The Life of al-Khwarizmi

Jun 11, 2020

There have been so many crucial advances in science over the past centuries. Everything from relativity and quantum mechanics to computing and space travel wouldn't have been possible without the mathematization of science and the development of algebra.

The word algebra can be traced back to the Arabic word al-jabr, which first appeared in the title of a manuscript written around 820l. That period also called the golden age of science because the scholars in the Islamic world showed a lot of applications of mathematics to science between the 9th and 14th centuries.

In this blog post, we will look at how the mathematical underpinnings of science apply today and trace their roots back to that golden age.

Our modern methods for solving mathematical problems involving Algebraic equations go back to the golden age. Everything started with the beautiful book al-Kitāb al-mukhtaṣar fī ḥisāb al-jabr, which translates as the compendious book on calculation by completion and balancing. The 9th-century Persian mathematician al-Khwarizmi is the author of the book.

al-Khwarizmi was just one of the many scholars who flourished in the 9th century. He spent his academic life in Baghdad, which was the center of learning at his time. The Abbasid rulers in Baghdad were generous patrons promoting knowledge and scholarship. They were instrumental in popularising science throughout the Islamic world. They had a deep interest in astronomy, medicine, and mathematics. In Baghdad, there was a famous Bayt al-Ḥikmah or the House of Wisdom. It was an extensive library, where scholars gathered to translate and write books—all sorts of scholars of religions working together in that one great movement. The translation was central to the early work of the House of Wisdom. For instance, those scholars were the ones who translated Euclid's book, the Elements. After that, Baghdad quickly became the most excellent center of knowledge of the medieval world.

Our history books tell us, the father of Algebra, Muhammad ibn Musa al-Khwarizmi was the one who introduced us to the "zero" in a perfectly simple way. When al-Khwarizmi was explaining zero to humanity for the first time in history, he stated that "If we subtract eight from the other eight, there will be no numbers appearing. So a little circle should be used to represent nothingness." He called that circle "ṣifr."

Moreover, al-Khwarizmi studied mathematics and geometry to apply his knowledge to the world. But first, the Abbasids had an enormous Empire, and they need to measure things or do some tax stuff. Also, shop owners and merchants were one of the most fundamental aspects of mathematics. They needed to know how to write numbers down.

At the beginning of the golden age, there were several systems in use, such as Arabic letters and Roman numerals. But al-Khwarizmi created a different number system which was going to the number system we use today, the decimal system. It is called the Hindu-Arabic numeral system. We add Hindu because it comes originally from India. Al-Khwarizmi transmitted Indians' knowledge first of the Islamic world and then for the rest of the world. Everywhere today, we use this decimal system 0-9. He made our life more comfortable.

Imagine you need to add up your bills but not using Roman numerals instead. Let's see how awkward that would be. Assume that your April bills are 42, 16, and 14. You can add these up very quickly and get 72. How about in Roman numerals? 42 would be XLII, 16 is XVI, and 14 is XIV. Then sum 72 will be LXXII, but it takes a lot longer to calculate.

In the late 12th century, the Italian mathematician Fibonacci traveled the world and came across these numbers in the Islamic empire. In 1202 he wrote his book Liber Abaci, the book of calculation, in which he promoted the use of the Hindu-Arabic numeral system over the Roman numerals - describing its many benefits for both merchants and mathematicians. However, uptake of the system was slow in Europe. In Florence, in 1299, they ban these numerals on the pretext that they were easier to falsify them Roman numerals. Fortunately, six hundred years after it was introduced to the Islamic world, common sense prevailed, and the numeral system was adopted throughout Europe eventually.

On the other hand, al-Khwarizmi wasn't the first man to solve the quadratic equations. Still, he was undoubtedly the first mathematician to provide the general method and the recipe for solving them. That's why he deserves to be called the father of algebra. Besides, the term algebra comes from the word al-jabr in the title of his book. What's most remarkable about this mathematical textbook none of his equations in it because al-Khwarizmi wrote his whole book in words alone.

al-Khwarizmi's book contains many practical everyday problems of the time, such as dividing up lands, paying laborers, or splitting up the inheritance. People in business and traders would have found the equations particularly helpful.

After many years, we still find algebra very useful! For instance, aviation is one of the most remarkable achievements of modern science. We've needed to master the mathematics of flights to be sure that the planes we build stay in the sky.

Algebra is a great way to be able to understand more than most of the mathematics involved in aviation in flying. It may sound awkward, but if you have a mathematics background and you dig into the equations of aviation, you will grasp the science of how to fly an airplane and understand the dynamics of what's going on in the aircraft. The mathematics that we are talking for this example is something called a quadratic equation where the unknown quantity x times itself. The quadratic equation of aviation, L = Cl * A * .5 * r * V^2, tells us how much lift an airplane can generate and how fast it needs to fly. It is the basis of all aviation.

The quadratic equation of aviation is not as complicated as many people might think. If we think about the lift equation, it looks complicated with lots of symbols. However, if you use some brackets, the lift equation says that lift is equal to some number times the square of the velocity. In other words, if you go twice as fast, you will get four times as much lift. That's why aerobatic airplanes are powerful. They need to fly fast to do those precise maneuvers. For instance, to roll the airplane, if you double the speed, you will roll four times as fast.

Let's give another example. Andy Green is a world record holder pilot. In 1997 he became the first and only driver to travel on land faster than the speed of sound officially. It is still the longest standing record in history, and up till this point, nobody has broken it. These days, they are building a new bloodhound supersonic to go a lot faster.

The Bloodhound has been designed using the latest engineering techniques and sophisticated computer modeling to create such an advanced vehicle. The Bloodhound engineers have solved thousands of equations. The crew is going to delimit the modern technology and make the speed 1600 kilometers an hour, which is 40% faster than the speed of sound. When traveling that fast, the equations deal with drag the force of resistance, and the car needs to overcome it to reach a thousand six hundred kilometers an hour.

To create such an advanced high-speed vehicle as well as quadratics, the Bloodhound engineers also needed to solve many other types of equations that al-Khwarizmi introduced to the world 1300 years ago.

Algebraic equations were something very complicated for the people at the time. al-Khwarizmi showed the recipe for carrying out fundamental calculations that would have been used in everyday life.

Developments in mathematics weren't the only legacy of the Golden Age. The translation movement had introduced scholars to a wide range of subjects. They made advances in fields as diverse as medicine and astronomy. They took mathematics, and they developed and applied it to optics, engineering, chemistry, biology, and physics. Science is no longer just a philosophical pursuit. The mathematization of science paved the way to a multitude of scientific advances.