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World: Nobel Prize For Physics Rewards Harnessing Superconductivity

Prague, 7 October 2003 (RFE/RL) -- This has been quite a week for the arcane field of superconductivity.

The Swedish Royal Academy of Sciences today awarded the 2003 Nobel Prize in physics to three scientists who expanded the complex theories explaining the phenomena of superconductivity and superfluidity and brought the fields to new levels of practical application.

In fact, winners Aleksei Abrikosov, Vitalii Ginzburg, and Anthony Leggett -- along with their pioneering predecessors and colleagues -- are the people who laid the foundation for yesterday's Nobel Prize in medicine.

The Nobel Prize in medicine was awarded to Paul Lauterbur of the United States and Peter Mansfield of Britain for advancing what has become a routine method for medical diagnosis and treatment, at least in the West. The technique is called magnetic resonance imaging (MRI) and it is used to examine almost all internal organs without the need for surgery. Creating the kind of magnetic field demanded by MRI would be impossible without superconductivity.

Peter Main, director of education and science for the British-based Institute of Physics, noted proudly that the winners of the Nobel Prize in medicine were physicists. "And they won it for, basically, putting people in magnetic fields and using that [kind of] magnetic techniques to look inside the human body," he said.

Superconductivity enables electrical currents to flow through a wire or other conductor with little of the resistance that ordinarily would sap the current's strength and produce heat. Main used the analogy of superfluidity to explain: "If you imagine a doughnut shape and you imagine setting up a flow of liquid around the doughnut so it sort of comes back on itself -- if you set up one of those flows it would last forever." Whereas, of course, a normal liquid's flow would gradually slow, then stop.

"The way to make a large magnetic field is basically to put a current -- is to use an electromagnet so you put a current through a coil of wire," Main continued. But there's a practical problem. "If you want a large field, you may have to put hundreds of amps through the coil. Now, if you put hundreds of amps through a piece of copper -- even the best-quality copper -- the amount of heat you will dissipate will require sort of the output of almost a small power station. And the amount of heat you will dissipate is enormous. You have to go through enormous lengths to get rid of the heat."

Superconductivity overcomes that problem. "With a superconductor, you can put 100 amps through a superconducting coil of wire and have no dissipation at all," Main explained.

An MRI is not, of course, the only practical application of superconductivity. Magnetic fields can be used to measure the tiny current of electricity in the human brain, enabling scientists literally to create a map of the thought process. They also can be used for the mundane purpose of separating trash for recycling.

And, of course, Main said, when fellow physicists admire the work of scientists such as Abrikosov, a Russian-American, Ginzburg, a Russian, and Leggett, a British-American, they think mainly of the advancement of human knowledge about how the universe works.

Alfred Nobel, who endowed the prizes, directed the Nobel Prize judges, however, to a somewhat more immediate standard. In his will, he said the prize should go to those who "shall have conferred the greatest benefit on mankind" and "shall have made the most important discovery or invention within the field of physics."

Main thinks few physicists were surprised by this year's choice or would wish to dispute it. The only surprise, he said, is that it took so long. Ginzburg, who is 87, did his best-known work in the 1950s and '60s. The 75-year-old Abrikosov and 65-year-old Leggett did their work in the 1970s.

Ginzburg, speaking today in Moscow, expressed surprise at being given the honor so late in life. "I had given up on it a long time ago. I didn't think they would give me the prize, and believe me, it didn't keep me from sleeping, it didn't worry me at all. Now that they've given it to me, it's very nice, that's all," he said.

The winners split an honorarium equivalent to $1.3 million.