Read an Excerpt
A LITTLE HISTORY OF SCIENCE
By WILLIAM BYNUM
YALE UNIVERSITY PRESS
Copyright © 2012 William Bynum
All right reserved.
ISBN: 978-0-300-13659-3
Chapter One
In the Beginning
Science is special. It's the best way we have of finding out about the world and everything in it – and that includes us.
People have been asking questions about what they have seen around them for thousands of years. The answers they have come up with have changed a lot. So has science itself. Science is dynamic, building upon the ideas and discoveries which one generation passes on to the next, as well as making huge leaps forward when completely new discoveries are made. What hasn't changed is the curiosity, imagination and intelligence of those doing science. We might know more today, but people who thought deeply about their world 3,000 years ago were just as smart as we are.
This book isn't only about microscopes and test tubes in laboratories, although that is what most people think of when they think of science. For most of human history, science has been used alongside magic, religion and technology to try to understand and control the world. Science might be something as simple as observing the sun rise each morning, or as complicated as identifying a new chemical element. Magic could be looking at the stars to foretell the future, or maybe what we would call a superstition, like keeping out of the path of a black cat. Religion might lead you to sacrifice an animal to appease the gods, or to pray for world peace. Technology might involve knowing how to light a fire or build a new computer.
Science, magic, religion and technology were used by the earliest human societies that settled in river valleys across India, China and the Middle East. The river valleys were fertile, which allowed crops to be planted each year, enough to feed a large community. This allowed some people in these communities enough time to focus on one thing, to practise and practise, and become expert at it. The first 'scientists' (though they wouldn't have been called that at the time) were probably priests.
In the beginning, technology (which is about 'doing') was more important than science (which is about 'knowing'). You need to know what to do, and how to do it, before you can successfully grow your crops, make your clothes, or cook your food. You don't need to know why some berries are poisonous, or some plants edible, to learn how to avoid the one and grow the other. You don't have to have a reason why the sun rises each morning and sets each evening, for these things to happen, each and every day. But human beings are not only able to learn things about the world around them, they are also curious, and that curiosity lies at the heart of science.
We know more about the people of Babylon (in present-day Iraq) than we do about other ancient civilisations, for a simple reason: they wrote on clay tablets. Thousands of these tablets, written almost 6,000 years ago, have survived. They tell us how the Babylonians viewed their world. They were extremely organised, keeping careful records of their harvests, stores, and state finances. The priests spent much of their time looking after the facts and figures of ancient life. They were also the main 'scientists', surveying land, measuring distances, viewing the sky, and developing techniques for counting. We still use some of their discoveries today. Like us, they used tally marks to keep count; this is when you make four vertical marks and cross through these diagonally with a fifth, which you might have seen in cartoons of a prison cell, made by the prisoners keeping count of how many years they have been locked up. Far more importantly, it was the Babylonians who said there should be sixty seconds in a minute and sixty minutes in an hour, as well as 360 degrees in a circle and seven days in the week. It is funny to think that there is no real reason why sixty seconds make a minute, and seven days make a week. Other numbers would have worked just as well. But the Babylonian system got picked up elsewhere and it has stuck.
The Babylonians were good at astronomy – that is, examining the heavens. Over many years they began to recognise patterns in the positions of stars and planets in the sky at night. They believed that the earth was at the centre of things, and that there were powerful – magical – connections between us and the stars. As long as people believed that the earth was the centre of the universe, they didn't count it as a planet. They divided the night sky into twelve parts, and gave each part a name associated with certain groups (or 'constellations') of stars. Through a heavenly game of Join-the-dots, the Babylonians saw pictures of objects and animals in some constellations, such as a set of scales and a scorpion. This was the first Zodiac, the basis of astrology, which is the study of the influence of the stars upon us. Astrology and astronomy were closely linked in ancient Babylon and for many centuries afterwards. Many people today know which sign of the Zodiac they were born under (I am a Taurus, the bull) and read their horoscopes in newspapers and magazines for advice about their lives. But astrology is not part of modern science.
