history of the chair

It seems that since humankind first stood up to see over the tall Savannah grasses, we’ve been looking for a place to sit back down. The historical record is not quite so succinct, however—but when early migratory peoples first settled down into a domesticated lifestyle, it appears one mark of the civilized person was a seat that elevated the body “away from the cold, damp floor” (de Dampierre 2006). By the simple act of constructing an artificial place to sit, humans began the long tradition of distinguishing themselves from the animal world. It is a form as simple as the bending of our knees and upright posture as our back, and yet that form is not so simple.
Sitting at the Dawn of Civilization
Archaeological evidence of sculptural relics at Neolithic building sites suggest chair and bench-like areas, so it appears that chairs emerged during the Stone Age. But it is not certain at what point during the expanse of time after the last Ice Age from about 10,000 B.C. to the dawn of civilization the first person crafted a seat with a back (or, alternatively, a simple platform with legs, like a stool) and then sat down on it (Crantz 1998). In addition, apart from simply elevating humans, humans of elevated status, in particular, have long been associated with the early history of chairs.
The Ancient World
It is believed that humans appeared in China as far back as 40,000 B.C., with relatively dense population patterns apparent in Mongolia by 20,000 B.C. Seats have been found in Chinese tombs but seem strictly utilitarian, and designs remain relatively unchanged through the sixteenth century, when a carpenter’s manual depicts standards of Chinese furniture in the form of woodblock prints. Records suggest that the vast majority of “the earliest Chinese did not use chairs, but instead knelt on the ground, leaning back on their heels to support their weight.”
The practice remained common through the tenth century and remains in use today in some traditional settings in Eastern Asia, where low cushions and mats are still frequently used to sit upon the floor (de Dampierre 2006). Like other civilizations, the stool—and in this case a folding stool—is considered the oldest Chinese elevated “seat.” All said, there are many ways to sit and many things upon which to sit, but the seat with a back and (most frequently) four legs is generally the Western concept known as a chair.
One need look no further than ancient Egypt for the earliest surviving physical examples of the Western world’s use of chairs. Egyptian tombs that have been unearthed contain chairs and stools from as far back as the Egyptian Old Kingdom, about 2680 B.C., well preserved by Egypt’s dry air. The most famous example dates to 1352 B.C.: the ornate throne sealed in the tomb of Pharaoh Tutankhamen, or King Tut. There is, however, hieroglyphic evidence of chair usage by all strata of society—though certainly not as pervasively as in modern society—dating back at least to the third millennium B.C. (Crantz 1998). These early examples demonstrate basic woodworking skill, which gradually gave way to advanced techniques in woodworking, including sophisticated joints, veneering, ivory and precious metal inlays, and cushioning of virtually all available materials. Indeed, “Egyptian craftsmen…created the fundamentals of all seating furniture,” including folding furniture (de Dampierre 2006).
Early in their history, chairs were largely used by higher strata of society, particularly in the form of thrones—so the simpler, backless version of the chair,the stool,was the primary seat of lower strata. Domestic furniture like the low-profile, rectangular-framed stools of ancient Egypt were “formed with a double cove construction of curved wooden slats…which pass through holes in the frame” (de Dampierre 2006).
Outside of Egypt, stelae from the Euphrates river valley in Mesopotamia depict the usage of chairs, particularly by kings, but Galen Crantz suggests the more humid climate prevented any wooden or rush-based chairs from surviving. The archaeological record from the other great early civilization across the Mediterranean—Greece and the Cyclades Islands—is similarly sparse, broken by devastating earthquakes and fires that disrupted and relocated entire civilizations. Few surviving pieces of artistry depict simple stools from the second millennium B.C., though the first cultures appeared in Greece as much as a thousand years earlier.
