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Willis E. Lamb Jr., 94; Nobel Prize-Winning Physicist

By Joe Holley
Washington Post Staff Writer
Monday, May 19, 2008

Nobel laureate Willis Eugene Lamb Jr., 94, a physicist whose discovery of a minute difference between two energy levels of the hydrogen atom led to a basic reconsideration of the concepts underlying the application of quantum theory to electromagnetism, died May 15 of a gallstone disorder at University Medical Center in Tucson.

A professor emeritus at the University of Arizona, Dr. Lamb received a 1955 Nobel Prize in physics for his experimental work on the fine structure of the hydrogen atom and for the discovery of what came to be called "the Lamb shift," a tiny deviation in the energy of an electron orbiting a hydrogen atom's nucleus. The discovery had enormous implications for the quantum theory of matter.

"He really changed our concept of how space and time are put together," said William H. Wing, a physics professor at the University of Arizona.

Dr. Lamb was born in Los Angeles and received an undergraduate degree in chemistry from the University of California at Berkeley in 1934. Remaining at Berkeley as a graduate student in theoretical physics, he conducted research for his thesis under the direction of J. Robert Oppenheimer, who was appointed by President Franklin D. Roosevelt in 1942 to head the Manhattan Project, which created the atomic bomb. He received his doctorate from the University of California at Berkeley in 1938 and joined the Columbia University physics faculty that same year.

From 1943 to 1951, he worked with the Columbia University Radiation Laboratory, where his research focused on how to make shorter, higher-frequency microwave sources for radar. That research led to his Nobel Prize-winning work.

In 1946, he put together what Wing called "a really clever experiment" to detect the shift in energy levels of the hydrogen atom, which would come to be called the "Lamb effect." "The apparatus I used," Dr. Lamb recalled in a 2000 interview, "was a combination of metal and glass. You might say the hydrogen atoms went in one end and came out the other end, and in between you did things with them involving microwaves and a magnetic field. The whole thing sat on a table maybe eight feet long."

In April 1947, his experiment succeeded. It revealed a minute but significant shift of energy in the hydrogen atom in different states. He continued to refine his experiment over the years and was able to make very precise measurements of the energy variable. He shared the Nobel Prize with Polykarp Kusch, a German American physicist who reached similar conclusions independently.

Dr. Lamb "was a physicist's physicist," said Wing, who became his post-doctoral student in 1968. "It was very important to him to get things really right."

He taught at Stanford, Oxford and Yale universities before moving to the University of Arizona in 1974. He received the National Medal of Science, the nation's highest scientific honor, in 2000 and retired as professor of physics and optical sciences three years later.

"Not that long ago, he told me he finally understood physics," said James C. Wyant, dean of the University of Arizona's College of Optical Sciences, speaking to the Arizona Daily Star last week.

Dr. Lamb's first wife, Ursula Schaefer, a University of Arizona historian, died in 1996. His marriage to Bruria Kaufman, an Israeli physicist, ended in divorce.

Survivors include his wife, Elsie Wattson Lamb of Tucson, who met him 27 years ago and married him this January; and a brother.

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