The Danish Peace Academy
SCIENCE AND SOCIETY
Chapter 1 THE BEGINNINGS OF CIVILIZATION
Early ancestors of man
Almost three million years ago, manlike creatures lived on the shores of Lake Rudolf in Kenya. The skull of one of these early “homenoids” was found in 1972 by Richard E. Leakey. Pouring fine sand into the reconstructed skull, Dr. Leakey and his associates measured the brain capacity as 800 c.c. - considerably less than the modern brain volume of 1400 c.c., but still remarkably large considering the early date of the skull. Potassium-argon dating of the volcanic ashes in which the skull was found established its age as approximately 2.8 million years.
At the Oldavai Gorge in Tanzania, not far from Lake Rudolf, Louis and Mary Leakey (Richard Leakey’s father and mother) discovered many remains of a somewhat more advanced homenoid which they called Homo habilis. Among these remains, which were shown to be 1.8 million years old, Louis and Mary Leakey found many chipped stones, probably representing tools and weapons used by Homo habilis. The discoveries of the Leakey family, as well as those of Raymond Dart and Robert Broom, indicate that the early evolution of the human race probably took place in Africa. The early ancestors of man seem to have been hunter-gatherers living in small bands on the East African grasslands.
We catch another glimpse of early man at the Terra Amata site at Nice in Southern France, where 300,000 years ago, in a warm period between the Mindel and Riss glacial eras, a small tribe came every summer to spend a few weeks hunting and food-gathering on the shore of the Mediterranian. The huts which these early people built on their brief summer visits to the beach are among the earliest man-made dwellings ever discovered. They were between 26 and 29 feet long, and were built in an oval shape out of leafy saplings leaned against a central ridge pole. The central ridge pole in each hut was supported by vertical tree trunks embedded in the sand. Around the oval perimeter of the huts were walls of large stones for protection against the wind, and inside the huts were hearths on which small fires were built. (This is almost the earliest use of fire known, although earlier hearths have been found in strata of the Mindel ice age at Vertesz¨olos in Hungary.)
Water for the camp came from a nearby spring. The level of the Mediterranian Sea was then 85 feet higher than it is today. It covered most of the plane of Nice, and near the camp it had cut a small cove with a sandy pebble-strewn beach into the western slope of Mount Boron. On the slopes of the mountain grew heather, sea pine, Aleppo pine and holm oak. A human footprint nine and one-half inches long is preserved in the sand of the ancient dune. Evidence shows that these summer visitors of 300,000 years ago spent their time gathering shellfish, hunting and making tools. Among the animals which they hunted were stag, an extinct elephant, wild boar, ibex, rhinoceros and wild ox. They stayed at Terra Amata only a few weeks each year, and then continued their travels, following the migrations of the animals which they hunted.
The Soultrian and Magdalenian cultures
In the caves of Spain and Southern France, not far from the Terra Amata site, are the remains of vigorous hunting cultures which flourished at a much later period, between 30,000 and 10,000 years ago. The people of these upper paleolithic cultures lived on the abundant cold- weather game which roamed the southern edge of the ice sheets during the Wurm glacial period: huge herds of reindeer, horses and wild cattle, as well as mammoths and wooly rhinos. The paintings found in the Dordogne region of France, for example, combine decorative and representational elements in a manner which contemporary artists might envy. Sometimes among the paintings are stylized symbols which can be thought of as the first steps towards writing.
In this period, not only painting, but also tool-making and weaponmaking were highly-developed arts. For example, the Soultrian culture, which flourished in Spain and southern France about 20,000 years ago, produced beautifully worked stone lance points in the shape of laurel leaves and willow leaves. The appeal of these exquisitely pressure-flaked blades must have been aesthetic as well as functional. The people of the Soultrian culture had fine bone needles with eyes, bone and ivory pendants, beads and bracelets, and long bone pins with notches for arranging the hair. They also had red, yellow and black pigments for painting their bodies.
The Soultrian culture lasted for 4,000 years. It ended in about 17,000 B.C. when it was succeeded by the Magdalenian culture. Whether the Soultrian people were conquered by another migrating group of hunters, or whether they themselves developed the Magdalenian culture we do not know.
The agricultural revolution
Beginning about 9,000 B.C., the way of life of the hunters was swept aside by a great cultural revolution: the invention of agriculture. Starting in western Asia, the neolithic agricultural revolution swept westward into Europe, and eastward into the regions which are now Iran and India.
