Fuel Cells

The principle of the fuel cell (FC) is similar to that of the electrical storage battery. However, whereas the battery has a fixed stock of chemical reactants and can ‘‘run down,’’ the fuel cell is continuously supplied (from a separate tank) with a stream of oxidizer and fuel from which it generates electricity. Electrolysis—in which passage of an electrical current through water decomposes it into its constituents, H2 and O2—was still novel in 1839 when a young Welsh lawyer–scientist, William Grove, demonstrated that it could be made to run in reverse. That is, if the H2 and O2 were not driven off but rather allowed to recombine in the presence of the electrodes, the result was water— and electrical current.

The mechanism of electrical generation was not fully understood until development of atomic theory in the twentieth century. Like a battery, an FC has two electrodes connected via an electrical load and physically separated by an electrolyte—a substance that will selectively pass either positive ions (acidic electrolyte) or negative ions (alkaline electrolyte). Oxidizer (e.g., O2) enters at one electrode and fuel (e.g., H2) at the other. At the cathode (the electrically positive electrode) atoms of fuel occasionally ionize, forming positively charged ions and free electrons. This is accelerated by a catalyst at the electrodes as well as suitable conditions of temperature and pressure. Similarly at the negative electrode (anode), oxidizer atoms spontaneously form negative ions. Then, depending on electrolyte, either positive or negative ions migrate through it to combine with ions of opposite polarity, while electrons (unable to pass through the electrolyte) flow through the electrical load from anode to cathode.

While the Second Law of Thermodynamics severely limits the efficiency of heat engines operating at practical temperatures, fuel cells can extract more power out of the same quantity of fuel compared to traditional combustion, since the hydrogen fuel is not converted to thermal energy, but used directly to produce mechanical energy. In principle, an FC consuming pure hydrogen and oxygen and producing liquid water can achieve an efficiency of 94.5 percent with an open-circuit potential of 1.185 volts. In practice a variety of losses cannot altogether be eliminated, but achievable efficiencies are considerably greater than those of most heat engines. Multiple cells connected in series supply higher voltages.

Practical challenges include electrolyte–electrode chemistry and physical properties, catalysts, fuel and oxidizer composition and purity, internal electrical losses, corrosion and other destructive chemical reactions, and a host of mechanical issues. Efficiency, silence, and lack of polluting emissions stimulated great interest, however. In searching for suitable systems, twentieth century researchers developed various approaches, most named for their electrolytes. Most of the developments in the field have come as a result of proprietary interests and the work of corporate
teams of researchers.

Alkaline FCs (AFCs)
From the 1930s Francis Bacon of the U.K., followed later by U.S. researchers, turned from acidic electrolytes to more tractable potassium hydroxide (KOH). Bacon also pioneered use of porous electrodes through which gaseous reactants diffused. The first major application of FC technology was in the U.S. space program where AFCs provide power (and potable water) for the space shuttles. The need for extremely pure H2 and O2 made AFCs uneconomic for more mundane applications.
Molten carbonate FCs (MCFCs)
MCFCs grew out of SOFC research (see below). In the 1950s Dutch investigators G.H.J. Broers and J.A.A. Ketelaar turned to molten lithium-, sodium, and potassium carbonates as electrolytes, as did Bacon in the U.K. At typical 650_C operating temperatures, MCFCs produce waste heat in a form useful for industrial purposes or to power turbines for added electrical output. High temperatures relax the need for costly catalysts while their carbonate chemistry is tolerant of carbon monoxide (CO), which as an impurity is problematic for alkaline fuel cells. However chemical and mechanical problems have thus far impeded wide application.

Phosphoric Acid FCs (PAFCs)
Interest in phosphoric acid as an electrolyte emerged slowly until the mid-1960s, after which PAFCs rapidly became the first FCs to see significant commercialization. At around 200_C, PAFC waste heat may be used to reform (convert) hydrocarbons or coal to H2 for fuel or power an auxiliary turbine. PAFCs are relatively tolerant of CO but sulfur must be separated. Units up to 250 kilowatts output are sold for fixed-site power applications and experimental units have shown promise in buses. Problems center on internal chemical reactions and corrosion.

Proton-Exchange Membrane FCs (PEMFCs)
In the early 1960s Thomas Grubb and Leonard Niedrach of General Electric in the U.S. developed a polymer membrane which, moistened with water, served as an effective and stable electrolyte. Initial space application attempts in the 1960s revealed reliability problems (and led to adoption of AFCs) but further development has held out strong promise for ground and marine vehicle applications as well as small fixed generators. Operating temperatures of less than 100_C and high power relative to size and weight, suit PEMFCs especially. Platinum catalysts are necessary and the H2 fuel must be essentially free of CO. By century’s end PEMFCs had shown some promise of being adaptable to liquid methanol in place of H2 fuel.

Solid-Oxide FCs (SOFCs)
Beginning in the 1930s experimenters first in Switzerland and Russia sought high-temperature (around 1000_C) solid ceramic electrolytes. At such temperatures, reactions proceed rapidly without costly catalysts and many fuel stocks can be reformed to produce H2 within the SOFC, while the waste heat can be used for many purposes. But physical and chemical problems of high-temperature operation have been difficult and it remained uncertain at century’s end how well the promise of SOFCs could be realized.

Metal FCs (MFCs)
To avoid problems of H2 supply or conversion some FC developers turned, late in the century, to metal fuels, usually zinc or aluminum. Electrolytes include liquid KOH and proton-exchange membranes. Waste products are metal oxides.

Conclusion
Over the twentieth century FCs moved from laboratory curiosity to practical application in limited roles and quantities. It is very possible that the twenty-first century will see them assume a major or even dominant position as power sources in a broad array of applications. Obstacles are largely economic and the outcome will be influenced by success in development of competing systems as well as FCs themselves.

Related Video: How Fuel Cells Work

All About Basketball

Basketball is a recreational and competitive sports with widespread appeal across age, gender, class, regional, and national lines, which reflects the game’s broadly based origins and early development. The game is played by two teams of five players, who attempt to score points by throwing a ball through an elevated hoop attached to a pole. Basketball was made in the United States, but by a Canadian. Devised by and for young white Protestant male competitors, it was quickly adopted by Catholics, Jews, African Americans, and females. Originally designed for exercise and the inculcation of moral values, it soon became a commercial pastime celebrated the world over.

Whatever the global appeal of soccer (association football), basketball is the game most played and most watched by people around the world. Hoops rattle throughout Asia, as well as Africa and South America. Professional leagues thrive in Europe,and even in distant Australia. In the United States, basketball attracts more participants and spectators than do football and baseball combined.In all,basketball is played by an estimated 200 million people on all continents. No other sport has enjoyed such recent increases in popularity, both in terms of those who play and the number of spectators. Some of basketball’s appeal can be explained by its unique status as a team game that is relatively simple, inexpensive, and easy to produce. People happily play one-on-one. In its  organized form, the game requires only five players at a time, half as many as a baseball or football team. Compared to most team sports, basketball needs little space and minimal equipment to play, and it leaves participants with few bruises and broken limbs. It can be played, and enjoyed, by female youths on a playground court or by an over-the-hill gang of businessmen on lunch break as well as by seasoned collegians and professionals.

The International Federation of Amateur Basketball has governed international play since the 1930s; the Olympics are the principal forum for competition. The United States, Soviet Union, and Yugoslavia have dominated international hoops since the 1950s. In recent years, televised competition has enhanced both the scope of basketball’s global appeal and the quality of play.

History
Basketball was literally created overnight, the result of an assignment posed by a physical education teacher in December 1891 at a Young Men’s Christian Association (YMCA) training college in Springfield,Massachusetts. A Canadian student, James Naismith (1861–1939), rose to the challenge of constructing an active indoor winter game that would prove attractive to young men.He typed up a rudimentary set of rules, had a janitor nail up peach baskets along the railing at each end of the Springfield gym, and invited his colleagues to toss a soccer ball into one of the two baskets. The first game consisted of two 15-minute halves, with 5 minutes’ rest between. Naismith’s physical education class numbered 18, so 9 men played on each team. Players had to pass the ball; no dribbling was allowed at first. That inaugural game was hardly a spectacle that anyone would recognize today.

Within its first decade basketball changed dramatically. Dribbling quickly became an acceptable means of moving the ball around the court. Standard team size was readjusted to seven, and finally set at five. The value of a field goal, originally set at three points, was changed to two points; foul shots, too, counted three at first, but were soon changed to one. Equipment also changed. By 1895 the old soccer ball was replaced by a slightly larger leather-covered basketball; peach baskets gave way to mesh-wire baskets with strings and pulleys that released the ball, and finally to a bottomless cord net fixed to an iron rim. Metal screens also made an early appearance behind baskets, in order to keep balcony spectators from guiding or deflecting shots.As more solid substance provided greater consistency for angled shots, wooden backboards became standard by the turn of the century.

