Stock Exchange

Stock Exchange, organized market for buying and selling financial instruments known as securities, which include stocks, bonds, options, and futures. Most stock exchanges have specific locations where the trades are completed. For the stock of a company to be traded at these exchanges, it must be listed, and to be listed, the company must satisfy certain requirements. But not all stocks are bought and sold at a specific site. Such stocks are referred to as unlisted. Many of these stocks are traded over the counter—that is, by telephone or by computer.

Major stock exchanges in the United States include the New York Stock Exchange (NYSE) and the American Stock Exchange (AMEX), both in New York City. Far more corporations list their stock on the NYSE than on the AMEX, however. Nine smaller regional stock exchanges operate in Boston, Massachusetts; Cincinnati, Ohio; Chicago, Illinois; Los Angeles, California; Miami, Florida; Philadelphia, Pennsylvania; Salt Lake City, Utah; San Francisco, California; and Spokane, Washington. In addition, most of the world’s industrialized nations have stock exchanges. Among the larger international exchanges are those in London, England; Paris, France; Milan, Italy; Hong Kong, China; Toronto, Canada; and Tokyo, Japan. These stock exchanges all have a central location for trading. The major over-the-counter market in the United States is the Nasdaq Stock Market (formerly, the National Association of Securities Dealers Automated Quotation [NASDAQ] system). The European Association of Securities Dealers Automated Quotation system (EASDAQ) is the major over-the-counter market for the European Union (EU).

Ozone

Ozone (Greek ozein, “to smell”), pale blue, highly poisonous gas with a strong odor. Ozone is considered a pollutant at ground level, but the ozone layer of the upper atmosphere protects life on Earth from the Sun’s harmful ultraviolet radiation.
Ozone is one of three forms, called allotropes, of the element oxygen. Ozone is triatomic, meaning that it has three atoms in each molecule (formula O3). Ordinary, or diatomic, oxygen (O2) is more stable than ozone and accounts for the bulk of oxygen in the atmosphere. Electrical sparks and ultraviolet light can cause ordinary oxygen to form ozone. The presence of ozone sometimes causes a detectable odor near electrical outlets.

The Apollo & NASA

Apollo Program, American manned lunar-space program designed to land an astronaut on the moon and return him safely to earth, as well as to overtake the former Soviet Union in the race to dominate space exploration. Conducted between May 1961 and December 1972 by the National Aeronautics and Space Administration (NASA), the program successfully landed Neil Armstrong—the first person to walk on the moon—and 11 other astronauts on the moon. The program included 12 manned missions: 2 into earth orbit (Apollo 7 and 9); 2 into lunar orbit (Apollo 8 and 10); 3 lunar landing missions (Apollo 11, 12, and 14); and 3 lunar exploration missions (Apollo 15, 16, and 17), which involved extended stays on the moon’s surface and more in depth scientific exploration. One mission was lost during a test on the launch pad (Apollo 1), and one mission returned to the earth before making a scheduled lunar landing (Apollo 13). Following the Apollo program, Apollo spacecraft were used to shuttle astronauts to and from the Skylab space station, and an Apollo spacecraft docked with the orbiting Soviet spacecraft Soyuz 19 in the Apollo-Soyuz Test Project.

The Apollo program was initiated by United States President John F. Kennedy on May 25, 1961. It was preceded by the manned Gemini program, which engineers used to develop the techniques that would be needed for the ambitious trip to the moon, and the unmanned Surveyor Program, which scientists used to probe the lunar surface. At the peak of Apollo preparations in 1965, NASA employed 36,000 civil servants, 376,700 contractor employees, and a yearly operating budget of $5.2 billion. Between 1961 and 1973, NASA spent approximately $25.4 billion on the Apollo missions.

In July 1969 astronauts Neil A. Armstrong and Edwin E. Aldrin, Jr., became the first human beings to set foot on the surface of the moon. The United States space program was in full swing at that time, and in July and August two space probes—Mariner 6 and Mariner 7—flew by Mars to gather data and return images of Earth’s neighboring planet. A September 1969 Scientific American article described some of the scientific information gathered during these three missions. During the same time period, the Soviet Union scheduled a manned mission to circle the moon (Zond 7)—just three weeks before Apollo 8. This mission was postponed and the spacecraft was later launched unmanned. The Soviets continued to develop and test their one-man Lunar Lander spacecraft in the earth’s orbit through August 1971, but a Soviet cosmonaut never reached the moon.

