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motion - 26 reference results
time and motion study, analysis of the operations required to produce a manufactured article in a factory, with the aim of increasing efficiency. Each operation is studied minutely and analyzed in order to eliminate unnecessary motions and thus reduce production time and raise output, which increases productivity. The first effort at time study was made by F. W. Taylor in the 1880s. Early in the 20th cent., Frank and Lillian Gilbreth developed a more systematic and sophisticated method of time and motion study for industry, taking into account the limits of human physical and mental capacity and the importance of a good physical environment.
simple harmonic motion: see harmonic motion.
retrograde motion, in astronomy, real or apparent movement of a planet, dwarf planet, moon, asteroid, or comet from east to west relative to the fixed stars. The most common direction of motion in the solar system, both for orbital revolution and axial rotation, is from west to east (counterclockwise as seen from the north celestial pole); revolution or rotation in the opposite direction is actual retrograde motion. Bodies in the solar system with real retrograde orbits include certain moons of the outer planets, and some asteroids and comets. With the exception of the rotation of Venus, there is no real retrograde motion among the planets, although the plane in which Uranus rotates and its five satellites revolve is tilted slightly more than 90° to the plane of the ecliptic, so that these motions are technically retrograde. All the planets exhibit apparent retrograde motion when they are nearest the earth; i.e., they appear to move backward (east to west) against the background of stars. The superior planets, whose orbits lie outside that of the earth, appear to move backward at opposition, because the earth is overtaking and passing them. (Of any two planets, the one closer to the sun has the greater orbital speed.) As a consequence, a superior planet's progress through the zodiac is interrupted by annual loops or switchbacks. The effect is similar to passing an automobile on a highway; observers in the faster car see the slower car apparently moving backwards as they overtake it. Mercury and Venus, the inferior planets, exhibit apparent retrograde motion when at inferior conjunction. They are then passing between the earth and the sun, overtaking the earth, and thus seem to move east to west, relative to both the sun and the background stars. In the geocentric Ptolemaic system, the retrograde motion of the planets was explained, using epicycles, as real retrograde motion; the modern heliocentric theory satisfactorily explains these motions as apparent, due to the relative speeds of the planets in their orbits about the sun.
proper motion, in astronomy, apparent movement of a star on the celestial sphere, usually measured as seconds of arc per year; it is due both to the actual relative motions of the sun and the star through space. Proper motion reflects only transverse motion, i.e., the component of motion across the line of sight to the star; it does not include the component of motion toward or away from the sun. The most distant stars show the least proper motion. Barnard's Star, one of the closest stars, has the largest measured proper motion, 10.27 sec of arc per year. The average proper motion of the stars that can be seen with the naked eye is 0.1″ per year.
perpetual-motion machine, device that would be able to operate continuously and supply useful work, in violation of the laws of thermodynamics. A machine that would produce more energy in the form of work than is supplied to it in the form of heat would violate the first law of thermodynamics, which is a special case of the law of conservation of energy (see conservation laws, in physics), and is known as a perpetual-motion machine of the first kind. A machine that would completely convert heat from a warm body into work, without letting any heat flow into a cooler body, would violate the second law of thermodynamics, which is concerned with entropy changes, and is known as a perpetual-motion machine of the second kind. There were a number of early attempts to design and construct various types of perpetual-motion machines; however, since the 19th cent., when the laws of thermodynamics became understood, most such attempts have been abandoned.
motion sickness, waves of nausea and vomiting experienced by some people, resulting from the sudden changes in movement of a vehicle. The ailment is also known as seasickness, car sickness, train sickness, airsickness, and swing sickness. The principal cause of the disturbance is the effect of motion on the semicircular canals of the inner ear, although other factors such as inadequate ventilation and fumes or noxious odors may contribute. Drugs are available that, when taken beforehand, prevent the occurrence of motion sickness.
motion pictures, movie-making as an art and an industry, including its production techniques, its creative artists, and the distribution and exhibition of its products (see also motion picture photography; Motion Picture Cameras under camera).

Origins

Experiments in photographing movement had been made in both the United States and Europe during the latter half of the 19th cent. with, at first, no exploitation of its technical and commercial possibilities. Serial photographs of racehorses, intended to prove that all four hooves do leave the ground simultaneously, were obtained (c.1867) in California by Eadweard Muybridge and J. D. Isaacs by setting up a row of cameras with shutters tripped by wires. The first motion pictures made with a single camera were by E. J. Marey, a French physician, in the 1880s, in the course of his study of motion.

In 1889 Thomas Edison and his staff developed the kinetograph, a camera using rolls of coated celluloid film, and the Kinetoscope, a device for peep-show viewing using photographs that flipped in sequence. Marketed in 1893, the Kinetoscope gained popularity in penny arcades, and experimentation turned to ways in which moving images might be shown to more than one person at a time. In France the Lumière brothers created the first projection device, the Cinématographe (1895). In the United States, similar machines, notably the Pantopticon and the Vitascope, were developed and first used in New York City in 1896.

At first the screenings formed part of vaudeville shows and arcades, but in 1902 a Los Angeles shop that showed only moving pictures had great success; soon "movie houses" (converted shoprooms) sprang up all over the country. The first movie theater, complete with luxurious accessories and a piano, was built in Pittsburgh in 1905. A nickel was charged for admission, and the theater was called the nickelodeon. An industry developed to produce new material and the medium's potential for expressive ends began to assert itself.

The earliest films were used primarily to chronicle contemporary attitudes, fashions, and events, and ran no longer than 10 minutes. At first, simple actions were filmed, then everyday scenes and, pivotally, gag films, in which a practical joke is staged as a simple tableau. The camera was first used in a fixed position, though soon it was pivoted, or panned, on its tripod or moved toward or away from a subject.

The medium's potential as a storytelling mechanism was realized very early in its history. The Frenchman George Méliès created the earliest special effects and built elaborate sets specifically to tell stories of a fantastic nature, usually as a series of tableaux. His Cinderella (1900) and A Trip to the Moon (1902) were major innovative accomplishments. The American Edwin S. Porter demonstrated that action need not be staged for cinema screen as for theater and early realized that scenes photographed in widely separate locales could be cut, or edited, together yet still not be confusing to the audience. His subject matter tended toward depictions of modern life; his Life of an American Fireman (1902) and The Great Train Robbery (1903) are among the first works to use editing as well as acting and stagecraft to tell their stories.

As business increased, the demand for product was met by many new companies incorporated to create the supply. Cooperation among the early filmmakers yielded to the demands of the marketplace, and each company tried to secure continued success through innovations meant to distinguish its product. Out of these efforts developed the star system, the establishment of physical plants (studios) where the films would be made, and the organization of the filmmaking process into interlocking crafts. The crafts people include actors, producers, cinematographers, writers, editors, and film laboratory technicians who work interdependently in a production effort overseen and coordinated by the director.

