A Little History Of Science: Needles and Numbers
Keep on travelling eastwards from Babylon and Egypt and you’ll find lands where ancient civilisations flourished on either side of the rocky Himalayas, in India and China. Some 5,000 years ago people were living there in towns and cities ranged along the Indus and Yellow River valleys. In those days, India and China were both immense territories, even larger than they are today. Both were part of vast overland and overseas trading networks – channelled along the spice routes – and their people had developed writing and science to a high level. The one helped the other: science benefited trade, and the wealth from trade allowed the luxury of study. In fact until about 1500, science in each of these civilisations was at least as advanced as in Europe. India gave us our numbers and a love of mathematics. From China came paper and gunpowder and that indispensible gadget for navigation: the compass.
Today, China is a major force in the world. Things like clothes, toys and electronic goods made there are sold all over the globe: check the label in your trainers. For centuries, however, people in the West looked at this vast country with amusement or suspicion. The Chinese did things their way; their country seemed both mysterious and unchanging.
We now know that China was always a dynamic country, and that its science too was constantly changing. But one thing remained unchanged there over the centuries: writing. Chinese writing is made up of ideographs, little pictures that represent objects, which look strange to alphabet users like us. But if you know how to interpret the little pictures, it means you can read old – very old – Chinese texts as easily as you can read more recent writings. In fact, we have China to thank for the invention of paper, which made writing much easier. The oldest example we know about dates from about ad 150.
Ruling China was never easy, but science could help. Perhaps the greatest-ever engineering project, the Great Wall of China, was begun during the fifth century bc, during the Eastern Zhou Dynasty. (Chinese history is divided into dynasties, associated with powerful rulers and their courts.) The Wall was meant to keep the barbarians from the north out, as well as to keep the Chinese in! It took centuries to complete, being constantly extended and repaired, and now runs for 5,500 miles. (For some years people thought the Wall could be seen from space, but it’s not true: China’s own astronaut failed to spot the structure.) Another remarkable engineering feat, the Grand Canal, was started under the Sui Dynasty, in the fifth century. Making use of some natural waterways en route, the thousand-mile Canal connected the large inland city of Beijing in the north with Hangzhou on the southern coast, and from there to the outside world. These monuments are powerful reminders of the skills of Chinese surveyors and engineers, but also of the tremendous amount of hard human labour their construction needed. The Chinese had invented the wheelbarrow, but labourers still had to dig, push and build.
The Chinese viewed the universe as a kind of living organism, in which forces connected everything. The fundamental force, or energy, was called Qi (pronounced Chee). Two other basic forces were yin and yang: yin, the female principle, was associated with darkness, clouds and moisture; yang, the male principle, with ideas of sunshine, heat and warmth. Things are never either all yin or all yang – the two forces are always combined in various degrees. According to Chinese philosophy, each of us has some yin and some yang, and the exact combination affects who we are and how we behave.
The Chinese believed that the universe was made up of five elements: water, metal, wood, fire and earth. These elements were not simply the ordinary water or fire that we see around us, but principles that went together to compose the world and the heavens. Each had different characteristics, of course, but also interlocking powers, much like Transformer toys. For example, wood could overcome earth (a wooden spade can dig it); metal could chisel wood; fire could melt metal; water could extinguish fire; and earth could dam water. (Think of the game Paper, Scissors, Stone, actually invented in China.) These elements, combined with the forces of yin and yang, produce the cyclical rhythms of time and nature, the seasons, cycles of birth and death, and the movements of the sun, stars and planets.
Since everything is made up of these elements and forces, every- thing is in some sense alive and joined. So a notion of the ‘atom’ as a basic unit of matter never developed in China. Nor did natural philosophers there think that they had to express everything with numbers in order for it to be ‘scientific’. Arithmetic was very practical: doing your sums when you were buying and selling, weighing goods, and so on. The abacus, a device with sliding beads on wires that you might have learned to count on, was written about in the late 1500s. It was probably invented earlier. An abacus speeds up counting, as well as addition, subtraction, multiplication and division.