In 1895, Naismith left Springfield for medical school and a YMCA job in Denver, largely leaving the supervision of basketball to his old Springfield colleague, Luther Gulick (1861–1918).Within the following year, Gulick and the YMCA passed the mantle of guardianship over to the Amateur Athletic Union (AAU). Committed to amateur (“gentlemanly”) sport, the AAU required players and teams to pay a fee and “register” their intention to comply with the amateur code and to compete only against other registered teams.

This policy played havoc with the many teams sponsored by local YMCAs, athletic clubs, settlement houses, churches, schools, and colleges who not only competed with each other but also indiscriminately played against whatever local or touring Professional teams they could schedule. Professional squads made their presence felt early in the history of basketball. In November 1896, a team in Trenton, New Jersey, rented the Masonic Temple, charged 25 cents for admission, and shared the profits after paying expenses. They also introduced a distinctive piece of equipment. A 12-foothigh mesh-wire fence, presumably designed to keep the ball in play, separated players from spectators. For more than two decades, professionals played within a cage of mesh-wire or net, causing basketball to be called the “cage” game.

Never did the AAU register a majority of the basketball teams in the United States. In 1905 seven coaches of powerful college teams drew up their own set of rules. Three years later the newly formed National Collegiate Athletic Association (NCAA) assumed responsibility for the rules governing college basketball. Finally, in 1915 the NCAA,AAU, and YMCA joined forces in establishing a single rules committee to oversee any further changes in basketball throughout North America. While refining its form and governance, Naismith’s new game expanded rapidly. Nearby colleges and athletic clubs embraced it as a competitive antidote to onerous gym exercises during New England’s frigid winters. One of the first converts to the game was Senda Berenson (1861–1954), a gymnastics instructor at Smith College.Early in 1892 she introduced the game to her female students, but divided the court into three equal sections and kept players confined to a single section in order to avoid exhaustion.Within the following year this distinctive form of “women’s basket ball” was being played not only at neighboring Mt. Holyoke College but also at distant Sophie Newcomb College in New Orleans, Louisiana, and at the University of California in Berkeley.

For a time, though, basketball remained primarily a YMCA commodity. Its place of origin—an aggressive new training college for YMCA leaders—ensured immediate widespread exposure. Copies of Springfield’s campus weekly, the Triangle, were mailed out regularly to every YMCA in North America. In the January 1892 issue of the Triangle, Naismith described his new game and heartily recommended it to YMCA leaders everywhere. Those leaders, in turn,wrote to the editor of the Triangle with news about the popularity of basketball as it was introduced to more than 200 YMCA gyms in the United States and Canada.

Many of those YMCA chapters and gyms were set on college campuses, especially in the Midwest and Pacific coast regions. Moreover, Springfield graduates— Naismith’s old classmates and fellow athletes—found teaching and coaching jobs in college programs,where they eagerly introduced basketball. High schools especially responded to that gospel, for the game proved useful for physical education classes and interscholastic competition. The women’s game was played with great passion, particularly in Iowa, Oklahoma, Missouri, and Texas high schools. By 1900 high school championship tournaments were held in conjunction with commercial exhibitions in Boston, Buffalo, and Chicago. In 1903 Gulick created a Public School Athletic League for New York City and supervised the construction of basketball courts in both elementary and high schools throughout the city. Within a decade,more than a dozen of the major cities in the United States sponsored similar city-wide leagues for public school athletes.

Basketball also thrived in rural and small-town schools. Hoops not only fed rural school and town pride; it also provided entertainment sorely lacking in remote places. After 1909, when the agricultural colleges of Iowa and Montana produced the first high school state basketball tournaments, land-grant institutions from Maine State College to Washington State College fulfilled their public service purposes by providing space and publicity for annual high school championship playoffs. In the 1920s national tournaments for public and parochial (Catholic) high schools began; by 1925 more than 30 state championship teams were competing at the National Interscholastic Tournament at the University of Chicago.

Early professional leagues also held tournaments to close out their seasons, but barnstorming proved to be the more lucrative route. Around the turn of the century, the Buffalo “Germans” and the New York “Wanderers” emerged as the premier professional teams that traveled afar competing with the best local talent available in armories, dance halls, and high school gyms. Their successors included the Troy Trojans and “Globe Trotters” from upstate New York, but the most successful of all the early touring teams was the Original Celtics. Founded in Manhattan in 1914, the Original Celtics capitalized on the use of the automobile as a popular means of transportation.At their barnstorming pinnacle in the 1920s, they often appeared in southern and western towns previously unreached by the railway. The loosely structured, theatrical character of Professional basketball made the game uniquely attractive to ambitious first-generation Americans.Heroes of the cage game had names like Dehnert,Holman, Lapchick, Friedman, Borgmann, Husta, and Chismadia. All were of East European or Irish heritage; most were Catholic or Jewish. African Americans, too, laid early claims on professional basketball as a means of fun and success. Founded in 1922, the all-black Harlem Renaissance Five quickly became the strongest opposition to the dominance of the Original Celtics.

Most spectator sports took a beating during the economic troubles that began in 1929, but the Depression worked to the advantage of high school and college basketball in the United States.As unemployment mounted, families found themselves unable to spend freely on commercialized amusements, causing social life in the local college and school to take on more importance. Basketball became a weekly social events.At the end of the decade of the 1930s, no less than 95 percent of all U.S. high schools sponsored varsity basketball teams.

A newly formed program, the Catholic Youth Organization (CYO), also made much of basketball’s sociable and socially healthy potential. Begun in 1930 as an antidote to juvenile delinquency in Chicago, the CYO was the Catholic equivalent to the Protestant YMCA and the Jewish Young Men’s Hebrew Association (YMHA). The CYO initially received most publicity for its sponsorship of interracial boxing tournaments, but basketball was always high on its agenda. Chicago’s CYO and B’nai B’rith champions met annually on the basketball court.

Basketball also went visibly international in the 1930s.At the hands of YMCA enthusiasts, the game had been introduced all over the world shortly after its creation. By 1930, fifty nations had adopted the sport. Despite the economic hardships, representatives from Asia and Africa as well as Europe convened in 1932 to form the International Federation of Amateur Basketball (FIBA). Chinese and Japanese students who had learned the game from YMCA missionaries before World War I introduced basketball at the University of Berlin in the mid-1930s. Nazi propagandists overlooked the game’s YMCA origins and gave it their stamp of approval on the grounds that basketball required not only speed and stamina but also an aggressive spirit that allegedly characterized the true German. At the Berlin Games of 1936, basketball became an official Olympic sport. Unfortunately,most of those games were played outdoors in a downpour of rain, with a U.S. squad beating a Canadian team, 19–8. By the mid-1930s, American basketball was thriving at the college level, particularly in New York City where promoter Ned Irish (1905–1982) arranged doubleheaders at Madison Square Garden featuring the best western teams against eastern powers St. John’s University, New York University, and Long Island University. Building on the foundation of these intersectional doubleheaders, the National Invitational Tournament (NIT) was created in 1938 as the first intercollegiate championship playoff. Some 16,000 spectators turned out to see Temple University win the first NIT. Impressed with that successful event, college coaches in 1939 created the NCAA tournament. Their first playoffs, at Northwestern University, suffered from inadequate publicity. The NCAA tournament remained second fiddle until 1951, when scandals discredited the NIT.

Despite the game’s growth during the 1930s, it was perceived by the American public as a second-rate sport.Not only did it lack the cachet of a major Professional organization until the late 1940s, it had modest national media coverage save the minuscule game summaries of YMCA, professional barnstorming teams, or amateur contests in local daily newspapers. The most significant watershed in basketball’s rise to international stature came during World War II. U.S. servicemen introduced the game to people the world over, and government-sponsored cultural Exchange tours fueled a steady flow of U.S. teams and coaches to all parts of the globe.

