PARALLEL WORLDS

   A parallel world is another universe situated "alongside" our own, displaced from it along a spatial fourth DIMENSION (parallel worlds are often referred to in sf as "other dimensions"). Although whole universes may lie parallel in this sense, most stories focus on parallel Earths. The parallel-world idea forms a useful framework for the notion of historical ALTERNATE WORLDS, and is often used in this way. Most of the "secondaryworlds" of modern FANTASY are explicit or implicit parallel worlds. Notable early sf extrapolations include J.H. ROSNY aine's "Un autre monde"(1895; trans as "Another World" 1962) and two stories by H.G. WELLS: "The Strange Case of Davidson's Eyes" (1895) and "The Plattner Story" (1896).The idea that other worlds lie parallel to our own and occasionally connect with it is one of the oldest speculative ideas in literature and legend; examples range from Fairyland to the "astral plane" of Spiritualists and mystics. There are two basic folkloristic themesconnected with the notion; in one, an ordinary human is translocated into a fantasy land where s/he undergoes adventures and may find the love and fulfilment that remain beyond reach on Earth; in the other, a communication or visitation from the other world affects the life of an individual within this world, often injuring or destroying that person. Both patterns are very evident in modern imaginative fiction, shapingwhole subgenres. Much of the overlap between sf, FANTASY and HORROR fiction-which makes clear-cut DEFINITIONS of the genres impossible - occurs by virtue of the promiscuous use of parallel worlds. The first pattern was modernized by Edgar Rice BURROUGHS, A. MERRITT and other PULP-MAGAZINE writers before the founding of AMAZING STORIES, and waseasily dressed up with pseudo-scientific jargon; a notable early example is The Blind Spot (1921; 1951) by Homer Eon FLINT and Austin HALL. Henry KUTTNER and C.L. MOORE wrote several Merrittesque SCIENCE-FANTASY novelsafter this fashion, notably The Dark World (1946; 1965) and Beyond Earth's Gates (1949 Startling Stories as "The Portal in the Picture"; 1954 dos).Among the first writers to co-opt parallel worlds for straightforward sf melodrama were Edmond HAMILTON, in "Locked Worlds" (1929), and Murray LEINSTER, in "The Fifth-Dimensional Catapult" (1931) and its sequels. Theidea was frequently used in humorous fashion by L. Sprague DE CAMP and others in UNKNOWN WORLDS. The second pattern, in which entities from a parallel world impinge on ours, was sciencefictionalized by William Hope HODGSON in The Ghost Pirates (1909); his earlier The House on theBorderland (1908) uses the landscapes of a parallel world to map and symbolically display the psyche of its protagonist. The renewal of such traditional horror motifs by sf imagery was taken further by H.P. LOVECRAFT in a manner imitated by his many disciples, including FrankBelknap LONG and Donald WANDREI.The early GENRE-SF writers were slow to develop more extravagant speculative possibilities, although one notable attempt to describe a parallel world with different physical laws from those holding in our own continuum was made by Clark Ashton SMITH in "The Dimension of Chance" (1932); this notion was eventually developed muchmore carefully and elaborately by Isaac ASIMOV in THE GODS THEMSELVES (1972). Raymond F. JONES's Renaissance (1944; 1951; vt Man of Two Worlds)is straightforward, and Fritz LEIBER's use of parallel alternative worlds in Destiny Times Three (1945; 1957) is quantitatively restrained. It was in the 1950s and 1960s that exploration of the quirkier corollaries of the basic notion really got under way. Clifford D. SIMAK imagined a more extensive series of Earths - all empty of humanity and thus available for colonization and exploitation - in Ring Around the Sun (1953) and examined the hazards of trading between parallel worlds in "Dusty Zebra" (1954) and "The Big Front Yard" (1958), as did Alan E. NOURSE in "Tiger by the Tail"(1951). Gordon R. DICKSON's Delusion World (1955 Science Fiction Stories as "Perfectly Adjusted"; exp 1961) features a city simultaneously occupied by two societies, each invisible to the other.A common variant of the theme is that of a multiplicity of almost-identical worlds existing in parallel: alternate worlds in which there has been no significant change. Examples include "The Celestial Plot" (1948; trans 1964) by Adolfo BIOYCASARES and "Next Door, Next World" (1961) by Robert Donald Locke. In Robert SILVERBERG's "Trips" (1974) transuniversal tourists wander aimlessly through worlds similar and dissimilar. Parallel worlds often feature eccentric societies, sometimes for purposes of SATIRE, and sometimes equally eccentric patterns of EVOLUTION - like that in Stephen BOYETT's The Architect of Sleep (1986), where raccoons have become thedominant technological species. Bob SHAW has used the notion cleverly in two original novels: The Two-Timers (1968), in which a man who has lost his wife inadvertently creates a parallel world in which she still exists, and A Wreath of Stars (1976), in which two worlds made of different species of matter co-exist until the approach of an anti-neutrino star shifts the orbit of one of them. A different kind of parallellism is featured in a group of stories in which "timeslips" bring different eras of earthly history into geographical proximity - a motif featured in "Sidewise in Time" (1934) by Leinster and October the First is Too Late(1966) by Fred HOYLE. The idea that parallel worlds might include literal versions of fictional worlds as well as alternative histories is proposed in "The Number of the Beast" (1980) by Robert A. HEINLEIN and more sensitively developed in Frankenstein Unbound (1973) by Brian W. ALDISS. Larry NIVEN's "All the Myriad Ways" (1969) deals tentatively with thepsychological implications of multiple universes. Richard COWPER's Breakthrough (1967) extrapolates the psychological attractions of theconcept, as do Christopher PRIEST's stories of the Dream Archipelago, including The Affirmation (1981).Modern uses of the theme usually imagine an infinite number of parallel worlds extending in a manifold which contains all possible Earthly histories and perhaps all possible physical universes. The notion that the perceived Universe is simply one single aspect of such a "multiverse" has been lent credence by the "many-worlds interpretation" of the enigmas of quantum mechanics propounded by, for example, John Wheeler, and popularized in nonfiction books by writers like Paul DAVIES and John GRIBBIN. Keith LAUMER's Worlds of the Imperium (1962)and its sequels deploy this kind of infinite series of parallel worlds in connection with alternative histories, as do Richard C. MEREDITH's At the Narrow Passage (1973) and its sequel and Frederik POHL's The Coming of theQuantum Cats (1986). Certain philosophical implications of the many-worlds interpretation are explored more-or-less seriously in a number of sf novels, including Aldiss's Report on Probability A (1968), Graham Dunstan MARTIN's Time-Slip (1986), Greg EGAN's Quarantine (1992) and Pohl and JackWILLIAMSON's The Singers of Time (1991).Modern fantasy novels - including most of those in the intermediate science-fantasy category - sometimes draw upon the legacy of sf recomplication in order to invigorate their use of parallel worlds. Notable examples include Roger ZELAZNY's Amber series and Michael MOORCOCK's many SWORD-AND-SORCERY series, which are all bound together (with some sf novels) within a hypothetical multiverse.

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