After a five-century gap in the archaeological record, paintings and sculpture starting from about the seventh century B.C. have been unearthed that show an evolution of design resulting in much more sophisticated furniture. As the culture evolved, Greek society’s focus on form, rhythm, precision, clarity, and proportion worked its way into all aspects of life, including furniture. Chairs, stools, and benches served all levels of society, a fact made evident by their surviving art and, more importantly, their literature (de Dampierre 2006).
Etymology
The Greek language lends to the Romantic languages a contraction of kathedra (also into Latin, cathedra), which is derived from kata, for “down,” and hedra, for “to sit.” The word passed into Middle English from the Old French chaiereand the variant chaise, which is variously in use in English for styles of chairs today (Jewell and Abate 2001). The other important related word, “throne,” arrives in the English language from the Indo-European base word dher, which means “to hold or support.” For Crantz, the distinction suggests that thrones were meant to support the privileged or royalty, while chairs, which anyone can use—in a literal physical sense—were meant to sit down. Meanwhile, in contrast to the upright back of the throne, a more reclined, relaxed, lighter Greek chair with a tilted back called the klismos found its way, alone, with commonly used stools into the next great Western civilization (1998).
The Roman Empire and the Dark Era of Chairs
In Rome, “the bed was the all-purpose piece of furniture,” a place where a Roman would not only sleep, but “eat, read, write, and socialize,” while formal dinner banquets were held upon U-shaped couches (Crantz 1998). Though more rare, chairs such as the upright thronus and the reclined cathedra were used for formal functions and lounging women, respectively. Like the work of many early civilizations, the mostly wooden pieces crafted during the Roman Empire have not survived to the present day. Existing evidence has shown that a few largely identical designs were used throughout the empire, from North Africa to Germany to Britain, and the more durable pieces incorporated various metal and stone.
Regarding hierarchy and posture in the Roman Empire, stools sufficiently supported children both in school and at the dinner table, while the father lounged on a couch and the mother sat in a chair (though later in the history of the Empire, it appears the mother reclined on a couch as well). The hierarchy also placed servants on stools, that time-honored seat of the masses. But the arrangement does speak to many cultures' tendency to situate their royalty and their gods in a chair, seated in an upright, supported position (though there are also examples of individuals slumping as in a clismos that complicate the picture).
While modern scholars have discouraged the use of terms such as “The Dark Ages” to describe the era between the sacking of Rome and the rise of the Renaissance, chairs saw very little development during the millennium of the Middle Ages. Indeed, those who sacked Rome took no interest in their culture—so along with Rome’s myriad technological advancements, the simpler things such as their chairs also virtually vanished from the minds of civilization. Throughout the Middle Ages, chairs in the standard definition were quite scarce, and their use was limited only to masters of the household, even in the richest households. Medieval folk often improvised places to sit, from storage chests or heavy high-backed chairs with chests under the seats that were anchored against walls (to prevent theft as well as indicate status) to benches like those used in church choirs—or they simply squatted in a way that is time-honored in other societies around the world (Crantz 1998).
The Chair Revival
The fifteenth century saw a centralization of urban trade centers and governments, and with a settling of society came a settling of wealthy noblemen. These individuals and families began investing in permanent homesteads, wherein chairs became free-standing pieces of furniture with specific functions, often still reserved for the elite. The Renaissance saw a revival of Antiquity and renewal of culture, and with the refreshed outlook came more sophisticated chairs with lighter, more complex construction and classically inspired decorative motifs. The most important innovation was the lighter construction. The Italian sgabello, for example, was a low, three-legged stool-inspired chair with a high balanced backrest. Its successor in the sixteenth century added the forth leg, lowered the back and, without any chest under the seat, it meant “the age of completely portable furniture that could be moved from room to room as need had come” (de Dampierre 2006).
