***Civ 2000 Civilization Advances Text File - Copyright (c) 1995 MicroProse Software, Inc. ***
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Advanced Flight
During World War II and in the years that followed, great leaps were made in the field of aviation. The military demands of the war necessitated the development of aircraft designed for long-range bombing, and for the transportation of troops and equipment. Although advances in aviation were made all over the world during this time, the Germans were particularly adept in the development of advanced flight technologies. In 1944, they developed the V-2 "buzz bomb", the first truly guided missile, capable of delivering 2000 pounds of explosives to targets nearly 200 miles away. The Germans also developed the Me 262, the first jet fighter plane, which was first used in 1945. Although both the V-2 and the Me 262 came too late to affect the outcome of World War II, both of these advances paved the way for the advanced flight technologies of today.

Alphabet
The ancestors of modern alphabets were the iconographic and ideographic symbols developed by ancient man, such as cuneiform and hieroglyphics. The first known alphabet, a combination of a number of early pictographic symbols known as North Semetic, developed between 1700 and 1500 BC. Four other alphabets, South Semitic, Canaanite, Aramaic, and Greek, had developed from the North Semetic alphabet by 1000 BC. The Roman alphabet, used by all the languages of western Europe including English, was derived from the Greek alphabet sometime after 500 BC. The Roman alphabet became one of the most widespread due to the extensive use of the Latin language during the reign of the Roman Empire. The development of alphabets were significant in the development of advanced civilizations because it allowed history and ideas to be written down, rather than memorized and passed along orally.

Amphibious Warfare
A combined land and sea attack, usually associated with the capture of a 
beach head or coastal area, is known as amphibious warfare. 
First attempted by the ancient Persians during the Battle of Marathon 
in 490 BC, successful coordination of amphibious assaults are considered
 to be among the most complex military operations. When ship-mounted guns
 were developed, naval vessels would open fire on ground forces and gun 
emplacements while merchant ships were used to land troops and supplies. 
The first modern amphibious assault took place at Gallipoli during 
World War I. Poorly planned and executed, this assault failed, 
but served as an example of the need for perfect coordination of forces 
in this type of attack. As battlefield communications improved, and the 
range of ship-mounted weapons increased, amphibious warfare became 
increasingly successful, and played a vital role in World War II. 
Today, amphibious operations are augmented by fast, armored landing vehicles;
 hovercraft that are capable of moving troops to and across the beach; 
and airborne assistance from planes and helicopters.

Astronomy
Astronomy originated as simple observation and recording of regular celestial movements for the purpose of time keeping and determining directional bearings. The ancient Greeks were among the first to study astronomy in detail. They described the use of stars for navigation at sea, and recorded the position of constellations during each season of the year for purposes of determining times for planting and harvesting. The Greek astronomer Aristarchus developed the theory that celestial motion could be explained by the fact that the Earth revolved on its axis once every 24 hours, and revolves around the sun along with the other planets. This theory was rejected at the time, only to be rediscovered nearly 2000 years later by Copernicus. These early students of astronomy compiled data that became the cornerstone for modern astronomical research.

Atomic Theory
Philosophers in ancient Greece were the first to use the term "atom" to describe the smallest possible bit of matter. They hypothesized that all things were made up of atoms, and could be theoretically broken down to into atoms. The atom, however, was indestructible. Study of atomic theory proceeded slowly. Experimental scientists of the 16th and 17th centuries developed methods of analyzing gases, liquids, and solids to determine the individual elements of which they were composed. The founder of modern atomic theory was British chemist John Dalton. Dalton's experiments explained how atoms link together to form molecules. He also explained the nature of these chemical bonds, and performed a number of experiments concerning the formation of various chemical compounds.

Automobile
The earliest attempts at producing a self-propelled vehicle date back to the late 1770s. These early vehicles used bulky steam engines for power. Despite constant improvements, the steam engine ultimately proved impractical for small vehicles. The development of the internal combustion engine in the late 1800s provided a small but powerful replacement for steam engines, able to achieve much higher speeds. The first practical automobiles were developed in the late 19th century, by automotive pioneers in France, Germany, and the United States. By the 1920s, a number of automotive manufacturing companies were operating in the U.S., including Ford and General Motors. By 1980, more than 300 million cars and 85 million trucks were in operation throughout the world. The popularity of the automobile has led to massive improvements in the highway systems in most industrialized countries. Unfortunately, automobiles are also one of the primary sources of air pollution, and resulted in an all time high demand for petrochemical fuels.

Banking
Many of the services performed by banks today can be traced back to medieval Europe. Certain families, such as the Medicis of Italy, were known for the banking duties they performed. These wealthy merchants pooled their surplus money into a bank, then loaned cash (with interest) to other commercial enterprises. The availability of this capital for investment made many new businesses possible, accelerating economic growth. The first modern banks were established in Europe during the late 1600s. The primary function of today's banking system is the granting of loans to consumers and businesses. In addition to loaning money and safeguarding deposits, banks also invest in government and private securities and bonds. Both the loan and investment functions of banks not only make profits for the bank itself, but stimulate the economy by providing funds for business growth and consumer purchases.

Bridge Building
Humans have been constructing crude bridges from the first time they laid logs across a stream or river they needed to cross. Although a brick arch bridge is said to have existed in Babylon in 1800 BC, most bridges of this time period were probably made of wood. The Romans developed bridge building to a degree that it took Western medieval engineers many years to match. Roman bridges were often composed of several stone arches which supported a flat road. Bridges of this type date back to as early as 219 BC. It wasn't until the mid-1800s that bridge designs began to incorporate metal for added strength and permanence. Early truss bridges used wooden trusses bound with iron tie-rods. By 1850, wooden trusses gave way to steel. Modern bridges incorporate designs ranging from concrete and steel arches to steel girder and suspension styles. The development of modern bridges constructed of durable materials was vital to the expansion of the worlds railroad and highway systems.

Bronze Working
Evidence of the use of bronze, an alloy of copper and tin, dates back to Thailand in 4500 BC. Several hundred years later, bronze working was discovered in the Middle East. Artifacts from this period show that bronze was initially used for decorative purposes only. This is because tin was not readily available. It wasn't until approximately 2000 BC, when tin was regularly imported from neighboring regions, that bronze replaced copper in the construction of larger items. Bronze was harder and less brittle than copper, and it held a sharper edge. Tools, weapons, and armor made from bronze were also cheaper to produce and more durable. The period of time when bronze was the metal of choice for such items was known as the Bronze Age. The Bronze Age lasted until iron working became prevalent in about 1200 BC.

Ceremonial Burial
Groping for an explanation of the world around them, the earliest humans developed the first concepts of religion. Gradually, rites of worship grew to include sacrifices, ceremonies, vigils, symbology, sacred items, and prayer. One significant step in the advance of worship was the ceremonial burial, often a ritual preparation of the deceased's body for the afterlife his or her culture anticipated. The remains of  ceremonial burials offer some of the most detailed information about past civilizations.

Chemistry
The earliest practical use of chemical processes were by metal smiths of the ancient world. These artisans learned how to use heat to melt various naturally occurring metals together to form alloys such as bronze. Early manufacturers of cloth also used primitive chemical processes to set dyes. In the following centuries, chemical processes were studied through the pseudo-science of alchemy, which attempted to change base metals into gold. Although alchemists were, of course, unsuccessful, they did develop many valuable chemical processes as a result. The manuscripts produced by alchemists were studied by succeeding generations, and an effective knowledge of chemistry had been accumulated by the late 13th century. In the 17th century, the ideas of alchemy finally died out as an increasing body of true chemical knowledge was gained through experimental analysis, leading to the modern science of chemistry.

