Number 32, May 1, 1991 by Phillip F. Schewe and Ben Stein NEW HIGH-REDSHIFT QUASARS have been discovered. A Cambridge-Greenwich-Pittsburgh team has reported finding a quasar, BR1202-07, with a redshift of 4.7. Meanwhile, James Gunn of Princeton (609-452-3802) has supposedly observed, but not yet announced, a quasar with a redshift of 4.9. (New Scientist, 27 April 1991.) EVIDENCE FOR A HEAVY NEUTRINO persists in an experiment being carried out at the Lawrence Berkeley Lab. Eric Norman (415-486-7483) and his colleagues study the beta decay of carbon-14 dissolved in a germanium detector. Writing in the May 13 issue of Physical Review Letters, the LBL team reports that in 1.4% of the decays, a neutrino (or some other unexplained neutral particle) with a mass of 17+/- 2 keV is emitted. This conclusion is similar to those reached by experimenters at Oxford (UK) and Zagreb (Yugoslavia). At last week's APS Spring meeting in Washington, D.C., Norman said that his group would continue its solid-state detector work but would also attempt to mount an experiment involving a gas-filled detector. Certain experiments done elsewhere, including a recent one at Caltech (Felix Boehm, 818-356-4266), fail to find evidence of the heavy neutrino. (Physics Today, May 1991.) THE ASTRO OBSERVATORY , looking at the sky at seldom-glimpsed extreme-ultraviolet wavelengths, has detected many hot stars normally overshadowed by the more prevalent but cooler stars shining at optical wavelengths. Astro, carried on board the Space Shuttle last December, made the first ultraviolet picture of the Crab nebula and found previously undetected features inside the globular cluster Omega Centauri (Theodore P. Stecher, NASA Goddard, 301-286-8718). Astro's x-ray detector was used to detect iron in the Perseus cluster of galaxies and to record its spectrum; according to Peter Serlemitsos (NASA Goddard, 301-344-5255), the determination of the distance to Perseus (224 million light years) represents one of the first times x rays (rather than visible light) were used to compute a redshift. (Science News, 27 April 1991.) SINGLE-CRYSTAL DIAMOND FILMS have been prepared by Jagdish Naraya of North Carolina State University. First implanting carbon atoms in a copper substrate, he then blasts his sample with laser light, which melts the surface layer. Carbon atoms reassemble on top as a single diamond thin film. If the single-crystal films can be scaled up in size from the present 100 square microns in area, then Naraya's process may be preferable for use in future diamond-based electronics rather than the chemical vapor deposition (CVD) technique which results in a polycrystalline sheet of diamond. (Science, 19 April 1991.) POLARIZED ELECTRONS are used in particle physics, surface physics, and a number of other research areas where spin effects are important. A new source of polarized electrons, prepared by a SLAC-Wisconsin-Berkeley team, can achieve a polarization of 70%; the best previous value was 50%. In the new process polarized electrons are generated when laser light is aimed at a 0.1 micron thick sheet of InGaAs. (T. Maruyama et al., Physical Review Letters for 6 May.)