American Film

The Early Years

The first American studios were centered in the New York City area. Edison had claimed the patents for many of the technical elements involved in filmmaking and, in 1909, formed the Motion Picture Patents Company, an attempt at monopoly that worked to keep unlicensed companies out of production and distribution. To put distance between themselves and the Patents Company's sometimes violent tactics, many independents moved their operations to a suburb of Los Angeles; the location's proximity to Mexico allowed these producers to flee possible legal injunctions. After 1913 Hollywood, Calif., became the American movie capital. At first, films were sold outright to exhibitors; later they were distributed on a rental basis through film exchanges.

Early on, actors were not known by name, but in 1910, the "star system" came into being via promotion of Vitagraph Co. actress Florence Lawrence, first known as The Vitagraph Girl. Other companies, noting that this approach improved business, responded by attaching names to popular faces and "fan magazines" quickly followed, providing plentiful, and free, publicity. Films had slowly been edging past the 20 minute mark, but the drive to feature-length works began with the Italian "spectacle" film, of which Quo Vadis (1913), running nine reels or about two hours, was the most influential.

Directors of the day, including D. W. Griffith, Thomas Ince, Maurice Tourneur, J. Stuart Blackton, and Mack Sennett, became known to audiences as purveyors of certain kinds, or "genres," of subject matter. The first generation of star actors included Charlie Chaplin, Buster Keaton, Mary Pickford, Douglas Fairbanks, Marie Dressler, Lillian Gish, William S. Hart, Greta Garbo, John Gilbert, Claudette Colbert, Rudolph Valentino, Janet Gaynor, Ronald Colman, Clara Bow, Gloria Swanson, Lon Chaney, and Will Rogers. During World War I the United States became dominant in the industry and the moving picture expanded into the realm of education and propaganda.

The Hollywood Studio Era

In the post-World War I period the production genius of such men as Samuel Goldwyn, Louis B. Mayer, Adolph Zukor, and Jesse L. Lasky, and the innovative talents of Cecil B. De Mille, Erich Von Stroheim, and Ernst Lubitsch were dominant. The year 1926 brought experiments in sound effects and music, and in 1927 spoken dialogue was successfully introduced in The Jazz Singer with Al Jolson. A year later the first all-talking picture, Lights of New York, was shown. With the talkies new directors achieved prominence—King Vidor, Joseph Von Sternberg, Rouben Mamoulian, Frank Capra, and John Ford. Sound films gave a tremendous boost to the careers of some silent actors but destroyed many whose voices were not suited to recording. Among the most celebrated stars of the new era were Clark Gable, Jean Harlow, Marlene Dietrich, Mae West, W. C. Fields, and the Marx Brothers.

Also in 1927 The Motion Picture Academy of Arts and Sciences was formed and began an annual awards ceremony. The prize, a figurine of a man grasping a star, was later dubbed Oscar. These awards did much to confer status upon the medium in that they asserted a definable quality of excellence analogous to literature and theater, other media in which awards are given for excellence. The Academy Awards also offered the bonus of gathering many stars in one place and thus attracted immediate and widespread attention. The star system blossomed: actors were recruited from the stage as well as trained in the Hollywood studios.

From the 1930s until the early 1950s, the studios sponsored a host of talented actors, foremost among whom were Ingrid Bergman, Joan Crawford, Bette Davis, Katharine Hepburn, Charles Laughton, Barbara Stanwyck, William Powell, Spencer Tracy, Humphrey Bogart, Leslie Howard, Gary Cooper, James Stewart, Cary Grant, Irene Dunne, Edward G. Robinson, Henry Fonda, Gregory Peck, James Cagney, Judy Garland, Bob Hope, James Mason, Fred Astaire, and Gene Kelly. Producers and directors such as David O. Selznick, Darryl F. Zanuck, Mervyn LeRoy, William Wyler, George Stevens, and Billy Wilder made significant contributions to cinematic art.

The medium had, after nickelodeon days, converted many legitimate theaters into movie houses. Later, during Hollywood's "golden age," thousands of sumptuous movie palaces were erected all over the United States, and drive-in movie theaters became popular outside urban centers. Since their inception the movies have always been termed an industry, with good reason. In 1938 there were more than 80 million single admissions per week (65% of the population). To meet the huge box-office demand, more than 500 films were produced that year.

The industry in its heyday (1930-49) was managed by a number of omnipotent studios, including Metro-Goldwyn-Mayer, Warner Brothers, RKO, Paramount, Twentieth Century-Fox, and Universal. They produced endless cycles of films in imitation of a few successful original types. The range of themes included the criminal underworld, behind-the-scenes newspaper dramas, westerns, musicals, costume romances, character series such as the Charlie Chan films, prison stories, mysteries, comedies, and Broadway shows. Because of their enormous investments and gargantuan rewards (the film industry's gross income for 1946, its best year, was nearly $2 billion), the studios were encouraged to repeat conventionalized formula pictures.

The Post-Studio Era

In the 1950s, two developments ended the studios' grip on the entertainment business: the overwhelming popularity of television began to eat into studio profits and the studios were forced by the federal courts to yield the control of distribution and exhibition that they had maintained by means of massive conglomerate corporations. In 1962 box-office receipts were only $900 million; by 1968 only 20 million people per week were going to a movie (10% of the population). Independent distributors and theaters took a huge cut of the industry's income after World War II, and the studios cut wages and laid off employees in a struggle to survive.

In order to compete with television the studio heads strongly urged technological innovation. In the 1950s experiments abounded with wide-screen processes, such as CinemaScope and Cinerama and stereophonic sound systems. The movies of the 1950s and 60s traded a bit of glamour for an increased sense of realism, providing vehicles for new directors, including Elia Kazan, John Frankenheimer, Stanley Kubrick, and Sidney Lumet, and for a great number of popular film stars, including Marlon Brando, Marilyn Monroe, Burt Lancaster, Montgomery Clift, Judy Holliday, James Dean, Paul Newman, Elizabeth Taylor, Charlton Heston, Doris Day, George C. Scott, Audrey Hepburn, and Sidney Poitier.

Eventually, c.1956 many studios began to produce material especially for television, including commercials, and to sell their old films for television reruns. Independent production became the norm, with the studios acting as distributors only, and new kinds of films emerged: horror, science fiction, and rock 'n' roll stories aimed at teen-agers proliferated. Concurrently, larger studio-backed films eschewed romanticism and sentimentality, fighting the long-imposed bans on depictions of a harsher reality and a more explicit sexuality.

The trend away from the glamorous celebrity image that began in the 1960s gained momentum in the 70s. The principal stars of these years include Jane Fonda, Barbra Streisand, Dustin Hoffman, Steve McQueen, and Woody Allen. Important American directors of the 1970s, 80s, and 90s include Peter Bogdanovich, Roman Polanski, Francis Ford Coppola, Robert Altman, and Martin Scorsese.