Chivalry
Chivalry was a code of rules governing the behavior of an aristocratic class of warriors known as knights. First appearing in the 12th century, the rules of chivalry governed the knights' behavior in battle, but in their personal lives as well. The chief chivalric virtues of piety, honor, valor, courtesy, chastity, and loyalty represented a fusion of Christian and military morality. A similar code of behavior known as "Bushido" or  "the way of the warrior" governed the behavior of the samurai warriors of ancient Japan. Although the strict practice of chivalry had all but disappeared by the 15th century, the ideals of chivalric behavior became the basis for what is now considered to be gentlemanly conduct.

Code of Laws
The earliest tribal civilizations were bonded together by mutual needs and beliefs. These groups were ruled by a tribal chieftain, who acted as an advisor, and enforcer of the will of the gods. No formal laws existed in these early cultures, but fear of the gods and a sense of tribal customs and morality kept order in the tribe. As societies became larger and more diverse, the need arose for established rules of conduct. The earliest known codes of laws existed in Babylon, India, and Palestine. The Twelve Tables of Rome, written in 500 BC, and its successors such as the Justinian Code, were the first codes of law to distinguish between public law, which involves the state, and private law, which concerns disputes between citizens. Roman law was the first formalized written system of laws, and went on to influence many of the legal systems of the modern world.

Combined Arms
Advanced flight technology, combined with the principles of amphibious warfare and mobile warfare, represent the potential for a devastating attack force. Combined air, sea, and ground assaults played a vital role in World War II. The Allied invasion of Normandy in June 1944 represented such an attack. Bombers and fighters were deployed over the target area to claim the skies, while naval vessels sat off the coast and bombarded the beach head. Transports then landed troops and equipment on the beach to begin a ground assault. Modern advances make today's combined assaults even more effective. Naval vessels and stealth aircraft equipped with cruise missiles and smart bombs soften enemy resistance before a ground assault. Helicopters drop and retrieve soldiers behind enemy lines in places not accessible to fixed-wing aircraft. Powerful armored tanks, such as the M1, can be quickly deployed, moving at speeds up to 60 miles per hour. Finally, the combined assault is coordinated through a network of sophisticated communication, targeting, and detection devices, allowing more precise deployment of forces than previously possible in history.

Combustion
The development of the internal combustion was a great advance of the Industrial Age. The forerunner of today's internal combustion engine was built in 1876 by German engineer Nikolaus Otto. Refinements on Otto's design over the next ten years led to more efficient and powerful engines based on his original design. The internal combustion engine forever changed world transportation. Early automobiles utilizing steam engines had proven to be both under-powered and impractical, but the fuel efficiency and compact size of the internal combustion engine allowed the automotive industry to flourish. Several variations, including the diesel engine designed by Rudolf Christian Karl Diesel, went on to revolutionize propulsion in shipping and other transportation industries.

Communism
Communism is conceptualized system of government in which resources 
and production facilities are the property of the entire society rather than individuals. 
In a communist society, labor is shared equally as well, and the benefits of labor are distributed according 
to need. Under such a system, all people would be equal, without class stratification. Although the basic 
idea of communism has existed since the time of Plato, modern communism is identified with the 
system of government described by Karl Marx and Fredrich Engels in the "Communist Manefesto". 
They believed that capitalistic systems, in which the rich upper class prospered through the exploitation 
of the powerless lower class, were bound to destroy themselves. 


Computers
A computer is a device capable of performing a series of repetitive arithmetic or logical functions far more quickly than the human brain. The earliest computers were designed to solve complex mathematical equations. British mathematician Charles Babbage conceived such a machine, called the Analytical Engine, in the 19th century. Many variations of analog, or mechanical, computing devices were built during the first half of the 20th century, and were used for such tasks as computing torpedo tracking in submarines and controlling bombsights. The growing study of electronics in the late 1940's led to the invention of the digital computer. The first all-electronic computer, containing 18,000 vacuum tubes and capable of hundreds of multiplications per minute, was built in 1946. Continuous advances in electronics since this landmark event rapidly reduced the size and increased the speed and efficiency of computers. Today, computers are commonplace, and are used in virtually every field of endeavor. Significant advances in computer technology continue to take place at an amazing pace.

Conscription
Compulsory enrollment in the armed forces has been practiced for thousands of years. The men of ancient Greece between the ages of 17 and 60 were obligated to serve in the militia, before the civilian militia was replaced by professionals in about 2000 BC. The modern form of conscription was introduced in France during the Revolution in 1789. By the 19th century, nearly every country except for Great Britain and the United States had instituted a program of peacetime conscription. Many of the combatants in both World Wars fought with forces composed largely of conscripted troops. The U.S. Selective Service Act of 1948 maintained peacetime conscription following World War II to maintain a powerful military. This act, which was to have expired in 1950, was extended due to the Korean War. Peacetime conscription in the United States continued until 1973, at which time military service became voluntary.

Construction
The development of masonry led to a widespread use of stone in simple structures such as fortifications, but due to the weight and cumbersome nature of stone blocks, more complex structures had to be made of simpler materials. The need for the widespread use of more durable and permanent materials eventually became apparent, forcing ancient artisans to learn new techniques. The biggest problem to overcome was finding a stable way to span the distance between two upright columns or walls using stone blocks. To solve this problem, fundamental architectural elements such as the arch and vault evolved. These basic construction techniques allowed larger and more elaborate buildings to be created from stone and mortar. Many of the buildings erected by these early builders are still standing, a testament to the sound construction techniques employed in their construction.

The Corporation
As businesses grow, they often find it necessary to raise large amounts of operating capital in order to expand their operations beyond a certain point, or to meet operating expenses. In these cases, one option available is to form a corporation and "go public", or sell shares of the business to investors. This arrangement allows the business to expand rapidly, while spreading the risks of the expansion among many people, reducing individual risk. Corporations also have legal advantages such as the right to sue, and the limitation of liability for the corporation's debt to the amount originally invested by the owners. Corporations as legal entities have existed since ancient Rome, although the joint-stock company as it is known today didn't begin operating until sometime in the 16th century.

Currency
As cities grew, their internal economies became more complicated. People became specialists, some primarily producing grain, some pottery, some bricks, etc. A system of barter developed, so that one individual's wares and services could be exchanged for those of another. Gold and silver were widely used in such transactions, but the pieces needed to be weighed and tested for purity each time they changed hands. In 600 BC, the Lydians found a way around this problem. They began the practice of shaping electrum, an alloy of gold and silver, into pieces of predetermined weight and purity, stamped with an official symbol. This idea caught on, and within 50 years, all the important trading centers of the world had adopted similar practices. The widespread use of currency created universal standards of value, allowing people from various societies to conduct business almost anywhere without being force to bring along bulky goods for trade and barter.