The Post–World War II Era
The American collegiate game enjoyed the national and international limelight until the early 1950s. Coached by the winningest coach in basketball history— Adolph Rupp (1901–1977)—Kentucky was the biggest winner of the period.Apart from a few tournament appearances by southern schools, basketball languished in football’s shadows in part because the region’s most talented black players were excluded from the leading teams and national tournaments. Formidable black college teams (for example, 1950s power Tennessee A&I coached by African American John McLendon, a Naismith student from Kansas) were forced to compete exclusively against each other in relative obscurity  Gamblers wagered millions of dollars weekly on the major games, triggering a national controversy in 1950–1951 when several New York City teams were implicated in a point-shaving scandal. By the time of this well-publicized scandal, the previously unpopular professional game was in the midst of a fundamental transformation. The pros were renowned for their physical, pushing, grabbing, and defensively oriented style played by a tough, beerdrinking, ethnically diverse group of industrial workers, many of whom had served stints in the military. Respectability came in 1946 when 11 businessmen— skilled in hockey and entertainment promotion—organized the Basketball Association of America (BAA) and brought a cleaner brand of basketball to a mainstream, middle-class audience. The newly formed BAA competed with a less profit-oriented and more knowledgeable, civic-minded National Basketball League (formed in 1937)—located in smaller midwestern, industrial cities. The two struggling leagues merged and formed the National Basketball Association (NBA) in 1949. The number of NBA franchises shrank to eight teams in 1954 as the well-financed, large-city franchises forced the smaller ones to relocate or fold.By the end of its first decade, the young NBA unquestionably showcased the best basketball in the world. The African

American Influence
The transformation of the professional game into its elegant, fast-paced, high-scoring contemporary mode derived from an increasingly innovative style of play centered around big men and an emergent generation of innovative African American players. The conservative horizontal offenses of the 1940s became more daring and vertical in the 1950s when quick forwards like “Jumping” Joe Fulks (1921–1976) and Kenny Sailors (1922–) popularized the jumpshot, and coaches developed tall players and built teams around them. As late as 1947, only 25 players on the 12 NBL teams were 6 feet, 6 inches (1.98 meters) tall or taller, reflecting the popular wisdom that large players were too clumsy and ill suited to the game’s demands.Those stereotypes were forever shattered by George Mikan (1924–) (6 feet, 10 inches [2.08 meters]),Bob Kurland (1924–) (7 feet [2.13 meters]) and Ed Macauley (1928–) (6 feet, 8 inches [2.03 meters]), whose dominance near the basket prompted the young NBA to widen the free throw lane and penalize goal tending. The most revolutionary rule change in the professional game,however,was the introduction of the 24-second clock in 1954,which prevented deliberate offensive stalling and thereby increased scoring by 30 percent over the following five years. The influence of a  black basketball aesthetic was just as revolutionary. Derived from the faster, louder, stop-and-go play of the cement, urban (particularly Harlem) courts, young black players learned that the game was not just about weaves and standard patterns, but also about explosive speed, deception, and slam dunks. Like improvisational jazz music of the 1950s, the emergent black style of play defied the established standards of traditional “white” performance. The Harlem Globetrotters was the most innovative team of the era, whose stars Reece “Goose”Tatum (1921–1967) and Marques Haynes (1926–) integrated improvisational bits from professional comedians and circus clowns into their performance. Organized in 1927 by a Jewish immigrant, Chicagoan Abe Saperstein, the barnstorming ’Trotters took their exciting court antics to the farthest reaches of the globe.

Despite the stellar quality of black basketball, the American professional ranks remained racially segregated until the early 1950s. Earl Lloyd (1928–), Chuck Cooper (1926–), and Nat “Sweetwater” Clifton (1922–) were the first African Americans to play in the NBA in 1950, but the league remained 80 percent white as late as 1960. Though the way was opened up by the Harlem Renaissance, Globetrotters, and several collegiate teams, it was in the NCAA’s Division I that the African American style burst through the locked doors of integrated national competition. Black collegians Bill Russell (1934–), Wilt Chamberlain (1936–), Elgin Baylor (1934–), Oscar Robertson (1938–), and Connie Hawkins (1942–) elevated the game to new levels in the 1950s and 1960s.

At the height of the civil rights movement in the United States, two white coaches devised systems that made black style integral to their teams’ personas and became the two longest running dynasties in basketball history. Arnold “Red” Auerbach (1917–), a feisty street-smart strategist born in Brooklyn to Russian Jewish immigrants, became coach of the Boston Celtics in 1950 and assembled a superb,balanced team around center Bill Russell. They won 11 NBA championships between 1959 and 1969. John Wooden (1910–), a devout Muscular Christian from small-town Indiana, built powerhouse teams at the University of California at Los Angeles (UCLA) around stellar centers such as Lew Alcindor (1947–) (later Kareem Abdul-Jabbar) and won nine national titles between 1964 and 1975.

Women’s Basketball
Between the late 1940s and early 1960s, U.S. women’s basketball became a true varsity sport. Teams had six players, and the court was divided so that the three forwards did the scoring and the three guards covered the backcourt. In 1971 the U.S. Congress passed Title IX legislation, which prohibited sex discrimination at federally funded academic institutions. Thereafter, teams were reduced to five and women were freed from the limits imposed by the halfcourt game. Increased funds to women’s athletics attracted first-rate coaches such as former collegian and Olympic star Pat Head Summitt (1952–) of Tennessee, who recruited players from a growing pool of quality high school talent. When the NCAA took control of women’s basketball in the late 1970s the large universities with strong programs (such as UCLA, Tennessee, Virginia, Texas, and USC) eclipsed traditional small college powerhouses and shifted the production of women’s basketball from New England and the Midwest to southern and western states. The NCAA’s prestigious Final Four tournament conferred the truly national scope of women’s basketball in 1982 and through increased network television coverage, expanded attendance 90 percent during the decade by the early 1990s.

The Olympics embraced women’s basketball in the 1976 Montreal Games. The Soviets won the gold medal in the 1976 and 1980 Games against an impressive field that included strong Chinese and Korean teams. In the aftermath of the 1976 Games, collegiate All-American stars Ann Meyers (1955–) of UCLA and Nancy Lieberman (1958–) of Old Dominion dominated U.S. women’s basketball. Both played in the 1976 Olympics, but their influence came later when they became the first women to be drafted by men’s professional teams, and then led the short-lived Women’s Professional League in 1979–1980. Four years later the United States, led by African American stars Cheryl Miller and Lynette Woodard (the first female member of the Harlem Globetrotters), defeated the Soviets 83–60 in the 1984 Games. In 1988 they repeated by defeating Yugoslavia for  another gold medal, which firmly established them as the world power of women’s basketball. In recent years, the women’s traditional “finesse” game has increasingly come to resemble the speedier, powerful, vertical male version.

The Modern Era
The era of stalwart professional dynasties ended with the creation of a rival professional league—the American Basketball Association (ABA)—in 1967, which shifted the NBA’s balance of power. By 1976, when the NBA absorbed four ABA teams, professional salaries averaged $110,000—more than twice what baseball and football players made.Moreover, the NBA Players’ Association won a collective-bargaining agreement, severance pay, first-class airfare, disability, medical insurance, and pensions. Despite the improvement in players’ salaries and overall play, however, the NBA limped along in television ratings and profitability throughout the 1970s. For the first time since the advent of the 24-second clock, the NBA enhanced the drama by adopting the three-point shot (from 23 feet, 9 inches [7.23 meters]).

The American professional game continues to provide the model for global competition. A U.S. “Dream Team” took advantage of revised FIBA eligibility rules that permitted professional athletes’ participation in the Olympics, to trounce all their opponents at the 1992 Barcelona Games by unprecedented margins. The Dream Team’s success propelled the game into the most geographically diffused and commercially lucrative phase of any sport in history. Even in places without a strong basketball tradition, like Britain, attendance for England’s National Basketball League has soared from an early 1970s’ average of 7,500 to 330,000 in 1985. The game’s popularity since the 1970s continues untrammeled in Latin America, and now China claims more players than the entire population of Europe. Efforts are currently under way to establish a Professional league in Asia, with likely locations for teams in Tokyo, South Korea, Taiwan, and the Philippines. Basketball has enjoyed even greater success on the European continent where NBA stars are celebrated in Italian, Spanish, and French newspapers and glossy magazines. Since 1987, basketball has been Italy’s second most popular sport. More than half the members of the national Spanish junior team are currently playing college ball in the United States.Moreover, of the 21 foreign players on NBA rosters in 1995, 14 had attended U.S. universities.

The renaissance of big-time college basketball came in the 1979 NCAA title game when two of the three dominant players of the 1980s—Earvin “Magic” Johnson (1959–) and Larry Bird (1956–)—were pitted against each other for the first time. The 6 foot, 9 inch “Magic”destroyed the stereotypical notions of how size dictated positions and, along with Bird, elevated creative passing and teamwork. Magic’s dexterity and court vision brought the brilliance of the black aesthetic to new heights. The Magic-Bird rivalry catapulted the month-long NCAA tournament atop the pinnacle of international sport just beneath the Olympics and World Cup competitions. Gross receipts for the NCAA tournament have increased from eight million dollars in 1979 to over 184 million dollars in 1995. The rivalry also sparked unprecedented interest in both the game and the basketball player as a marketable celebrity. Buoyed by the advertising agency’s success in marketing athletic shoes and sportswear (e.g., Nike, Reebok, and Converse) with superstar endorsers, basketball stars, especially Michael Jordan (1963–), have become some of the world’s highest paid athletes and most recognizable personalities.

