Getting acquainted with figures of fun

NET RESULTS: I only made it to one event during Maths Week last week, but I couldn't have asked for a more fascinating and enjoyable one: a lecture entitled From Abacus to Zenith: the Islamic mathematical legacy in early modern Europe.

Given by Dr François Charette last Thursday in the entirely appropriate setting of the Chester Beatty Library, the talk touched upon the elements I most expected - why we have words such as "algebra" and "algorithm" from the Arabs - but serendipitously veered off into wholly unexpected places, such as a lengthy discussion of astrolabes.

But even a discussion of word sources was highly informative. I had read before how "algebra" comes from the Arabic al-Jabr and that the word is used in the title of a book on the kind of balancing equations we now call algebra. But I hadn't know that the word means "restoration" or "reunion" and actually comes from the practice of bone-setting.

While I knew the word algorithm also comes to us from the Middle East, I hadn't realised it was a westernised corruption of the name of the Persian mathematician who wrote that very book on algebra, Muhammad ibn Musa al- khwarizmi. Al-khwarizmi was run together and gradually became algorithm, the term for a mathematical formula.

The book was published about 820. While Europe groped its way through the Dark Ages, science and mathematics were flourishing in the Islamic world. Dr Charette pointed out wryly that Baghdad "was a centre of culture and science around 900 - it was called 'The City of Peace'".

From the 9th to 12th centuries, the Arabs produced a roster of important mathematicians, astronomers and scientists, said Dr Charette, whose doctorate focused on a single, enigmatic Persian manuscript (simply called "Persian 102") in the Beatty collection that seems to be a guide to all the known astronomical instruments of time, nearly 150 of them.

One of those mathematician- astronomers was - another surprise to me - Omar Khayyam, better known now for his other forte, writing poetry.

His Rubaiyat of Omar Khayyam, translated in the 19th century by Edward Fitzgerald, still sells well year after year, 900 years later.

Not bad for a bit of writing whipped out in between solving cubic equations and proposing that the Earth revolved around the Sun.

The mathematical explorations of the time were driven by specific cultural needs, which makes complete sense when you think about it.

Tell that though to the average 15-year-old struggling with basic algebra - I sure could never figure out what the point of it was back then, or why it had to be inflicted on resentful teenagers.

However, that ancient Arab world had problems it wanted to solve. Many of Al-khwarizmi's theories were developed to work out complex problems related to Islamic laws on inheritance, according to Dr Charette.

Another mathematical challenge was working out the geometrical patterns so important to Islamic art and architecture. It was also important to know the time of day and to work out prayer times, which vary depending on how close to the equator one was located (because some prayer times were in part calculated by the lengths of a shadow). During prayers of course people needed to know the direction to face toward Mecca - "an interesting problem of applied trigonometry", Dr Charette said.

Just as the Arabs gathered the mathematical knowledge of prior centuries through translations of the ancient Greeks, much of the knowledge of the Islamic world was in turn transmitted to the Europeans, he said.

Evidence for this movement of information is clear through texts and detailed drawings of scientific instruments such as astrolabes, used to calculate such things as the time of day and the position of heavenly bodies.

Dr Charette argued however that there's also evidence of "hidden transmission".

For example, "Kepler's volume on mathematics is full of Arabic precedents", he says. Also, a so-called "universal astrolabe", was announced as an English invention in the 16th century, even though Arabs had been using them since the 11th century, he said.

As the talk drew to a close, one of the Beatty curators brought out the Persian 102 manuscript, as well as an exquisitely beautiful bronze Arabic astrolabe from the museum collection for the audience to see close up. I

It was a unique moment of connection to the real lives, activities and objects that make up a lived history. I don't think I'll ever view algebra in quite the same way again.

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