Democracy
Democracy is ruling system where the citizens have a great deal of control over the actions of the government, either directly or through elected representatives. Democratic governments can be traced back to the city-states of ancient Greece and Rome. Citizens would gather in a public forum, and each one would have the opportunity to speak and vote on issues affecting the community. This direct democracy system was possible due to the relatively small populations of the city-states. Starting in the 17th century, the monarchs of Europe began to be stripped of their absolute power, and by the end of the 19th century the citizens had a strong voice in government in many European nations. Large populations made public forums impractical, so the people elected groups of representatives to carry their views to the ruling powers. Strictly speaking, this type of system more closely resembles a republican system rather than a true democracy. This type of representative democracy is considered the best governing system in the modern world because of the personal and economic freedom enjoyed by the citizens.

Economics
The ideas of supply and demand, and philosophies concerning trade and the production and consumption of goods and services, are concepts that have existed since the dawn of mankind. As societies became more complex, however, people began to study these abstract concepts in a more formal way. The first recorded study of economics as a science, rather than a philosophical or political concept, was the book "The Wealth of Nations" by Scottish economist Adam Smith. This book represents the first attempt to fully analyze sources of income and the distribution of wealth. Smith's analysis of economics served as a guide by which many of the governmental economic policies of the present day were formed.

Electricity
The phenomenon of electricity in the forms of lightning, static electricity, and magnetism has been witnessed by humans since the dawn of time. Electricity was not seriously studied, however, until the 17th century. Early electrical pioneers studied various electrical phenomena, and built devices both to generate and to measure electrical charges. In 1892, the electron theory was advanced by Hendrik Antoon Lorentz, a Dutch physicist. This theory, which explains electricity as a reaction between positively and negatively charged electrons, formed the basis for modern electrical theory. Based on Lorentz's work, early engineers such as Thomas Edison pioneered methods allowing the widespread use of electricity as a power source.

Electronics
The field of electronics deals with the practical application and manipulation of electricity and electromagnetic phenomena. The invention of the vacuum tube in the early 20th century marked the beginning of modern electronics. The vacuum tube was capable of amplifying weak radio signals, allowing them to be transmitted over greater distances. Vacuum tubes also allowed music and voice to be superimposed onto radio waves for transmission. The early study of electronics revolutionized a number of fields, especially the field of communications. Because of the vacuum tube, the technology of radio communications was highly developed by World War II. After the war, electronics research continued to advance rapidly. Post-war advances include the earliest examples of digital computers and, eventually, transistors and integrated circuits: miniaturized replacements for the vacuum tube.

Engineering
Engineering is the application of scientific and mathematical principles to the design and/or manufacture of theoretical systems and physical objects. Prior to the mid-18th century, all engineering functions were carried out by military engineers. Their work involved the construction of roads, bridges, fortifications, and the performance of other duties relating to the military. In the late 18th century, civil engineers took over all nonmilitary engineering functions. Other fields of engineering prior to the 20th century included mining engineers, who designed mines and methods of mining, and mechanical engineers, who dealt with the design and construction of machinery. As new technologies developed, new fields of engineering developed along with them. Today, there are engineers specifically trained in nearly every field, from electronics and computers to chemistry and atomics.

Environmentalism
For centuries, human society has taken the gifts of nature for granted. As civilization grew, humans spread out across the face of the planet, taking what they needed from the land and producing more and more waste materials with little regard for the future. In the late 1960's, a growing number of people became concerned about the growing problems of pollution and the destruction of natural habitats. This movement led to the formation of groups like the Environmental Protection Agency (EPA). The EPA's aim is to reduce all types of pollution. To this end, the agency has imposed strict laws and guidelines concerning the disposal of hazardous materials, set clean water standards, and studied more effective techniques of solid waste disposal. The primary goal of the environmental movement as a whole is to make sure that the environment is safe and intact for future generations to enjoy.

Espionage
As far back as 500 BC, the Chinese military strategist Sun Tzu stressed the importance of the gathering of covert information about one's enemy. Although every world government has strict laws and penalties to deal with spies, covert intelligence is an important political, technological, and military commodity. During times of war, covert operatives provide important information about enemy troop movements and weapons technology. Spies may also be called upon to perform acts of sabotage in order to delay or divert the enemy. In peacetime, organizations such as the CIA use operatives to keep track of potential political situations abroad. Spying is not limited to politics and war; industrial spies are often used to gain information about rival companies.

Explosives
An explosive is a chemical compound or mixture that undergoes rapid combustion and produces heat, gas, and pressure effects. The earliest explosive compound known was gunpowder, which was first used 13th century, and was the only explosive known for hundreds of years. The first modern explosive, a compound known as nitroglycerin, was discovered in 1846. Compounds similar to nitroglycerin are the most commonly used explosives today. Explosives vary in brisance, or shattering effect, and in their stability under various environmental conditions. Aside from their obvious use in weaponry, explosives are also used in such peaceful applications as rocket propellants and for mining and demolition work.

Feudalism
In the unsettled times following the collapse of Charlemagne's Frankish empire, a new social and political system arose in Europe, called feudalism. Derived from the concept of monarchy, feudalism was a hierarchical system in which each descending stratum owed allegiance to those above. The king, whose authority was second only to God, granted tracts of land, or fiefs, to his barons. The barons might then grant smaller estates to knights, who swore to protect and serve the baron. The knights, in turn, might then grant fractions of their fiefs to subordinates who would serve the knights. At the bottom of the feudal pyramid were the serfs, who could not own land, and acted essentially as slave laborers who worked the land for their masters. Feudalism began to decline in the 13th century, when standing armies and mercenaries began to fulfill the protective role once served by the vassals and knights.

Flight
The idea of flight has tantalized humans since the dawn of time. Studies regarding the possibility of producing a flying machine date back to the 13th century. In the 16th century, Leonardo da Vinci proposed a number of inventions that eventually came to pass, including the propeller and the parachute. Throughout the 19th century, various engineers experimented successfully with gliders, and experiments with compressed air and steam engines attempted to produce self-powered flight with limited success. The key to success in powered flight was the invention of the internal combustion engine. Just after the turn of the 20th century, Orville and Wilbur Wright made the first four controlled,  sustained human flights at Kitty Hawk, N.C. The technology of flight advanced rapidly from this landmark event, and within a relatively few years, aircraft were circling the globe, safely delivering passengers and mail at record speeds.

Fundamentalism
Fundamentalism is a governing system whose laws and doctrines are rooted in the extremist and controversial views of religion. Fundamentalists believe in the absolute truth and infallibility of their religion, accepting nothing short of a literal interpretation of the scriptures of their faith. Their views are sometimes so radical as to put them at odds with even the most devout traditionalists of the religion in question. Fundamentalist movements have appeared from time to time throughout the world, including a widespread movement of Christian fundamentalism in the U.S. in the early 20th century. In some cases, most notably in areas of the Middle East, these movements are so widespread that entire nations fall under Fundamentalist rule. Such governments, backed by a fanatical military force, can be a serious threat to any country that opposes their radical views.

Fusion Power
Nuclear Fusion is the process by which two atomic nuclei combine to form one heavier atomic nucleus,  giving off tremendous energy as a by-product. This type of nuclear reaction, which is the process by which stars such as the sun produce heat and light, requires very high temperatures and an enormous amount of pressure to initiate, and a reliable system of fuel containment to sustain. Fusion reactions have been produced in artificial environments on Earth by bombarding deuterium with high-energy particles accelerated in a cyclotron. Unfortunately, the amount of energy released in the reaction was considerably less than the energy required to accelerate the particles. Brief fusion reactions have been demonstrated in the detonation of thermonuclear weapons, but these reactions are useless for power generation because they cannot be controlled. If a way can be found to produce a controlled fusion reaction, this technology offers great promise as a source of electric power. The combination of abundant fuel sources and no harmful byproducts makes fusion power a safe alternative to the dangerous side effects produced by nuclear fission.