The game’s hold on the American imagination is reflected in the emergence of a cadre of successful basketball films.Unlike baseball, football, and boxing,basketball was largely ignored by filmmakers until the late 1970s, but recently has become part of a pervasive sports, media, and entertainment enterprise. Since the 1970s filmmakers have moved away from silly, frivolous scripts to ones that dramatize the contradictory nature of basketball in contemporary society.The commercial success of White Men Can’t Jump (1991) and the artistic recognition conferred upon the documentary Hoop Dreams (1995) illuminate the importance of urban playgrounds as breeding grounds of big-time talent, the centrality of the black aesthetic, and the game’s promise of social mobility for millions of young people throughout the world.

What is Spyware?

Spyware represents a new type of malware that poses a signifi cant threat to business and home users. Unlike those who create other forms of malware, such as viruses, spyware authors are not motivated by curiosity or a desire to establish a reputation. Instead, they are attracted to the possibility of making large amounts of money quickly and easily.

In general, spyware describes a category of software designed to capture and record confi dential information without a user’s knowledge or consent. Key loggers, as discussed in chapter three, are a typical example of spyware. Some Trojans can also be classifi ed as spyware.

Applications for spyware range from monitoring the actions of a spouse to industrial espionage. Although early spyware programs were quite primitive, modern applications have a number of sophisticated features that make them diffi cult to detect and remove. Like viruses, the most advanced programs are able to disable or delete security software, and some even pose as spyware removal tools. Spyware can be grouped into a number of categories, including the following:

• Data miners: Programs that collect information about a user, supposedly with his knowledge and/or consent. Spyware developers sometimes justify the use of such software by referring to the use of clickthrough agreements.

• Monitoring tools: Software intended to report on a user’s activities, including the use of Trojans and key loggers.

• Trackers: Programs that monitor Internet activity, recording information such as the sites visited by a user. Trackers do not necessarily record personally identifi able information.

• Annoyware: A type of adware that attempts to force advertising on users by opening multiple browser windows, pop-ups, and so on.

• Browser hijackers. Sometimes called home-page hijackers, these programs hijack the user’s home page and can also make other changes, such as changing the default search engine or altering system settings.

• Dialers. A type of program that alters the settings used to make dial-up connections to the Internet, usually with the aim of calling premium rate numbers at the expense of the user. The numbers called are often linked with services that provide pornography, causing some people to become too embarrassed to make a complaint.

About Trojans

A Trojan will usually appear as a game, utility, or some other innocuous file in order to gain access to a computer system. When the user launches the program, it first installs the Trojan before continuing to work in the way the user expects. In this way, the user becomes responsible for infecting his own machine.

Like viruses, Trojans are able to alter files, delete data, and display messages. However, Trojans tend to be designed for two main purposes: gathering information and taking control of an infected system. Once active, a Trojan will scan the user’s hard disk for sensitive information, such as passwords, credit card details, and anything else of value. Once this information has been gathered, the Trojan will wait for an opportunity to phone home. Usually, the Trojan waits until the user is online and then sends the information it has collected in an e-mail. By waiting until there is some Internet activity, the Trojan often escapes the user’s notice.

Some Trojans install a key logger to monitor all activity on the infected computer. A key logger records every key pressed by the user and stores the data in a file on the computer’s hard disk. By monitoring a computer over a period of time, the key logger is able to collect a wide variety of information, including all passwords and user names typed by the user, the contents of any outgoing e-mail messages, the contents of word-processing  documents, and any information entered into any forms displayed on Web pages. Even a single online transaction may provide enough information to defraud the computer’s owner. For instance, if a user makes a purchase from an online store, such as Amazon.com, the key logger will have an opportunity to record his account details and credit card information.

From time to time, the key logger will need to send the information it has collected to its owner. It is at this time that the user may notice an unusual surge in Internet traffi c caused when the key logger sends its data by e-mail. Some of the most sophisticated key loggers try to reduce the risk of detection by minimizing the amount of data transmitted by e-mail. This is achieved by compressing the data file after deleting any data that has been sent before. It is also possible for a key logger to transmit the data file at regular intervals or when it reaches a certain size. This prevents the program from attempting to send large files that may cause increased Internet traffic for hours at a time. Some programs are even capable of splitting a large data fi le into several parts so that it can be sent a little at a time.

Some Trojans are used to establish control over the computers they infect. Sometimes, only partial control is needed and users may be unaware that a Trojan is sending out e-mail or taking part in a denial of service attack. However, some Trojans allow a third party to take complete control over the infected computer, just as if they were sitting in front of it. The Trojan acts as a remote-control application, allowing its owner access to all of the computer’s resources including programs, data files, printers, disk drives, webcams, and network services, such as Internet access. Once control has been taken over the machine, users are virtually powerless to interfere except by switching the power off. The best-known example of this kind of Trojan is Back Orifice, which was produced by a hacking group known as the Cult of the Dead Cow.

Codec

Short for “coder/decoder,” a codec is essentially an algorithm for encoding (and compressing) a stream of data for transmission, and then decoding and decompressing it at the receiving end. Usually the data involved represents audio or video content. Typically the data is being downloaded from a Web site to be played on a personal computer or portable player. A codec is described as “lossy” if some of the original information is lost in the compression process. It then becomes a question of whether the loss in quality is perceived by the user as significant. A codec that preserves all the information needed to re-create the original file is “lossless.” For most purposes, the much greater size of the lossless version of a file is not worth the (often imperceptible) increase in quality or fidelity. A codec is usually used in connection with a “container format” that specifies how the encoded data is to be stored in a file. Often a container can hold more than one data stream and even more than one kind of media (such as video and audio). When one refers to a Windows WAV file, for example, one is actually referring to a container. Most of the popular codecs and file formats are proprietary, which creates something of a dilemma for users who prefer open-source solutions. However, while most Linux distributions do not include support for formats such as MP3 out of the box, distributions such as Ubuntu are now making it easier for users to choose nonsupported proprietary codecs if desired. The preceding table lists some codecs likely to be encountered by program developers and consumers.

Dynamics

Dynamica is a term coined by Gottfried Wilhelm Leibniz (1646–1716) in 1689 during his Italian journey, referring to his doctrine of forces. In that year, he composed an extensive work called Dynamica, which remained unpublished at the time. His major publication on the subject is “Specimen Dynamicum,” which appeared in the Acta eruditorum for 1695, in which he tried to reconcile a variety of metaphysical and mechanical traditions relevant to the notion of force on the basis of a grid of the following four notions: (1) active primitive force is a purely metaphysical entity expressing the activity of substances and is also called entelechy; (2) active derivative force is somehow the phenomenal manifestation of an aggregate of metaphysical substances and is measured by living force, or vis viva; (3) passive primitive force is purely metaphysical and expresses the imperfection of substances; (4) is passive derivative force, which is also called inertia, is its phenomenal manifestation. The connection between metaphysical and phenomenal levels was and still is especially problematic in this account. Leibniz further introduced the distinction between vis viva, which pertains to actual motion and is proportional to the square of velocity, and vis mortua, or dead force, which pertains to the very beginning of motion and is proportional to infinitesimal velocity. Examples of the latter are Christiaan Huygens’s (1629–1695) centrifugal, and Isaac Newton’s (1642–1727) centripetal, forces.

