ANTIGRAVITY

   The idea of somehow counteracting GRAVITY is one of the great sf dreams: it is gravity that kept us earthbound for so long, and even now the force required to escape the gravity well of Earth or any other celestial body is the main factor that makes spaceflight so difficult and expensive. The theme of antigravity appeared early in sf, a typical 19th-century example being apergy, an antigravity principle used to propel a spacecraft from Earth to Mars in Percy GREG's Across the Zodiac (1880) and borrowed for the same purpose by John Jacob ASTOR in A Journey in Other Worlds (1894). C.C.DAIL's Willmoth the Wanderer, or The Man from Saturn (1890) uses a convenient antigravity ointment to smear on the wanderer's space vehicle. More famously, in THE FIRST MEN IN THE MOON (1901) H.G.WELLS used movable shutters made of Cavorite, a metal that shields against gravity, to navigate a spacecraft to the Moon. Other unexplained antigravity devices remained popular for a long time, especially in juvenile sf, as in the flying belt used by BUCK ROGERS or the antigravitic flubber, flying rubber, in the film The ABSENT-MINDED PROFESSOR (1961). In two notable short stories of the 1950s about the discovery of antigravity, however - Noise Level (1952) by Raymond F.JONES and Mother of Invention (1953) by Tom GODWIN - there are (not very convincing) attempts to give it a scientific rationale. Much more famous (and more convincing - although still wrong) is James BLISH's explanation of the antigravity effect used by his SPINDIZZIES, the devices that enable whole cities to cross the Galaxy in the series of stories and novels collected as CITIES IN FLIGHT (omni 1970): in one, Bridge (1952), he invokes physicists Paul Dirac (1902-1984) and P.M.S.Blackett (1987-1974) in several pages of formulae purporting to show that both magnetism and gravity are phenomena of rotation. The term antigravity is scorned by physicists. Einstein's General Theory of Relativity sees a gravitational field as equivalent to a curving of spacetime. Thus an antigravity device could work only by locally rebuilding the basic framework of the Universe itself; antigravity would require negative mass, a concept conceivable only in a universe of negative space which could not co-exist with our own. Charles Eric MAINE confronted Einstein head-on when, in Count-Down (1959; vt Fire Past the Future US), he proposed that, if gravity were curved space, all that was necessary to permit antigravity - he made it sound easy - was to simply bend space the other way. The proliferation in the 1970s and 1980s of bestselling popularizing books about modern physics may have something to do with the fact that antigravity, for so long a popular theme, is now seldom used by sf writers. See also: IMAGINARY SCIENCE; POWER SOURCES.