Future Technology
Since the dawn of mankind, human needs and desires have combined to produce ideas and inventions that make life easier and more productive. New technological breakthroughs have become an almost daily occurrence in the modern era, and new ideas will continue to drive human knowledge to higher and higher levels well into the future.

Genetic Engineering
Genetic Engineering involves the manipulation of deoxyribonucleic acid (DNA). DNA contains the genetic "code" which determines the inherited traits of living organisms. By removing a section of an organism's DNA and replacing it with that of another organism, the characteristics of the organism can be altered. Since its inception, genetic engineering has produced a number of important benefits, such as isolating the gene for interferon, a rare substance that may be of great value in the treatment of viral diseases and cancer. Genetic manipulation may someday also provide a cure for  birth defects and inherited diseases. Unfortunately, there are also potential dangers involved in this technology. Genetically engineered diseases, more communicable and virulent than any occurring in nature, could potentially be created in the laboratory by accident or maliciously. Such viruses could be used as a dreadful biological weapon. Domestic and international regulations regarding genetic experimentation exist to prevent such a situation from occurring.

Guerrilla Warfare
In extreme situations, usually spawned by an oppressive or militaristic system of government, small groups of citizens have been known to form armed factions. In many cases, these splinter groups lack the numbers, finances, and armament to start a full-scale revolution. Instead, they adopt a practice of undermining governmental authority through covert military operations. These operations usually take the form of hit-and-run raids, where rebel soldiers launch a surprise attack on an enemy target, then disappear into hiding, only to strike again at some other time and place. Such tactics, known as guerrilla warfare, seldom have any lasting effect individually. However, over many years, guerrilla factions can become a serious threat to governmental authority if the rebels cannot be caught and suppressed. Tactics of this sort were used to great effect by the partisan forces in Nazi-occupied Europe during World War II.

Gunpowder
Gunpowder is a chemical mixture of saltpeter, sulfur, and charcoal. When ignited, it burns rapidly and explodes if contained to any degree. Gunpowder is believed to have been developed by the Chinese, who used it in fireworks as early as the ninth century, but it did not reach Europe until the 14th century. Europeans immediately saw the potential of this substance, and was manufactured for use in weapons as early as 1334. The discovery of gunpowder led to the invention of firearms, such as the musket, which led to the replacement of archers in most armies of the world by the late 1500s. Gunpowder marked one of the major technological turning points in military history, significantly changing the way wars were fought.

Horseback Riding
The horse was first domesticated for transportation and warfare by tribesmen on the Asian steppes. These tribesmen used their superior mobility and speed to overwhelm the proto-civilizations just rising in southeast Europe and the Middle East. In about 2000 BC, domestic horses were introduced into Babylonia. Within the next several centuries, horses had spread throughout much of Europe and northern Africa. It was not long before nearly every civilization had put horses to work as field animals and as a means of transportation. Horses also went on to play an important role in the military conflicts of nearly every civilization in the world, both as mounts for horsemen and cavalry, and as draft animals for pulling war chariots and heavy weapons into battle.

Industrialization
Industrialization involves the use of machines to dramatically increase productivity. Production of goods became concentrated in factories, where the combination of specialization of labor and automation reduced labor costs and, ultimately, the cost of the final manufactured product to the consumers.  Industrialization revolutionized living standards, both positively and negatively. The rapid growth of production industries and the reduced cost of production has led to the prosperity of some of the richest families in history. Industrialization has also led to the creation of a blue collar working class. In newly industrialized nations, these workers, skilled only in their chosen trade, were often underpaid and forced to endure abominable working conditions.

Invention
The contrivance of a previously unknown device, method, or process which can, in turn, be used to accomplish an objective in a ways thought to be impossible, is known as invention. Essentially, inventiveness is the ability to take one or more newly discovered concepts and find a way to put them to practical use. The earliest inventions of mankind date back to ancient stone and metal tools used for hunting, digging, and other everyday tasks. After writing allowed the ideas of various civilizations to be exchanged and studied, mankind's inventions became increasingly more useful and innovative. Most inventions are geared toward improving or simplifying human existence in some way. Often, inventions themselves make it possible to make new discoveries, which then go on to inspire better and more innovative inventions.

Iron Working
Although examples of iron ornamentation date back to 4000 BC, the use of iron for tools, weapons, and other practical purposes did not become common until much later. Prior to this time, bronze was the most widely used metal for such purposes. Although the term "Iron Age" denotes a period of time starting at around 1000 BC, iron replaced bronze as the metal of choice at different times in different places. Although more common than both copper and tin, the component metals of bronze, iron is seldom found in a free state; it is most commonly found mixed with other minerals and elements. In order to be used, the iron must be separated from the ore. Once this technique was developed, and forges hot enough to melt the iron were developed, iron working became commonplace. Worked iron was harder, less brittle, and could hold a much sharper edge than bronze. Iron has remained an important metal throughout history, and is one of the major components in the production of steel.

Labor Union
Labor unions arose in the 18th and 19th century in response to the poor working conditions brought on by an intense competition for jobs, and the increasing dependence of the working class on their employers created by the move toward industrialization. Early labor unions, formed by skilled laborers in specific fields, met with opposition from both employers and the government. In the 19th century, laws were passed legalizing trade unions, and by the 20th century unions were formed in semi- or unskilled fields such as mining, transportation, and dock working. Binding their interests together and bargaining collectively, trade unions forced factory and business owners to provide better working conditions and economic status of their workers.

The Laser
Laser is an acronym for "Light Amplification by Stimulated Emission of Radiation". Lasers produce an amplified, coherent beam of light by using photons to energize or excite the electrons in the beam. The principles for the underlying theory of the stimulated emission of light was first proposed by Einstein in 1917. The first helium-neon gas laser was built in 1961. Years of research and development have led to a wide variety of laser applications in many different fields. Lasers can be used for everything from the precision cutting of almost any material and performing micro-surgery to reading digital data and music information off of a compact disc. The military currently uses lasers for weapons targeting systems, and it has been proposed that laser technology could be used to defend against an enemy missile attack.

Leadership
Through the Middle Ages, military forces were only assembled as needed, and continued to serve until the current conflict had ended. Though certain leaders had proven to be adept and occasionally brilliant in their methods, the short periods for which they served made their fame short-lived. As regular armies became more prevalent, military leaders had the opportunity to distinguish themselves through the formulation of brilliant military tactics. The tactics of leaders such as these would be studied by successive generations, and modified to fit new situations up to and including the present day.

Literacy
Writing was a powerful new tool for the advancement of knowledge, but, like all tools, it was only useful if employed. Literacy, the ability to read and understand a written language, was originally a skill limited to priests and scribes. Because of this, knowledge was still spread to the masses orally. Eventually, improving systems of education brought literacy to private citizens. Civilizations in which a high percentage of the population was literate had faster technological and economic growth than those where literacy was less common. In the modern world, while industrialized nations such as the U.S. enjoy widespread literacy, undeveloped nations still have illiteracy rates approaching 80 percent of their overall population. Illiteracy severely stunts the development of a country, even more so now than in the ancient world.