Leibniz developed his views in several works and tried to establish many laws of nature, such as the law of conservation of force, or vis viva, on the metaphysical foundations provided in his system. Although Leibniz’s metaphysical preoccupations are extreme even by seventeenth-century standards, at the time notions like motion and force had much larger philosophical dimensions than the modern reader may suspect. Ca. 1700 the notion of dynamics had a distinctive Leibnizian flavor that Newton found particularly irritating and distasteful. In a manuscript, he complained that “Galileo began to consider the effect of Gravity upon Projectiles. Mr Newton in his Principia Philosophiae improved that consideration into a large science. Mr Leibniz christened the child by a new name as if it had been his own, calling it Dynamica…. But his mark must be set upon all new inventions. And if one may judge by the multitude of new names and characters invented by him, he would go for a great inventor.” Although Leibniz’s dynamics was primarily a science of living forces, in the quotation above Newton portrayed it as dealing with his own force, a notion more similar to Leibniz’s dead force. Almost exactly a century after Leibniz had coined the term, Joseph-Louis Lagrange (1736–1813), in his classic Mécanique analytique (1788), defined dynamics as the science of accelerative forces and of the motions they produce. In his historical outline, he portrayed Galileo Galilei (1564–1642) as the founder of dynamics, a science later perfected by Huygens. Lagrange went on to argue with involuntary irony that mechanics and, therefore, dynamics were then revolutionized by Newton. Thus, by that time it had become customary to call dynamics a doctrine of forces based, unlike Leibniz’s, on accelerations, such as Newton’s. Newton himself had given the greatest possible emphasis to his doctrine of forces by stating in his Principia mathematica philosophiae naturalis (1687) that the whole burden of philosophy consists in investigating the forces from the phenomena of motion and then from the forces to demonstrate the phenomena. The term dynamics is also used by some historians in the sense of science of motion, rather than strictly of forces, and is contrasted to statics, or the science of equilibrium of bodies. Ernst Mach (1838–1916), for example, devoted the first two parts of his influential Die Mechanik in ihrer Entwickelung (1883; ninth edition, 1933) to the development of the principles of statics and of dynamics, which in his view had been founded by Galileo and by which he meant a science of motion. These preliminary reflections leave the scholar of the Scientific Revolution with the problem of whether it is legitimate or helpful to talk of a history of dynamics in the seventeenth century, including such actors as Galileo and Huygens, and extending back to the medieval scientia de motu (science of motion) and scientia de ponderibus (science of weight) and even to the Quaestiones mechanicae attributed to Aristotle (384–322 B.C.E.) or to one of his immediate disciples. The answer to this question depends on several factors, such as whether dynamics is taken to mean a science of accelerative forces, a science of motion, or a science of the causes of motion. Further, it depends on the aims and purposes of one’s historical research. Historians, however, ought to be aware of the categories of their actors, even if for a variety of reasons they decide not to follow them, and make a conscious and deliberate decision, as opposed to taking for granted that dynamics always existed and that its history can, therefore, be written unproblematically.

IBM PC

By 1981, a small but vigorous personal computer (PC) industry was offering complete desktop computer systems. Apple’s Apple II offered color graphics and expandability through an “open architecture”—slots into which cards designed by third-party vendors could be plugged. While the Apple II had its own DOS (disk operating system) as did Radio Shack’s TRS-80, most microcomputers sold in the business market used CP/M, an operating system developed by Gary Kildall and his company Digital Research. Meanwhile, IBM, the world’s largest computer company (see ib m), had quietly created a special team headed by Phillip (“Don”) Estridge and tasked with designing a personal computer. Unlike the case with the company’s mainframe development, the team was given considerable freedom in choosing architecture and components—but they were told they would have to have a machine ready for the market in one year. Because of the short time frame, the team chose thirdparty components already well established in the market, including the monitor, floppy disk drive, and a printer.

Unlike Apple and most other companies, IBM created two separate video display systems, one monochrome (MDA) for sharp text for business applications and the threecolor CGA system for the game and education markets. The IBM team also adopted standards from the emerging microcomputer industry instead of trying to use existing mainframe standards. For example, they used the ASCII code to represent characters, not the EBCDIC code used on IBM mainframes. They also chose the Intel 8086 and 8088 microprocessors, which had an instruction set similar to that of the Intel 8080 used in many CP/M systems (see microprocessor). This would make it easy for software developers to create IBM PC versions of their software quickly so that the new machine would have a repertoire of business software. One might have expected that IBM would also adopt a version of CP/M as the PC’s operating system, taking advantage of the closest thing to an existing industry standard. However, CP/M was relatively expensive, and negotiations with Digital Research stumbled, leaving an opening for a much smaller company, Microsoft, to sell a DOS based on software it had licensed from Seattle Computer Products. While IBM did offer CP/M and another operating system based on the UC San Diego Pascal development system,
Microsoft DOS, which became known as PC-DOS (and later MS-DOS), was cheapest and effectively became the default offering.

When IBM officially announced its PC in April 1981, Apple took out full-page ads “welcoming” the new competitor to what it considered to already be a mature industry. But by the end of 1983, a million IBM PCs had been sold, dwarfing Apple and other brands. From then on, while Apple would go on to announce its distinctive Macintosh in 1984, the IBM machine would set the industry standard. To most people, “PC” would mean “IBM PC.”

Distributed Computing

This concept involves the creation of a software system that runs programs and stores data across a number of different computers, an idea pervasive today. A simple form is the central computer (such as in a bank or credit card company) with which thousands of terminals communicate to submit transactions. While this system is in some sense distributed, it is not really decentralized. Most of the work is done by the central computer, which is not dependent on the terminals for its own functioning. However, responsibilities can be more evenly apportioned between computers.

Today the World Wide Web is in a sense the world’s largest distributed computing system. Millions of documents stored on hundreds of thousands of servers can be accessed by millions of users’ Web browsers running on a variety of personal computers. While there are rules for specifying addresses and creating and routing data packets (see Internet and tcp/ip), no one agency or computer complex controls access to information or communication (such as e-mail).

What is Encryption?

The use of encryption to disguise the meanings of messages goes back thousands of years (the Romans, for example, used substitution ciphers, where each letter in a message was replaced with a different letter). Mechanical cipher machines first came into general use in the 1930s. During World War II the German Enigma cipher machine used multiple rotors and a configurable plugboard to create a continuously varying cipher that was thought to be unbreakable. However, Allied codebreakers built electromechanical and electronic devices that succeeded in exploiting flaws in the German machine (while incidentally advancing computing technology). During the cold war Western and Soviet cryptographers vied to create increasingly complex cryptosystems while deploying more powerful computers to decrypt their opponent’s messages.

In the business world, the growing amount of valuable and sensitive data being stored and transmitted on computers by the 1960s led to a need for high-quality commercial encryption systems. In 1976, the U.S. National Bureau of Standards approved the Data Encryption Standard (DES), which originally used a 56-bit key to turn each 64-bit chunk of message into a 64-bit encrypted ciphertext. DES relies upon the use of a complicated mathematical function to create complex permutations within blocks and characters of text. DES has been implemented on special-purpose chips that can encrypt millions of bytes of message per second.

Hybrid Automobiles

In technology, as in biology, a hybrid is the result of ‘‘cross-fertilization,’’ in this case referring to the application of technologies to produce a similar yet slightly different entity. Recent research in the history of automotive technology shows that hybridization has been much more common than previously thought. Thus, the automobile itself can be viewed as a hybrid with a century-long history of crossover phenomena from electrical engineering to mechanical engineering that resulted in an ‘‘electrified gasoline car.’’

The term hybrid, however, is generally reserved for combinations of propulsion systems in automobiles. Most common in the history of the automobile is the thermoelectric hybrid, mainly a combination of the internal combustion engine (gasoline or diesel) and an electric propulsion system (electric motor, battery set). Thermomechanical hybrids are possible when a combustion engine is combined with a flywheel system in which part of the kinetic energy during braking can be stored and released the moment this energy is needed, for instance for acceleration from standstill. Similarly, thermohydraulic hybrids combine combustion engines with a hydraulic energy storage system (a pump and a hydraulic accumulator).

Electroelectric hybrids are also known; in these cases the actual propulsion is done by one electric motor, but the energy supply is a combination of battery storage and a supply from overhead trolley wires. Combinations of trolley systems and mechanical flywheel storage systems have also been built. Viewed from this perspective, the automobile as we know it at the end of the twentieth century is but one case among many possibilities. Thermoelectric hybrids are nearly as old as automotive technology. Before 1900, the Belgian automobile producer Henri Pieper developed a car that was equipped with an electromagetically controlled carburetor. His patents were later bought by car manufacturers like Siemens– Schuckert (Germany), Daimler (Coventry, U.K.) and the French Socie´te´ Ge´ne´ rale d’Automobiles e´lectro-Me´caniques (GEM). In 1908 the latter company proposed a Pieper-like hybrid called ‘‘Automobile Synthesis.’’ At about the same time, German battery producer AFA (now Varta AG) bought a Pieper to develop a special battery for hybrid car applications. Another famous hybrid vehicle builder was the French electrical engineer Louis Krie´ ger. He started hybrid development in 1902 and produced a car he drove during the rallye from Paris to Florence a year later. In 1904 his hybrid was the sensation of the Paris automobile show. In 1906 he conceived a drive train based on an electric propulsion system and a gas turbine, and in the same year he developed a hybrid taxicab, 100 of which were intended to be built.

