Nobel Prize In Physics

Nobel Prize In Physics

Three honored for developing fundamental theory that explains why matter persists
Elizabeth K. Wilson

This year's Nobel Prize in Physics pays homage to symmetry breaking, an abstruse but critical theory in physics that explains why matter should have persisted after the Big Bang. Developed in the 1960s and '70s, symmetry breaking also led to predictions about new types of quarks, which are subatomic particles that make up particles such as protons and neutrons.

The prize will be shared by three researchers. Yoichiro Nambu, 87, of the Enrico Fermi Institute at the University of Chicago, will receive half the $1.4 million prize for, in the words of the Royal Swedish Academy of Sciences, "the discovery of the mechanism of spontaneous broken symmetry in subatomic physics."

The other half of the prize will be shared by Makoto Kobayashi, 64, of the High Energy Accelerator Research Organization in Tsukuba, Japan, and Toshihide Maskawa, 68, of the Yukawa Institute for Theoretical Physics at Japan's Kyoto University, "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature."

Kobayashi, who was reached by phone in Japan during a press conference at the Nobel Foundation in Stockholm announcing the prize, said he was "very glad" to have been honored. "It was a surprise—I did not expect it," he said.

Symmetry breaking is one of the cornerstones of the so-called standard model, which unites theories of matter and three of the four fundamental forces in nature—the electromagnetic, strong nuclear, and weak nuclear forces—professor Lars Bergström, secretary of the Nobel Committee for Physics, said at the conference, which was broadcast over the Web.
The theories also have implications for chemistry, notes Richard L. Hahn, a nuclear chemist at Brookhaven National Laboratory. "The concepts of symmetries and symmetry breaking are fundamental to our understanding of the universe in which we live and to all of the sciences, chemistry as well as physics," he says. "The eventual creation of the chemical elements in the early stages ... of the universe is also tied to these processes."

The ultimate importance of symmetry breaking is illustrated by the events that occurred after the Big Bang, when a slight imbalance or spontaneous "breaking" of symmetry between matter and antimatter particles allowed what we know as regular matter to establish a predominant presence over antimatter in the universe. If that had not occurred, matter and antimatter would have existed in equal amounts, and the particles would have simply annihilated each other.
"Because of this small breaking...we can sit here," Bergström said.
Source: C&EN