Machine Tools
One of the most important steps in the move toward industrialization was the ability to precisely shape or "machine" solid metal into a desired form. Through mechanical, chemical, and other means, machine tools mold and shape raw materials into precision parts for complex machinery. The first machine tool, a horizontal boring device, was produced in the late 1700's. The development of measuring devices accurate to within a millionth of an inch allowed for the mass production of items with interchangeable parts. The technology of the 20th century has produced computer-controlled machine tools that can be adapted to a wide variety of applications. The speed and accuracy of these machines allows for the economical mass production of extremely complex products.

Magnetism
The phenomenon of magnetism was known to the ancient Greeks, Romans, and Chinese. They observed that lodestone, an iron-bearing ore, attracted other iron. They also noted that pieces of iron that came into contact with lodestone gained magnetic properties as well. The electromagnetic force of attraction and repulsion between various substances is due to the motion of positively and negatively charged electrons. Every magnet has a positive and a negative side, called poles. Poles with a like charge repel one another, and poles with opposite charges attract one another. The study of magnetic phenomena soon showed that a free-floating magnet aligns itself with the Earth's magnetic field, one pole of the magnet pointing north, the other south. This was an important discovery, and led to the invention of the compass in the early 13th century. The use of the compass revolutionized sea travel by reducing the reliance on landmarks and stars for navigation.

Map Making
Maps provide a diagrammatic representation of an area, showing terrain features, cities, and other landmarks. The earliest maps, dating back to the second century BC, were etched clay tablets charting Babylonian lands for the purposes of taxation. Around the same time, the Chinese produced regional maps drawn on silk cloth. In between 600 and 200 BC, the Greeks produced several maps of the known world, including the first map showing a primitive system of latitude and longitude. These early maps were primarily used by traders and merchants. Seamen, who often set their courses based only on the tales brought back by previous voyagers, benefited most from the science of map making.

Masonry
The early dwellings of most tribal cultures were built of materials that were readily available and easy to work with, such as bricks of clay and mud. As tribes gave up their nomadic ways and settled the first cities, they soon found they had a need for more permanent and durable structures. The skill of masonry was developed to fill this need. The earliest stone structures consisted of little more than rocks which were stacked atop one another to form crude walls. Artisans soon began to square off the rocks, forming them into regular shapes and stacking them. These early examples of masonry used no mortar; the weight of the stacked stones provided overall strength and stability. Without the use of mortar and knowledge of architectural techniques, masonry was used primarily for simple structures such as fortifications. However, some examples of early masonry are quite spectacular, including the Great Pyramids in Egypt, which are still standing after thousands of years.

Mass Production
The idea of mass production began to take shape along with the factory system. The automation of production greatly increased productivity with a corresponding decrease in price for manufactured goods. In 1913, automobile manufacturer Henry Ford introduced the idea of assembly lines in his automobile plants. Products being built were conveyed from one work station to another along the line.  At each station, a worker expertly repeated a discreet segment of the assembly process. The product then moved to the next station, and so on until the finished product rolled off the end of the line. This innovative combination of specialization of labor and the use of automation revolutionized production of complex goods. Word of Ford's assembly line technique spread quickly, and this production method soon came to be used in most of the industrialized nations of the world.

Mathematics
Rudimentary arithmetic was purely quantitative, used to keep track of quantities and measurements in trade. Building on this fundamental base, ancient civilizations began to formulate more complex mathematical concepts. As early as 1800 BC, the Egyptians had developed a system for working with fractional numbers and simple algebraic problems. They also formulated geometric formulae for finding area and volume, and came up with a constant for determining the area of a circle that was very close to the value of pi. By about the 5th century BC, the mathematicians of Greece had greatly contributed to both geometry and algebra. Around the same time, advanced mathematics was applied to other sciences and fields of study such as astronomy and mechanics. One of the earliest applications of mathematical principles was in the construction of complex weaponry such as the catapult.

Medicine
Primitive man attributed the onset of serious disease as the influence of the gods, or possession by evil spirits. Over time, however, it was found that such "possessions" could be treated through the use of elixirs made from plant extracts. Methods were also developed to clean and treat wounds, and set fractured bones. The ancient Greeks established the first schools to teach medical sciences in around 500 BC. The texts produced by the students of these schools, most notably Hippocrates,  who is considered the father of medicine, based his theories of the human body on observation and reasoning rather than supernatural intervention. Continued study of diseases over the years, combined with the dissection and study of the human body in the 13th century, pointed out flaws in early Greek theories, and led to more accurate medical texts based on detailed analysis rather than conjecture. By the 18th century, the same methods of analysis and observation used by scientists in other fields were applied to the study of medicine. This paved the way for the increasingly effective methods of treatment and surgery that have prevailed over the last 200 years.

Metallurgy
Metallurgy is the study of the properties of metals and the methods used to separate metal deposits from metal-bearing ores. Through the course of history, artisans have switched the materials from which they constructed weapons and tools to harder, more durable metals as they were discovered. However, metallurgy as a science wasn't studied in earnest until the powers of Europe began to compete against one another in an attempt to design better and more effective weapons starting in about the 14th century. Constant improvements in metallurgy led to the discovery of new metals and alloys that were stronger, lighter, and cheaper. As a result of this race for military dominance, Europe produced some of the most advanced weaponry in the world during this time period.

Miniaturization
Early radios and other electronic devices relied on vacuum tube technology. Because the tubes took up a great deal of space, the devices that utilized them tended to be very bulky and cumbersome. In the late 1940's, the development of the transistor provided a compact alternative to vacuum tubes. Transistors were capable of achieving the same level of power amplification achieved by tubes while taking up much less space, and using only a fraction of the power. Starting in the 1960's, the integrated circuit provided still another level of miniaturization. An integrated circuit the size of a transistor could perform the function of 20 transistors. Today, the microprocessor, a modern refinement of the original integrated circuits, can incorporate the functions of several complete printed circuit boards into a single, low-power consumption chip less than two inches square, allowing for the construction of hand-held computers with more computing power than the huge mainframes used in the 70's and 80's.

Mobile Warfare
The idea of using heavy weapons on the battlefield dates back to the 15th century when heavy cannons were mounted on wheels and towed into battle by horses. This first use of mobile artillery, devastatingly effective in its time, pales in comparison to the tactics used in 20th century armored warfare. Tanks were first used during World War I. A successful assault utilizing 400 tanks in November 1917, resulting in the capture of 8000 enemy troops and 100 guns near Cambrai, paved the way for a significant shift in battlefield tactics. During World War II, armored vehicles were used extensively throughout Europe and Africa by both Allied and Axis powers. The might and mobility of an armored assault was more than a match for countries who lacked proper defenses against such an attack. Armored warfare still plays an important role in battlefield tactics. This was proven in the Persian Gulf war, where the M1 Abrams tank proved to be vital a component of the ground assault force in Kuwait.

Monarchy
Rule by monarchy developed as a logical extension of the absolute rule of tribal chieftains. Many of the earliest monarchs, such as those in ancient Egypt, claimed that they ruled by divine right. In the spread of European monarchy during the Middle Ages, however, rulership was generally conveyed upon a leader who could most effectively raise and command an army. Monarchies are dynastic, with rule of the country passing to the eldest son when the king dies or retires. Monarchs had absolute rule over their subjects, severely limiting the personal and economic freedom of all citizens except for nobility and the rich upper-class. Although monarchies ruled most of Europe for centuries, the unhappiness of lower-class citizens eventually grew intolerable, causing several major revolutions. By the end of the beginning of the 18th century, the power of the European monarchs had been severely limited, paving the way for participatory systems of government.