A change came with the release of Jaws (1975), an unassuming suspense picture that unexpectedly grossed over $100 million by appealing to all ages and both sexes. Filmmakers were now encouraged to speak to the widest possible audience. The result was a series of films given over to spectacle. Star Wars (1977) cracked the $200 million barrier, and E.T. (1982) earned over $300 million. While many of these films aroused criticism for representing the triumph of special effects over any kind of human values, the net effect was to draw the audience back into movie theaters, and many movies, including those without spectacular elements, succeeded during this period. This trend has continued into the 21st cent. The leading directors are Steven Spielberg and George Lucas, the latter more active as a producer.

Two developments that greatly enhanced profitability in the 1980s were the development of low-cost videocassette recorders (VCRs), which allow films to be shown at home, and the government's relaxation of the decrees separating production from distribution. The studios first felt that videocassettes would weaken the theatrical market; the reverse was true, as viewers became more interested in movie entertainment in general. Of the latter, studio co-ownership of various theater circuits assured wider distribution of films.

Beginning in the 1960s, many of the old movie palaces began to be divided into two or more auditoriums due to weakening attendance. When audiences returned in the 1980s, multiplexes, or theaters with multiple auditoriums, became the norm and mushroomed in suburban shopping malls and urban centers. In the early 1990s, however, the recession was reflected in movie attendance. By the turn of the decade, two major studios, MGM and Orion, suffered financial difficulties, and two others, Columbia and Universal, were bought by Japanese electronics companies, although Universal later became part of a French conglomerate.

One of the few positive motion-picture trends during the late 20th and early 21st cent. was the development and proliferation of IMAX. The format, which debuted in Japan in 1970, utilizes special film and projectors, features a gigantic screen and huge sound system, and has been used to take viewers on ultrarealistic trips to earthly (e.g., Everest, 1998) and outer-space (e.g., Destiny in Space, 1994) destinations. The province of museums for roughly two decades, the system was later extended to theaters and a number of films were reformatted to fit IMAX screens. By 2002, 180 IMAX films had been made, some in 3-D, and 225 large-screen IMAX theaters were in operation, 110 of them in the United States.

Censorship

After several scandals led to the fear that the immorality perceived to be rampant in Hollywood might appear on screen, the Motion Picture Producers and Distributors of America, headed by Will H. Hays, was established in 1922 as a film review board. The Production Code, popularly known as the "Hays Code," a highly restrictive set of guidelines for movie content, was promulgated in 1934 and complied with by virtually every Hollywood producer. In the late 1960s, the determination of what constituted pornography was turned over to the states for enforcement at the same time that filmmakers were attempting to break away from the Production Code's bans on sexuality and violence.

In 1966, the Production Code was abandoned completely and succeeded by the Motion Picture Code and Rating Program. Adopted to avoid a threatened state-controlled system, the program has characterized itself as providing guidance for parents, not for filmmakers. The program initially assigned each film one of four ratings: G (general audiences, without restrictions), M (mature audiences, parental guidance advised), R (restricted audiences, no one younger than 18 admitted without a parent or guardian), and X (no one younger than 18 admitted). The age limit may be adjusted by individual state rulings. M was eventually supplanted by PG (parental guidance suggested), PG-13, was introduced for films that might contain material inappropriate for pre-teenagers, and NC-17 replaced X, which had become associated with pornographic films.

Bibliography

See G. Battcock, The New American Cinema (1967); K. Brownlow, The Parade's Gone By (1968); R. Manvell, New Cinema in the USA (1968); R. Adler, A Year in the Dark (1970); D. Shipman, The Great Movie Stars: The Golden Years (1970); P. Trent, The Image Makers: Sixty Years of Hollywood Glamour (1972); P. Gilliatt, Unholy Fools (1973); C. Higham, The Art of the American Film, 1900-1971 (1973); P. Kael, I Lost It at the Movies (1965), Kiss Kiss Bang Bang (1968), Going Steady (1970), Deeper into Movies (1974), and For Keeps (1994); A. Brower and T. L. Wright, Working in Hollywood (1990); R. Barrios, A Song in the Dark: The Birth of the Musical Film (1995); K. M. Cameron, America on Film (1997); W. K. Everson, American Silent Film (1998); J. Basinger, Silent Stars (1999); T. Doherty, Pre-Code Hollywood (1999); M. A. Vieira, Sin in Soft Focus (1999).

British Film

Britain has produced some of the most illustrious talents in the history of film. Early efforts (c.1929) by the producer J. Arthur Rank to achieve a world market for British films were realized with the work of such postwar directors as Alfred Hitchcock, Carol Reed, David Lean, and the Hungarian-born Alexander Korda. Their films were literate and often suspenseful and brought international fame to such actors as Laurence Olivier, Ralph Richardson, John Mills, Paul Scofield, Merle Oberon, and Michael Redgrave. Alec Guinness, Peter Ustinov, Peter Sellers, and Terry Thomas created comedies that are sophisticated and singularly British in their sense of humor.

Major British directors of the 1960s include the American-born Joseph Losey, Tony Richardson, Sidney Furie, and John Schlesinger. Among the great number of notable British actors of recent years are Dirk Bogarde, Peter Finch, Michael Caine, Vanessa Redgrave, Stanley Baker, Glenda Jackson, Richard Burton, Julie Christie, Peter O'Toole, Maggie Smith, Alan Bates, John Gielgud, Claire Bloom, Albert Finney, Kenneth More, Michael York, Tom Courtenay, and Robert Shaw.

After a long dry spell in the 1970s, the British film industry returned to life with the formation of several new production companies such as Enigma, Working Title, Handmade Films, and Palace. A new television outlet, Channel 4, also produced many movies for theatrical release. Directors whose careers were stalled by the doldrums of the previous period now produced mature works: Stephen Frears (My Beautiful Laundrette), Mike Leigh (High Hopes, Life Is Sweet), and Mike Newell (Dance with a Stranger, The Good Father) among them. A new crop of actors came to the public's attention, including Gary Oldman, Daniel Day-Lewis, Natasha Richardson, Rupert Everett, Helen Mirren, Ben Kingsley, Jeremy Irons, Bob Hoskins, Kenneth Branagh, and Emma Thompson.

Bibliography

See R. Low, The History of the British Film (4 vol., 1973); C. Barr, ed., All Our Yesterdays (1990); J. Caughie and K. Rocket, ed., The Companion to British and Irish Cinema (1996).; S. Street, British National Cinema (1997); A. Aldgate and J. Richards, Best of British (new ed. 1999).

