the geometric representa-tion of conic sections and developed the calculus of two errors,which practically led him to the concept of differentiation. He isalso reported to have collaborated in th e degree measurementsordered by Mamun al-Rashid were aimed at measuring of volumeand circumference of the earth.

The development of astronomical tables by him was a signifi-cant contribution to the science of astronomy, on which he alsowrote a book. The contribution of Khawarizmi to geography is alsooutstanding, in that not only did he revise Ptolemy's views ongeography, but also corrected them in detail as well as his map ofthe world. His other contributions include original work related toclocks, sun-dials and astrolabes.

Several of his books were translated into Latin in the early12th century. In fact, his book on arithmetic, Kitab al-Jam'a wal-Tafreeq bil Hisab al-Hindi, was lost in Arabic but survived in a Latintranslation. His boo k on algebra, Al-Maqala fi Hisab-al Jabr wa-al-Muqabilah, was also translated into Latin in the 12th century, andit was this translation which introduced this new science to the West"completely unknown till then". He astronomical tables were alsotr anslated into European languages and, later, into Chinese. Hisgeography captioned Kitab Surat-al-Ard, together with its maps,was also translated. In addition, he wrote a book on the Jewishcalendar Istikhraj Tarikh al-Yahud, and two books on the astrolabe.He also wrote Kitab al-Tarikh and his book on sun-dials wascaptioned Kitab al-Rukhmat, but both of them have been lost.

The influence of Khawarizmi on the growth of science, ingeneral, and mathematics, astronomy and geogr aphy in particular,is well established in history. Several of his books were readilytranslated into a number of other languages, and, in fact, constitutedthe university text-books till the 16th century. His approach wassystematic and logical, and not only did he bring together the thenprevailing knowledge on various branches of science, particularlymathematics, but also enriched it through his original contribution.No doubt he has been held in high repute throughout the centuriessince then.