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[en] Two primary theories are being advanced to explain the behavior of electron pairs in high-temperature superconductors. One theory is a modification of the BCS theory, which has phonons creating stable electron pairs. The new modification states that electron pairs tunnel between the copper oxide layers. The tunneling process augments the binding energy of the paired electrons, allowing superconductivity to persist at elevated temperatures. A competing theory relies on a different pairing mechanism, namely magnetic disturbances, or spin fluctuations, in the crystal lattice. Electrons pair in the wake of a magnetic wave in the lattice, analagous to but fundamentally different from the mechanical wave of a phonon. If the first theory is correct, electron pairs should carry a kind of angular momentum referred to as s-wave character. If the second theory is correct, the pairs should have d-wave character. Preliminary experiments performed to test the theories have hinted at d-wave behavior, but more experiments need to be performed
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[en] Data from the Mars Observer, the first of a new series of unmanned planetary observers, will make Mars one of the best understood of the planets. Of the eight instruments that will be bolted onto the frame of the Mars Observer, four are devoted to elemental and compositional studies of the Red Planet's surface and atmosphere. These include the Gamma Ray Spectrometer, the Visual and Infrared Mapping Spectrometer, the Pressure Modulator Infrared Radiometer, and the Thermal Emission Spectrometer. The other instruments on board - the Mars Observer Camera, a magnetometer, a radar altimeter and radiometer, and radio science equipment - will provide detailed pictures of the surface as well as in-depth data about the planet's magnetic field, surface topography, and atmospheric structure. The data will contain information about how all of these Martian features change during different periods of time
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[en] Swiss researchers have discovered a new superconducting material made of two distinct new compounds. The compounds are related to a previously reported compound of mercury, barium, copper, and oxygen, which superconducts at 94 K. Each unit of the multilayered crystal structure contained only one copper oxide layer. The new compounds have two and three layers, respectively, of copper oxide. The new material from these two compounds starts to superconduct at 133 K
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[en] Pons and Fleischman have published new findings in their cold fusion research. They do not ascribe their results to nuclear fusion but do rule out chemical mechanisms. In the new work they measure the amount of time it takes to boil off a certain amount of heavy water in a cell containing palladium and platinum electrodes. By knowing the rate at which electric power enters the cell, they can calculate how much power should be consumed in boiling off the water. The actual power input falls short by a factor of about 4. The total amount of heat released over the 25-day span of the experiment (including the boil-off period) comes out to 6% more than the input of power could explain, notes a researcher doing similar work at SRI International. Previous critics of their work have not changed their minds about the unreliability of Pons' and Fleischman's work
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[en] Atoms swollen with energy can serve as supersensitive detectors. They also probe the shadow realm where the quantum world of the atom gives way to the familiar classical world. Created in the laboratory, where they live for a few milliseconds inside vacuum chambers, Rydberg atoms acquire their girth when one or sometimes two of their electrons are excited to very high energy levels, displacing them far from the nuclear core. This article describes the atoms, the history of their identification, and future possibilities. 2 figs
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