By Steve Koppes
Photo by Dan Dry

On the same day that most 2008 Nobel laureates received their medals and diplomas in Stockholm from the King of Sweden, the University of Chicago’s Yoichiro Nambu received his prize from the Swedish Ambassador to the United States at a special ceremony on campus.

Nambu, the Harry Pratt Judson Distinguished Service Professor Emeritus in Physics, shared the 2008 Nobel Prize “for the discovery of spontaneous broken symmetry in subatomic physics.” Swedish Ambassador Jonas Hafström presented the Nobel Prize to Nambu on Wednesday in Assembly Hall at International House. The event’s approximately 200 guests included Nambu’s son, John, Nobel laureates from the University of Chicago and other institutions, University leaders, members of its Board of Trustees and of the Physics Department.

“It is a privilege for me to convey to you, Professor Nambu, the warmest congratulations of the Royal Swedish Academy of Science,” Hafström said. “On behalf of His Majesty the King, Carl the XVI Gustav, I will now present the 2008 Nobel Prize in Physics.”

During his acceptance speech, Nambu explained how spontaneous symmetry breaking (SSB) is one of the special laws of physics that applies to large numbers of subatomic particles. “SSB arises from a kind of group mentality, group psychology, among the constituents,” he said.

By analogy, Nambu noted that when a group of people gathers in a large, open area, they are likely to be looking in various directions—any direction is as good as any other. But there are times one man in the crowd begins looking in one direction, and then people around him follow suit. “That’s a broken symmetry,” Nambu said, a behavior that subatomic particles also display.

Nambu follows a line of Chicago Nobel laureates that began in 1907, when the University’s Albert Michelson received the Nobel Prize in Physics.

“The University of Chicago has had the good fortune to have many of its leading scholars recognized by the Nobel Prize” since its inception in 1901, said University of Chicago President Robert J. Zimmer in his introductory remarks. “Professor Nambu’s work exemplifies a defining element of the culture of the University of Chicago and a key part of its ability to advance knowledge and improve lives.”

Nambu’s research in subatomic particle physics “have helped redefine the field and continue to be explored by researchers and laboratories throughout the world. He is still asking the questions that animate further discovery,” Zimmer said.

Originally published on December 10, 2008.