French Film

In the 1920s there was enormous creative film activity in France led by Louis Delluc and a group of directors around him—Abel Gance, Jean Epstein, and Germaine Dulac. Along with such directors as René Clair, Jean Renoir, and Carl Dreyer, they created films with an impressionistic and literary flavor. Later French films reflected first the optimism and then the despair of international events, as in Renoir's Grand Illusion (1937) and Marcel Carné's Port of Shadows (1938). In the postwar era H. G. Clouzot, René Clément, and Robert Bresson directed important films.

In the late 1950s the "new wave" of young directors, including Alain Resnais, Louis Malle, François Truffaut, and Jean-Luc Godard, made innovations in cinematography and dramatic approach. Their efforts achieved a new cinematic intimacy and a relaxed mood. French film stars who attained international acclaim during this period include Jean Gabin, Arletty, Gérard Philipe, Brigitte Bardot, Jean-Paul Belmondo, Jeanne Moreau, Catherine Deneuve, Yves Montand, Simone Signoret, and Jean-Louis Trintignant. Among the foremost directors of this period were Claude Chabrol, Eric Rohmer, and the Greek-born Costa-Gavras.

From the 1970s to the 1990s, the filmmakers of the new wave became curiously like the directors they had sought to replace, working on literary adaptations and stories of the occupation. A new group emerged, much more amorphous, concerned with reflecting their vision of present-day France. Among the new directors are Jean-Jacques Beneix (Diva, Betty Blue), Luc Besson (Subway, La Femme Nikita), and Leos Carax (Boy Meets Girl, Bad Blood).

The stars introduced by these films are notable for affectlessness: Beatrice Dalle, Christopher Lambert, Thierry Lhermitte, Jean-Hugues Anglade, Tcheky Karyo, and Anne Parrilaud, though some have found more range in subsequent works. The most successful star of the 1970s, 80s, and 90s has been Gérard Depardieu, who can make as many of five films in a year and is often credited for keeping the French cinema viable on the world market despite strong competition from the American film industry.

Bibliography

See R. Armes, The French Cinema since 1946 (2 vol., rev. ed. 1970) and French Cinema (1985); G. Sadoul, French Film (1953, repr. 1972); E. Ehrlich, Cinema of Paradox (1985); C. Crisp, The Classic French Cinema, 1930-1960 (1993) J. D. Andrew, Mists of Regret (1995); G. Vincendeau, ed., The Companion to French Cinema (1996).

German Film

The great era of German cinema began in 1919 with Robert Wiene's Cabinet of Dr. Caligari. It was written by Carl Mayer, who was among the most influential artists working in the German film industry in the 1920s. The films of this era were expressionist in style, paralleling developments in the other arts. Other notable directors, such as G. W. Pabst, F. W. Murnau, Max Ophuls, and Fritz Lang, brought the medium to new heights of imaginative production. A decline set in c.1925 when Hollywood attracted many German directors, technicians, and actors to the United States.

The advent of Hitler drove any remaining top talent abroad, and the industry did not recover its position after the war. Beginning in the early 1970s a group of young filmmakers revitalized the industry, attaining a world audience for their films: Wim Wenders (Kings of the Road and Wings of Desire), Werner Herzog (Aguirre, the Wrath of God and Fitzcarraldo) and R. W. Fassbinder (over 40 films, including The Marriage of Maria Braun and Querelle) led the renaissance.

Bibliography

See R. Manvell and H. Fraenkel, The German Cinema (1971); H. H. Wollenberg, Fifty Years of German Film (1948, repr. 1972); T. Elsaesser, New German Cinema (1989); T. Ginsberg, ed., Perspectives on German Film (1996); S. Allan and J. Sandford, ed., Defa: East German Cinema, 1946-1992 (1999); T. Elsaesser and M. Wedel, ed., The BFI Companion to German Cinema (1999).

Italian Film

The films of Roberto Rossellini in the 1940s gave new impetus to the Italian cinema. Thereafter followed a cycle of exciting, compassionate, grimly realistic films from such directors as Vittorio De Sica, Luigi Zampa, Giuseppe de Santis, and Luchino Visconti. These films, usually concerned with social themes, were successful in Italy only after they had won a foreign market. In the 1950s, in order to win box-office appeal, a tendency to produce marketable and sensational movies diminished the reputation of Italian filmmakers.

Quality and international acclaim were restored by Federico Fellini, Michelangelo Antonioni, and Bernardo Bertolucci. Italian film stars who have won popularity abroad include Sophia Loren, Marcello Mastroianni, Giulietta Masina, Monica Vitti, Raf Vallone, and Anna Magnani. The Italian industry suffered periodic crises from the 1970s to the 1990s, but produced new films by various masters and introduced an intriguing series of comic-centered films inspired by cartoons and clowning. Cinema Paradiso (1989) became the most successful Italian film released in the United States until Roberto Benigni's Oscar-winning Life is Beautiful (La Vita e Bella, 1997), a bittersweet comedy about the Holocaust in Italy.

Bibliography

See V. Jarratt, The Italian Cinema (1951, repr. 1972); P. Leprohon, The Italian Cinema (tr. 1972); P. Bondanella, Italian Cinema (1993); J. Hay et al., The Companion to Italian Cinema (1996).

Japanese Film

Since World War II, films produced in the East have had an increasingly appreciative Western audience. Akira Kurosawa's films, including Rashomon, Seven Samurai, and Yojimbo, are enormously popular action stories, in effect Japanese "westerns." Kurosawa's many productions, Kenju Mizoguchi's Ugetsu, and such delicately wrought works as Tokyo Story and The Flavor of Green Tea over Rice by Yasujiro Ozu brought worldwide acclaim to their directors and to Toshiro Mifune, who starred in many of Kurosawa's films. Japanese film became somewhat less culturally hermetic in later years, with directors such as Shohei Imamura (Vengeance Is Mine) and Juzo Itami (Tampopo) introducing a mixture of Japanese and Western influences into their work.

Bibliography

See D. Richie, The Japanese Movie: An Illustrated History (1982) and Japanese Cinema: An Introduction (1990); S. Galbraith, The Japanese Filmography (1996).

Russian Film

Dziga Vertov launched a weekly newsreel in 1922 urging new experiments in film technique, and Lev Kuleshov opened a cinema workshop to explore the psychological effects of film images. The result was the emergence of the Soviet epic films of the period 1925 to 1930. Encouraged by Lenin's belief that the film was of primary importance in the development of Soviet society, V. I. Pudovkin, Aleksandr Dovzhenko, and especially Sergei Eisenstein made films based on Russian history. Their superbly photographed, intensely dramatic films are classics of cinematic art.

The Soviet film industry was prolific but aesthetics were usurped by ideological heavy-handedness. Various thaws, however, produced intriguing works, including those by Sergei Paradjanov (The Color of Pomegranites) and Andrei Tarkovsky (Andrei Rublev). The breakdown of the Communist system has left the industry (now scattered among several newly independent nations) in an uncertain state.