Numbers were also used to calculate the length of the days and years. As early as 1400 bc, the Chinese knew that the year is 365 1/4 days long, and, like most early civilisations, they used the moon to calculate the months. As with all ancient peoples, the Chinese measured a year as being the length of time it took for the sun to return to its starting point in the sky. The cycles in the movements of planets like Jupiter, and of the stars, fit nicely into the idea that everything in nature is cyclical. The ‘Supreme Ultimate Grand Origin’ was an immense calculation to find out how long it would take for the whole universe to make a complete cycle: 23,639,040 years. This meant that the universe was very old (though we now know it is much older). The Chinese also thought about how the universe was structured. Some of the early Chinese star maps show that they understood how to represent, on a two- dimensional map, things that exist in a curved space. Xuan Le, who lived in the later Han Dynasty (ad 25–220), believed that the sun, moon and stars floated in empty space, driven by the winds. This was very different to the ancient Greek belief that these heavenly bodies were fixed in solid spheres, and is much more like how we understand space today. Stargazers in China recorded unusual events very carefully, so their records, since they go back so far, are still useful to modern astronomers.
Since the Chinese believed that the earth was very old, they had no difficulty recognising fossils as the hardened remains of plants and animals that had once been alive. Stones were grouped according to such things as hardness and colour. Jade was espe- cially prized, and craftsmen carved pieces of jade into beautiful statues. Earthquakes are common in China, and although no one could explain why they occur, in the second century ad, a very learned man called Zhang Heng used a hanging weight that swayed when the earth shook, to record the earth’s tremors.
This was a very early version of what we call a seismograph, a machine which draws a straight line until the earth moves, when it wiggles.
Magnetism was understood for practical purposes. The Chinese learned how to magnetise iron by heating it to a high temperature and letting it cool while it was pointing in a north–south direction. China had compasses long before they were known in the West, and they were used both for navigation and for fortune telling. Most commonly, they were ‘wet’: just a magnetised needle floating in a bowl of water. We are used to saying that compass needles point north, but for the Chinese they pointed south. (Of course our compasses point south too – just with the opposite end of the needle. It doesn’t really matter which direction you choose, as long as everyone agrees on it.)
The Chinese were skilled chemists. Many of the best were Taoists, members of a religious group who followed Lau Tsu, who lived some time between the sixth and the fourth century bc. (Tao means ‘Way’ or ‘Path’.) Others followed Confucius or the Buddha. The philosophies of these religious leaders influenced the attitudes of their followers towards the study of the universe. Religion has always influenced how people view their surroundings.
The chemistry that the Chinese were able to perform was quite sophisticated for their time. For instance, they could distil alcohol and other substances, and could extract copper from solutions. By blending charcoal, sulphur and potassium nitrate, they made gunpowder. This was the first chemical explosive and the spring- board for the invention of both fireworks and weapons. You could say gunpowder showed the yin and yang of the chemical world: it exploded prettily in tremendous firework displays at court while also being used to fire guns and cannons on eastern battlefields as early as the tenth century. It is not certain exactly how the recipe and instructions for making this powerful substance arrived in Europe, but there is a description of it there in the 1280s. It gradually made war everywhere more deadly.
The Chinese also had alchemists, who sought the ‘elixir of life’: some substance that would increase how long we can live, or maybe even make us immortal. They failed to find it, and in fact several emperors would have lived longer had they not taken these experimental, poisonous ‘cures’. However, searching for this magical substance revealed many drugs that could be used to treat ordinary diseases. As in Europe, Chinese doctors used extracts of plants to treat diseases, but they also made compounds from sulphur, mercury and other substances. The Artemisia plant was used to treat fevers. It was made into an extract and burnt on the skin at specific points to aid the flow of the ‘vital juices’. The recipe and method were recently discovered in a book about drugs written around 1,800 years ago. Tested in a modern laboratory, it was found to be effective against malaria, a leading cause of death today in tropical countries. One of the symptoms of malaria is a high fever.