Meanwhile, in establishing the divine authority of royalty of the seventeenth century, the thrones of those such as Louis XIV, Queen Christina of Sweden, and Alexis I of Russia were magnificent and majestic. In the court of Louis XIV, in particular, the hierarchy of chairs was strictly regulated, the most important being the armchair—a term first used in this century (Crantz 1998), followed in order by the chair with a back, stools, and hassocks. However, “in the king’s presence most people had to remain standing. Permission to use a stool—the only seat allowed in his presence—was a coveted honor” (de Dampierre 2006).
The era of chairs in the seventeenth and eighteenth centuries saw a flourish of high style, beginning with the Baroque and moving through the Rococo, Neoclassical, and the cult of Antiquity: styles that merged evolving taste in decorative arts with the form and status of chairs. During the period of the Restoration in England (into the late eighteenth century), inlaid decorative elements and ornate carving became more common. Most importantly, at the same time, chairs were simply becoming “more common as life became more sociable” (de Dampierre 2006).
Europe and America alike focused on status in chair production beginning even in the pre-Colonial era of the United States. Stools and benches continued to be used by the masses while people of status, who could afford them, were those who purchased and used chairs up until the nineteenth century. Into the 1800s, however, chairs became more commonplace in American households, with usually enough provided for every member to sit down to dinner. Indeed, by the 1830s, factory-manufactured “fancy chairs” such as those by Sears, Roebuck, and Co. allowed families to purchase machined sets. The Industrial Revolution became the great democratizer of the once-elite chair (Crantz 1998).
La Chaise Moderne
The twentieth century saw a range of intriguing chair design influenced by the various artistic movements, beginning with Art Nouveau and Art Deco. Art Deco emerged with the Machine Age, which included austerely styled but well-crafted pieces by names like Le Corbusier and Bauhaus. Additional artistic styles that worked their way into chair design included Cubism, Surrealism, the Baroque, and a “primitive” style that looked to the “timeless innovation” of the long (but sparsely recorded) history of African chairs and stools, particularly “those for ritual, political, or symbolic use” (de Dampierre 2006).
The inter-war period, in particular, saw a flourishing of unique style prompted by the passionate Modernist pursuit of proper form. The chair was based upon “the sociological expression of modern values” and, as a result, those early twentieth-century chairs have become admired classics, particularly among designers, but with varying influence on the public (Crantz 1998). Artistic movements of the early 1900s have been variously adapted by contemporary designers both as a retrospective and to meet the demands of consumers, whose interests cover styles across the decades. The other side of the picture still portrays a “non-aesthetic aesthetic” of chair ergonomics, or design that favors function over form, to the physiological benefit of the consumer (de Dampierre 2006).
Somewhere in the middle of social theory and ergonomics exists the ideal chair. But when the wide array of applicable theories and artistic sensibilities combine with a world of distinct cultural aesthetics, the perfect chair is as individual as the person designing it. It could be an ergonomically perfect model designed for a day of productivity in the office, or a simple barstool, efficient in design but fully functional and serving a specific purpose implicit in its name. Meanwhile, outlets such as Ikea and World Market display chairs at the opposite ends of the design spectrum, from the stylish but inexpensive manufactured chair to the fairly traded, hand-crafted artisan imports from around the world.
Finally, one chair, perhaps, has outdone them all: the ubiquitous one-piece polypropylene plastic chair, that three-sixteenth-of-an-inch “resin chair” which is manufactured around the world and shows up in virtually every imaginable setting. At first glance, it is a practical, tacky piece that is more an after-thought than an object of attention. But as even the Smithsonian Institute has avowed, the resin chair is inextricably tied to the history of chairs, incorporating the postwar pursuit of progressive design with ease of manufacture, portability, and basic comfort (Gosnell 2004).
The electric one


