Number 148, October 19, 1993 by Phillip F. Schewe and Ben Stein A NANOSCOPIC STONEHENGE consisting of 48 iron atoms individually placed in a circle (143 angstroms across) on a copper substrate, has been devised by scientists at IBM in San Jose (Science, 8 Oct. 1993). Electrons in the surface copper atoms are scattered and confined by the presence of the iron atoms. The resultant electron standing waves, as elementary quantum mechanics textbooks would suggest, are circular, like the concentric ripples you get by dropping a stone into a pond; in this case, however, the waves can be visualized using a scanning tunneling microscope. The IBM scientists hope to use a stadium-shaped version of their quantum enclosure to study the possible chaotic behavior of electrons in a quantum system. (Science News, 9 Oct.) ARSENIC, SELENIUM, THALLIUM, AND LEAD have been detected in the gas between stars, researchers from the University of Wisconsin-Madison have reported (Oct. 10 Astrophysical Journal Letters). These elements, the heaviest yet detected in interstellar gas, were identified using the Hubble Telescope's High Resolution Spectrograph, which analyzed the ultraviolet light from two nearby stars and found gaps in the spectrum corresponding to absorption of light by these elements in interstellar space. A repaired Hubble telescope should be better equipped to perform yet more comprehensive studies of the composition of interstellar gas. Such studies promise insights into the process leading to the formation of stars. (Science News, 16 October 1993.) WHAT IS THE HIGGS BOSON AND WHY DO WE WANT TO FIND IT? Britain's science minister, William Waldegrave, posed this question---no small matter for a man who must oversee particle-physics expenditures of tens of millions of pounds---in the form of a contest. He proposed to give a bottle of champagne to the best single-page explanations. The five winning entries employed colorful metaphors, comparing, for example, the Higgs field to a room crowded with political party workers who, when Margaret Thatcher enters the room, gather around her, slowing her progress through the room and enhancing her "effective mass." Another article compares the Higgs field to the grain in a plank of wood, detectable only when you move against the grain. (The five brief articles are printed in the Sept. 1993 issue of Physics World.) POLYMER LED'S ARE NOW MORE EFFICIENT than conventional LEDs in laboratory tests. Standard semiconductor LEDs, made of inorganic materials, typically have efficiencies of 1-2% but the new LEDs, made of organic polymer materials, emit 4 photons for every 100 electrons injected into the material, corresponding to a 4% efficiency. A 25% efficiency is believed possible for these plastic, light-emitting materials, and potential applications include luminous rescue uniforms and flat-screen video displays. The materials used to make the LEDs come from a new class of polymers called poly(cyanoterephthalylidene)s. (Neil C. Greenham et al., Nature, 14 October 1993; Science News, 16 October 1993.)