Medical books began to be written in China as early as the second century bc, and ancient Chinese medicine lives on throughout the world today. Acupuncture, which involves sticking needles into certain areas of the skin, is widely practised to help cure disease, deal with stress, and ease pain. It is based on the idea that the body has a series of channels through which the Qi energy flows, and so the acupuncturist uses the needles to stimulate or unblock these channels. Sometimes operations are carried out with little more than the needles inserted into the patient’s body to block out the pain. Modern Chinese scientists work just like their colleagues in the West, but Traditional Chinese Medicine (TCM) still has many followers all over the world.
So does traditional Indian medicine. It is called Ayurveda, and is based on works known by this name written in the ancient language, Sanskrit, between about 200 bc and ad 600. Ayurveda taught that there are fluids in the body, called doshas. There were three of these: vata is dry, cold and light; pitta is hot, sour and pungent; and kapha is cold, heavy and sweet. These doshas are necessary for the proper functioning of our bodies, and when there is too much or too little of one or more of them, or when they are in the wrong place, disease occurs. Inspecting the patient’s skin, and feeling the pulse, were also very important as the Indian doctor tried to decide what the disease was. Drugs, massage and special diets could correct the imbalance. Indian doctors used the juice from the poppy, which produces the drug opium, to calm their patients and relieve their pain.
One other ancient Indian medical work, the Susruta, concentrated on surgery. Some of the operations it describes are remark- ably delicate for this early period. For example, when a patient suffered from a cataract (a clouding in the lens of the eye which makes it hard to see) the surgeon would gently stick a needle into the eyeball and push the cataract to one side. Indian surgeons also used flaps of the patient’s own skin to repair damaged noses, probably the earliest instance of what we call plastic surgery.
This Ayurvedic medicine was associated with Hindu practitioners. When Muslims also settled in India in about 1590, they brought their own medical ideas, based on ancient Greek medicine interpreted by early Islamic doctors. This medicine, called Yunani (which means ‘Greek’), developed side by side with the Ayurvedic system. Both continue to be used in India today alongside the medicine we are all familiar with – Western medicine.
India had its own scientific traditions. Stargazers in India made sense of the heavens, the stars, sun and moon by drawing on the work of the Greek astronomer Ptolemy, and some scientific works from China that had been brought back by Indian Buddhist missionaries. There was an observatory at Ujjain, and one of the earliest Indian scientists whose name we know, Varahamihira (c. 505), worked there. He collected old astronomical works and added his own observations. Much later, in the sixteenth century, observatories were built at Delhi and Jaipur. The Indian calendar was quite accurate, and like the Chinese, Indians believed that the earth was very old. One of their astronomical cycles was 4,320,000 years long. Indians shared in the search for an elixir that would convey long life. They also looked for a way to create gold from ordinary metals. But the most important contribution made by Indian science was in mathematics.
It is from India, via the Middle East, that we have the numbers we call ‘Arabic’: the familiar 1, 2, 3 and so forth. The idea of ‘zero’ first came from India, too. Along with the numbers we still use, Indian mathematicians also had the basic idea of ‘place-holding’. Take a number like 170. The ‘1’ = 100, it holds the ‘hundreds’ place; the ‘7’ = 70, it holds the ‘tens’ place; and the zero holds the ‘units’ place. It comes so naturally to us that we don’t even think about it, but if we didn’t have place-holding, writing large numbers would be much more complicated. The most famous ancient Indian mathematician, Brahmagutpa, who lived in the seventh century, worked out how to calculate the volumes of prisms and other figures. He was the first person to mention the number ‘0’, and knew that anything multiplied by 0 is 0. It took almost 500 years before another Indian mathematician, Bhaskara (b. 1115) pointed out that anything divided by 0 would be infinity. Modern mathematical explanations of the world would be impossible without these concepts.
Whereas traditional medical systems in India and China still compete with Western medicine, in science it’s different. Indian and Chinese scientists work with the same ideas, tools and aims as their colleagues elsewhere in the world. Whether in Asia or anywhere else, science now is a universal science, which developed in the West.
But remember that we got numbers from India, and paper from China. Write out the ‘9 times’ table, and you are using gifts that are very old, and from the East.