- Adrienne Bernhard
- BBC Future
The House of Wisdom sounds a bit like a fantasy: there is no trace of this ancient library, destroyed in the 13th century, so we cannot be sure where it was located or what exactly it looked like.
But this prestigious academy was in fact a major intellectual powerhouse in Baghdad during the Islamic Golden Age, and the birthplace of such transformative mathematical concepts as the common zero and our modern “Arabic” numbers.
Founded as a private collection for Caliph Harun Al-Rashid in the late 8th century, and later converted into a public academy some 30 years later, the House of Wisdom appears to have brought scientists from around the world to Baghdad, drawn by the vibrant intellectual curiosity of the city and freedom of expression (Muslim, Jewish and Christian scholars were allowed to study there).
With an archive as formidable in size as the current British Library in London or the Bibliothèque Nationale in Paris, the House of Wisdom eventually became an incomparable center for the study of the humanities and sciences, including mathematics, astronomy, medicine, chemistry, geography, philosophy, literature and the arts, as well as some more dubious subjects such as alchemy and astrology.
To invoke this great monument, therefore, requires a leap of imagination (think of the Citadel in Westeros or the library at Hogwarts), but one thing is certain: the academy ushered in a cultural renaissance that would completely alter the course of mathematics.
The House of Wisdom was destroyed in the Mongol siege of Baghdad in 1258 (according to legend, so many manuscripts were thrown into the Tigris River that its waters turned black with ink), but the discoveries made there introduced a powerful abstract mathematical language that later it would be adopted by the Islamic empire, Europe and, ultimately, the entire world.
“What should matter to us is not the precise details of where or when the House of Wisdom was created,” says Jim Al-Khalili, professor of physics at the University of Surrey.
“Much more interesting is the history of scientific ideas themselves and how they developed as a result. “
Tracing the mathematical legacy of the House of Wisdom involves a bit of time travel into the future, so to speak.
For hundreds of years until the decline of the Italian Renaissance, one name was synonymous with mathematics in Europe: Leonardo da Pisa, known posthumously as Fibonacci.
Born in Pisa in 1170, the Italian mathematician received his primary instruction in Bugia, a commercial enclave located on the African coast of Barbary (north coast of Africa).
At age 20, Fibonacci traveled to the Middle East, captivated by ideas that had come from western India through Persia.
When he returned to Italy, Fibonacci published Liber Abbaci, one of the first Western works to describe the Hindu-Arabic number system.
When Liber Abbaci first appeared in 1202, only a few intellectuals knew the Hindu Arabic numerals.
European merchants and scholars still clung to Roman numerals, which made multiplication and division extremely cumbersome (try multiplying MXCI by LVII!).
The Fibonacci book demonstrated the use of numbers in arithmetic operations, techniques that could be applied to practical problems such as markup, currency exchange, weight conversion, barter, and interest.
“Whoever wants to know the art of calculating, its subtleties and ingenuity, must know how to compute with figures by hand,” wrote Fibonacci in the first chapter of his encyclopedic work, referring to the digits that children now learn in school.
“With these nine figures and the sign 0, called zephyr, any number can be written.”
Suddenly math they were available to everyone in a usable form.
However, Fibonacci’s great genius was not only his creativity as a mathematician, but his keen understanding of the advantages known to Muslim scientists for centuries: his calculation formulas, his system of decimal places, his algebra.
In fact, Liber Abbaci relied almost exclusively on the algorithms of the 9th century mathematician Al-Khwarizmi.
His revolutionary treatise presented, for the first time, a systematic way of solving quadratic equations.
Due to his discoveries in the field, Al-Khwarizmi is often referred to as the father of algebra, a word we owe to him, from the Arabic al-jabr, “the restoration of broken parts”, and in 821 he was appointed an astronomer and Chief Librarian of the House of Wisdom.
“The Al-Khwarizmi treaty introduced the Muslim world to the decimal number system,” explains Al-Khalili. “Others, like Leonardo da Pisa, helped to transmit it throughout Europe.”
Fibonacci’s transformative influence on modern mathematics was therefore a legacy owed in large part to Al-Khwarizmi.
And so, two men separated by nearly four centuries were connected by an ancient library: the most celebrated mathematician of the Middle Ages drew on the experience of another pioneering thinker, one whose breakthroughs were made at an iconic institution of the Islamic Golden Age. .