Bibliography

See S. M. Eisenstein, Film Form and Film Sense (tr. 1949, repr. separately 1969) and Notes of a Film Director (rev. ed. tr. 1970); J. Leyda, Kino: A History of the Russian and Soviet Film (1960, repr. 1983); T. J. Slater, ed., Handbook of Soviet and East European Films and Filmmakers (1992).

Swedish Film

Victor Sjöström and Mauritz Stiller were the two men most responsible for the first flowering of Swedish films (c.1917-c.1924); Sjöström's Phantom Chariot (1920) was especially notable. When the Swedish film attained success and a world market, Hollywood and the German studios stepped in and hired the best technicians and artists, effectively destroying the industry. After World War II, Gösta Werner, Arne Sucksdorf, and Alf Sjöberg (especially his Torment, 1947) gained international repute. Film in Sweden was brought to unprecedented heights in the visionary works of Ingmar Bergman, a giant of modern cinema. He retired from filmmaking in 1983. Other modern Swedish directors of note include Bo Widerberg and Mai Zetterling. In 1987, Lasse Hallstrom's My Life as a Dog became the most successful Swedish film released abroad.

Bibliography

See J. Donner, The Personal Vision of Ingmar Bergman (1964); P. Cowie, Swedish Cinema (1966); A. Kwiatowski, Swedish Film Classics (1983); P. O. Qvist and P. Von Bagh, Guide to the Cinema of Sweden and Finland (1999).

Nontheatrical Film

Special types of films include the documentary, the newsreel, and the animated cartoon. The documentary, broadly defined, includes the newsreel, the travelogue, the educational film, and all other fact or nonfiction films, as well as some sorts of advertising. The term also includes artistic, interpretive films of the type that developed out of the work of Robert Flaherty (1920s and 30s) and Pare Lorentz (1930s) in the United States and John Grierson (1930s and 40s) in England. The documentary proved its value in the schoolroom and in training programs during World War II and has been widely used as a medium for propaganda since its inception. Documentary films on a vast range of subjects and exploiting every imaginable film technique are a primary staple of television entertainment.

The newsreel, introduced by Charles Pathé, was a series of short, generally unrelated films of current events, shown primarily as adjuncts to feature-film programs. The scope of the newsreel was broadened by the historical concept of the March of Time series (begun 1934); the newsreel was superseded by television news coverage in the early 1950s.

The animated cartoon is traditionally defined as a series of static drawings or scenes arranged and photographed and then synchronized with sound. In France in 1905, Émile Cohl produced several films with animated puppets, and in 1907, he made the first films to use animated drawings. American pioneers include Winsor McCay, who made Gertie the Dinosaur (1909); Bud Fisher, who began his "Mutt and Jeff" cartoons c.1918; Pat Sullivan, who produced "Felix the Cat" cartoons (1924); Chuck Jones, who in collaboration with Isador (Friz) Freleng, Tex Avery, and others, oversaw and animated (1930s-1960s) the Loony Tunes and Merry Melodies series (Bugs Bunny, Porky Pig, Daffy Duck, Elmer Fudd, et al.) at Warner Brothers (Jones also created (1949) the Road Runner series and later worked with on Dr. Seuss film cartoons; Freleng subsequently created the Pink Panther); and, of course, the celebrated Walt Disney.

Beginning with the Disney studios' Tron (1982), animation has become increasingly computer generated, largely due to the work of two California-based animation studiosa—DreamWorks and Pixar. Their early computer-made feature films include Pixar's Toy Story movies (1995, 1999) and A Bug's Life (1998) and DreamWorks' Antz (1998). By 2000, traditional cartoons were in decline and most U.S. film animation (with the exception of nearly all the features produced by Disney) was digital, seemingly three-dimensional, and computer-generated. In DreamWorks' Shrek (2001) and Shrek 2 (2004) and Pixar's Monsters, Inc. (2001), Finding Nemo (2003), and The Incredibles (2004), computer animation reached new heights of technological sophistication and complexity. Their seemingly real characters, voiced by actors but otherwise completely electronic in origin, interact in an apparently organic environment.

The Polar Express (2004) combined live action and animation, digitizing and transforming the body and face movements of actors into the actions of computerized characters that inhabit a three-dimensional, computer-generated world. The boundaries of traditional animation continued to expand as animation and live action were increasingly merged and the technology employed to combine the two became increasingly sophisticated. These advances are evident, for example, in the processed live action of Richard Linklater's A Scanner Darkly (2006) and in the motion-capture techniques used to change human dancers into dancing penguins in George Miller's Happy Feet (2006).

Although animation has been generally treated as a children's medium, some animators, such as Ralph Bakshi, have aimed their works at adults, and the Disney organization, after several moribund years, began a series of features aimed equally at kids and at their parents, such as The Little Mermaid (1989), Beauty and the Beast (1991), and The Lion King (1994), which have proved to be extremely successful at the box office. Another notable talent is Don Bluth, who produced An American Tail and The Land before Time, combining old-fashioned full-animation with up-to-date wit.

Late 20th-century Japanese animation, much of it computer-generated, has been extremely influential. By the early 21st cent. some 60 percent of Japanese films and many television programs were in the style known as anime [Jap.=animation], which usually represents a fusion of Japanese pictorial tradition, particularly wood-block prints, with characters and stories in the American idiom. The style began in the 1950s with the work of Osamu Tezuka, creator of the Astro Boy comic book (1951) and television series (1963). Characterized by somewhat jerky movements and big-headed characters (as in the well-known Pokémon series), these films do not stress realism, but attempt to capture expressive gesture and mood. Anime films range from Disney-style adventures to surrealist fantasies, and many mix genres. Particularly impressive is the work of Hayao Miyazaki, e.g., the complex and brooding Princess Mononoke (1997) and the later Spirited Away (2001). Other outstanding anime films include Katusuhiro Otomo's Akira (1988), Mamoru Oshii's Ghost in the Shell (1996), Satoshi Kon's Perfect Blue (1997), and Rintaro's Fritz Lang-inspired Metropolis (2000).

Bibliography

See K. C. Lahue, World of Laughter: The Motion Picture Comedy Short, 1910-1930 (1966); R. L. Snyder, Pare Lorentz and the Documentary Film (1968); A. Rosenthal, The New Documentary in Action (1971); J. Lenburg, The Encyclopedia of Animated Cartoons (1991); M. Barrier, Hollywood Cartoons (1999); S. J. Napier, Anime from "Akira" to "Princess Monoke" (2000).

General Bibliography

See K. Macgowan, Behind the Screen (1965); A. Bazin, What Is Cinema? (1967); B. Crowther, The Great Films (1967); D. Shipman, The Great Movie Stars (2 vol., 1970-72); D. Robinson, The History of World Cinema (1973); J. D. Andrew, The Major Film Theories (1976) and Concepts in Film Theory (1984); K. Brownlow, Hollywood, the Pioneers (1979); D. Cook, A History of Narrative Film (1981); G. Mast, A Short History of the Movies (1986); B. F. Kawin, How Movies Work (1987); I. Konigsberg, The Complete Film Dictionary (2d ed. 1997); D. Thomson; A Biographical Dictionary of Film (rev. ed. 2004) and The Whole Equation: A History of Hollywood (2004).

motion picture photography or cinematography, photographic arts and techniques involved in making motion pictures.

