1ST-GRADE MATH---PRIMITIVE QUANTUM COMPUTERS have arrived earlier than expected, and they have already performed simple calculations, researchers announced at last month's AAAS meeting in Seattle. Whereas ordinary computers essentially manipulate on-off switches each representing a 0 or a 1, quantum computers are potentially more powerful because they employ quantum systems which can exist in two states simultaneously to represent both 0 and 1 at the same time. Independently, an MIT-Los Alamos team and a Harvard-MIT group have proposed an unexpected way to make a quantum computer: use a cup of liquid. When exposed to a magnetic field, one in a million of the atoms will settle into a "spin" state in which the atoms' internal magnets are aligned with the field. One can then cause each of these spins to act as a "quantum bit" (or "qubit") by firing electromagnetic pulses which cause each spin to enter two states simultaneously. Subsequent pulses can then perform logic operations, by exploiting the fact that the spin state of a particular kind of atom can affect the spin state of a different atom in the same molecule or in a neighboring one. By manipulating the spins in three distinct types of quantum systems that exist within the liquid, the MIT-Los Alamos group has constructed a three-qubit system that has successfully executed the mathematical calculation 1+1=2. With their current approach, the researchers believe 10-qubit systems may be possible. (Science, 17 January; The Economist, February 22, 1997; also see MIT Media Lab site on quantum computation)

DECELERATION CAN BE AS IMPORTANT AS ACCELERATION when doing atom-trap experiments. A team of physicists at the Max Planck Institute (Heidelberg; contact Rudolf Grimm, r.grimm@mpi-hd.mpg.de) and the Ecole Normale Superieure (Paris) have succeeded in slowing cesium atoms, just out of the oven, from a velocity of 160 m/sec down to a speed (8 m/sec) where they can easily be captured in a trap, all in a space of only 10 cm, rather than the customary 1 m. Just as important as the slowdown are the tight beam focus and the narrow range of final velocities among atoms in the beam. This is potentially important for future atom lithography applications and for Bose-Einstein condensate studies. The deceleration is accomplished through the palpable force of laser light. Besides producing an efficient collimation of cold atom beams, this laser scheme can be used to "clean" beams by removing unwanted isotopes and might help to manipulate exotic atoms which cannot be controlled by other means. (J. Soding et al., Physical Review Letters, 24 February 1997.)

THE NAMES OF ELEMENTS 104-109 have finally been accepted by nuclear scientists and certified by the International Union of Pure and Applied Chemistry. The delay over the names was caused partly by rival claims to priority; the pertinent experiments rendered mere handfuls of atoms. Physics and chemistry students worldwide will now have to memorize the following additions to the Periodic Table: Rutherfordium (abbreviated Rf, element 104), Dubnium (Db, 105), Seaborgium (Sg, 106), Bohrium (Bh, 107), Hassium (Hs, 108), and Meitnerium (Mt, 109). (The New York Times, 4 March 1997.)

COMET HALE-BOPP, inherently brighter than last year's Comet Hyakutake, should put on a brilliant display from March on into May. During the best viewing, late March to early April, the comet is in the evening sky to the northwest. (Sky & Telescope, April 1997.)