https://susainc.orgSept. 10, 2020–
By: Nazila Fathi
Let’s begin the school year with a question: where does x, the go-to symbol for the unknown quantity in mathematical equations, come from?
We know that algebra was born in the Middle East during the Golden Age of medieval Islamic civilization. Its roots can be traced to the work of Muhammad Kharazmi, or Al-Khwarizmi as Arabs refer to him, and his 9th-century book, Kitab al-jabr wal-muqabala, or al-jabr later morphing into algebra in English.
Kharazmi was a Persian mathematician, astronomer, astrologer geographer and a scholar in the House of Wisdom in Baghdad. He was born in Persia of that time around 780 AD and was one of the most prominent scholars of his era.
Kharazmi wrote in Persian and Arabic, using the Arabic script, none of which have a single letter that is even close to x.
So, what is the origin of x?
The Ancient Roots of Algebra
Although Kharazmi is known as the father of algebra, he was not the only person who invented algebra. Many people at different times and in different places discovered and developed it.
Babylon and Egypt are the two places that were at the center of the development of algebra in the ancient world. Both of these civilizations used algebra in different ways and for different reasons. There is evidence that Babylonians first made basic use of algebra and pioneered its beginnings in the field of mathematics as early as 1900 to 1600 BC. The tablet known as the Plimpton 322 displays pythagorean triples and other forms of mathematics. The Babylonians used algebra to work out the area of items and the interest on loans, among other things. It had a real use and purpose.
We also know Euclid, a Greek mathematician who flourished in Alexandria, Egypt, around 300 BC, contributed to algebra. The great 7th-century Indian mathematician and astronomer Brahmagupta wrote some important works on both mathematics and astronomy as well.
In other words, algebraic ideas were discovered multiple times by different people. In ancient times, the news did not travel as fast it does in modern times. Therefore, it was natural for people to discover new ideas in different parts of the world without knowing that those same ideas had been developed by people in other regions.
The House of Wisdom
When the Arabs conquered Persia, the country we call Iran today, they banned the depiction of the human face, figures or any kind of animate beings. The idea stemmed in part from the prohibition of idolatry and from the belief that the creation of living forms is God’s prerogative. So, during their rule, from 750 to 1258 AD, artists focused on geometric patterns. Islamic craftsmen turned geometry into an art form because pictures of people were not allowed in holy places.
The geometric designs in Islamic art are often complex and sophisticated, which indicates their creators had knowledge of geometry, numbers and math. Those designs are still used in Persian carpets and kilims and other forms of arts around the Muslim world.
In 762, the Abbasid Caliph al-Mansur moved his capital to Baghdad. Later, the Caliph al-Ma’mun (813-833) established the House of Wisdom, or the Grand Library of Baghdad, which became a major public academy and intellectual center. Through the 9th and 10th centuries, it acted as a center for the great translation program of knowledge that scholars had accumulated and built on through their own discoveries. Al-Hajjaj translated Euclid into Arabic later in this century. Indian scholars brought Brahmagupta’s astronomical works where they translated them into Arabic. The work of Greek scholar, Diophantus, was also translated and Baghdad became a center for learning, attracting many scholars from the known world.
It is fair to say that Kharazmi took advantage of the works that had been translated into Arabic at the House of Wisdom and wrote his book on algebra. He was probably the first among a number of scholars who showed how the geometrical constructions of Euclid and the arithmetical heritage from Diophantus’ Arithmetica, and the ideas from the Middle East and Indian scholars could make sense together. He blended the ideas and defined clearly the classes of problems to be solved.
Let’s go back to the question of x. At the House of Wisdom, Kharazmi and other mathematicians referred to the unknown quantity as shay, meaning the thing in Arabic.
But when Kharazmi’s book was translated into Latin in the 12th century, shay was translated into Greek as xei. Old Spanish had “sh” sound routinely spelled with x, which later evolved to a sound at the back of the throat. Gradually, xei was shortened to x and so the unknown became x as we know it today.
In fact, ‘algorithm’ is taken from the Latin version of Kharazmi’s name too. When his book was translated into Latin some 300 years after his death, his name was Latinized and became Algoritmi, which shows just how important his influence on mathematics was.
How did Algebra Shape the Modern World?
Today, algebra is used extensively in engineering and construction planning to ensure that buildings, bridges, airplanes, and more are built safely and correctly. In the financial sector, algebra is used in predicting risks and in assessing economic impacts.
Algebra has been crucial to the development of science and the way we live today. None of the great achievements of modern science would be possible without the development of algebra. Google, the internet, mobile phones, computer games wouldn’t exist without algebra and algorithms.
iPhones, iPads or digital televisions would never be invented without it.
Algebra is essential and students learn it in high school. It helps develop the brain.
When my kids ask how algebra will help them in life, I tell them that it trains their mind to think logically. Algebra and math teach them to break down and solve problems. They might reach a point where they don’t use algebra on a daily basis. But their brain will have been trained to think in a logical way, which will not only help them in the workplace, but also in daily life, when buying something, negotiating with someone, or having to address a complex problem.