n 1881, capital punishment was in common use in the United States--but that usually meant hanging, or occasionally a firing squad. Enter New York dentist Albert Southwick, who saw an old drunk accidentally electrocute himself on a power generator with no visible pain. He told a friend in the legislature, and the idea of executing people using the modern marvel of electricity began to take hold.

The Truth About Cats and Dogs:

The forerunner of commercial electricity was Thomas Edison, whose direct current (DC) approach was safer than George Westinghouse's newer alternating current (AC) technology--but inferior in every other discernible respect. To protect the safety of the American public (and his commercial interests), Edison held a demonstration in which he used a 1,000-volt alternating current generator to kill cats, dogs, and a large horse. Waiting in the wings were legislators eager to adopt Southwick's vision of a humane, electricity-based form of execution.

Chapter 489:

Southwick soon became part of a New York legislative panel charged with the goal of eliminating gruesome forms of execution by replacing them with electrocution. In 1888, before the electric chair had technically been invented, the State of New York added Chapter 489 to its state code--establishing electrocution as the state's official execution method.

The Strange Death of William Kemmler:

In March of 1889, William Kemmler murdered his lover Matilda Ziegler. He was sentenced to die two months later in Auburn Prison's electric chair, the first in the country. It took eight agonizing minutes to kill him but it did the job, and electrocution soon became the most widely used method of legal execution in the United States.

The Mercy Seat:

Between 1890 and 1973, over 4,000 people were executed in the electric chair--from infamous murderers to accused traitors to railroaded black defendants in the South. Perhaps the most famous electric chair executions of this era were those of Bruno Hauptmann (1936), the alleged murderer of the Lindbergh baby, and Julius and Ethel Rosenberg (1953), alleged spies for the Soviet Union.

An Outdated Method:

After the death penalty came back from a four-year moratorium in 1977, the electric chair began to be replaced replaced by the gas chamber and lethal injection; only 154 people were put to death by electrocution. (Among them: Ted Bundy.) Gruesome botched executions, in which faulty equipment tortured prisoners to death or simply burned them alive, became almost routine--most notably in Florida, where the equipment was not well maintained and was occasionally used by undertrained staff.

The Nebraska Case:

By February 2008, the electric chair had mostly become a novelty. Only one state--Nebraska--still used it as a primary method of execution, all others having relegated it to optional status for prisoners who wanted a more distinctive death. So when the Nebraska Supreme Court ruled that the electric chair constituted death by torture, there was little outcry. If the electric chair is ever used to execute prisoners again, it will most likely be on an extremely small-scale basis.

The Electric Chair Outside of the United States:

The electric chair is sometimes used in the Philippines, but no other country on Earth currently uses it as an execution method.

The rocking one

Although the first rocking chairs in existence were believed to have originated around the early to mid 1700’s in England, the rocking chair was originally utilized as a garden sitting chair. The Windsor rocking chair was called such because of it place of origination, Windsor Castle, around the beginning of the 1700’s. It was a wooden rocking chair, wood being the easiest medium through which to create such a piece of furniture, and since its creation has given birth to many new variations of the rocking chair; such as the glider rocking chair. In the timeline of rocking chairs, the wicker rocking chair came after the creation of the Windsor, which was mainly a wood rocking chair with a heavily rounded hoop back with spindles that gave it the appearance of a bird cage.Just as outdoor rocking chairs and porch rocking chairs are popular today, in the first days of rocking chairs people enjoyed the relaxing, undulating back and forth motion while taking in the beauty of nature in the garden. This gentle motion created by the rocking chair is found soothing by many, similar to the motions of a swaying cradle. Often outdoor rocking chairs are displayed on porches and have since become an American standard for relaxation and household outdoor enjoyment.
After its creation in England, the rocking chair was said to have been become mainstream in America around 1750. Benjamin Franklin is often widely credited with the first wood rocking chair creation, which he made by simply modifying an existing chair and adding gliders to it. Benjamin Franklin apparently adopted the bowed rockers from a baby’s cradle to fit the design of an ordinary chair and thus, the rocking chair was born. However, historians have had varying opinions on the validity of historical evidence to support Mr. Franklin as the originator in America. We do however know that both the rocking horse and the rocking cradle predate the rocking chair. By the end of the 18th century, rocking chairs became the most common type of outdoor porch furniture. The rocking chair soon became a mainstream household object, with the adult rocking chair being used as a symbol of status for many grandparents and heads within families during the early 19th century in the mid west.
The rocking chair gains its ability to rock in such a way because of a unique feature, the wooden rocking chair only makes contact with the floor in two places at any one point in time. Without this feature, the wood rocking chair would not be a rocking chair at all; however one could easily classify it as a stool, bench, ottoman, or just a plain old chair. There is an ergonomic benefit associated with rocking chairs as well. Due to the center of gravity of the user being met and the angle utilized, the rocking chair leaves its user at an almost weightless state.
In the late 1800’s, the first lightweight rocking chair called the bentwood rocking chair was crafted by German craftsman named Michael Thonet. He utilized a type of steamed wood, which he then bent and manipulated to achieve the graceful look of the bentwood rocking chair. With their high affordability and lightweight but beautiful designs, the bentwood rocking chair became an extremely popular among outdoor rocking chairs across America and the rest of the world.
The modern rocking chair design has been pushed to the limit. Everything from glider rocking chairs, to portable children’s rocking chairs, and even a high tech rocking chair called the Gravitron have been inspired by the classic wooden rocking chair. It is hard to further perfect the simple design associated with rocking chairs, but the mediums through which they have been designed since their creation has vastly differed. From high tech steel rocking chairs, to rocking surfboard chairs, to even high tech collapsible rocking chairs; the rocking chair has undergone transformations over the years, but all in all has withstood the test of time.

