Paul Chu —— Searching for High Temperatures Below Zero

Seeing a superconductor at work is like watching a magic trick; it's surprising and puzzling.

Take an ordinary tray and place in it a superconductor and a little magnet. At room temperature, the two will stick together. Add liquid nitrogen, chill the superconductor to a certain temperature, and watch what happens.

The magnet will rise up about half a centimeter and hover in the mist given off by the liquid nitrogen. Bump it, and the magnet will turn and bounce around, sort of like the spaceship in Close Encounters.

Demonstrating superconductivity is a snap, but finding materials that will superconduct at comparatively high temperatures has taken over half a century.

Ever since the discovery in 1911 by the Dutch scientist H. K. Onnes that mercury loses its electrical resistance when cooled to near absolute zero (－273℃), scientists from all over the world have been trying to discover materials that superconduct at higher temperatures.

The reason is simple: Room-temperature superconductors would revolutionize world industry. Their zero resistance could cut down losses in a city's electrical trans-mission system and allow electricity to be stored overnight for use during peak hours the next day. And their magnetic properties could levitate a superfast train, lift heavy materials in factories, or eliminate friction just about anywhere.

For the past seventy years, the search has been extremely slow. Then this February, a pair of research teams led by Paul C. W. Chu of the University of Houston and Chu's former student Wu Mao-k'un of the University of Alabama finally achieved a breakthrough. They found a new metallic oxide compound that superconducts at a comparatively high temperature (－175℃) achievable with inexpensive liquid nitrogen.

Chu's breakthrough got its start last year. That spring K. Alex Muler and J. Georg Bednorz, researchers at an IBM laboratory in Switzerland, found a material that superconducts at －238℃.

Their advance was not much noticed at the time, but Chu read their paper and, using it as a foundation, had increased the superconductivity ceiling to －233℃ by the end of last year. But the real break-through came at the end of this January, when he suddenly pushed the ceiling up to －175℃.

Paul Chu was born and raised in the central Taiwan village of Chingshui, Tai-chung County, where he received all his primary, middle, and high school education. He recalls that his Chinese teacher used to imbue the students with the concept that "to the virtuous, money is not important." "It didn't mean much to me at the time," Chu says, "but now I think he was right."

During his twelve years as a researcher, he has received many lucrative offers from companies to serve as a consultant, but has always preferred to go his own way. Chu says that if he had thought about making money, it would have distracted him from his research and he would never have made the discovery he did.

Mrs. Chu, the daughter of the mathe-matician Ch'en Hsing-shen, also works in physics. They have a six-year-old son and a 13-year-old daughter. The family lives simply; they go to museums and concerts together on weekends and holidays, and Chu keeps a garden.

As to the future, Chu hopes to raise the temperature of superconductivity even further and produce superconducting wires that can be used in use in experiments.

If a material can be created that superconducts at room temperature, it would revolutionize industry. "Who knows?" Chu says, "Someone may be making a new discovery even while we're talking."

The Difference Between Conductors and Superconductors [Picture]

Raising the Superconductor Temperature Ceiling [Picture]

[Picture Caption]

The results of Paul Chu's research into superconductive materials may set off a new industrial revolution.

The magnetic properties of a superconductor which suspend this little magnet in air could facilitate the development of floating trains.

Chu's family.

Superconductors' zero resistance would reduce losses in electric transmission.