The Babylonians were only one of several powerful groups in the ancient Middle East. We know most about the Egyptians, who settled along the River Nile as early as 3,500 BC. No civilisation before or since was so dependent on a single natural feature. The Egyptians relied on the Nile for their very existence, for every year as the mighty river flooded it brought rich silt to replenish the land around its banks, and so prepare it for the next year's crops. Egypt is very hot and dry, so a lot of things have survived for us to admire and learn from today, including many pictures, and a kind of pictorial writing, called hieroglyphics. After Egypt was conquered first by the Greeks and then by the Romans, the ability to read and write hieroglyphs disappeared, and so for almost 2,000 years the meaning of their writing was lost. Then, in 1798, a French soldier found a round tablet in a pile of old rubble in a little town near Rosetta, in the north of Egypt. It had a proclamation written in three languages: hieroglyphics, Greek, and an even older form of Egyptian writing called demotics. The Rosetta Stone came to London, where you can see it today in the British Museum. What a breakthrough! Scholars could read the Greek and therefore translate the hieroglyphs, decoding the mysterious Egyptian writing. Now we could really begin to learn about the ancient Egyptians' beliefs and practices.
Egyptian astronomy was similar to the Babylonians', but Egyptian concern with the afterlife meant that they were more practical in their stargazing. The calendar was very important, not only to tell them when it was the best time to plant, or when to expect the Nile to flood, but also to plan religious festivals. Their 'natural' year was 360 days – that is, twelve months made up of three weeks lasting ten days each – and they added an extra five days at the end of the year to keep the seasons from slipping. The Egyptians thought that the universe was shaped like a rectangular box, with their world at the base of the box, and the Nile flowing exactly through the centre of that world. The beginning of their year coincided with the flooding of the Nile, and they eventually linked it with the nightly rising of the brightest star in the night sky, which we call Sirius.
As in Babylon, the priests were important in the courts of the Pharaohs, the Egyptian rulers. The Pharaohs were considered to be divine, and able to enjoy a life after death. This is one reason why they constructed the pyramids, which are really gigantic funeral monuments. Pharaohs, their relatives and other important people, along with servants, dogs, cats, furniture and food supplies, were placed in these massive structures to await new life in the next world. To preserve the bodies of important people (after all, it wouldn't do to turn up in the afterlife rotten and stinking) the Egyptians developed ways of embalming the dead. This meant first of all removing the internal organs (they had a long hook for scooping out the brain through the nostrils) and placing them in special jars. Chemicals were used to preserve the rest of the body, which was then wrapped in linen and put in its final resting place in its tomb.
Embalmers would have had a pretty good idea of what the heart, lungs, liver and kidneys looked like. Unfortunately, they did not describe the organs that they removed, so we don't know what they thought the organs did. However, other medical papyri have survived, and these do tell us about Egyptian medicine and surgery. As was common at the time, the Egyptians believed a mix of religious, magical and natural things caused diseases. Healers would have recited spells while giving their remedies to patients. But many of the cures invented by the Egyptians do seem to have come from careful observation of illnesses. Some of the medicines they put on dressings for wounds after injury or surgery might well have kept the wound free from germs and so aided healing. This was thousands of years before we even knew what germs were.
At this stage of history, counting, astronomy and medicine were the three most obvious 'scientific' fields of activity. Counting, because you need to know 'how many' before you can plant enough crops and trade with other people, or to see if you have enough soldiers or pyramid builders at your disposal. Astronomy, because the sun, moon and stars are so closely related to the days, months and seasons, that carefully noting their positions is fundamental for calendars. Medicine, because when people fall sick or are injured, they naturally seek help. But in each of these cases, magic, religion, technology and science were mixed, and for these ancient Middle Eastern civilisations, we have to guess a lot about why people did what they did, or how ordinary people went about their daily lives. Ordinary people are always difficult to know about, since it was mostly powerful people, who could read and write, who have left the records of history. This was also true in two other ancient civilisations that started at about the same time, but in faraway Asia: China and India.
Chapter Two
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, everything 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 3651/4 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.
(Continues...)
Excerpted from A LITTLE HISTORY OF SCIENCE by WILLIAM BYNUM Copyright © 2012 by William Bynum. Excerpted by permission of YALE UNIVERSITY PRESS. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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