A Breakthrough From 212 B.C.
TRAINS THAT FLOAT ON magnetic fields while zipping along at airplane speeds, and frictionless ball bearings that never need oiling--these are two of the dreams promised by so-called high-temperature superconductors. To move those visions closer to reality, researchers at Israel's Weizmann Institute of Science are harnessing a 2,000-year-old idea.
Shimon Reich, a Weizmann chemistry professor, believes the key to making better superconductors is processing speed--instantly melting the various ingredients to preclude their passing through undesirable intermediate phases. But he tried every high-tech furnace he could find, with no luck.
Then Reich turned to a mirror like the one Archimedes supposedly used in 212 B.C. to focus the sun's rays and torch the Roman ships blockading Syracuse.
The parabolic mirror at Weizmann's solar-power center concentrates the sun's energy into a superhot beam that instantly melts the materials, says Reich. Although he is still exploring the technique's promise, Reich has already produced compounds based on yttrium-barium-copper-oxide that can carry a current of 40,000 amperes per square centimeter. That's roughly 100 times more than the same materials after conventional processing.