In Austria, Lohner built 52 hybrids between 1898 and 1910, designed by electrical engineer Ferdinand Porsche. These cars were later sold by Daimler, Germany, which founded a separate company for this purpose, Socie´te´ Mercedes Mixte. In Germany several local fire companies built thermoelectric fire engines, some of these a combination of an electric motor with batteries and a steam engine. In this configuration, the electric drive system was meant for quick starting and for use during the first few kilometers of the trip. After ten minutes, when kettle pressure had built up, the steam engine took over to propel the truck to the fire location. All in all however, no more than a hundred or so hybrids were sold in Europe before World War I. In the U.S., there was even less hybrid construction activity during this period, the most famous being the Woods Dual Power, which was produced during the war. Hybrids were supposed to combine the advantages of two systems while avoiding their disadvantages. For instance, because the thermal element in the hybrid system was often used (in combination with the electric motor, which for this purpose had to be repolarized to become an electricity generator) to supply a part of the stored electricity, the battery set in a hybrid tended to be smaller. It was lighter than that in a full-blown electric motor where all the energy for a trip had to be stored in the batteries before the start of the trip. In most cases the combination of systems led to a more complex and expensive construction, jeopardizing state-of-the-art reliability standards, and complicated control problems, which would only be overcome with the emergence of postwar automotive electronics. Also, despite the lighter battery, the total drive train became heavier. For this reason hybrid alternatives were especially popular among producers of heavy vehicles such as buses and trucks in which the relative importance of the drive train weight is less. Well-known examples in this respect are the brands Fisher (U.S.), Thornicroft (U.K.) and Faun (Germany). The popularity of hybrid propulsion systems among engineers was not only, and according to some analysts not primarily, the result of technical considerations. During the first quarter century of automotive history, when the struggle between proponents of steam, electric, and gasoline engine propulsion was not yet over, hybridization often functioned as a strategic and social compromise as well. This was very clear in the case of the German fire engine community before World War I. A fierce controversy raged over the apparent unreliability of the gas combustion engine, but the proponents of electric drive trains, who boasted that electric drive trains guaranteed quick starting, high acceleration, high reliability, and no danger of fuel explosions in the neighborhood of fires, were not strong enough to monopolize the field. Several fire officials then opted for a hybrid drive, combining the advantages of electric with the advantages of the combustion engine (primarily a greater driving range), but they encountered heavy resistance from a combination of both other fire officials and the established automobile industry. Nevertheless, in 1910 the German fire engine fleet included about 15 heavy hybrids.

As with the electric alternative, hybrid automobiles experienced a revival during the last quarter of the twentieth century. This resulted in at least one commercially available hybrid automobile, the Toyota Prius. During this period, the issue of energy consumption played a role as well. Heavily subsidized by local, regional, and federal governments in Europe, Japan, and the U.S., hybrid projects used new light materials such as magnesium, plastics, and carbon fibers; and sophisticated electronic control systems (borrowed from related industries such as aerospace and information and communication technology) to enable very energy efficient solutions, initially to the surprise of many engineers. For example, a Dutch–Italian hybrid bus project resulted in exhaust emissions that were barely measurable and demonstrated very low energy consumption rates. Similar results in other experimental areas have been possible because of sophisticated combinations of small engines, flywheel systems with continuously variable transmissions, and even engine concepts that were considered obsolete, such as Sterling engines, micro gas turbines, and two-stroke engines. By now, the field of possible alternatives is so vast that several classification schemes have been proposed. The most common classification is that which distinguishes between ‘‘series hybrids,’’ where the electric element is positioned between the thermal element and the drive wheels, and ‘‘parallel hybrids,’’ where both the thermal and the electric element can be used separately to propel the vehicle. At the beginning of the twenty-first century, the ‘‘mild hybrid’’ was the latest development, in which the electric system is so small that it resembles the electric starter motor. If this development materializes, automotive history will have come full circle, producing a true compromise of an electrified gasoline car.

Parallel Worlds

A world neighbouring the world of experience, but displaced from it in such a fashion as to be imperceptible and inaccessible in normal circumstances. In the days when people routinely thought of the world as a plane, it seemed reasonable to think of parallel worlds above and below it, the former often being identified with the realm of the gods and the latter with the realm of the dead. In Greek mythology both realms were equipped with portals, Mount Olympus serving as a conduit between Earth and heaven while various caverns gave admittance to the Underworld. Both notions are reflected in cosmological ideas that persisted throughout the Middle Ages and into the Renaissance, although notions of divine reward and punishment often redistributed the dead between the two realms; they were preserved in various descendant schools of *occult science, in which the Notion of ‘‘higher planes’’—especially the ‘‘astral plane’’— retains considerable imaginative authority. The Underworld is associated with many western European folkloristic accounts of supernatural beings, cropping up in many of the tales that served as ancestors to modern fairy tales, but is confused with conceptualisations in which such beings live invisibly alongside human society, either as animistic ‘‘elemental spirits’’ or in variously veiled enclaves only partially or periodically accessible to humans. The latter version became the standard strategy of literary fairy tales, laying imaginative groundwork for the extrapolation of the notion that there might be an array of parallel universes laterally displaced from ours in a fourth dimension. The latter notion was popularised at the end of the nineteenth century by such writers as C. H. *Hinton and dramatised in such stories as H. G. Wells’ ‘‘The Plattner Story’’ (1896), William Hope Hodgson’s The House on the Borderland (1908) and The Ghost Pirates (1909), and Gerald Grogan’s A Drop in Infinity (1915). Such stories often retain echoes of the mythical thesis, placing the shades of the dead in a parallel world, while The House on the Borderland transplanted a notion commonly associated with dream fantasy, using the landscapes of a parallel world to map and symbolically display the psyche of its protagonist.

The idea of parallel worlds displaced in a fourth spatial dimension underwent a spectacular boom in twentieth-century fiction. It was established as a useful framework for the science-fictional accommodation of alternative histories in the 1930s, encouraged by such exercises in speculative nonfiction as J. W. Dunne’s attempts to explain supposedly prophetic dreams in An Experiment with Time (1927), which led him to construct an ambitious account of The Serial Universe (1934). It was accommodated into the pulp magazines before the advent of specialist science fiction pulps in such stories as A. Merritt’s classic portal fantasy ‘‘The Moon Pool’’ (1918), Austin Hall and Homer Eon Flint’s The Blind Spot (1921; book, 1951), and Philip M. Fisher’s ‘‘Worlds Within Worlds’’ (1922), and was thus established as a standard generic motif, given a more scientific gloss in such versions as Murray Leinster’s ‘‘The Fifth-Dimension Catapult’’ (1931) and ‘‘The Fifth-Dimension Tube’’ (1933).

The notion of Faerie as a parallel world made similar progress in twentieth-century fantasy fiction, generalised in J. R. R. Tolkien’s notion of fantasy settings as ‘‘Secondary Worlds’’. Secondary Worlds are usually conceivable as parallel worlds even when the inclusion of connective portals does not make the relationship explicit. The narrative utility of fantasies featuring such portals is obvious, in that they allow characters to step from the experienced world into a Secondary one, arriving as naive and inquisitive strangers whose own learning process educates the reader; Farah Mendlesohn’s ‘‘Towards a Taxonomy of Fantasy’’ (2003) identified portal fantasy as a major sector of modern fantastic fiction, intermediate in its narrative technique between immersive fantasy and intrusive fantasy. Although much science-fictional portal fantasy deals with shortcuts through space and trips through time rather than shifts into paralel worlds, the development of parallel worlds in genre science fiction made a very significant contribution to the broader genre of portal fantasy, evolving a new jargon of ‘‘dimensional doorways’’ and ‘‘gates’’ that helped to add psychological plausibility to their fantasy counterparts.

Science-fictional portals retain the same essential magicality as well as the same narrative function as portals to Faerie and its analogues, and such devices became—very appropriately—a key motif of the hybrid subgenre of science-fantasy. They facilitated genre crossovers with the same ease that they facilitated transfer between primary and secondary worlds, as illustrated by such archetypal hybrids as A. Merritt’s The Face in the Abyss (1923–1930; rev. book, 1931), C. L. Moore’s The Dark World (1946; book, 1965; by-lined Henry Kuttner) and Andre Norton’s Witch World (1963), and the chimerical crossovers that became typical of Astounding Science Fiction’s fantasy Companion Unknown, whose key templates were established by L. Sprague de Camp. The occult tradition of parallel worlds fiction, which had latched on to the notion of the fourth dimension in the late nineteenth century, also gave rise to a hybrid subgenre, carried forward by such works as John Buchan’s ‘‘Space’’ (1911) and Algernon Blackwood’s ‘‘The Pikestaffe Case’’ (1924). This too was imported into the pulp magazines, most conspicuously by H. P. Lovecraft—whose deployment of the relevant jargon was echoed by his many disciples, including August Derleth, Frank Belknap Long, and Clark Ashton Smith. Some of these writers brought a new ingenuity into their developments of the idea, especially Smith, whose ‘‘City of the Singing Flame’’ (1931) introduced Merrittesque portal fantasy into the science fiction pulps, and whose ‘‘The Dimension of Chance’’ (1932) attempts to describe a parallel world with variant physical laws.