See also photography, still.

The Camera

The motion picture camera (see under camera) was developed from simple multi-image devices that, when spun or flipped, displayed the parts of a continuous movement, which, combined with the ocular principle of persistence of vision, produces the illusion of movement. The camera takes a series of photographs on negative film; when the positive is moved through a projector at a speed consistent with that of the camera, they throw a realistically perceived moving image on a wall or screen.

Film Editing

In the first decade of filmmaking, pioneers Georges Méliès and Edwin S. Porter found that the effect of motion could be warped, shooting the film at a slower speed than it was projected to produce a speeded-up image (and vice versa) which could be used for comical or fantastical purposes. Porter and especially D. W. Griffith discovered that cutting, or editing, strips of films did not destroy the viewer's ability to comprehend the flow of images.

Griffith developed the use of the close-up, a full view of a detail within the larger image, often a hand, face, or object, the audience retaining the context of the scene into which the close-up was cut. With this method, Griffith was able to bind the audience closer to the characters on the screen, intensifying emotional involvement with the story. Griffith also experimented with cutting scenes widely separated in space but meant to communicate a temporal simultaneity. Thus, in The Lonesdale Operator (1909), when the heroine is menaced by the villain, Griffith could cut to her approaching rescuers and through ever-shorter alternations between the two actions could imply that the rescuers were coming closer until, finally, the two converge in the same frame and the heroine is rescued. Griffith's use of editing became extremely sophisticated, but was a largely intuitive process.

The initial codification of editing possibilities and the theory and application of it for aesthetic purposes began in the Soviet Union in the 1920s. Montage, the cutting of images so that meaning could be generated from their juxtaposition, was devised by Sergei M. Eisenstein and demonstrated with unusual power in the scene depicting the slaughter of civilians by Russian troops on the Odessa steps in the classic film The Battleship Potemkin (1925). In this scene, hundreds of shots, some on screen for no longer than a second or two, communicate an overwhelming sense of violence and terror while depicting no direct violence in any one image. Filmmakers in general incorporated editing as one element of a total work rather than the determining element of the work itself.

Early Cinematography

Cinematography is the act of lighting and photographing the images. Its history includes aesthetic elements, such as the way a set or location may be lighted to bolster the drama. Also important are technological elements, which broaden the expressive capacity of the image and even affect the environment of the film-watching experience, for example, the variety of framing options offered by masking the screen or, later, through methods intended to increase the medium's panoramic possibilities.

Striking work on this level was done in Germany during the 1920s, as filmmakers worked to bring expressionism, then a movement in drama and painting, to their medium. Fritz Lang and F. W. Murnau tried through manipulation of the image to portray the psychic and emotional states of their films' characters. Through an increased attention to the meanings that could be generated through sculpting the individual images with light and particularly darkness, they evolved a highly subjective film style in which these elements were combined to reflect the mental state of the characters. This sort of subjectivity is particularly vivid in Murnau's The Last Laugh (1924), in which the tribulations of a hotel doorman who faces a series of humiliations is so vividly expressed through the photographic treatment that no titles (intercut written texts) were necessary to explain the narrative.

Sound

From 1927, the addition of the soundtrack to film posed the problem of incorporating sound into the visual repertoire of the silents. The first feature with dialogue, The Jazz Singer (1927), used a film and phonograph method that allowed for camera mobility but was difficult to synchronize. It was soon displaced by a method in which sound and image were recorded together and projected on a single piece of film.

Directors such as René Clair and Rouben Mamoulian were pioneers in the effort to use sound creatively and in conjunction with the image, but most films simply recorded dialogue to accompany static images, as early sound recording methods required that the camera be encumbered within a soundproof booth. As the technological difficulties of sound recording receded, the image regained its prominence and the stalled work begun in the twenties went forward.

Sound and Cinematography: Citizen Kane

Orson Welles's Citizen Kane (1941) is a compendium of photographic techniques combined with a creative use of sound. Welles and cinematographer Gregg Toland developed or enhanced techniques for allowing the drama to develop on multiple planes of vision and sound. Deep focus photography, which Toland had used in more limited fashion in earlier films, allowed actors and objects to remain in focus whatever their distance from the camera. Using this method, multiple actions could be staged within a single frame and remain comprehensible, allowing for complex interactions between foreground and background.

The soundtrack followed suit. Welles created a complex soundtrack that merged multiple dialogues, sometimes spoken simultaneously, and music into a comprehensible whole. Toland also developed ways to light sets so that it was no longer necessary to avoid extreme low-angle shots for fear of exposing the lamps; the effect of allowing different, often extreme, camera angles was to intensify the meaning of a given shot or scene.

Color

While sound was rapidly merged with the image, color proved more difficult. Many early films were hand-painted, and various mechanical methods of suggesting color were developed. But the technology necessary to reproduce color comparable to that perceived by the eye only developed during the 1920s and attained a full palette in 1933 with the introduction of three-color Technicolor. Ironically, by this time, black-and-white was assumed to represent "reality" on screen and color was first used primarily in musicals, fantasies, and large-scale spectacles. Color replaced black-and-white as the dominant medium during the late 1950s, perhaps because it could be marketed as an alternative to black-and-white television.

Wide-Screen and Other Processes

The studios responded to television, and its rapid siphoning of the movie audience, with a battery of technical "advances," many of them modernized versions of processes developed two to three decades earlier. Three techniques were introduced that employed panoramic framing, which met with varying degrees of success. The standard film aspect ratio had been 1.33:1, nearly square. In 1953, Twentieth Century-Fox studio initiated CinemaScope, with an aspect ratio of 2.35:1. CinemaScope is an anamorphic process, using a lens while filming which squeezes a wide image onto a standard-sized frame of film; the image is unsqueezed via a complementary lens on the projector. A competing system, VistaVision, has a ratio of 1.85:1, accomplished by turning the film strip 45 degrees and photographing and projecting the film horizontally. These aspect ratios became the industry standard.

A third process, Cinerama, used three cameras to photograph a scene and three projectors that showed the image on a curved screen. The intention was to duplicate peripheral vision and thus trick the mind into generating a realistic three-dimensional image. Artistically, Cinerama reached its apex with 2001: A Space Odyssey (1968), in which director Stanley Kubrick used the format to convey the enormousness of outer space. Expensive and cumbersome, the format was retired in 1973.