We use the word Macrocosmos to mean "everything there is". We will see that the Cosmos and the Universe are just small parts of the Macrocosmos. So how could it have begun?
Perhaps it was created out of nothing. To us, used to the idea that energy cannot be created, this seems impossible, but even today we find two kinds of matter (matter and antimatter) being created together out of nothing in quantum fluctuations. What is more, gravitational energy is equal and opposite to the matter energy in a closed space. This means that starting from nothing gravity and matter might have separated to create the Macrocosmos.
The amounts of energy in the Macrocosmos were small. The inflation theory predicts the Universe began with only 25g of matter! However this matter was crammed into a very very tiny space, creating an extremely high energy density.
About 300 thousand years after the Big Bang, the Universe had cooled enough for electrons to be captured by protons and alpha particlesto form atoms.
An electron is pulled towards a proton because their opposite electric charges attract each other. They stick together to form a totally new kind of object called an atom of hydrogen. In the same way two electrons were attracted to each alpha particle, which contained two protons, and were held close to it. The atom they made is called a helium atom.
Atoms are fantastic things. Around the outside of the atom the electron forms a large thin shell. Inside the atom is empty space, except for the tiny heavy proton at the center. An atom is like a football.
The electron in an atoms is like the skin of the football. Under this skin the atom is almost empty. At the center is something a football doesn't have. Held at the center by the electric force is the tiny proton. This is called the nucleus of the atom. The young Universe was full of hot atoms, moving around and bouncing off each other. They made a gas.
Once all the electrons were atoms trapped in atoms, the fog of the Universe cleared.
A galaxy is an island of billions of stars, separated from other galaxies by a vast ocean of almost empty space. In this story we look at one particular galaxy (the Milky Way), since that is the one we know best, the one where we live. But we should not forget that, scattered far and wide across the Universe, there are billions of other galaxies, probably very similar to ours.
Galaxies are either spiral (about 70% of galaxies - similar to the Milky Way) or elliptical (about 30%). A few are other shapes. It is not clear how the different shapes arose. Spirals are probably more interesting than ellipticals, since stars are formed continuously in them. It is probably this which has allowed life to form in the spiral galaxy where we live.
After a while the stars formed in an open star clusterdrift apart, probably pulled by the attraction of passing stars. Let's focus down on one star and see how it works.
A star (such as the Sun) is a ball of gas which has, at its heart, a nuclear fusion reactor. It is important to know something about how stars work, for several reasons.

• One star, the Sun, is the source of almost all the energy used by living things, including humans. We could not survive without it.
• If we could copy the Sun in a small and controlled way, we believe we could obtain a great deal of energy on Earth without creating a lot of pollution.
• Stars are the places where large atoms are built. Past generations of stars formed the gas and dust from which the planets and life were made.

