18 - 09
Earlier this month, there was this exchange between two German politicians:
“Mr. Best…I find it alarming that in Volkingen many house numbers are displayed in Arabic numerals. How would you like to take action against this creeping foreigner infiltration?”
To which Mr. Otfried replied:
“You just wait until I am mayor. I will change that. Then there will be normal numbers.”
The joke was on Mr. Best, seeing as what he calls ‘normal numbers’ are what are actually known as Arabic numbers.
They are so-called because the numbers 0-9 came to Western civilization via a 12th Century Latin translation of the work of Muhammad ibn Musa al-Khwarizmi (circa 780-850 A.D.), feted worldwide as the Father of Algebra.
To be true to the origins of these numbers, they are called Hindu-Arabic numerals; the numbers, and especially the zero as a placeholder, are a much older Indian invention. Al-Khwarizmi’s translated treatise, Algoritmi de numero Indorum (On the Calculation with Hindu Numerals), acknowledges as much. ‘Algorithm’ is derived from this title, and that’s why he’s also called the Grandfather of Computer Science: the humble Hindu zero that his book introduced to the West is one of the two characters used in computer binaries (0,1).
But Muhammad Al-Khwarizmi did more than just revise and improve much older texts; he served as the director of the House of Knowledge in the Baghdad, then the capital of the Abbasid Caliphate, and from his position introduced numerous original works on mathematics, astronomy, astrology, and geography.
He is known as the father of algebra for his al-Kitab al-mukhtasar fi hisab al-jabr wa’l-muqabala (The Compendious Book on Calculation by Completion and Balancing).
His treatise is almost patronizingly elementary, but it is this simplicity that helped reveal the fundamental principles of solving algebraic challenges, including quadratic equations: if you have solved any equation by moving a negative value across the equals sign (=) so that it becomes an easier-to-deal-with positive value (‘completion’), or reducing it to its simplest form, then you have al-Khwarizmi to thank for establishing these principles in 830 AD.
With these two books, he staked his claim as a mathematician, and with a third, he established himself in Geography.
His Kitab surat al-Ard (the Image of the Earth) built upon Ptolemy’s Geography, vastly improved the book, providing a map of the known world and the coordinates of 2402 towns and geographical landmarks.