Also during the 1950s, 3-D, which reproduced depth perception through the use of glasses that merged split images, proved unworkable and headache inducing. However, in the early 1990s a much more sophisticated 3-D technique, IMAX, was introduced. Requiring a headset equipped with infrared sensors, liquid crystal lenses, and stereo speakers, its effects are remarkably lifelike. It uses images produced by two spools of synchronized film whose frames are more than ten times the size of conventional 35-mm images. It was uncertain whether or not the process would prove viable for large-scale production and acceptable to large audiences.

Prominent Cinematographers

Cinematography developed as a separate craft very early in film history; the first prominent cinematographer was Billy Bitzer, who worked on Griffith's films. The best cinematographers develop styles that carry over to the films of the many directors with whom they work. Occasionally, a collaboration between a director and cinematographer will produce a series of films of unusually consistent photographic quality. The foremost American cameramen from the first half of the 20th cent. include Gregg Toland (Wuthering Heights, The Grapes of Wrath, Citizen Kane), Charles Rosher (Sunrise, The Yearling), James Wong Howe (The Thin Man, The Rose Tattoo, Picnic, Hud), Lee Garmes (Morocco, Shanghai Express, Duel in the Sun), and Karl Freund (The Last Laugh, Metropolis, Camille).

The French directors of the "new wave" of the 1960s, including Alain Resnais, Louis Malle, François Truffaut, and Jean-Luc Godard, revolutionized photographic technique by using newly invented smaller cameras and faster film stocks requiring less deliberate lighting techniques. These films feature a rawer style, more usually associated with documentary, that attempts to present an unmediated naturalistic narrative. The basic methodology was carried back into a documentary movement loosely grouped under the cinéma vérité rubric. Hollywood filmmakers adapted these methods, but continued to strive for a photographically "perfect" environment, in which the audience is never made aware of the mechanics of producing a movie.

Some prominent cinematographers of the last 20 years include Sven Nykvist (Persona and virtually every film directed by Ingmar Bergman after 1960), Gordon Willis (The Godfather, Annie Hall), Vittorio Storaro (Apocalypse Now, The Sheltering Sky), Vilmos Zsigmond (Close Encounters of the Third Kind, McCabe and Mrs. Miller) and Nestor Almendros (The Story of Adele H., Places in the Heart).

Bibliography

See S. M. Eisenstein, Film Form and Film Sense (tr. 1949, repr. separately 1969) and Notes of a Film Director (rev. ed. tr. 1970); H. M. Geduld, ed., Film Makers on Film Making (1967); R. L. Bare, The Film Director: A Practical Guide to Motion Picture and Television Techniques (1971).

motion picture camera: see under camera.
motion, the change of position of one body with respect to another. The rate of change is the speed of the body. If the direction of motion is also given, then the velocity of the body is determined; velocity is a vector quantity, having both magnitude and direction, while speed is a scalar quantity, having only magnitude.

Types of Motion

Uniform motion is motion at a constant speed in a straight line. Uniform motion can be described by a few simple equations. The distance s covered by a body moving with velocity v during a time t is given by s=vt. If the velocity is changing, either in direction or magnitude, it is called accelerated motion (see acceleration). Uniformly accelerated motion is motion during which the acceleration remains constant. The average velocity during this time is one half the sum of the initial and final velocities. If a is the acceleration, vo the original velocity, and vf the final velocity, then the final velocity is given by vf=vo + at. The distance covered during this time is s=vot + 1/2 at2. In the simplest circular motion the speed is constant but the direction of motion is changing continuously. The acceleration causing this change, known as centripetal acceleration because it is always directed toward the center of the circular path, is given by a=v2/r, where v is the speed and r is the radius of the circle.

The Laws of Motion and Relativity

The relationship between force and motion was expressed by Sir Isaac Newton in his three laws of motion: (1) a body at rest tends to remain at rest or a body in motion tends to remain in motion at a constant speed in a straight line unless acted on by an outside force, i.e., if the net unbalanced force is zero, then the acceleration is zero; (2) the acceleration a of a mass m by an unbalanced force F is directly proportional to the force and inversely proportional to the mass, or a = F/m; (3) for every action there is an equal and opposite reaction. The third law implies that the total momentum of a system of bodies not acted on by an external force remains constant (see conservation laws, in physics). Newton's laws of motion, together with his law of gravitation, provide a satisfactory basis for the explanation of motion of everyday macroscopic objects under everyday conditions. However, when applied to extremely high speeds or extremely small objects, Newton's laws break down.

Motion at speeds approaching the speed of light must be described by the theory of relativity. The equations derived from the theory of relativity reduce to Newton's when the speed of the object being described is very small compared to that of light. When the motions of extremely small objects (atoms and elementary particles) are described, the wavelike properties of matter must be taken into account (see quantum theory). The theory of relativity also resolves the question of absolute motion. When one speaks of an object as being in motion, such motion is usually in reference to another object which is considered at rest. Although a person sitting in a car is at rest with respect to the car, both in motion with respect to the earth, and the earth is in motion with respect to the sun and the center of the galaxy. All these motions are relative.

It was once thought that there existed a light-carrying medium, known as the luminiferous ether, which was in a state of absolute rest. Any object in motion with respect to this hypothetical frame of reference would be in absolute motion. The theory of relativity showed, however, that no such medium was necessary and that all motion could be treated as relative.

Bibliography

See J. C. Maxwell, Matter and Motion (1877, repr. 1952).

harmonic motion, regular vibration in which the acceleration of the vibrating object is directly proportional to the displacement of the object from its equilibrium position but oppositely directed. A single object vibrating in this manner is said to exhibit simple harmonic motion (SHM). More complex harmonic motion can be analyzed as combinations of two or more simple harmonic motions. Examples of objects whose motion approximates SHM are a pendulum swinging in a small arc, a mass bouncing at the end of a stretched spring, and air molecules vibrating back and forth as a sound wave passes. Simple harmonic motion is a periodic motion; that is, it repeats itself at regular intervals. The time required for one complete vibration of the object is the period of the motion. The inverse of the period is the frequency, which is the number of vibrations per unit of time. The maximum displacement of the object from its central position of equilibrium is the amplitude of the motion. At maximum displacement the velocity of the object is zero; the velocity is greatest when the object passes through its equilibrium position. These terms are commonly used to describe any periodic phenomenon, e.g., wave motion and the rotation or revolution of an astronomical body. For any real harmonic motion, various forces act to reduce the amplitude with each vibration, i.e., to damp the motion. If these forces are small compared to the restoring force arising from the original displacement, then the object will vibrate a number of times with successively smaller amplitudes until the motion gradually dies out; this is known as damped harmonic motion. For a certain value of the damping forces, the object returns to its original position in a minimum amount of time and comes to rest at that position; such motion is termed critically damped. If the damping forces are large compared to the restoring force, the object returns slowly to its original position without vibrating at all; the system is said to be overdamped.
colorization, motion picture, electronic process that uses computers to add color to black-and-white movies, creating new colored videotape versions. Invented by Canadians Wilson Markle and Brian Hunt, the process was first used in 1970 and became viable in the late 1980s. Proponents of colorization argue that it makes old movies more acceptable to the public. The process was enthusiastically backed by Ted Turner, whose 1986 proposal to colorize all the black-and-white films in the MGM archives, which he owns, led to a storm of opposition and to denunciations by such figures as John Huston, Jimmy Stewart, and Woody Allen, among others, who saw colorization is a defilement of the original work. The process became particularly controversial in the late 1980s when such monochrome film classics as Casablanca, Citizen Kane, and It's a Wonderful Life were threatened with colorization. Since that time, the demand for colorized films has greatly diminished. Some old television programs, however, continue to appear in colorized versions.
Newton's laws of motion: see motion.

