Every algorithm carries the name of a ninth-century scholar from Khwarazm
When Europeans translated a Baghdad arithmetic book into Latin in the 12th century, its author's name came out as Algoritmi. That garbled label became our word algorithm, and the title of another of his books gave us algebra. Muhammad ibn Musa al-Khwarizmi left two of the most-used words in modern science.
Remarkably little is certain about his life. He lived roughly from 780 to 850, and his name means someone from Khwarazm, a region of Greater Iran that now lies in Turkmenistan and Uzbekistan. One chronicler added an epithet linking him to Qutrubbul near Baghdad, which some historians accept and the scholar Roshdi Rashed dismisses as a copyist's slip that merged two people. Another label hints at Zoroastrian ancestry, though the devout preface to his algebra shows he wrote as a Muslim. Whatever his origins, he wrote entirely in Arabic.
Around 820 he was appointed astronomer and head of the library at the House of Wisdom, the Baghdad institution founded by Caliph al-Ma'mun, where Greek and Sanskrit science was being translated. Encouraged by the caliph, he wrote a popular manual on calculation packed with problems from trade, surveying and inheritance law. It reduced equations to six standard forms and solved them with two moves: al-jabr, restoring by adding the same amount to both sides, and al-muqabala, balancing like terms. He justified completing the square geometrically, all in plain words, since symbolic notation did not yet exist.
Solomon Gandz argued he deserves the title father of algebra more than Diophantus, because he taught the subject for its own sake rather than as number theory. Robert of Chester put the book into Latin in 1145, and it served as the main mathematics textbook in European universities until the 16th century.
His other work travelled just as far. A treatise from about 825 on calculating with Hindu numerals spread decimal place-value notation through the Middle East and Europe. He corrected Ptolemy's coordinates for Africa and the Middle East, wrote on the astrolabe and sundial, produced accurate sine and cosine tables, and oversaw 70 geographers on a world map for al-Ma'mun.
Source: Al-Khwarizmi