So stars play a key part in our story.
We have seen that a small red giant, up to 1.5 times the size of the Sun, turns into a white dwarfwhen it dies. Larger red giants, however, die in a more spectacular way.
Once the nuclear fuel is exhausted in a red giant, the core starts to cool and the internal pressure falls, leading to contraction. In large red giants this is a sudden and catastrophic event so that the star collapses. As the outer layers of the star fall they gain heat. This triggers nuclear fusion in these outer layers and they explode in a spectacular explosion called a supernova, becoming for a few days brighter than a whole galaxy.
With so much energy it is possible to fuse iron nuclei into even heavier ones such as uranium nuclei. As the star explodes it throws out the nuclei which it has made. On their way out they pick up electrons and become atoms. The helium, oxygen, carbon, nitrogen, iron, uranium and other heavy atoms made by the star are scattered back to dust in the disc of the galaxy. In this way the atoms made in one generation of stars are passed on to be used by the next.
So all the atoms in your body (except hydrogen) were made in a supernova 5 billion years or more ago.
What happens next depends on the size of the original star.
We have seen that a small red giant, up to 1.5 times the size of the Sun, turns into a white dwarfwhen it dies. Larger red giants, however, die in a more spectacular way.
Once the nuclear fuel is exhausted in a red giant, the core starts to cool and the internal pressure falls, leading to contraction. In large red giants this is a sudden and catastrophic event so that the star collapses. As the outer layers of the star fall they gain heat. This triggers nuclear fusion in these outer layers and they explode in a spectacular explosion called a supernova, becoming for a few days brighter than a whole galaxy.
With so much energy it is possible to fuse iron nuclei into even heavier ones such as uranium nuclei. As the star explodes it throws out the nuclei which it has made. On their way out they pick up electrons and become atoms. The helium, oxygen, carbon, nitrogen, iron, uranium and other heavy atoms made by the star are scattered back to dust in the disc of the galaxy. In this way the atoms made in one generation of stars are passed on to be used by the next.
So all the atoms in your body (except hydrogen) were made in a supernova 5 billion years or more ago.
What happens next depends on the size of the original star.
Planets are lumps of gas and rock held close to a star by the force of gravity. We live on planet Earth going round star Sun, along with eight other planets. Together these are called the solar system.
Because stars form in dark clouds of dust and molecules in open star clusters, it is difficult to watch them form. So the story of how planets formed which we have just given has not been confirmed by observation.
About 20 planets have been discovered near Sun-like stars, although they are hard to see. Looking for planets near a star is a bit like trying to watch a moth flying around a spotlight which is pointing at you -- you get dazzled by the light. See the article Giant Planets Orbiting Faraway Stars for an explanation of how they are found.
Since discs of gas and dust have been detected around some young stars, we guess that planets might be common. But none of the planets so far discovered are like our Solar System. Indeed these discoveries are challenging current theories of the origin of planets.
If planets like ours are common, then life too could be common in the Galaxy.
We will now focus down on one tiny planet: the Earth. Notice from our diagram and model of the solar system how small it is compared to the Sun and the giant planets Jupiter and Saturn. If we didn't live here we probably wouldn't even notice it!