Motion of a particle moving at a constant speed on a circle. Though the magnitude of the velocity of such an object may be constant, the object is constantly accelerating because its direction is constantly changing. At any given instant its direction is perpendicular to a radius of the circle drawn to the point of location of the object on the circle. The acceleration is strictly a change in direction and is a result of a force directed toward the centre of the circle. This centripetal force causes centripetal acceleration.

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Analysis of the time spent in going through the different motions of a job or series of jobs in the evaluation of industrial performance. Such studies were first instituted in offices and factories in the U.S. in the early 20th century. They were widely adopted as a means of improving work methods by subdividing the different operations of a job into measurable elements, and they were in turn used as aids in standardization of work and in checking the efficiency of workers and equipment.

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Repetitive back-and-forth movement through a central, or equilibrium, position in which the maximum displacement on one side is equal to the maximum displacement on the other. Each complete vibration takes the same time, the period; the reciprocal of the period is the frequency of vibration. The force that causes the motion is always directed toward the equilibrium position and is directly proportional to the distance from it. A pendulum displays simple harmonic motion; other examples include the electrons in a wire carrying alternating current and the vibrating particles of a medium carrying sound waves.

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In astronomy, the actual or apparent motion of a body in a direction opposite to that of the predominant (direct or prograde) motions of similar bodies. Observationally and historically, retrograde motion refers to the apparent reversal of the planets' motion through the stars for several months in each synodic period. This required a complex explanation in Earth-centred models of the universe (see Ptolemy) but was naturally explained in heliocentric models (see Copernican system) by the apparent motion as Earth passed by a planet in its orbit. It is now known that nearly all bodies in the solar system revolve and rotate in the same counterclockwise direction as viewed from a position in space above Earth's North Pole. This common direction probably arose during the formation of the solar nebula. The relatively few objects with clockwise motions (e.g., the rotation of Venus, Uranus, and Pluto) are also described as retrograde.

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Apparent motion of a star across the celestial sphere at right angles to the observer's line of sight, generally measured in seconds of arc per year. Any radial motion (toward or away from the observer) is not included. Edmond Halley was the first to detect proper motions; the largest known is that of Barnard's star, about 10 seconds yearly.

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Motion that is repeated in equal intervals of time. The time of each interval is the period. Examples of periodic motion include a rocking chair, a bouncing ball, a vibrating guitar string, a swinging pendulum, and a water wave. Seealso simple harmonic motion.

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Mathematical formula that describes the motion of a body relative to a given frame of reference, in terms of the position, velocity, or acceleration of the body. In classical mechanics, the basic equation of motion is Newton's second law (see Newton's laws of motion), which relates the force on a body to its mass and acceleration. When the force is described in terms of the time interval over which it is applied, the velocity and position of the body can be derived. Other equations of motion include the position-time equation, the velocity-time equation, and the acceleration-time equation of a moving body.

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Sickness caused by contradiction between external data from the eyes and internal cues from the balance centre in the inner ear. For example, in seasickness the inner ear senses the ship's motion, but the eyes see the still cabin. This stimulates stress hormones and accelerates stomach muscle contraction, leading to dizziness, pallor, cold sweat, and nausea and vomiting. Minimizing changes of speed and direction may help, as may reclining, not turning the head, closing the eyes, or focusing on distant objects. Drugs can prevent or relieve motion sickness but may have side effects. Pressing an acupuncture point on the wrist helps some people.

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or movie

Series of still photographs on film, projected in rapid succession onto a screen. Motion pictures are filmed with a movie camera, which makes rapid exposures of people or objects in motion, and shown with a movie projector, which reproduces sound synchronized with the images. The principal inventors of motion-picture machines were Thomas Alva Edison in the U.S. and the Lumière brothers in France. Film production was centred in France in the early 20th century, but by 1920 the U.S. had become dominant. As directors and stars moved to Hollywood, movie studios expanded, reaching their zenith in the 1930s and '40s, when they also typically owned extensive theatre chains. Moviemaking was marked by a new internationalism in the 1950s and '60s, which also saw the rise of the independent filmmaker. The sophistication of special effects increased greatly from the 1970s. The U.S. film industry, with its immense technical resources, has continued to dominate the world market to the present day. Seealso Columbia Pictures; MGM; Paramount Communications; RKO; United Artists; Warner Brothers.

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Change in position of a body relative to another body or with respect to a frame of reference or coordinate system. Motion occurs along a definite path, the nature of which determines the character of the motion. Translational motion occurs if all points in a body have similar paths relative to another body. Rotational motion occurs when any line on a body changes its orientation relative to a line on another body. Motion relative to a moving body, such as motion on a moving train, is called relative motion. Indeed, all motions are relative, but motions relative to the Earth or to any body fixed to the Earth are often assumed to be absolute, as the effects of the Earth's motion are usually negligible. Seealso Brownian motion; periodic motion; simple harmonic motion; simple motion; uniform circular motion.

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Relations between the forces acting on a body and the motion of the body, formulated by Isaac Newton. The laws describe only the motion of a body as a whole and are valid only for motions relative to a reference frame. Usually, the reference frame is the Earth. The first law, also called the law of inertia, states that if a body is at rest or moving at constant speed in a straight line, it will continue to do so unless it is acted upon by a force. The second law states that the force math.F acting on a body is equal to the mass math.m of the body times its acceleration math.a, or math.F = math.mmath.a. The third law, also called the action-reaction law, states that the actions of two bodies on each other are always equal in magnitude and opposite in direction.

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Any of various physical phenomena in which some quantity is constantly undergoing small, random fluctuations. It was named for Robert Brown, who was investigating the fertilization process of flowers in 1827 when he noticed a “rapid oscillatory motion” of microscopic particles within pollen grains suspended in water. He later discovered that similar motions could be seen in smoke or dust particles suspended in air and other fluids. The idea that molecules of a fluid are constantly in motion is a key part of the kinetic theory of gases, developed by James Clerk Maxwell, Ludwig Boltzmann, and Rudolf Clausius (1822–88) to explain heat phenomena.

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