Number 24, 7 March 1991 by Phillip F. Schewe and Ben Stein AXIONS WITH A MASS OF 3 eV TO 8 eV have been ruled out by an astronomical search carried out at Kitt Peak Observatory. The Standard Model of particle physics calls for the existence of axions, which help to preserve certain symmetries pertaining to the strong nuclear force, but does not prescribe their mass. Theoretical arguments suggest two axion mass "windows": 10-6 to 10-3 eV and 3 to 8 eV. Cosmologists are also interested in axions as a possible constituent of dark matter. University of Chicago scientists (Michael S. Turner, 312-702-7974) sought evidence for the 3-8-eV axions in the form of photons (from the decay of the axions) in three rich galactic clusters. The lack of such photons seems to have closed the 3-8-eV axion window. (Physical Review Letters, 18 March.) THE TOP QUARK MUST EXIST , according to Michael Peskin of Stanford University (415-926-3250), who spoke in October at a meeting devoted to top-quark physics. Otherwise the Standard Model, which (besides giving us the axion) holds that there are six quarks (up, down, charm, strange, top, bottom), would be at odds with the experimental evidence. For example, experiments involving the bottom quark (fractionally-charged quarks are never observed in isolation but only in groups of two or three, in composite particles called hadrons) imply the existence of a 2/3-charged partner. Furthermore, studies of (CP-violating) neutral kaon decays require the existence of six quarks. The top quark has been sought unsuccessfully at several labs. Only Fermilab, with total collision energies as high as 1.8 TeV, may have the necessary energy for producing tops; but even at Fermilab the tops might be overlooked in an ocean of background scattering events. Only much greater statistics, aided by more intense beams (requiring a beamline upgrade), will settle the issue. Meanwhile Fermilab has established a minimum mass for the top of 89 GeV. (Cern Courier, Jan/Feb 1991.) PRODUCING ORIENTED POLYMERS is like cooking spaghetti in reverse: scientists must take tangled polymer molecules and straighten them out by a variety of stretching and squeezing techniques. The resultant material can be stronger than steel (the lined-up covalent bonds reinforce each other) and a better conductor than copper (electricity flows better if the polymer's backbone is straight). Dupont's Kevlar, for example, is five times stronger than steel, although only along its principal axis (it is used to reinforce other materials). Oriented plastics are used in sporting goods and aerospace products, but so far their high costs and complicated processing have kept them from even wider applicability. New research may change this. Plastic batteries, pollution monitors, and "smart windows" which produce solar-photovoltaic electricity are a few of the anticipated products. (Science, 22 Feb.; contact Alan Heeger, UC Santa Barbara, 805-961-3184.) THE SOUTH POLE WILL BE THE SITE for a new infrared telescope complex. The Pole is not only extremely dry (water vapor absorbs infrared radiation), but the stars seen there do not rise and fall; instead they circle around a point directly overhead. A nine-university consortium will operate the observatory, where the first instruments will be installed later this year. (The New York Times, 5 Mar. 1991.)