ANTIMATTER

   The concept in PHYSICS that forms of matter may exist composed of antiparticles, opposite in all properties to the particles which compose ordinary matter, has a special appeal to sf writers. The idea itself was first formulated by the physicist Paul Dirac (1902-1984) in 1930; the confirmation of the existence of such particles came soon, with the discovery of the positron (the anti-electron) in 1932. However, although antiparticles can be and are created in the laboratory, this has never been done in sufficient quantity (less than one trillionth of a gram to date) to form what we would think of as antimatter. It is a concept that must at the moment remain theoretical; aside from isolated particles (low-energy antiprotons have been detected in high-altitude balloon experiments), there may be little or no natural antimatter anywhere in the Universe. Antimatter cannot easily exist in our world, since it would combine explosively with conventional matter, mutually annihilating 100% of both forms of matter to create energy, a point basic to the plot of Paul DAVIES's Fireball (1987). Thus antimatter would make a fine power source if only we knew how to store it: no problem it seems for Scottie, the engineer in STAR TREK, since the starship Enterprise is fuelled by it. An early sf view of antimatter's potential usefulness appears in Jack WILLIAMSON's Seetee Ship (1942-43 ASF; 1951) and its sequel Seetee Shock (1949 ASF; 1950), originally published as by Will Stewart. (Seetee stands for CT, which in turn stands for ContraTerrene matter, an old sf term for antimatter.) Antimatter galaxies, or even an entire antimatter universe created in the Big Bang at the same time as our matter universe, have been postulated by physicists, with the enthusiastic support of the sf community. A.E.VAN VOGT was one of the first to use this idea, which has since become a CLICHE