Domain Name System

Domain Name System (DNS), in computer communications, a method of translating Internet addresses so that computers connected in the Internet can find each other. A DNS server translates a numerical address assigned to a computer (such as 207.46.228.91) into a sequence of words, and vice versa. A DNS name, written in lowercase letters with words separated by periods, takes the form of username@computer.zonename. Username is the name or account number used to log on. The hostname (Whitehouse in the example above) is the name of the computer or Internet provider; it may consist of several parts. Zonename indicates the type of organization. Common zone names include com (commercial organization), edu (educational), gov (government), and net (networking organization).

Gold

Gold, symbol Au (from Latin aurum, “gold”), soft, dense, bright yellow metallic element. Gold is one of the transition elements of the periodic table; its atomic number is 79. Pure gold is the most malleable and ductile of all the metals. It can easily be beaten or hammered to a thickness of 0.000013 cm (0.000005 in), and 29 g (1.02 oz) could be drawn into a wire 100 km (62 mi) long. It is one of the softest metals (hardness, 2.5 to 3) and is a good conductor of heat and electricity. Gold is bright yellow and has a high luster. Finely divided gold, like other metallic powders, is black; colloidally suspended gold ranges in color from ruby red to purple
Gold is extremely inactive. It is unaffected by air, heat, moisture, and most solvents. It will, however, dissolve in aqueous mixtures containing various halogens such as chlorides, bromides, or some iodides. It will also dissolve in some oxidizing mixtures, such as cyanide ion with oxygen, and in aqua regia, a mixture of hydrochloric and nitric acids. The chlorides and cyanides are important compounds of gold. Gold melts at about 1064° C (about 1947° F), boils at about 2808° C (about 5086° F), and has a specific gravity of 19.3; its atomic weight is 196.97.

Diamond

Diamond, mineral form of the element carbon, valued as a precious stone. Diamond is the hardest natural mineral and has many other exceptional properties that collectively make it an important industrial and scientific material. Unique geologically, diamonds form at great depths within Earth and are typically billions of years old.
Diamonds are crystals composed of pure carbon. In nature, diamond crystallizes from hot carbon-rich fluids. This crystallization requires tremendous heat and pressure—1000 to 1200°C (1800 to 2200°F) of heat and 50 kilobars of pressure. (One bar is based on the pressure the atmosphere exerts at sea level, about 1.02 kg per sq cm, or 14.7 lb per sq in; 50 kilobars is 50,000 bars.) The pressures and temperatures at which natural diamond forms only occur deep underground. Scientists believe that diamonds form at depths greater than 150 km (93 mi), and there is evidence that some diamonds formed as deep as 670 km (420 mi) beneath Earth’s surface.

Dollar

Dollar, name of various coins and paper money formerly or currently in use in parts of Europe, Africa, Asia, Oceania, and the western hemisphere. It is the standard value, or unit of account, in the monetary systems of Canada and the United States. The word dollar comes from the old German Daler or Taler, an abbreviation of joachimsthaler, the name of a silver coin, imprinted with an effigy of St. Joachim, which was first struck (1519) in what is now Germany. Later, a large milled-edged silver coin called peso duro (hard dollar as it is known in English) was minted in Spain and widely used in the Spanish and English colonies of the New World.

Euro

Euro, monetary unit of the European Union (EU). On January 1, 2002, euro-denominated coins and bills went into circulation in 12 of the 15 EU member states—Austria, Belgium, Finland, France, Germany, Greece, Italy, Ireland, Luxembourg, The Netherlands, Spain, and Portugal. The euro replaced the currencies of these nations.

The adoption of the euro was the final step in the EU’s plan for Economic and Monetary Union (EMU). EMU was designed to establish a single currency and a single monetary authority for EU member states, and was an integral part of the 1991 Maastricht Treaty that founded the EU. In order to make the euro a stable currency, the EU set stringent economic criteria that member countries had to meet before they could adopt the euro. These criteria dealt with things such as levels of inflation, amount of budget deficit and government debt, and stability of the existing national currency.

On January 1, 1999, the euro went into use for accounting purposes and electronic fund transfers in 11 participating EU member states. Greece, the 12th participating member, did not officially adopt the euro until January 1, 2001. Between 1999 and 2002, the euro coexisted with the currencies of the participating states. Starting in 2002 euro notes and coins became legal tender and entered circulation in the 12 states. The member states’ old currencies were to remain legal tender until the end of February 2002, when all monetary transactions were to be conducted in euros.

The bank of issue for the euro is the European Central Bank (ECB), which was established in June 1998 and began operation on January 1, 1999. The ECB, located in Frankfurt, Germany, has total control over all EU monetary policies, including setting interest rates and regulating the money supply.

The euro is divided into 100 cents. Euro notes are issued in denominations of 5, 10, 20, 50, 100, 200, and 500 euros. Coins are issued in denominations of 1, 2, 5, 10, 20, and 50 cents, and 1 and 2 euros. Although bills are identical in all countries, each country issues its own coins, which have a common design on one side and a national design or emblem from the country of issue on the other.