Early pulp science fiction writers initially mined the melodramatic potential of parallel worlds in a brutally straightforward fashion, in such accounts of monstrous invasion as Edmond Hamilton’s ‘‘Locked Worlds’’ (1929) and Donald Wandrei’s ‘‘The Monster from Nowhere’’ (1935) and such accounts of heroic expeditions as Clifford D. Simak’s ‘‘Hellhounds of the Cosmos’’ (1932) and E. E. Smith’s Skylark of Valeron (1934; book, 1949). Its uses became more sophisticated in the 1940s, in such stories as Harry Walton’s ‘‘Housing Shortage’’ (1947), but it enjoyed a spectacular leap forward in the 1950s and 1960s in the context of what eventually came to be called the ‘‘multiverse’’: an infinitely extendable manifold of alternative histories.

The notion of the multiverse is implicit in such early pulp science fiction stories as Harl Vincent’s ‘‘Wanderer of Infinity’’ (1933) and ‘‘The Plane Compass’’ (1935)—the latter refers to a ‘‘superuniverse’’— and became more explicit in such time police stories as Fritz Leiber’s Destiny Times Three (1945) and Sam Merwin’s House of Many Worlds (1951) before Michael Moorcock pasted the new label on it, and demonstrated its utility as a framing concept linking the very various worlds described within his texts into an inherently chimerical superstructure. Clifford D. Simak’s Ring Around the Sun (1953) is an early celebration of the extrapolation of the idea of paralel worlds to embrace an infinite series of Earth clones— all empty of humankind in this version, and hence available for *colonisation. Simak went on to examine the possibilities of interparallel trade in ‘‘Dusty Zebra’’ (1954) and ‘‘The Big Front Yard’’ (1958). Traditional notions of parallel existence continued to echo in science fiction—as the notion of invisible coexistence did in Gordon R. Dickson’s ‘‘Perfectly Adjusted’’ (1955; exp. book 1961 as Delusion World) and transfigurations of dream fantasy in Christopher Priest’s Dream Archipelago series (1976–1999)—but the more interesting developments of the Notion involved its extension in new philosophical directions. These included the extensive exploration of paralel selves in such existential fantasies as Adolfo Bioy Casares’ ‘‘La trame ce´leste’’ (1948; trans. as ‘‘The Celestial Plot’’), Robert Donald Locke’s ‘‘Next Door, Next World’’ (1961), Brian W. Aldiss’ Report on Probability A (1968), Larry Niven’s ‘‘All the Myriad Ways’’ (1969), and Graham Dunstan Martin’s Time-Slip (1986). Other existential fantasies employing parallel worlds include Richard Cowper’s Breakthrough (1967), Robert A. Heinlein’s The Number of the Beast (1980), and Kevin J. Anderson’s ‘‘The Bistro of Alternate Realities’’ (2004), and such tales of transuniversal tourism as Robert Silverberg’s ‘‘Trips’’ (1974), Robert Reed’s Down the Bright Way (1991), and Alexander Jablokov’s ‘‘At the Cross-Time Jaunter’s Ball’’ (1987) and ‘‘Many Mansions’’ (1988). One significant narrative advantage of the use of parallel worlds is that it cuts out the necessity for elaborate modes of *transportation between fictional constructions. Faster-than-light travel is no less arbitrary a facilitating device than interdimensional portals, as is evident in the synthesis of the two kinds of portal in the ‘‘stargate’’, but the idea of a galactic community did retain an imaginative advantage by virtue of its resonance with the majesty of the night sky: the ‘‘higher’’ of the two original parallel worlds.

For much of the twentieth century, the idea of parallel worlds was regarded by scientists as an amusing corollary of mathematical fancy, but it became increasingly significant in theoretical physics as atomic theory and quantum mechanics became increasingly complicated, eventually acquiring a certain respectability when it was co-opted in 1957 by Hugh Everett and John Wheeler as the ‘‘many worlds’’ interpretation of quantum mechanical uncertainty. The number of dimensions theoretically required to account for the exotic behaviour of subatomic particles increased dramatically with the advent of string theory, and the notion of parallel universes became a key element of some versions of inflationary cosmology. Parallel worlds stories illuminated by ideas drawn from these developments in theoretical physics include Isaac Asimov’s The Gods Themselves (1972), Bob Shaw’s A Wreath of Stars (1976), Frederik Pohl’s The Coming of the Quantum Cats (1986) and The Singers of Time (1991; with Jack Williamson), and Stephen Baxter’s Manifold trilogy (1999–2002). This is, however, one instance in which fiction has conspicuously failed to keep imaginative pace with the theory. One of the originators of string theory, Michio Kaku, became an outspoken advocate of the notion that the real existence of parallel worlds is no mere metaphysical hypothesis, but can be proven, providing a definitive summary of the issue in Parallel Worlds (2005). The inflationary version of the many worlds hypothesis was given an added twist by the proposition that there must be an ongoing process of ‘‘natural selection’’ favouring the proliferation of those universes that are most hospitable to the formation of new sub-universes, and that this intra-multiversal evolutionary process might be responsible for the implication of intelligent design inherent in the cosmological anthropic principle. Scientific American devoted a special issue to such questions in May 2003. Liza Randall’s Warped Passages: Unraveling the Universe’s Hidden Dimensions (2005) calls individual universes ‘‘branes’’ (short for membranes) and the multiverse ‘‘the bulk’’.

Soul

Medieval and Renaissance scholars understood anima (soul) as the entity whose presence made a thing alive. Following Aristotle (384–322 B.C.E.), they believed that plants and animals as well as humans possessed souls but that only the human soul survived death. United with a properly prepared body, the human soul carried out vegetative and sensitive functions. In the view of most Aristotelians down to the Renaissance, the soul did not require a body for intellectual functions. The mechanical philosophers of the seventeenth century, while not denying the existence of the human soul, argued that organs alone were sufficient for vegetative and sensitive functions. A comparison of the mechanist theories of René Descartes (1596–1650) with the vitalist theories of William Harvey (1578–1657) in physiology and embryology illustrates how early attempts to banish soul from the science of life foundered upon the variety and complexity of vital functions.

In De motu cordis (On the Motion of the Heart, 1628), Harvey showed, contrary to the prevailing Galenic physiology, that blood returned to the heart through the veins and that systole was the active phase of heart motion. Although he likened the heart’s motion to that of a pump, Harvey was no mechanical philosopher. He believed that the blood was the seat of the soul and that the heart restored and perfected the blood upon its return from the extremities before pumping it out again. Descartes readily accepted the circulation of the blood but denied that the heart possessed any “unknown or strange faculties” for the restoration of the blood. He claimed that the heat of the heart was sufficient to explain not only the restoration of the blood but cardiac motion as well. Where the vitalist Harvey could readily accept an active systole, the mechanist Descartes found an active diastole easier to accommodate. Descartes dismissed Harvey’s assertion of an active systole and claimed, instead, that drops of blood entered the ventricles, were vaporized by cardiac heat, distended the ventricles, and so achieved enough pressure to force open the valves and enter the arteries. Unable to explain active systole in a heart deprived of the souls vital powers, Descartes returned to the theory of active diastole, which Harvey had already shown was false.

In De generatione animalium (1651), Harvey, relying chiefly on the examination of chick eggs at different stages of development, proposed that fetal development took place by epigenesis, by the sequential derivation of parts from a principal particle that, for vertebrates, was the blood. Harvey believed that the blood—the first material to emerge from the homogeneous mass of the egg—became the seat of the soul and, as the source of animal heat and vital spirits, guided all subsequent differentiation. Harvey’s willingness to attribute epigenesis to the soul rather than to mechanical processes allowed him to avoid the absurd consequences of preformation.

Timekeeping

Mankind first developed a sense of time from observations of nature. For the short term, he observed the movement of heavenly bodies—the sun and moon held particular importance, heralding the seasons and the months. For the long term, birth and death events—of themselves and their livestock—marked the passage of time. One of the earliest inventions was the astrolabe, which astronomers used to track stars and planets. The first such instrument may have been made in the second century by the greatest astronomer of ancient times, the Greek Hipparchus, and was brought to perfection by the Arabs. Early artificial means of timekeeping to provide an estimate of the hour were all analogue in nature, whether passive, like the sundial, or dynamic, like the sandglass or water-clock, which measured time by rate of flow. The sundial probably began with a stick thrust into the ground; the position of its shadow corresponded to the hour of the day. Very elaborate sundials have been constructed which compensate for the sun’s relative position during the year, and ingenious pocket versions have been popular from time to time. However, all such instruments are worthless if the day is cloudy, and after the sun goes down. Therefore, particularly for stargazers, independent means of time estimation were important. The simple sandglass, in which sand is made to run through a small opening, was adequate only for short durations. However, running water can power a mechanism indefinitely. The greatest water-clock ever made was a building-sized astronomical device, constructed by Su Sung in China in 1094, to simulate the movements of sun, moon and the principal stars. Chinese philosophers thought that because water flows with perfect evenness, it is the best basis for timekeeping. However, in this belief they were wrong; the secret of accurate timekeeping is to generate and count regular beats, which is a digital rather than an analogue process. This may be surprising, and not just to the ancients in China, because except for intra-atomic events time can be regarded as a continuous phenomenon.