By neolithic times, farming and stock breeding were well established in the Near East. Radio-carbon dating shows that by 8,500 B.C., people living in the caves of Shanidar in the foothills of the Zagros mountains in Iran had domesticated sheep. By 7,000 B.C., the village farming community at Jarmo in Iraq had domesticated goats, together with barley and two different kinds of wheat.
At Jerico, in the Dead Sea valley, excavations have revealed a prepottery neolithic settlement surrounded by an impressive stone wall, six feet wide and twelve feet high. Radio-carbon dating shows that the defenses of the town were built about 7,000 B.C.. Probably they represent the attempts of a settled agricultural people to defend themselves from the plundering raids of less advanced nomadic tribes.
By 4,300 B.C., the agricultural revolution had spread southwest to the Nile valley, where excavations along the shore of Lake Fayum have revealed the remains of grain bins and silos. The Nile carried farming and stock-breeding techniques slowly southward, and wherever they arrived, they swept away the hunting and food-gathering cultures. By 3,200 B.C. the agricultural revolution had reached the Hyrax Hill site in Kenya. At this point the southward movement of agriculture was stopped by the great swamps at the headwaters of the Nile. Meanwhile, the Mediterranian Sea and the Danube carried the revolution westward into Europe. Between 4,500 and 2,000 B.C. it spread across Europe as far as the British Isles and Scandanavia.
Mesopotamia; the invention of writing
In Mesopotamia (which in Greek means “between the rivers”), the settled agricultural people of the Tigris and Euphraties valleys evolved a form of writing. Among the earliest Mesopotamian writings are a set of clay tablets found at Tepe Yahya in southern Iran, the site of an ancient Elamite trading community halfway between Mesopotamia and India.
The Elamite trade supplied the Sumarian civilization of Mesopotamia with silver, copper, tin, lead, precious gems, horses, timber, obsidian, alabaster and soapstone. The practical Sumerians and Elamites probably invented writing as a means of keeping accounts.
The tablets found at Tepe Yahya are inscribed in proto-Elamite, and radio-carbon dating of organic remains associated with the tablets shows them to be from about 3,600 B.C.. The inscriptions on these tablets were made by pressing the blunt and sharp ends of a stylus into soft clay. Similar tablets have been found at the Sumarian city of Susa at the head of the Tigris River.
In about 3,100 B.C. the cuneiform script was developed, and later Mesopotamian tablets are written in cuneiform, which is a phonetic script where the symbols stand for syllables.
In the imagination of the Mesopotamians (the Sumerians, Elamites, Babylonians and Assyrians), the earth was a flat disc, surrounded by a rim of mountains and floating on an ocean of sweet water. Resting on these mountains was the hemispherical vault of the sky, across which moved the stars, the planets, the sun and the moon. Under the earth was another hemisphere containing the spirits of the dead. The Mesopotamians visualized the whole spherical world-universe as being immersed like a bubble in a limitless ocean of salt water.
By contrast with their somewhat primitive cosmology, both the mathematics and astronomy of the Mesopotamians were startlingly advanced. Their number system was positional, like ours, and was based on six and sixty. We can still see traces of it in our present method of measuring angles in degrees and minutes, and also in our method of measuring time in hours, minutes and seconds.
The Mesopotamians were acquainted with square roots and cube roots, and they could solve quadratic equations. They also were aware of exponential and logarithmic relationships. They seemed to value mathematics for its own sake, for the sake of enjoyment and recreation, as much as for its practical applications. On the whole, their algebra was more advanced than their geometry. They knew some of the properties of triangles and circles, but did not prove them in a systematic way.
Although the astronomy of the Mesopotamians was motivated largely by their astrological superstitions, it was nevertheless amazingly precise. For example, in the beginning of the fourth century B.C., incredibly accurate tables of new moons, full moons and eclipses were drawn up by Nabu-rimani; and about 375 B.C. Kidinnu, the greatest of the Babylonian astronomers, gave the exact duration of the solar year with an accuracy of only 4 minutes and 32.65 seconds. (This figure was found by observing the accumulated error in the calender over a long period of time.) The error made by Kidinnu in his estimation of the motion of the sun from the node was smaller than the error made by the modern astronomer Oppolzer in 1887.
In medicine, the Mesopotamians believed that disease was a punishment inflicted by the gods on men, both for their crimes and for their errors and omissions in the performance of religious duties. They believed that the cure for disease involved magical and religious treatment, and the diseased person was thought to be morally tainted. However, in spite of this background of superstition, Mesopotamian medicine also contained some practical remedies. For example, the prescription for urinary retention was as follows: “Crush poppy seeds in beer and make the patient drink it. Grind some myrrh, mix it with oil and blow it into his urethra with a tube of bronze. Give the patient anemone crushed in alppanu-beer.”