Yet there is a very good reason why we should look at this planet and no other. The Earth is the only planet on which water forms a liquid, which is essential for life. The reason has to do with its distance from the Sun. A planet further from the Sun, like Mars, is so cold that water freezes into ice. Closer to the Sun, like Venus, water boils and all the molecules fly apart. Only on the Earth can water form that marvelous substance, liquid water. The Earth, like most of the other planets in the Solar System, has an almost perfectly circular orbit. This is unusual. In most of the other planetary systems studied the planets have oval (elliptical) orbits. If the Earth had an oval orbit, travelling sometimes near to the Sun and sometimes far from it, life could not have evolved on the planet. At times the oceans would have boiled and at times they would have frozen, and life as we know it would have been difficult if not impossible.
Because they were made from a spinning disc, all planets spin like tops and they orbit (go round) the Sun. The Earth spins once a day and orbits once a year. The points which the Earth spins round are called the north and south poles.
Earth is the third planet from the Sun.
Life is a chemical system involving two types of molecules, proteins and nucleic acids, working together in a very special way. First we will look at these two types of molecule in turn. Next we will look at how they work together to make life. Then, when we know a little about what life is, we will think about how this beautiful chemistry might have started.
The first cellsappeared on Earth about 3.5 billion years ago. These early cells were very similar to the simplest cells we find on Earth today, called bacteria (sometimes called germs). Note that one of these is called a bacterium. Later bacteria evolved many new features. For example bacteria could swim. They used a long twisted whip-like tail called a flagellum fixed to a wonderful tiny rotating motor. This made the flagellum twist round and so pushed or pulled the bacterium along!
Bacteria have only one cell each. They can be round (coccus), rodlike (bacillus), or curved (vibrio, spirillum, or spirochete). Bacteria live almost everywhere on Earth, including the soil, water, organic matter, and the bodies of multicellular animals (eukaryotes). Some bacteria benefit humans and other plants and animals. Others are harmful; bacteria are the chief cause of infectious diseases in humans.
Bacteria differ from more advanced cells such of those found in animals and plants because they have no membrane around their nucleus nor any organelles. Simple cells like this are called prokaryotes. Bacteria make up the group which biologists call monera.
Archaebacteria are probably living fossils, similar to the earliest bacteria.
At some stage in history a process called continental drift began. We do not know when because the rocks have been squashed and changed so much since then, but it is important because it is still happening today. Some people think that it is one cause of ice ages.t is the heat generated by radioactive decay inside the Earth which drives this process. Today the theory of plate tectonics, which includes continental drift, forms a framework for the study of geology and the earth. Hot rock rises up from the mantle and spreads out on the surface to form the ocean floor. As the ocean floor spreads it pushes the continents around. They move one or two centimeters each year. As the continents move around they sometimes hit each other, creating mountains. This is how the Alps and the Himalayas were created. Mountains like this are on the inside of continents. Sometimes continents do not hit head on, but rub past each other. Since they do not have smooth edges, the rubbing is jerky and uneven. Pressure builds up and is then suddenly released. This creates earthquakes. The San Andreas fault in California is an example of this. n some places the floor sinks back down into the mantle, usually at the edge of a continent. As it sinks it melts and hot rock rises up, creating volcanoes along the coast. The Andes are being created in this way. Sometimes the volcanoes lie in an arc just off the coast of a continent. The islands of Japan are being formed like this.
t seems that the evolution of all successful animals began with ancestors similar to modern flatworms. Around 570 million years ago more advanced animals appeared.
Three types of animals were so successful that they are still the commonest animals today. All three types had hard outer coverings on their bodies. We call them