Monorails

It was during the period before the First World War that monorails first caught public attention, although as early as 1824, H.R.Palmer had proposed a monorail in which divided vehicles would hang down either side of a single rail supported on trestles. An experimental horse-powered line was built, without lasting effect. About 1880, however, the French engineer C.F.M.T.Lartigue built about 190km (120 miles) of similar lines in North Africa along which wagons which hung down either side of the rail like panniers were hauled by horses or mules. The system was demonstrated in London in 1886, but with a steam locomotive designed by Mallet: it had a pair of vertical boilers and two grooved wheels. This led to construction of the 15km (9 miles) Lartigue monorail Listowel & Ballybunion Railway in Ireland, cheap to build, opened in 1888, steam worked, and successful in operation until 1924.

The managing director of the Lartigue Railway Construction Company was F. B.Behr who developed a high-speed electrically powered monorail, demonstrated in Belgium at 132kph (82mph) in 1897. He promoted a company which was authorized in 1901 to build such a line between Liverpool and Manchester, upon which the cars were to travel at 175kph (109mph): but the Board of Trade was hesitant over their braking abilities and capital for construction could not be raised. It was at this period, however, that the Wuppertal Schwebebahn was built in Germany, an overhead monorail with electrically powered cars suspended from it. The first section was opened to traffic in 1901; the line eventually extended to some 13km (8 miles) and continues to operate successfully to the present day. In 1903, Louis Brennan patented a monorail system in which the cars would run on a single rail and use gyroscopes to maintain their stability; this was built and demonstrated in 1909 with a petrol-electric vehicle, but despite the attraction of cheap construction was never put into commercial use. There have been many subsequent proposals for monorails, some of which have been built. The Bennie monorail, in which a suspended car was driven by an airscrew, was demonstrated in the 1920s; the most notable of many systems proposed since the Second World War has been the Alweg system in which the track is a hollow concrete beam supported on concrete pylons; not strictly a monorail, for a narrow track on the top of the beam is used for the carrying wheels of the vehicles, while additional wheels bearing on the edges of the beam cater for side thrust. With the exception of the Wuppertal line, monorails and the like have seen little use in public service, and have always had greater success in exciting public imagination.

Probes to the Moon

While most of the publicity and glory of lunar exploration has been given to the manned Apollo missions, it was the unmanned probes of the early and mid- 1960s that paved the way for these missions. The first four American attempts at launching a lunar probe were unsuccessful and on 12 September 1959 the Soviet Union launched the Luna 2 probe, which impacted 800km (500 miles) north of the visual centre of the moon. It thus became the first man-made body to reach a celestial object. Very soon after Luna 2, the Russians again achieved a space ‘first’ when Luna 3 photographed the invisible face of the moon. After these early days, the pace of lunar probe launches accelerated. The American Ranger series of spacecraft were intended to photograph the lunar surface in advance of the Apollo landings. The first six Ranger missions were failures, but Ranger 7 (launched 28 July 1964) sent back more than 4000 high-resolution photographs before impacting in the Sea of Clouds. Two more later Rangers returned more than 13,000 images between them.

In 1963 the Russians were planning for a lunar soft landing. The first attempts were unsuccessful. Luna 9 finally succeeded in 1966 and the spacecraft returned the historic first pictures from the moon’s surface. The rapid sequence of the Russian lunar launches leading up to Luna 9 was a direct response to its American competitor, the Surveyor spacecraft. Surveyor 1 softlanded on the moon barely four months after Luna 9, returning 11,000 pictures over a six-month period. The Surveyor craft were more sophisticated than the Luna vehicles. Further Surveyor landings examined the surface in regions representative of Apollo landing sites. At the same time as the Surveyor craft were landing on the moon, the Americans were launching Lunar Orbiter spacecraft aimed at returning very high resolution photographs of the lunar surface.

During 1969 while all the American efforts were directed towards the Apollo programme, the Russians were landing more lunar craft in a bold attempt to soft-land and return to earth with lunar soil samples. This ambitious programme failed to pre-empt the Apollo 11 landing, but in 1970 Luna 16 did achieve the goal of returning a sample to earth. The Russians never tried to send men to the moon, concentrating solely on robot explorers. Luna 21 carried a rover vehicle (called Lunokhod) which for four months roamed over 37,000 metres (23 miles) on the surface under command from ground control.

Beta Testing

Beta Testing, in computer science, the formal process of soliciting feedback on software that is still under development. In a beta test, software is sent to select potential customers and influential end users (known as beta sites), who test its functionality and determine whether any operational or utilization errors (bugs) still exist in the program. Beta testing is usually one of the last steps a software developer takes before releasing the product to market; however, if the beta sites indicate that the software has operational difficulties or an extraordinary number of bugs, it is common for the developer to conduct another beta test. A beta test usually includes a draft version of a product’s documentation, which is reviewed along with the software.

Chipset

In personal computers a chipset is a group of integrated circuits that together perform a particular function. System purchasers generally think in terms of the processor itself (such as a Pentium III, Pentium IV, or competitive chips from AMD or Cyrix). However they are really buying a system chipset that includes the microprocessor itself and often a memory cache (which may be part of the microprocessor or a separate chip—see cache) as well as the chips that control the memory bus (which connects the processor to the main memory on the motherboard.) The overall performance of the system depends not just on the processor’s architecture (including data width, instruction set, and use of instruction pipelines) but also on the type and size of the cache memory, the memory bus (RDRAM or “Rambus” and SDRAM) and the speed with which the processor can move data to and from memory.

In addition to the system chipset, other chipsets on the motherboard are used to support functions such as graphics (the AGP, or Advanced Graphics Port, for example), drive connection (EIDE controller), communication with external devices, and connections to expansion cards (the PCI bus). At the end of the 1990s, the PC marketplace had chipsets based on two competing architectures. Intel, which originally developed an architecture called Socket 7, has switched to the more complex Slot-1 architecture, which is most effective for multiprocessor operation but offers the advantage of including a separate bus for accessing the cache memory. Meanwhile, Intel’s main competitor, AMD, has enhanced the Socket 7 into “Super Socket 7” and is offering faster bus speeds. On the horizon may be completely new architecture. In choosing a system, consumers are locked into their choice because the microprocessor pin sockets used for each chipset architecture are different.

Optical Character Recognition Devices

An optical character recognition device, often abbreviated as OCR, is able to recognize text that is printed in a specific type font. Early OCR equipment could only read one type face (like this one) in dot matrix form. Scanners are a form of OCR family that can read almost any type font and their accuracy depends in large part on the text or recognition software used. The device converts light—an analog continuous wave form—into digital binary bits of zero and one [0,1] which is a discrete wave form. To accomplish this, scanners use electronic components such as charge-coupled devices (CCD), a diode that is light sensitive when electrically charged, or photomultiplier tubes (PMT), a light sensitive tube that detects light at any intensity by amplifying it. PMTs are usually associated with drum scanners. Some examples of scanners are as follows.

Limits of Science

What does all this have to do with nonmathematical topics like religion, agnosticism, and metaphysics? The answer is that Goedel’s theorem points out a basic limitation of science. We notice that all of science taken as a whole is an example of an infinite mathematical system to which Goedel’s theorem does apply. The axioms of the system may be taken to be the “laws” or theories that have been discovered in the various disciplines. Giving credit to the scientists, let us assume that the laws discovered by them have been thoroughly examined so that they are not mutually contradictory. In other words, we are assuming that the set of axioms is not inconsistent. This is a statement in favor of science, because if the axioms are indeed inconsistent, then as it stands now, there is something wrong in science that needs to be rectified.

We can now apply Goedel’s theorem. We conclude that the set of laws that we have is incomplete, that there exist questions in the system that cannot be answered yes or no using these laws. The system under consideration is nothing but nature itself, so we conclude that the laws of science as they stand now cannot answer all questions about nature. Now, take a particular question. To answer it, we shall need to add a new axiom—that is, discover a new law. This particular question will now get answered, but science will now be a new system to which Goedel’s theorem shall again apply. Now there will be some other question that cannot be answered.

Notice that this process will never come to an end. Even if we worked for a million years, science at that time would still be an incomplete bunch of axioms, and there would be questions about nature that cannot be answered yes or no. We thus conclude that science has a basic limitation: that there will be no time in the future when it has completely fathomed the depths of nature. It is a set of axioms that will always remain incomplete. This is a fact that gives us a glimpse into reality.