Geography

Geography, science that deals with the distribution and arrangement of all elements of the earth's surface. The word geography was adopted in the 200s bc by the Greek scholar Eratosthenes and means “earth description.” Geographic study encompasses the environment of the earth's surface and the relationship of humans to this environment, which includes both physical and cultural geographic features. Physical geographic features include the climate, land and water, and plant and animal life. Cultural geographic features include artificial entities, such as nations, settlements, lines of communication, transportation, buildings, and other modifications of the physical geographic environment. Geographers use economics, history, biology, geology, and mathematics in their studies.

Geography may be divided into two fundamental branches: systematic and regional geography. Systematic geography is concerned with individual physical and cultural elements of the earth. Regional geography is concerned with various areas of the earth, particularly the unique combinations of physical and cultural features that characterize each region and distinguish one region from another. Because the division is based only on a difference in approach to geographic studies, the two branches are interdependent and are usually applied together. Each branch is divided into several fields that specialize in particular aspects of geography.

Automobile

INTRODUCTION
Automobile, self-propelled vehicle used primarily on public roads but adaptable to other surfaces. Automobiles changed the world during the 20th century, particularly in the United States and other industrialized nations. From the growth of suburbs to the development of elaborate road and highway systems, the so-called horseless carriage has forever altered the modern landscape. The manufacture, sale, and servicing of automobiles have become key elements of industrial economies. But along with greater mobility and job creation, the automobile has brought noise and air pollution, and automobile accidents rank among the leading causes of death and injury throughout the world. But for better or worse, the 1900s can be called the Age of the Automobile, and cars will no doubt continue to shape our culture and economy well into the 21st century.
Automobiles are classified by size, style, number of doors, and intended use. The typical automobile, also called a car, auto, motorcar, and passenger car, has four wheels and can carry up to six people, including a driver. Larger vehicles designed to carry more passengers are called vans, minivans, omnibuses, or buses. Those used to carry cargo are called pickups or trucks, depending on their size and design. Minivans are van-style vehicles built on a passenger car frame that can usually carry up to eight passengers. Sport-utility vehicles, also known as SUVs, are more rugged than passenger cars and are designed for driving in mud or snow.





In 2001 manufacturing plants in more than 35 countries produced 39.5 million passenger cars. About 7.3 million passenger vehicles were produced in North America in 2001. For information on the business of making cars, see Automobile Industry.

The automobile is built around an engine. Various systems supply the engine with fuel, cool it during operation, lubricate its moving parts, and remove exhaust gases it creates. The engine produces mechanical power that is transmitted to the automobile’s wheels through a drivetrain, which includes a transmission, one or more driveshafts, a differential gear, and axles. Suspension systems, which include springs and shock absorbers, cushion the ride and help protect the vehicle from being damaged by bumps, heavy loads, and other stresses. Wheels and tires support the vehicle on the roadway and, when rotated by powered axles, propel the vehicle forward or backward. Steering and braking systems provide control over direction and speed. An electrical system starts and operates the engine, monitors and controls many aspects of the vehicle’s operation, and powers such components as headlights and radios. Safety features such as bumpers, air bags, and seat belts help protect occupants in an accident.

Automobile Industry

INTRODUCTION
Automobile Industry, industry that produces automobiles and other gasoline-powered vehicles, such as buses, trucks, and motorcycles. The automobile industry is one of the most important industries in the world, affecting not only the economy but also the cultures of the world. It provides jobs for millions of people, generates billions of dollars in worldwide revenues, and provides the basis for a multitude of related service and support industries. Automobiles revolutionized transportation in the 20th century, changing forever the way people live, travel, and do business.

The automobile has enabled people to travel and transport goods farther and faster, and has opened wider market areas for business and commerce. The auto industry has also reduced the overall cost of transportation by using methods such as mass production (making several products at once, rather than one at a time), mass marketing (selling products nationally rather than locally), and globalization of production (assembling products with parts made worldwide). Between 1886 and 1898, about 300 automobiles were built, but there was no real established industry. A century later, with automakers and auto buyers expanding globally, automaking became the world's largest manufacturing activity, with nearly 58 million new vehicles built each year worldwide.

As a result of easier and faster transportation, the United States and world economies have become dependent on the mobility that automobiles, trucks, and buses provide. This mobility allowed remote populations to interact with one another, which increased commerce. The transportation of goods to consumers and consumers to goods has become an industry in itself. The automobile has also brought related problems, such as air pollution, congested traffic, and highway fatalities. Nevertheless, the automobile industry continues to be an important source of employment and transportation for millions of people worldwide.