Professor Yoichiro Nambu wins Nobel Prize in physics

Nobel committee cites professor’s discovery of the “mechanism of spontaneous broken symmetry in subatomic physics.”

By Mimi Yang

[img id=”76820″ align=”alignleft”] Yoichiro Nambu, 87, the Harry Pratt Judson Distinguished Service Professor Emeritus in Physics and the Enrico Fermi Institute, was awarded the 2008 Nobel Prize in Physics on Tuesday for his work on “the discovery of the mechanism of spontaneous broken symmetry in subatomic physics,” according to the selection-committee’s citation for the award.

Nambu’s work is considered foundational to the Standard Model of elementary particle physics, which attempts to describe the interactions between the smallest building blocks of matter with three out of the four fundamental forces: strong, weak, and electromagnetic.

The symmetry Nambu explored is somewhat different from geometrical symmetry, which says that a square looks the same, even if it is rotated 90 degrees. In physics, symmetry means that our universe is indistinguishable from one that has undergone fundamental changes in particle charge, direction, and time. Nambu’s work involved situations where this symmetry, which should be constant, suddenly broke.

When asked to explain broken symmetry at a press conference on Tuesday morning, Nambu noted that there was no physical reason to look at him during the conference, and yet, a decision was made to set up the chairs so that they faced the stage—a form of symmetry breaking. The example garnered laughter from those gathered, and facing, Nambu.

In the same press conference, Provost and physics professor Thomas Rosenbaum extolled the significance of Nambu’s discoveries.

“Nambu’s work is emblematic of what we try to accomplish here at the University of Chicago: a genuinely great scholar asking fundamental questions that then have impact across the discipline and across the disciplines,” he said. Rosenbaum also called Nambu, “a wonderful, modest man and a generous colleague.”

Professor Jeffrey Harvey, a member of the particle theory group at the U of C, echoed Rosenbaum, noting the depth and significance of Nambu’s work in particle physics and string theory. Nambu’s work is “fundamental to what particle physicists do,” Harvey said in a phone interview.

Harvey noted that Professor Nambu is a “sweet gentleman, not a self-promoter at all,” remarkable perhaps for a man whose work has been applied to areas as disparate as superconductivity, magnetism, and condensed matter.

Although he was not cited for his discoveries in string theory, a still-developing field in theoretical physics, Harvey called Nambu responsible for the ideas of strings, one-dimensional objects whose interactions are postulated by string theory. “In a way, you could call him one of the founders of string theory,” he said.

Harvey praised Nambu’s ability to foresee developments in physics. “He is a decade ahead of everyone else,” Harvey said.

Nambu was born in Toyko in 1921. In an e-mail, he said that his interest in science began in childhood and cited Thomas Edison as his childhood hero. Inspired by Hideki Yukawa, who would later become Japan’s first Nobel Prize winner, he studied physics in college. In 1952, he immigrated to the United States at the invitation of Robert Oppenheimer, who directed the Manhattan Project, which led to the creation of the atomic bomb. Two years later, he became a researcher at the University of Chicago; an associate professorship followed in 1956 and a full professorship in 1958.

A perennial contender for the Nobel Prize—by his estimation “a candidate every year for the past 30 years or so”—Nambu was surprised to receive the Prize this year. “I did not expect it in any way this particular time, and, I must say, I was very surprised when I got the news,” he said.

Fellow Nobelist and U of C physicist James Cronin noted that many Nobel Prizes have already been awarded to physicists whose work was dependent on Nambu’s.

Although Nambu has now been retired for 17 years, he recalled his time at the University fondly, writing. “I fell in love with U of C because of the free, open, and friendly atmosphere of the department and the institutes.”

“At the [Enrico Fermi] Institute, there were physicists working in various fields, as well as chemists and geophysicists. All sciences are related. I learned many things from them, and I was treated like a member of a large family.”

At the press conference, Nambu said, “There are very many great names here” and that “listening to them was the greatest stimulation.”

Asked for his advice to young scientists hoping to follow in his footsteps, Nambu stressed the importance of thinking thoroughly for oneself. “Think independently, and think all the time. I like to tackle a problem (I do not mean an exam problem) first by myself, and then look up somebody’s answer, if there is one,” he wrote.

Nambu shared his prize with Makoto Kobayashi and Toshihide Maskawa, who also studied symmetry; they will share half of the $1.4 million prize while Nambu will receive the other half.

In winning the Nobel Prize, Nambu joins a group of 82 other Prize winners affiliated with the University as a students, researchers, or faculty members, and as the 28th winner in physics.