Background
Muḥammad ibn Mūsā al-Khwārizmī was born in Persia of that time around 780.
Muhammad ibn Musa al-Khwarizmi
Muhammad ibn Musa al-Khwarizmi
Muhammad ibn Musa al-Khwarizmi
Muhammad ibn Musa al-Khwarizmi
Muhammad ibn Musa al-Khwarizmi
Muhammad ibn Musa al-Khwarizmi
Muhammad ibn Musa al-Khwarizmi
Muhammad ibn Musa al-Khwarizmi
Muhammad ibn Musa al-Khwarizmi
Astronomer geographer mathematician astrologer scholar
Muḥammad ibn Mūsā al-Khwārizmī was born in Persia of that time around 780.
Al-Khwārizmī lived in Baghdad, where he worked at the "House of Wisdom" (Dār al-Ḥikma) under the caliphate of al-Maʾmūn. The House of Wisdom acquired and translated scientific and philosophic treatises, particularly Greek, as well as publishing original research. Al-Khwārizmī’s work on elementary algebra, Al-Kitāb al-mukhtaṣar fī ḥisāb al-jabr waʾl-muqābala ("The Compendious Book on Calculation by Completion and Balancing"), was translated into Latin in the 12th century, from which the title and term algebra derive. Algebra is a compilation of rules, together with demonstrations, for finding solutions of linear and quadratic equations based on intuitive geometric arguments, rather than the abstract notation now associated with the subject. Its systematic, demonstrative approach distinguishes it from earlier treatments of the subject. It also contains sections on calculating areas and volumes of geometric figures and on the use of algebra to solve inheritance problems according to proportions prescribed by Islamic law. Elements within the work can be traced from Babylonian mathematics of the early 2nd millennium BCE through Hellenistic, Hebrew, and Hindu treatises.
In the 12th century, a second work by al-Khwārizmī introduced Hindu-Arabic numerals (see numerals and numeral systems) and their arithmetic to the West. It is preserved only in a Latin translation, Algoritmi de numero Indorum ("Al-Khwārizmī Concerning the Hindu Art of Reckoning"). From the name of the author, rendered in Latin as Algoritmi, originated the term algorithm.
A third major book was his Kitāb ṣūrat al-arḍ ("The Image of the Earth"; translated as Geography), which presented the coordinates of localities in the known world based, ultimately, on those in the Geography of Ptolemy (flourished 127-145 CE) 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 a world map for al-Maʾmūn and participated in a project to determine the circumference of the Earth, which had long been known to be spherical, by measuring the length of a degree of a meridian through the plain of Sinjār in Iraq.
Finally, al-Khwārizmī also compiled a set of astronomical tables (Zīj), based on a variety of Hindu and Greek sources. This work included a table of sines, evidently for a circle of radius 150 units. Like his treatises on algebra and Hindu-Arabic numerals, this astronomical work (or an Andalusian revision thereof) was translated into Latin.
Muhammad ibn Musa al-Khwarizmi died in c. 850 being remembered as one of the most seminal scientific minds of early Islamic culture.
Al-Khwārizmī’s major accomplishments were the books he wrote on mathematics and science. His mathematical books introduced the ideas of algebra and Hindu-Arabic numerals to Western mathematicians during the Middle Ages. His scientific works concerned geography and astronomy.
Till today, Muhammad Al-Khwarizmi is acknowledged by many as the "Father of Modern Algebra." He is also fondly appreciated as one of the pioneers of modern science during the Islamic Golden Age (which is the Middle East’s equivalent of the Renaissance). As an inspirational teacher and writer, his efforts (more than anyone else’s) helped in advancing the mathematical knowledge of medieval Europe. It was Al-Khwarizmi’s works that honed the mathematical skills of Abu-Kamil Ibn-Aslam Shuja: the first person who employed irrational numbers as coefficients and solutions to equations. Abu-Kamil would in turn influence Leonardo Fibonacci, who gained fame in Europe by introducing and popularizing the Asian math methods, which Al-Khwarizmi had advanced and preserved. Due to his enormous reputation as a mathematician, Al-Khwarizmi’s contributions to astronomy, geography, and other fields are often overshadowed by the ones he made to mathematics. The lunar impact crater, Al-Khwarizmi, is named after him: in addition to numerous concepts, awards, and research centers.
Al-Khwarizmi’s algebra is regarded as the foundation and cornerstone of the sciences. To al-Khwarizmi we owe the world "algebra," from the title of his greatest mathematical work, Hisab al-Jabr wa-al-Muqabala. The book, which was twice translated into Latin, by both Gerard of Cremona and Robert of Chester in the 12th century, works out several hundred simple quadratic equations by analysis as well as by geometrical example. It also has substantial sections on methods of dividing up inheritances and surveying plots of land. It is largely concerned with methods for solving practical computational problems rather than algebra as the term is now understood.
Al-Khwarizmi confined his discussion to equations of the first and second degrees. He also wrote an important work on astronomy, covering calendars, calculating true positions of the sun, moon, and planets, tables of sines and tangents, spherical astronomy, astrological tables, parallax, and eclipse calculations, and visibility of the moon. His astronomical work, Zij al-sindhind, is also based on the work of other scientists. As with the Algebra, its chief interest is as the earliest Arab work still in existence in Arabic.
His most recognized work as mentioned above and one that is so named after him is the mathematical concept Algorithm. The modern meaning of the word relates to a specific practice 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 about 1200 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.
Of great importance also was al-Khwarizmi’s contribution to medieval geography. He systematized and corrected Ptolemy’s research in geography, using his own original findings that are entitled Surat al-Ard (The Shape of the Earth). The text exists in a manuscript; the maps have unfortunately not been preserved, although modern scholars have been able to reconstruct them from al-Khwarizmi’s descriptions. He supervised the work of 70 geographers to create a map of the then “known world”. When his work became known in Europe through Latin translations, his influence made a permanent mark on the development of science in the West.
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-Khwarizmi in ninth-century Baghdad.
While his major contributions were the result of original research, he also did much to synthesize the existing knowledge in these fields from Greek, Indian, and other sources. A number of minor works were written by al-Khwarizmi on topics such as the astrolabe, on which he wrote on the Jewish calendar. He also wrote a political history containing horoscopes of prominent persons.