Monotheism
Monotheism is the belief that there is only one God. Perhaps the oldest monotheistic religion is Judaism. The original Israelites were polytheistic in a sense, since they did not deny the existence of other gods in addition to their own. However, after being exiled to Babylonia in 586 BC, the Judeans turned to a truly monotheistic religion, where the God of Israel was seen as the universal God ruling the destiny of all nations. The scriptures of Judaism became part of the teachings of the two most widespread monotheistic religions, Christianity and Islam. More developed than earlier polytheistic beliefs, monotheistic religions tend to encompass and structure the entire lifestyles of the people who practice them.

Mysticism
People of the ancient world were fascinated and awed by the forces of nature surrounding them. Earthquakes, storms and other phenomena were generally regarded as signs from heaven. Individuals and groups arose to formulate explanations for these events, and pass the knowledge along to the tribe. The priests and priestesses of mysticism, often called oracles, claimed union with the divine through meditation and trance-like contemplation. Primitive mysticism offered mankind the first, tenuous links with the powers that shaped their world, and represented the first move toward the organized polytheistic and monotheistic religions to come.

Navigation
In the early days of seafaring, sailors operated solely through a process known as "piloting", in which the position and course of the ship was determined by referring to geographical landmarks. The need to stay in view of the shore severely limited the extent of sea voyages. Through experience, sailors learned to apply the science of astronomy to their profession, noting the positions and movement of particular stars. They realized that even when the shore was out of sight, they could steer by certain reliable stars. This crude,  yet practical application of astronomy allowed the adventurous to sail into the unknown with a reasonable chance of finding their way. As a result, ship building technology quickly improved, producing larger, more stable ships designed for longer voyages.

Nuclear Fission
According to Einstein's theory of relativity, even the smallest bit of matter is equivalent to a tremendous amount of energy. For instance, two pounds of matter, if converted completely into energy, would produce energy equivalent to the explosive force of 22 megatons of high explosives. In 1939, based on German experiments that successfully split the uranium atom, physicists were able to explain the process of nuclear fission.  When a large, unstable atomic nucleus splits (fissions) the result is two or more smaller, more stable nuclei accompanied by the release of tremendous amounts of energy and lingering, deadly radioactivity. The first application of this powerful technology was in warfare. A top-secret research effort in the U.S. known as the Manhattan Project studied the fission process, and eventually produced the first atomic bombs, which were dropped on the Japanese cities of Hiroshima and Nagasaki in 1945. These relatively small bombs, the only atomic weapons ever used in a war, each produced an explosion equivalent to more than 20,000 tons of TNT. The nuclear weapons of today are capable of producing explosions thousands of times more powerful.

Nuclear Power
In addition to its potential for destruction, the energy released in nuclear fission was seen as a potential source of controlled power generation. By 1944, large-scale nuclear reactors were in operation for the production of plutonium, although the energy produced by these reactors was not used. Following World War II, increased efforts were turned toward the extensive use of nuclear power to produce electricity. Nuclear power plants use the radiant energy of a controlled nuclear reaction to heat water, converting it to steam to turbines that generate electricity. The major drawback to nuclear fission is the lack of a safe means of disposal for the waste produced by the reaction, which retains its lethal radioactivity for hundreds of years. Another hazard is the possibility of a malfunction in the reactor that could lead to a meltdown of the core. Despite massive safety precautions, human error and equipment failures can lead to devastating accidents such as the explosion at Chernobyl in 1986, in which at least 30 people were killed and thousands lost their homes and face possible long-term illness after exposure to near-lethal doses of radiation. Because of growing public concern, the development of new nuclear power plants has slowed as scientists search for viable solutions to these problems.

Polytheism
Polytheism is the belief that the world and the environment is ruled or controlled by a number of different gods or divinities. Many ancient religions were polytheistic, notably those of the Egyptians, the Greeks, the Norse, and the Romans. Often, polytheistic religions have different gods for each force of nature and earthly phenomenon; for instance: a sun god, a moon god, a god of thunder, a god of the forests, and so forth. The reason for such diversity in divine beings probably stems from ancient civilizations attempting to find explanations for natural events they could not understand. Although some isolated examples still exist today, most polytheistic religions have either died out or evolved into monotheism.

Philosophy
The term philosophy comes from a Greek term meaning "love of wisdom". In ancient Greece, literacy and an interest in the natural world were common in a burgeoning upper class. In their leisure time, these people contemplated principles of thinking and being, logic and mathematics, and the natures of reality and existence. In ancient times, the study of philosophy was indistinguishable from the study of science, and many of the theories formulated by the early  philosophers became the basis for studies in the fields of astronomy, medicine, chemistry, and physics. The teachings and writings of the ancient philosophers of Greece and the Orient also, in part, laid the groundwork for many of the world's oldest organized religions.

Physics
Physics is the study of the many forms of matter and energy and of the way they interact with themselves and each other. A number of ancient races made observations about certain aspects of physics, such as planetary motion, but were unable to develop theories as to the reasons for these motions. Some of the earliest applications of physics were by the Greek mathematician Archemedes, who applied physics to create such devices as levers and screws. It was not until the 17th century that experimental methods and scientific measuring devices led to true understanding of many fundamental physical laws. Early scientists such as Johannes Kepler and Sir Isaac Newton began to disprove the theories of the ancient Greek philosophers and scientifically prove their theories concerning the laws of physics. Discoveries in physics rarely have direct application, but they provide a basic understanding of the laws governing the universe, thus forming the basis for practical advances in technology.

Plastics
One of the spin-offs of research into more efficient refining of crude oil was the invention of plastics,  organic polymer materials that retain their strength when molded into almost any shape. Plastics were first developed in the 1860's in an attempt to find a substitute for ivory. Starting in the 1920s, a flurry of research into the nature and fabrication of plastics resulted in widespread developments in the field, including the formulation of Plexiglas and nylon in the late 1930s. The boom in plastics research and development continued into and after World War II. Plastics were quickly adopted as cheap, sturdy substitutes for more traditional materials such as glass, rubber, and silk. It seemed that plastics were one of the most practical achievements of the Industrial Age. Unfortunately, despite their usefulness, plastics have proven to be an environmental hazard. Since most plastics are not biodegradable, they are very difficult to dispose of. The significant pollution problem posed by plastics has been alleviated to an extent through the widespread implementation of recycling programs.

Pottery
The invention of pottery was essential to the development of agricultural societies. To get the most out of seasonal crops and domesticated animals, a tribe needed sturdy, waterproof containers in which to store and protect surplus food. The discoveries of the properties of clay, and the invention of the kiln, and the potter's wheel made it possible to build such containers. The earliest examples of Western pottery dates back to as early as 6500 BC. Most of the examples from this period were strictly utilitarian. Although its use continued to be primarily practical, decorative pottery soon became a ritualistic and aesthetic art form in cultures all over the world. Some of the most impressive examples of artistic pottery come from the pre-Columbian cultures of South America, and from the Ming dynasty in 14th century China.