• Molluscs
• Arthropods
• Vertebrates

All animals which do not have backbones (everything except the vertebrates) are called invertebrates.
The molluscs and arthropods belong to a group of animals called the protostomia, while the vertebrates are deuterostomia.
he animals we lump together as fish actually consist of several very different groups of vertebrates:

• Jawless fish
• Bony fish
• sharks
• ray finned fish
• lobe finned fish

The first fish appeared about 500 million years ago.
Once the plants and arthropods were living on land there was plenty of food for any vertebratewhich could manage to come out of the water. Some fish lived in ponds which dried up in summer. Their swim bladders evolved into lungs which they used to breathe air. They used their fins to crawl from one pond to another and these evolved into legs, two at the front and two at the back.
The vertebrates which emerged from the water and became land animals around 350 million years ago we call amphibians "am-fib-ee-ans". Their name means "both lives" because they lived both in water and on land at different times in their lives.
Leaving the water was one of the greatest steps ever taken by our ancestors. It needed changes in every part of the body. The most obvious changes were the appearance of legs and the ability to breathe. Other changes were not so obvious but were just as important. For example the way the blood flowed round the body had to change.
Amphibians were still not totally free from the water. They needed to return to it to reproduce (like the ferns and the arthropods before them). Their eggs were laid and fertilized in water and the young developed in the water just like their fishancestors. But when amphibians grew up they left the water to live on the land. Most frogs and newts are still at this stage of evolution. By 350 million years ago ferns the size of trees were common. They had solved most of the problems of living on land but were still tied to moist ground for their reproduction. Many ferns grew in swamps. They grew from a small underground growth called a prothallus. The sperm swam from one prothallus to fertilize the egg on another. Without water or wet ground they could not reproduce.
When they died some ferns fell into the swamp. Decomposition could not happen because there was no oxygen in this water so the plants were buried and eventually turned into the stone we call coal.
The ferns we see today are still among the most primitive of plants. Their fronds uncurl and carry spores on their undersides.
Soon a group of vertebrates called reptiles solved the problem of how to reproduce without water, and they did it in exactly the same way, as the insects. Fertilizationoccurred before the eggs were laid, by the male injecting sperm into the female's body.
She used it to fertilize her eggs which she then covered with a tough water-proof skin and laid on land. No surface water was needed for reproduction.
Reptiles had scaly skin. They probably could not keep themselves warm when the weather was cold or at night-time, and may have become slow and sleepy at these times, although there is some debate about this.
Plant seeds could not grow or spread very quickly. They needed the wind to carry the pollen to the egg. Also it took over a year for the plant to store enough food in the seed to make sure the baby plant could grow.
About 200 million years ago a new kind of plant evolved. It attracted insects using colored flowers, and gave them sugary nectar to eat. Bees, butterflies and other animals evolved to eat the nectar offered by the flowers. While eating they picked up pollen on their bodies which they carried to other flowers.
The pollen itself was different. It carried two sperm. One fertilized the egg. The second fertilized the flower which then grew rapidly into a fruit. The seed used this for food. These flowering plants could grow and make fruits in just a few weeks, so they spread much faster than the seed plants. Fruits, berries and nuts appeared, so there was lots of new food for animals. New animals evolved to eat the fruit. The land became filled with the color and scent of many beautiful blooms. The hardwood trees and other plants of the tropical rain forest, now being so rapidly destroyed by people, are of this kind.
Improvements in reproduction were happening in the vertebrate world too. Instead of laying their eggs, female mammals kept them inside their bodies while they developed. In this way they protected their young, feeding them and giving them oxygen. The young could develop larger brains and more advanced bodies than any reptile.
After birth the young were looked after by their mothers, who fed them a rich food called milk. Mammals were the only animals able to make this wonderful food. Then began a long period of care and training when the young learnt from their parents.
Unlike dinosaurs, who probably needed the Sun's heat to keep them warm, the mammals had fur to keep them warm. They also had a better blood system.
Mammals were also far more intelligent than dinosaurs. Even the stupidest mammal is a genius compared to the brightest reptile. Their long development, when they are cared for by their mother, is what lets mammals' brains grow so much more than reptiles'.
Mammals first appeared about 200 million years ago. It is strange that while the mammals had better bodies and brains than the dinosaurs, even so for a long time they were unable to spread. This was probably because most life-styles were already taken by the less advanced but more common dinosaurs. Mammals stayed as small shrew-like insect-eating animals, perhaps only coming out at night.
Some people find it hard to accept that humans have evolved from animals. Yet there are many facts leading to that idea. Human cells are eukaryotic, the same as animal cells. Our chromosomes and genes are almost identical to some of the apes. So are our tissues and organs. Fossil bones have been found, showing how people evolved.
The main difference between people and other animals is their ability to think, which comes from the large size of their brain, and their use of language.
Modern people (Homo Sapiens) seem to have evolved in Africa about 100 thousand years ago (although the date is far from clear) and lived there while the Neanderthals were spreading around the world.
An interglacial (warm period) began 35 thousand years ago. Then modern people came out of Africa and spread. Within a few thousand years they replaced the Neanderthals in Europe and Asia. Then about 25 thousand years ago the weather turned cold again and a glacial began. During the glacial, people improved the tools used by Neanderthals, developing specialized tools for different jobs.
But the thing which really set them apart from Neanderthals was their use of art and decoration. Cave paintings, beads, clay statuettes, carvings on the handles of tools, all show a more developed sense of art than Neanderthals ever did.
Many animals were hunted to extinction and people spread around the world.
The weather turned warm 11 thousand years ago and the present interglacial began. Many of the glaciers melted, it rained heavily, and the oceans rose 100 meters. New animals and plants replaced the old. People took up two different ways of life: Nomads and farmers.
Computers are now being invented and have already
left the Earth and begun to explore the solar system.
They will soon begin to design themselves,
and so become independent of their human inventors.
There are vast resources in space and huge amounts of energy,
so computers will rapidly colonise this corner of the Galaxy.
The Sun will eventually burn up the Earth,
but by that time organic life will be largely irrelevant.
The Universe will probably end by cooling and expanding to almost empty space.