Dawn of Discovery:
The morning of January 29, 1987 began like any other in the small physics lab at UAH. The daily routine consisted of arriving at dawn, staying well into the night and conducting a battery of tests requiring unwavering concentration, a steady hand and patience during the long hours.
Though they could not have known what the day would bring, the scientist and students in that tiny lab were about to make a profound scientific discovery, one that would amaze the world, making headlines in major newspapers from coast to coast and around the globe.
Just a few hours later, Dr. Maw-Kuen Wu, Professor of Physics, James Ashburn and C.J. Torng achieved superconductivity – the ability to transport electricity without resistive losses – at 95 degrees Kelvin, surpassing a goal that scientists throughout the world had been seeking for three quarters of a century.
The breakthrough came on the heels of months of hard work for the UAH team They had been working in conjunction with researchers at the University of Houston to raise the temperature at which superconductivity could be achieved. The threshold world experts sought to cross was the 77-degree Kelvin mark – the temperature at which liquid nitrogen could be used as the coolant for producing superconductive material.
With this goal, firmly in mind, not only was Wu adhering to a grueling schedule, but his two assistants, Ashburn and Torng, willingly kept up while juggling their master’s level course work.
The tantalizing prospect of being first to make a superconductor at temperatures in the liquid nitrogen range kept the trio motivated while working straight through the holidays, including Christmas Eve and Christmas Day.
“It’s difficult to describe to someone outside the scientific field the importance of higher temperature superconductivity,” Wu said.
Liquid nitrogen is significantly less expensive and approximately 50 times more efficient than the quickly evaporating helium necessary as a coolant at lower temperatures. Thus, higher temperature superconductivity could mean cheaper, more efficient electricity in applications from high speed computers to daily power usage.
Wu and his cohorts knew the significance of what they were attempting on that January dawn. They also knew the frustration.
Ashburn, who received his bachelor’s degree in physics from UAH only months before the startling and stupendous discovery, would often joke with friends who stopped by the lab (the only place to catch him during his waking hours).
His usual quip went something like, “Hey, do you want to see history in the making?” Then he would try yet another in a long sequence of elemental alloys, without success.
Ashburn was in good company. Since its identification in 1911 at a temperature of only 4 degrees above absolute zero, superconductivity had crept in small, sometimes faltering increments, toward warmer temperatures. It wasn’t until 1973 that scientists observed superconductive characteristics at 23.2 degrees Kelvin (minus 419 degrees Fahrenheit). Then, in 1986, researchers at an IBM laboratory in Zurich, Switzerland reported achieving superconductivity at 30 degrees Kelvin in a copper, oxygen, barium and lanthanum compound.
The IBM research renewed interest in the possibility of reaching the liquid nitrogen range. UAH’s Wu substituted strontium for barium in the compound and managed to raise the temperature to 36 degrees Kelvin. This step forward paled in comparison to the events of January 29th.
Ashburn and Torng assisted Wu in mixing the powders that would make history. Using what they’d learned from the other elemental combinations, the three applied new ideas and changed several variables simultaneously to make the compound. They compressed a mixture of copper, oxygen, barium and yttrium into a tiny pellet and fitted it with platinum wires or “leads.” This compound was different from any they had tried before. They could feel it.
“For one thing, it had a greenish appearance,” Ashburn recalled. When they cooled it with helium, a computer screen showed a graph measuring the material’s resistance. At about 95 degrees Kelvin, a line on that graph dropped sharply to zero – zero resistance. This was it!
“We wanted to confirm it,” Ashburn said. As he busied himself carrying a container of liquid nitrogen down the hall, Wu began preparing another sample. “I noticed his hands were quivering. It takes a very steady hand to attach the leads,” Ashburn explained.
“When I weighed out the additional materials for the sample, I realized my hands were shaking also,” Wu admitted. The second sample confirmed their earlier results, and he called the University of Houston to announce a discovery.
The very next day, he was in Houston further verifying the results using laboratory equipment there. The reality of higher temperature superconductivity began to sink in. Wu’s words to describe the discovery were, “We’ve hit the jackpot!”
Excitement spread, but the details could not be disclosed until Wu and Houston’s Dr. Paul Chu completed scientific reports on their findings. On February 16, the National Science Foundation, UAH and the University of Houston announced the discovery.
The story was carried on the front page of The New York Times, The Boston Globe and The Atlanta Journal-Constitution, among others, and has since appeared in more than 40 national and international publications and on Cable News Network and National Public Radio’s “All Things Considered.”
In the words of National Science Foundation officials, “The discovery could lead to profound technological and sociological changes throughout the world.” Applications for superconductors, from levitating trains similar to Walt Disney’s monorails to magnets for the proposed Super-collider atom smasher, appear more practical than ever in light of the UAH discovery.
Since January 29th, a day that surely will go down in the annals of scientific history as a “dawn of discovery,” much research is continuing at the University.
“I want to be able to explain the physics of what happened,” said Wu, who still maintains long hours in the lab as he delves into the mystery of the new material. Wu also is conducting experiments with other alloys.
He suffers constant jet lag from the busy travel schedule he keeps speaking at professional conferences and to colleagues at other universities. But, his complaint is only that he wishes to spend as much time as possible in his lab.
“He’s a brilliant young scientist,” said UAH Physics Department Chairman Dr. Graeme Duthie.
Wu was invited to present his findings at the now famous meeting of the American Physical Society held in Boston last spring. Many a reporter noted the transformation of hundreds of usually conservative scientists into an excited throng at that meeting, where enthusiasm for the material discovered at UAH was at a fevered pitch. Some likened the scientists to fans at a rock concert. Wu concurred, saying it was “very, very exciting.”
That excitement continues. Wu has been nominated for the National Medal of Technology for this discovery. This prestigious award gives Presidential recognition to individuals and companies that make outstanding contributions to technology and technological manpower.
Alabama Senator Howell Heflin said in making the nomination, it is in recognition of those who are “improving the well-being of our country through the promotion of technology.”
The next temperature goal for world scientists is to find a room temperature superconductor. That, claim some experts, is impossible.
Just on year ago, liquid nitrogen range superconductors also were dismissed by many as impossible. But doubt turned to glee last winter. Meanwhile, scientists and engineers everywhere are hard at work coming up with literally thousands of applications for the new superconductors
Obviously, the emphasis now is on the possibilities