Radio
Prior to Gugliemo Marconi's invention of the radio in 1896, long-distance communication was carried out either by mail or over miles of cable via telegraph. Marconi's first demonstration of the radio telegraph transmitted a message just over one mile without the use of wires. Continued improvements increased transmission range to over 200 miles by early 1901, and by the end of the year a single letter ("A") had been transmitted across the Atlantic Ocean. By 1905, many ships were equipped with radio telegraphs for ship-to-ship and ship-to-land communications, and by 1915 the invention of the three-element vacuum tube, or triode, made it possible to regularly transmit voice messages over the airwaves. Throughout the years, radio has been refined not only for communication, but for detection and ranging (Radar) and astronomy.

Railroad
The predecessors to modern railroads were wagonways, which were constructed in England starting in the 16th century. Wagonways were roads of parallel planks upon which coal wagons were pulled by horses at a greater speed than would have been possible on dirt roads. Wagonways were gradually improved by adding cross-ties and iron strips to reinforce the track. Eventually, the planks became metal rails, and evolved into the type of rails used on today's railroads by the start of the 19th century. Soon after the steam locomotive was introduced in 1829, they replaced horse-drawn wagons, giving birth to the railroad. Originally developed in Britain and the eastern United States as a method of hauling heavy mining ores and freight, railroads outshone canals in their ability to operate across any ground and in nearly any weather. When railroads started carrying passengers as well as goods, the potential for safe, fast,  inexpensive transport became clear. Railroads led to a dramatic increase in the amount of cargo,  passengers, news, and troops that could be moved quickly over great distances.

Recycling
Increasing world population has led to an inevitable increase in the amount of garbage produced by society. Conventional disposal methods, such as burial in a landfill, have proven inadequate to handle the growing waste problem. One solution to this problem is the reuse of discarded materials through recycling. Although scrap metals and other materials have been reused in manufacturing processes for some time,  true recycling is a broad-based, household-by-household effort. The increasing pollution generated by industry and consumerism, added to the depletion of natural resources, make the re-use of materials less a concern of efficiency and more a necessity for the survival of the human species. Not only does the recycling of waste materials prevent the unwanted build-up of garbage, it saves energy and slows the depletion of natural resources such as trees and petroleum products.

Refining
When the demand for oil-based fuels for lighting and other purposes began to soar in the 19th century, scientists began searching for a way to make use of crude oil. This research led to techniques in which crude oil was broken down, or refined, into a number of different fuels, including kerosene and gasoline. As consumer demand continued to increase, commercial refineries were set up to purify crude oil. The new petroleum products produced as a result of the development and perfection of the refining process led to the use of oil-based fuels in many consumer and industrial applications. These included the use of gasoline to power automobiles, and the use of oil for heating and for the generation of electrical power.

Refrigeration
Prior to World War I, ice was the most widely used means of refrigeration for perishable items. After the war, electrical refrigerators became commonly available. The availability of these systems allowed for more constant and efficient cooling, in turn allowing perishable meats, dairy products, and other items to be stored, or even frozen, for long periods of time. As a result, food producers could increase their output, since excess food could be stored for later sale or consumption. The concept of the wholesale selling of bulk foods (known as the supermarket) was, in part, made possible by improved refrigeration. The same method used in food refrigeration was also developed for use in air conditioners.

The Republic
The republic is a system of government in which the citizens appoint, by popular vote, a head of state and officials to represent the views of the general public. The concept of the republic first appeared in ancient Rome, where local provinces sent elected representatives to the Senate, which governed all Roman lands. Both the head of state and the local representatives in a republic are elected; no one is granted a position by birth or divine right. Republican governments are similar in some ways to democracies, in that they offer a great deal of personal, financial, and political freedom to their citizens. The main difference between the two systems is that a true democracy allows the participation of every voting citizen in any and all political matters, whereas in a republic, the views and opinions of the people are represented by a body of elected officials. Although an effective system, personal agendas of political representatives may act to decrease the effectiveness in representing the views of the people. Due to human nature, corruption is fairly common in a republican government.

Robotics
The creation of machines to assist in, and increase the efficiency of, the manufacturing process gave birth to the factory system of production and started the Industrial Revolution. The invention of digital computers in the late 1940's, and their refinement over the next several decades, took factory automation one step further. Computer-controlled machines, called robots, were designed to perform repetitive or dangerous tasks more quickly than humans. Experimental robots capable of simple manipulation of objects were in operation by the late 1960s. The first robots used on an assembly line were commissioned by General Motors in the 1970's. Constant improvements in the computer field have allowed the production of incredibly versatile robots, capable of performing a wide variety of tasks under virtually any environmental condition. Robots today are widely used in manufacturing, scientific research, and space exploration.

Rocketry
Rockets are projectiles that are propelled by the expulsion of gases generated in a combustion chamber. The first solid-fuel rockets, invented by the Chinese in the 13th century, used a mixture similar to gunpowder for fuel. Although rockets were used in warfare to set fire to buildings and the sails of ships for nearly 500 years, it wasn't until the early 19th century that the first crude explosive rockets were used in battle. Research and design efforts by scientists such as Robert Goddard in the 20th century refined rocket design to produce faster, better controlled rockets. During World War II, this new technology was used to create the German V-2 "buzz bomb", the first true guided missile. Scientific developments since World War II have been applied to adapt the rocket for use in even more powerful and accurate weapons with incredible range. The rocket is also used in peaceful application such as the launch of satellites and the exploration of space.

Sanitation
The increased waste produced by growing populations over time eventually led to potential health hazards. It then became necessary to come up with systems to dispose of garbage and human waste in a sanitary manner. Plumbing systems designed to remove waste water from dwellings and public buildings became commonplace, as did sewage plants which treated the wastewater before it was dumped into local waterways. Landfills were established, and garbage was collected for sanitary disposal in dumps and landfills a safe distance from the general population. These measures led to a healthier environment, and allowed for further population growth.

Seafaring
As empires grew and trade expanded to new areas, travel by sea became increasingly important to the civilizations of the world. Experienced sailors passed down their lore and techniques to new generations who sailed to increasingly distant lands. Originally, these long voyages were trade-oriented. But the ability to travel great distances led to a new breed of adventurers whose goal was primarily one of exploration. The Vikings were some of the earliest and most successful explorers in history. Their knowledge of the sea and experience with long ocean voyages allowed explorers such as Leif Ericson to successfully cross the Atlantic and land in the Americas more than 500 years before Columbus. The pioneering spirit of these early ocean travelers formed the basis for the seafaring traditions of generations to come.

Space Flight
Utilizing the now well-developed science of rocketry, the modern exploration of space began in October, 1957 when the Soviet Union launched Sputnik 1. This tiny satellite orbited the earth for 57 days, providing information on radiation and other phenomena in the upper atmosphere. Within less than a year, the United States had also launched a satellite, Explorer 1. This started the "space race", years of competition between the U.S. and Russia to achieve new frontiers in space exploration. Space flight advanced rapidly from the simple sub-orbital flights of the 1950's, to manned missions to Earth's moon in the late 1960's. The rapid growth of space technology led to many practical applications, such as weather and surveillance satellites, and vastly improved worldwide communications. Today, although hindered by severe government budget cuts, the exploration of space continues. Plans in the near future call for continued orbital exploration via the space shuttle program, and the eventual construction of the multi-national, manned space station "Freedom" in the early 21st century.

