Tuesday, November 6, 2007


Abu Abdullah Mohammad Ibn Musa al-Khwarizmi was born at Khwarizm (Kheva), south of Aral sea, near modern day Uzbekistan. Very little is known about his early life, except for the fact that his parents had migrated to a place south of Baghdad. The exact dates of his birth and death are also not known, but it is established that he flourished under Al- Mamun at Baghdad through 813-833 and probably died around 840 C.E.

Al-Khwarizmi flourished while working as a member of the House of Wisdom in Baghdad under the leadership of Caliph al-Mamun, the son of the Caliph al-Harun al-Rashid, who was made famous in the Arabian Nights. The House of Wisdom was a scientific research and teaching center.

It was Al-Khwarizmi's most famous book called al-Kitab al-mukhtasar fi Hisab al-jabr w'al mugabalah ("The Compendious Book on Calculation by Completion and Balancing") that we derive the name "algebra", the European version for the word al-jabr. These words refer to the systematic study of the solution of linear and quadratic equations. His major contributions to mathematics, astronomy, astrology, geography and cartography provided foundations for later and even more widespread innovation in algebra, trigonometry, and his other areas of interest. His systematic and logical approach to solving linear and quadratic equations gave shape to that discipline of algebra. The book was first translated into Latin in the twelfth century.

Al-Khwarizmi's most recognized work, Algoritmi de numero Indorum, and one that is so named after him, is the mathematical concept Algorithm. The modern meaning of the word relates to a specific routine for solving a particular problem. Today, people use algorithms to do addition and long division, principles that are found in Al-Khwarizmi's text written over 2000 years ago. Al-Khwarizmi was also responsible for introducing the Arabic numbers to the West, setting in motion a process that led to the use of the nine Arabic numerals, together with the zero sign.

Al-Khwarizmi further systematized and corrected Ptolemy's data in geography as regards to Africa and the Middle east. Another major book was his Kitab surat al-ard ("The Image of the Earth"; translated now as Geography), which presented the coordinates of localities in the known world as based, ultimately, on those in the Geography of Ptolemy but with improved values for the length of the Mediterranean Sea and the location of cities in Asia and Africa.

He also assisted in the construction of the first globe of the known world for the caliph al-Ma'mun and participated in a project to determine the circumference of the Earth, supervising the work of 70 geographers to create the map of the then "known world".

When his work was copied and transferred to Europe through Latin translations, it had a profound impact on the advancement of basic mathematics in Europe. He also wrote on mechanical devices like the astrolabe and sundial.

Al-Khwarizmi's Zīj al-sindhind ("astronomical tables") 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 one of many Arabic zijes based on the Indian astronomical methods known as the sindhind.

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.

The influence of Khawarizmi on the growth of science, in general, and mathematics, astronomy and geography in particular, is well established in history. Several of his books were readily translated into a number of other languages, and, in fact, constituted the university textbooks till the 16th century. His approach was systematic and logical, and not only did he bring together the then prevailing knowledge on various branches of science, particularly mathematics, but also enriched it through his original contribution. No doubt he has been held in high repute throughout the centuries since then.

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