Perhaps because so little is known about the House of Wisdom, historians are occasionally tempted to exaggerate its scope and purpose, giving it a mythical status somewhat at odds with the few remaining historical records.
“Some argue that the House of Wisdom was not as great as it was in the eyes of many,” says Al-Khalili.
“But his association with men like Al-Khwarizmi, with his work in mathematics, astronomy and geography, is strong evidence for me that the House of Wisdom was closer to a real academy, not just a repository of translated books. “.
The library’s scholars and translators also went to great lengths to ensure that their work was accessible to the reading public.
“The House of Wisdom is fundamentally important, as it is through the translations there (Arab scholars who translated Greek ideas into the vernacular) that we form the basis of our mathematical understanding,” says June Barrow-Green, professor of history of mathematics at the Open University. in the United Kingdom.
The palace library was both a window into number ideas from the past as a site of scientific innovation.
Long before our current decimal system, the binary number system that programs our computers, before Roman numerals, before the system used by the ancient Mesopotamians, humans used the first counting systems to record calculations.
While we may find each of these imponderable or outdated systems, the different numerical representations can teach us something valuable about the structure, relationships, and historical and cultural contexts from which they arose.
These reinforce the idea of place value and abstraction, helping us better understand how numbers work.
They show that “the Western way was not the only one,” says Barrow-Green. “There is real value in understanding different number systems.”
When a former merchant wanted to write “two sheep,” for example, he could inscribe an image of two sheep in clay. But this would not be practical if you wanted to write “20 sheep”. Sign-value notation is a system in which the number symbols that are added together signify a value; in this case, draw two sheep to represent the actual amount.
A vestige of sign value notation, Roman numerals somehow persisted despite the introduction of the Al-Khwarizmi system, which relied on the position of digits to represent quantities.
Like the towering monuments they were inscribed on, Roman numerals survived the empire that spawned them, be it by accident, feeling, or purpose, no one can say for sure.
This year marks the 850th anniversary of the birth of Fibonacci. It could also be the moment that threatens to undo the trajectory of the Roman numerals.
In the UK, traditional clocks have been replaced by easier-to-read digital clocks in school classrooms, fearing that students will no longer be able to tell analog time correctly.
In some regions of the world, governments have removed them from road signs and official documents, while Hollywood has moved away from using Roman numerals in sequel titles.
The Superbowl abandoned them for their 50th game, concerned it would confuse fans.
But a global shift away from Roman numerals reveals a growing lack of ability to calculate in other aspects of life.
Perhaps more importantly, the disappearance of the Roman numerals shows what the policies are that govern any broader discussion of mathematics.
“The question of whose stories we tell, whose culture we privilege, and what forms of knowledge we immortalize in formal learning is inevitably influenced by our Western colonial heritage,” says Lucy Rycroft-Smith, editor and developer of Cambridge Mathematics.
Rycroft-Smith, a former math teacher, is now a leading voice in math education and studies the differences between global curricula.
While Wales, Scotland, and Ireland do not include Roman numerals in their learning goals, and the US has no standard requirements, England explicitly states that students must be able to read Roman numerals up to 100.
Many of us won’t find anything special in the MMXX figure (that’s 2020, if you don’t know).
We can vaguely recognize Fibonacci by the famous pattern that bears its name: a recursive sequence that begins with 1 and is thereafter the sum of the two previous numbers.
The Fibonacci sequence is certainly remarkable, appearing with astonishing frequency in the natural world: in seashells and plant tendrils, in the spirals of sunflower heads, in cones, animal horns and the arrangement of leaf buds on a stem, as well as in the digital realm (in computing and sequencing).
Their patterns often make their way into popular culture as well: in literature, film, and the visual arts; as a chorus in song lyrics or orchestral scores; even in architecture.
But Leonardo da Pisa’s most enduring mathematical contribution is something that is rarely taught in schools.
That story begins in a palace library nearly a thousand years ago, at a time when most of Western Christendom was in intellectual obscurity.
It is a story that should dismantle our Eurocentric view of mathematics, highlight the scientific achievements of the Islamic world, and defend the continuing importance of long-ago numerical treasures.
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Digsmak is a news publisher with over 12 years of reporting experiance; and have published in many industry leading publications and news sites.