Al Juarismi, the wise man who gave the algorithm its name
A little before the Christmas holidays, the inauguration of a bust dedicated to the Arab sage Mohammad ibn Musa Al Juarismi took place in the gardens of the Plaza de Ciencias of the Complutense University of Madrid. The statue was donated by the Government of Uzbekistan, culminating more than six years of arduous efforts between various organizations, among which the Faculty of Physics of the Complutense University and the Royal Spanish Naval League have played a prominent role. The character may be unknown to the general public, but his name gave rise to one of the most used words in the field of technology: the algorithm.
Al Juarismi lived between the 8th and 9th centuries and was a member of the House of Wisdom that Al Mamun, the seventh of the Abbasid caliphs, had founded in Baghdad around 813. This institution, in imitation of the old library-museum of Alexandria, intended to collect all the knowledge of Greek, Persian and Hindu scientists, peoples that had largely been conquered by Islam. There, among many others, the works of Ptolemy, Euclid, Menelaus, Galen and Hippocrates were translated into Arabic. Hindu algebra and astronomy were also translated. Thanks to labor, many of these works were not lost in the mists of time and reached the West centuries later, partly through Spain and its Toledo School of Translators.
Al Juarismi was a geographer, astronomer, and mathematician. In geography, he left us a world map that updated Ptolemy’s maps. In astronomy, he made some astronomical tables with the situation of the five planets then known, the Sun and the Moon, which survived until the 13th century, being the basis of the so-called Alphonsine tables, created under the reign of Alfonso X El Sabio.
But his best known contributions were to mathematics. Your book Al jabr, gave name to the discipline that we know today as algebra and it explained the method we currently use to solve second degree equations. And, thanks to his treatise on arithmetic, the Western world learned of the Hindu system of positional decimal numbering, of the importance of zero – a novelty with respect to previous numbering systems – and of the procedures for adding, subtracting, multiplying and divide numbers in the decimal system that all children learn today in school.
Al Juarismi was so successful in explaining this system that Arabic numbers are often spoken of when, in fact, their origin is in India. And he was so didactic in exposing the method to operate with decimal numbers, that those operations received the name of algorithm, a word formed from its name. Also the word figure is a derivative of it.
Over time, any routine and systematic procedure to solve a problem was called an algorithm. With the advent of computers and programming languages in the 20th century, algorithms took on the appearance of long texts written in jargon only suitable for beginners.
Currently, there is also talk of “the algorithm”, in the singular, to refer to that kind of Big Brother that monitors our access to the internet and our social networks to offer us advertising or news adapted to our individual preferences. In reality, this supposed algorithm has more to do with artificial intelligence and with the processing of immense amounts of data than with the original meaning of the word. In any case, these procedures would be a different type of algorithm.
It is fair, then, to honor the memory of this wise man who has done so much for our progress, although many are probably unaware of it. Al Juarismi is well worth a walk through the Madrid University City to get closer to this beautiful monument erected in his memory.
Ricardo Pena He is Professor of Computer Languages and Systems at the Complutense University of Madrid.
Chronicles of the Intangible is a space for the dissemination of computer science, coordinated by the academic society SISTEDES (Society for Software Engineering and Software Development Technologies). The intangible is the non-material part of computer systems (that is, software), and its history and its evolution are related here. The authors are professors at Spanish universities, coordinated by Ricardo Peña Marí (professor at the Complutense University of Madrid) and Macario Polo Usaola (professor at the University of Castilla-La Mancha).