A Little History Of Science: Science in Islam
Galen did not live to see the decline of the Roman Empire, but by ad 307 it had been split in two. The new emperor, Constantine (280–337), moved his seat of power to the east – to Constantinople, now Istanbul in modern Turkey. There he would be nearer to the eastern part of the Empire, lands that we now call the Middle East. The learning and wisdom contained in the Greek and Latin manuscripts, as well as the scholars who were able to study them, began to move eastwards.
A new religion arose in the Middle East: Islam, which followed the teachings of the great prophet Muhammad (570–632). Islam would come to dominate most of the Middle East and North Africa, and even as far as Spain and East Asia, but in the two centuries after Muhammad’s death, the new religion was largely confined to Baghdad and other settlements in the area. All Muslim scholars studied the Qur’an, the central religious text of Islam. Yet many of them were also interested in the many manuscripts that had been brought there after Rome was attacked in 455. A ‘House of Wisdom’ was established in Baghdad, which encouraged ambitious young men to join in the translation and study of these old manuscripts.
Many of the old manuscripts were still in the original Greek or Latin, but others had already been translated into Middle Eastern languages. The works of Aristotle, Euclid, Galen and other thinkers of ancient Greece were all translated – a very good thing too, as some of the original versions have since disappeared. Without Islamic scholars, we wouldn’t know half as much as we do about our scientific ancestors. And more than that: it was their translations that formed the foundation of European science and philosophy after about 1100.
Islamic science straddled East and West, just as the Muslim lands did. Aristotle and Galen were just as admired in Islamic lands as they were in Europe; Aristotle made his way into Islamic philosophy, and Galen became the master of medical theory and practice. Meanwhile, ideas from India and China were introduced to the West. Paper from China made it much easier to produce manuscripts, though they still had to be copied by hand, and mistakes were common. From India came the numerals 1 to 9, the idea of 0, and place-holding, all invented by Indian mathematicians. Europeans could do calculations using Roman numerals, such as I, II and III, but it was difficult, even if that was what they were used to. It’s simpler to use 4 × 12 than IV × XII, isn’t it? When Europeans translated Islamic works into Latin, they called these numerals ‘Arabic’ – strictly speaking, they should have said ‘Indian- Arabic’, but what a mouthful! The word ‘algebra’ actually comes from the term aljabr, in the title of a widely-translated book by a ninth-century Arab mathematician.
Islamic scholars made many significant discoveries and observations. If you have ever climbed up a mountain, or gone to a country that is high above sea level, you might know that breathing is more difficult because the air is thinner. But how high would you have to go before you couldn’t breathe any more? In other words, how high is the atmosphere, the band of breathable air that surrounds the globe? Ibn Mu’adh, in the eleventh century, hit upon a smart way of finding out. He reasoned that twilight – that is, when the sun has set, but the sky is still light – happens because the sun’s dying rays are being reflected by water vapour high in the atmosphere. (Many Islamic scholars were interested in such tricks of the light.) Observing how fast the sun had disappeared from the evening sky, he worked out that the sun at twilight was 19 degrees below the horizon. From there, he calculated that the height of the atmosphere was fifty-two miles – not so far off the height of sixty-two miles we now think is correct. Simple, but very impressive.
Other Islamic scholars investigated the reflection of light in a mirror, or the strange effect of light passing through water. (Put a pencil in a half-filled glass of water: it looks bent, doesn’t it?) Most Greek philosophers had assumed that seeing something involved light coming out of the eye, hitting the object that was being viewed, and bouncing back. Islamic scientists mostly favoured the more modern view, that the eye receives light from the things we see, which the brain then interprets. Otherwise, as they pointed out, how is it that we can’t see in the dark?
Many in the Middle East did see in the dark: their astronomers looked at the stars, and their charts and tables of the night skies were better than those of Western astronomers. They still thought that the earth was the centre of the universe, but two Islamic astronomers, al-Tusi in Persia and Ibn al-Shatir in Syria produced diagrams and some calculations that were important to the Polish astronomer Copernicus 300 years later.
Medicine, more than any other Islamic science, had the greatest impact on European thinking. Hippocrates, Galen and the other Greek doctors were lovingly translated and commented on, but several Islamic doctors also made names for themselves. Rhazes (c. 854–c. 925), as he is known in the West, wrote important works in several subjects besides medicine; he also left an accurate description of smallpox, a much-feared disease, which often killed its victims and scarred those who survived. Rhazes distinguished smallpox from measles, which is still a disease that children and some adults catch. Like smallpox, measles produces a rash and fever. Smallpox is now happily extinct, the result of an international campaign to protect people by vaccination, led by the World Health Organization (WHO). The last case occurred in 1977: Rhazes would have been pleased.
Avicenna (980–1037) was the most influential Islamic doctor.
Like many other eminent Islamic scholars, he was busy in many fields: not just medicine, but also philosophy, mathematics and physics. As a scientist, Avicenna developed Aristotle’s views on light, and corrected Galen on a number of points. His Canon of Medicine was one of the first books in Arabic that was translated into Latin, and it was used as a textbook in European medical schools for almost 400 years. It is still used in some modern Islamic countries, which is unfortunate, since it is sadly out of date now.
For more than 300 years, the most important scientific and philosophical work was done in Islamic countries. While Europe slept, the Middle East (and Islamic Spain) was busy. The most important places were Baghdad, Damascus, Cairo, and Cordoba (in Spain). These cities all shared one characteristic: enlightened rulers who valued and even funded research, and were tolerant of scholars of all faiths. Thus, Christians and Jews as well as Muslims contributed to this movement. Not all Islamic rulers were happy for knowledge to be gained from whatever source; some held that the Qur’an contained everything a person needed to know. These tensions continue today. Science has always been strongest in cultures that are open to the new, since finding out about the world can produce surprises.