Until recently it was believed that the Mesopotamians had no idea of hygiene and preventive medicine. However, the following remarkable text was published recently. It is a letter, written by Zimri-Lim, King of Mari, who lived about 1780 B.C., to his wife Shibtu: “I have heard that Lady Nanname has been taken ill. She has many contacts with the people of the palace. She meets many ladies in her house. Now then, give severe orders that no one should drink in the cup where she drinks. No on should sit on the seat where she sits. No one should sleep in the bed where she sleeps. She should no longer meet many ladies in her house. This disease is contagious.”
We can guess that the Mesopotamians were aware of some of the laws of physics, since they were able to lift huge stones and to construct long aquaducts. Also to their civilization must be credited a great cultural advance: the invention of the wheel. This great invention, which eluded the civilizations of the western hemisphere, was made in Mesopotamia in about 3600 B.C..
The early Hebrew culture was closely related to that of the Mesopotamian region, and a vivid picture of the period which we have been describing can be obtained by reading the Old Testament.
It may seem surprising that so many of the early steps in the cultural evolution of mankind were taken in a region much of which is now an almost uninhabitable desert. However, we should remember that in those days the climate of the Near East was very different - very much wetter and cooler than it is now. Even today, the process of drying up after the last ice age is not yet complete, and every year the Sahara extends further southward.
Early metallurgy in Asia Minor
Whatever the ancient civilizations of the Near East knew about chemistry and metallurgy, they probably learned as “spin-off” from their pottery industry. In the paleolithic and neolithic phases of their culture, like people everywhere in the world, they found lumps of native gold, native copper and meteoric iron, which they hammered into necklaces, bracelets, rings, implements and weapons. In the course of time, however, after settled communities had been established in the Near East for several thousand years, it became much more rare to find a nugget of gold or metallic copper.
Although the exact date and place are uncertain, it is likely that the first true metallurgy, the production of metallic copper from copper oxide and copper carbonate ores, began about 3,500 B.C. in a region of eastern Anatolia rich in deposits of these ores. It is very probable that the discovery was made because colored stones were sometimes used to decorate pottery. When stones consisting of copper oxide or copper carbonate are heated to the very high temperatures of a stone-ware pottery kiln in a reducing atmosphere, metallic copper is produced.
Imagine a potter who has made this discovery - who has found that he can produce a very rare and valuable metal from an abundant colored stone: He will abandon pottery and go into full-scale production as a metallurgist. He will try all sorts of other colored stones to see what he can make from them. He will also try to keep his methods secret, exaggerating their miraculous character, and he will try to keep a monopoly on the process. Such was probably the beginning of metallurgy!
However, it is impossible to keep a good thing secret for long. Knowledge of smelting and refining copper spread eastward along the mountain chain to Khorassan and Bukhara, and from there southward to Baluchistan, whose mines supplied copper to the peoples of the Indus valley. Also, from Bukhara, metallurgy spread northeast through the Kizal Kum desert to the ancestors of the Shang tribe inhabiting the Yellow River valley in China.
By 3,000 B.C., Summer, Egypt and Cyprus also had adopted metallurgy and had even discovered secret methods of their own. Egypt obtained its copper ores from mines in Sinai, while Sumer imported ore from Oman. The use of the Oman copper ores was fortunate for the Sumerians, because these ores contain as much as fourteen percent tin and two percent nickel, so that the metal produced by reducing them is natural bronze, whose properties are much more desirable than those of copper. The demand for bronze continued even after the Oman ores were exhausted, and eventually it was discovered that bronze could be produced artificially by adding tin and nickel to copper.
The Egyptian civilization
The prosperity of ancient Egypt was based partly on its rich agriculture, nourished by the Nile, and partly on gold. Egypt possessed by far the richest gold deposits of the Middle East. They extended the whole length of the eastern desert, where more than a hundred ancient mines have been found; and in the south, Nubia was particularly rich in gold. The astonishing treasure found in the tomb of Tutankhamen, who was certainly not the most powerful of the pharaohs, gives us a pale idea of what the tombs of greater rulers must have been like before they were plundered.