Steam Engine
The steam engine is a device that uses steam to generate power. Water, heated by burning fuel (usually coal or wood), turns to steam. The steam is contained in a chamber where it builds up pressure, causing a piston to move. The motion of the piston drives a turbine, the motion of which produces power which can be use for such purposes as producing motion or generating electricity. The early principles of this device were understood as early as the late 17th century, but it wasn't until 1769 that Scottish engineer James Watt patented a practical design for what was to become the basis for the modern steam engine. The invention of the steam engine led to a number of  landmark developments, including the steam locomotive and the earliest examples of automobiles. Steam engines remained the chief means of motive power in the transportation industry until the invention of the more powerful and compact internal combustion engine. Steam turbines are still in use today in a number of applications including the generation of electrical power.

Stealth
It has long been recognized that in warfare, the best advantage available is surprise. If one can approach an enemy undetected, the attack has a better chance of being successful. The widespread use of radar starting in World War II greatly decreased the possibility of surprise for an airborne assault. Planes could be detected from miles away, giving the enemy a chance to prepare for the attack. Over the years, the military has employed many different approaches to solve this problem. The most recent development is "Stealth" technology. Stealth planes are painted with radar-absorbing paint, and designed in such a way as to minimize the number of angular surfaces from which an enemy can bounce a radar signal. The engines are also hooded to reduce the plane's heat signature. The result is an aircraft capable of approaching an enemy target, launching an attack, and returning to base with little chance of detection. The F-117A Stealth Fighter was used with great effectiveness by US forces in the Persian Gulf War in 1991.

Steel
The iron alloys produced up until about the 14th century were made by heating a mixture of iron ore and charcoal in a forge, then pounding the molten metal to drive out the impurities or "slag". Occasionally, the iron mixture would absorb more carbon, creating steel rather than wrought iron. Because steel proved to be less brittle and more resistant to corrosion than iron, techniques were developed to produce steel. This was done by blowing a coal derivative called coke through molten iron. Most modern steel making utilizes the "blast furnace", developed by Henry Bessemer in 1855, to accomplish this task on a large-scale basis. The strength and other qualities of steel made it the material of choice for warships, planes, and many other vehicles.

Superconductor
Any material through which an electrical current can pass with relatively little resistance is known as a conductor. When an electric current passes through most conductors, part of that current is lost due to resistance, which varies depending on the conducting material and the ambient temperature. Some conductors, when cooled to temperatures near absolute zero, lose all resistance to current. These are known as superconductors. Because no energy is lost to resistance, superconductors can lead to a wide variety of practical uses. These include super-fast computers, powerful electromagnetic fields strong enough to contain fusion reactions, and the completely efficient generation and transmission of electrical power. Although the extremely low temperatures necessary to produce superconductivity have limited its uses thus far, recent developments hint that some unusual materials may be superconductive even at room temperatures. The isolation and large-scale production of these materials would lead to a new revolution in the field of electronics.

Tactics
The science of the deployment of military forces to accomplish a short-range goal or objective is known as tactics. In unique or difficult situations, the maneuvers and methods of attack must be chosen wisely to give ones troops the maximum possible advantage over the enemy by taking advantage of the enemy's weaknesses. The successful tactics of military commanders are studied by their successors for possible modification and use under current conditions. Although tactics that work well in certain situations may not always be successful when used again, proven military tactics have worked well in many different battle situations throughout history. The vast amount of advanced equipment and resources available in modern warfare make the proper tactical coordination of a campaign vital, but difficult to achieve with total success.

Theology
Theology is the study of God and religious truth. Theologians take a more or less scientific approach to questions of religion, deeply studying the underlying meaning of scriptures and religious teachings rather than "taking them on faith". Theological seminaries teach courses of study in theology to prepare people as priests and clergymen. Many of the earliest colleges of the western world were originally established for this purpose. Theological study helped to remove some of the superstitions that had surrounded religion for so long, and brought religious study into a more enlightened age.

Theory of Gravity
In the 17th century, Sir Isaac Newton developed the law of universal gravitation. This law recognized that every mass in the universe exerts an attraction on every other mass. Newton postulated that gravity was a universal force that affected all matter. Newton's theory served to explain the forces of attraction between the Earth and nearby objects, as well as the forces that affect the motion of planets and other astronomical bodies. In the early 20th century, Albert Einstein's special theory of relativity led to a major reinterpretation and clarification of Newton's theory of gravity. Scientists now believe that gravity affects energy as well as matter, and that gravity is actually a fundamental warping of the fabric of space-time. Some theorize that the force of this warping is transmitted by as-yet-unobserved particles called gravitons.

Trade
One of the oldest and most widespread social institutions is the exchange of goods, or trade. Most ancient trade consisted of barter, where two traders would exchange goods with one another. The widespread practice of trade allowed civilizations to exchange raw materials and goods which they had in abundance or could easily produce, for items that were rare or nonexistent in their geographic region. The introduction of regulated currency that could be exchanged for items resulted in easier, more convenient trade. Merchants soon roamed the world, connecting different lands with webs of economic interdependence. In addition to goods and profits, traders also brought back. Well-traveled traders like Marco Polo were among the most learned sources on the cultures and traditions of foreign lands.

University
Institutes of higher learning, such as the Academy of Plato in Athens which taught advanced philosophical principles, existed in the ancient world. It was not until the 12th century, however, that the model for the modern university system was born. In the Middle Ages, some royal governments and ecclesiastical organizations founded exclusive schools dedicated to training young men in specific professions. At that time, each university specialized in a single topic like law, theology, music, or medicine. Through the centuries, universities diversified to include a number of different fields of study. Modern universities consists of several faculties, or colleges, each of which has a specific curriculum. In addition to their roles as learning institutions, universities have, since their inception, acted as centers for scientific research and advancement.

Warrior Code
The samurai of feudal Japan lived by a doctrine known as "Bushido", or "the way of the warrior". This code of behavior stressed such virtues as loyalty, courage, and politeness. The honor of the warrior could only be maintained if the rules of the code were followed. A similar code of behavior known as chivalry was later developed under the feudal system in medieval Europe. Although the strict adherence to both Bushido and chivalry were abandoned along with the feudal system in the 1800's, certain principals of discipline and behavior inherent in these systems can still be found in the military today.

The Wheel
The invention of the wheel represented a major turning point in human civilization. The first wheels, disks carved from solid wood, may have been built as early as 3500 BC. The earliest use of this device was the potter's wheel, used to spin and shape clay pottery. It was not long before the true potential of the wheel was discovered, and wheeled carts soon replaced the sledge as a means of transportation. Rapid developments, such as wheels consisting of a ring with radial spokes, made the wheel even more practical by reducing its weight. By using the wheel, mankind gained the ability to work more efficiently and travel more quickly. Besides its use in transportation, the wheel went on to become the basic principle behind almost every mechanical device.

Writing
The development of writing is considered one of the most important advances of civilization. The earliest forms of writing were simple symbols and marks, used to keep accounts and inventories. Some cultures developed pictographic symbols to tell stories and record events. Eventually, complete systems of writing were developed, capable of conveying any thought that could be expressed orally. At this point, scribes replaced the oral historian as the chief keepers of records. Writing allowed the presentation of information in a form that could be reliably transmitted from person to person made it possible for ideas, history, and knowledge to be stored permanently and passed between cultures more reliably than through oral recitation.

