The name Baghdad in recent times has implications that almost everybody loves to hate. And yet it was not always so. Indeed, Baghdad was once in Paradise. In the second chapter of Genesis we are told that Eden is contained by four rivers, two of which are the Euphrates and the Tigris which run like tram-lines down the Mesopotamian valley of Iraq.
It was on one of these, the Euphrates, that there grew the ancient city of Babylon, noted for its luxury and Hanging Gardens. And on the Tigris, not too far away, there grew Baghdad.
It was in this region that the art of writing was invented, and it was from here, too, that our present system of numbers had its European origins. Numbers of one kind or another have been with us since time immemorial. Many systems of numerals, like our own, were based on the number 10, for the simple reason that humans have 10 fingers, and no doubt used them as an aid when counting first started. But the Mayans, the Aztecs and indeed the ancient Celts counted in twenties, while the Greek and Arab astronomers of old used a sexagesimal system, based on the number 60. Relics of this still remain in the way we reckon time, and in the notation that we use for latitude and longitude.
Our present system of numbers was born in southern India some 15 centuries ago. Its first adventure in this direction dates from about AD773, when a traveller from India arrived in Baghdad and explained it to the inhabitants.
Some years later, Abu Ja'far Mohammed ibn-Musa al-Khowarizmi wrote a lengthy treatise on the subject, and it was through the writings of this scholar of Baghdad that the so-called Arabic system of numerals became widely known, a system which made possible the simple arithmetical techniques we use today. The Indian arrangement had two big advantages: it incorporated both a zero and a place value system; the convention that each digit is associated with units, tens or hundreds depending on its position in a multi-digit number.
These innovations allowed calculations to be carried out in a way which was impossible with, for example, the old alphabetical system of the Romans.
Al-Khowarizmi, in addition, donated two well-known words to the language of mathematics. His original treatise was called Al-jabr w'al- muqabalah and the first word of the Arabic title later came to designate the branch of mathematics known as algebra.
And the Latin version of his surname was Algorismi, from which we get the mathematical term, algorithm.