In the religion of ancient Egypt, the distinction between the gods and the pharaohs was never very clear. Living pharaohs were considered to be gods, and they traced their ancestry back to the sun-god, Ra. Since all of the pharaohs were thought to be gods, and since, before the unification of Egypt, there were very many local gods, the Egyptian religion was excessively complicated. A list of gods found in the tomb of Thuthmosis III enumerates no fewer than seven hundred and forty! The extreme conservatism of Egyptian art (which maintained a consistent style for several thousand years) derives from the religious function played by painting and sculpture.
The famous gods, Osiris, Isis, Horus and Set probably began their existence as real people, and their story, which we know both from hieroglyphic texts and from Pliney, depicts an actual historical event - the first unification of Egypt: Osiris, the good ruler of the lower Nile, was murdered and cut to pieces by his jealous brother Set; but the pieces of Osiris’ body were collected by his faithful wife Isis, who performed the first mummification and thus made Osiris immortal. Then Horus, the son of Osiris and Isis, like an Egyptian Hamlet, avenged the murder of his father by tracking down his wicked uncle Set, who attempted to escape by turning into various animals. However, in the end Horus killed Set, and thus Horus became the ruler of all of Egypt, both the lower Nile and the upper Nile.
This first prehistoric unification of Egypt left such a strong impression on the national consciousness that when a later pharaoh named Menes reunified Egypt in 3,200 B.C., he did so in the name of Horus. Like the Mesopotamian story of the flood, and like the epics of Homer, the story of the unification of Egypt by Horus probably contains a core of historical fact, blended with imaginative poetry. At certain points in the story, the characters seem to be real historical people - for example, when Osiris is described as being “handsome, dark-skinned and taller than other men”. At other times, imagination seems to predominate. For example, the goddess Nut, who was the mother of Osiris, was thought to be the sky, while her husband Geb was the earth. The long curved body of Nut was imagined to be arched over the world so that only the tips of her toes and fingers touched the earth, while the stars and moon moved across her belly. Meanwhile her husband Geb lay prostrate, with all the vegetation of the earth growing out of his back.
The idea of the resurrection and immortality of Osiris had a strong hold on the ancient Egyptian imagination. At first only the pharaohs were allowed to imitate Osiris and become immortal like him through a magical ceremony of mummification and entombment. As part of the ceremony, the following words were spoken: “Horus opens the mouth and eyes of the deceased, as he opened the mouth and eyes of his father. He walks! He speaks! He has become immortal! ... As Osiris lives, the king lives; as he does not die, the king does not die; as he does not perish, the king does not perish!” Later the policy became more democratic, and ordinary citizens were allowed mummification.
The tradition of careful mummification and preservation of the pharaohs led to the most impressive and characteristic expression of Egyptian civilization: the construction of colossal stone temples, tombs and pyramids. Ordinary houses in Egypt were made of brick, but since the tombs, in theory, had to last forever, they could not use brick or even the finest imported ceder wood. They had to be made entirely of stone.
The advanced use of stone in architecture began quite suddenly during the reign of Zoser in the Third Dynasty, in about 2,950 B.C.. During the Second Dynasty, a few tentative and crude attempts had been made to use stone in building, but these can hardly be thought of as leading to the revolutionary breakthrough in technique which can be seen in the great step pyramid of Zoser, surrounded by an amazing series of stone temples, and enclosed by a wall 33 feet high and nearly a mile long.
It is tempting to believe that this sudden leap forward in architectural technique was due to the genius of a single man, the first scientist whose name we know: Imhotep. The ancient Egyptians certainly believed that the whole technique of cutting and laying massive blocks of stone was invented entirely by Imhotep, and they raised him to the status of a god. Besides being King Zoser’s chief architect, Imhotep was also a physician credited with miraculous cures. After his deification, he became the god of medicine, and his tomb became a place of pilgrimage for sick people seeking to be cured, more or less in the manner of Lourdes.
The craftsmanship of the pyramid builders has never been surpassed in any country. No scholar has been able to explain fully the methods by which they were able to fit enormous blocks of stone together with such astonishing accuracy. However, it is known that their method of quarrying was as follows: Along the line where a limestone block was to be split away from a cliff, a V-shaped groove was cut with copper tools. Along the bottom of the groove, wedge-holes were drilled, and wooden wedges were hammered into the holes. The wedges were soaked in water, and the force of expansion split the block away from the cliff face. Obviously, this is a slow and laborious method of quarrying, and therefore from the standpoint of economy it was better to cut one huge block rather than a hundred small ones. Also, from the standpoint of achieving enormous size and permanence in the finished structure, large blocks were by far the best.
