Word: magnetism
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...political power. Japan's national charter renounces war. Portugal's forbids private ownership of television stations. Peru reprints its charter in the Lima telephone directory, filling ten pages of fine print. Yet beneath such diversity, each document can trace its rights and freedoms to U.S. soil. Says Joseph Magnet, a law professor at Canada's University of Ottawa: "America has been and remains the great constitutional laboratory for the entire world...
...sense of triumph." Argonne Ceramist Roger Poeppel now talks of building a furnace ten feet long to fire his group's wire almost continuously as it is extruded. "We think it will be flexible enough to twist into cable," he says, "and cable is the building block for magnetic coils and electrical transmission lines. With two miles of wire, we'll make a superconducting magnet. To get a practical device + is now the race...
...professional journals -- of new superconducting materials and ever higher temperature ranges. An effect that once could be detected only with sophisticated equipment has become a common sideshow at conferences: a sample of one of the new materials is placed in a dish of liquid nitrogen, and a magnet placed above it. Since superconductors repel magnetic fields, a phenomenon called the Meissner effect, the magnet remains suspended in midair...
High-temperature superconducting magnets may become important in the maglev, or magnetically levitated, trains under development in Japan and West Germany. And scientists at Japan's Mercantile Marine University in Kobe have already developed a working scale model of a ship with a propulsion system based on magnetism. Physicist Yoshiro Saji sends current through the seawater from an onboard electric generator via ship-bottom electrodes. A superconducting magnet, also on board, creates a strong magnetic field. As the electromagnetic field produced by the electric current pushes against the field of the magnet, the ship moves forward. Saji has already moved...
Leon Lederman, director of Fermilab, agrees. "Even if, miracle of miracles, in the next two years they solve all the problems of brittleness and high current," he says, "we would still need lots of experience to understand the materials well enough to make good magnets. A superconducting accelerator magnet is a Swiss watch of precision." One problem: superconducting magnetic fields are so strong they can actually deform the accelerator magnets that produce them. While physicists have learned to deal with that phenomenon at Fermilab, they have no idea how to handle fields that could be many times as strong...