In building the great pyramid of Cheops (c. 2,600 B.C.), on which 100,000 men were said to have worked 30 years, 2,300,000 blocks were used. The average weight of the stones was two and one half tons, but many of them weighed as much as fifteen tons, and the enormous slabs of granite which form the roof of the king’s chamber weigh almost fifty tons apiece.
The blocks were dragged from the quarries on sleds pulled with ropes by teams of men. On the front of each sled stood a man, pouring water in front of the runners, so that the clay on which they slid would be made slippery. Also standing on the sled, was a foreman who clapped his hands rhythmically to coordinate the movements of the workmen. His clapping was amplified by a second foreman, who banged two blocks of wood together in the same rhythm.
The Egyptian hieroglyphic (priest writing) system began its development in about 4,000 B.C.. At that time, it was pictorial rather than phonetic. However, the Egyptians were in contact with the Sumerian civilization of Mesopotamia, and when the Sumerians developed a phonetic system of writing in about 3,100 B.C., the Egyptians were quick to adopt the idea. In the cuneiform writing of the Sumerians, a character stood for a syllable. In the Egyptian adaptation of this idea, most of the symbols stood for combinations of two consonants, and there were no symbols for vowels. However, a few symbols were purely alphabetic, i.e. they stood for sounds which we would now represent by a single letter. This was important from the standpoint of cultural history, since it suggested to the Phoenicians the idea of an alphabet of the modern type.
In Sumer, the pictorial quality of the symbols was lost at a very early stage, so that in the cuneiform script the symbols are completely abstract. By contrast, the Egyptian system of writing was designed to decorate monuments and to be impressive even to an illiterate viewer; and this purpose was best served by retaining the elaborate pictographic form of the symbols.
The invention of paper
The ancient Egyptians were the first to make books. As early as 4,000 B.C., they began to make books in the form of scrolls by cutting papyrus reeds into thin strips and pasting them into sheets of double thickness. The sheets were glued together end to end, so that they formed a long roll. The rolls were sometimes very long indeed. For example, one roll, which is now in the British Museum, is 17 inches wide and 135 feet long.
(Paper of the type which we use today was not invented until 105 A.D.. This enormously important invention was made by a Chinese eunich named Tsai Lun. The kind of paper invented by Tsai Lun could be made from many things: for example, bark, wood, hemp, rags, etc..
The starting material was made into a pulp, mixed together with water and binder, spread out on a cloth to partially dry, and finally heated and pressed into thin sheets. The art of paper-making spread slowly westward from China, reaching Baghdad in 800 A.D.. It was brought to Europe by the crusaders returning from the Middle East. Thus paper reached Europe just in time to join with G¨utenberg’s printing press to form the basis for the information explosion which has had such a decisive effect on human history.)
The flooding of the Nile
The date of the flooding of the Nile was predicted each year by the priests, so that the farmers could move their families and possessions in time. The Egyptian calender contained 365 days, 360 of which were ordinary days and five of which were holidays on which the birthdays of the principal gods were celebrated. The 360 ordinary days of the calender were divided into 36 weeks of ten days. Three weeks formed a month, so that the year consisted of twelve months, each with approximately the same number of days as the moon’s period. However, the exact number of days in a year is not 365 but 365.2422..., and therefore the Egyptian calender gradually got out of phase. The priests then found that the most invariant method of predicting the flooding of the Nile was by observing the return of the star Sirus.
The periodic flooding of the Nile meant that each year the land had to be surveyed and boundary lines redrawn. Thus the flooding of the Nile, with its surveying problems, together with the engineering problems of pyramid building, led the Egyptians to develop the science of geometry (which in Greek means “earth measurement”).
An ancient Egyptian papyrus book on mathematics was found in the nineteenth century and is now in the British Museum. It was copied by the scribe Ahmose in c. 1,650 B.C., but the mathematical knowledge which it contains is probably much older. The papyrus is entitled “Directions for Attaining Knowledge of All Dark Things”, and it deals with simple equations, fractions, and methods for calculating areas, volumes, etc..
The Egyptians knew, for example, that a triangle whose sides are three units, four units, and five units long is a right triangle. They knew many special right triangles of this kind, and they knew that in these special cases the sum of the areas of the squares formed on the two short sides is equal to the area of the square formed on the longest side. However, there is no evidence that they knew that the relationship holds for every right triangle. It was left to Pythagoras to discover and prove this great theorem in its full generality.
Suggestions for further reading
1. Jaquetta Hawkes and Sir Leonard Wooley, Prehistory and the
Beginnings of Civilization, George Allen and Unwin (1966).