An American and two Japanese scientists will share the Nobel Prize in Physics for 2008.

The Royal Swedish Academy of Sciences awarded one-half of the prize to Yoichiro Nambu, of the Enrico Fermi Institute at the University of Chicago, for discovering spontaneous broken symmetry in subatomic physics.

The other half goes jointly to Makoto Kobayashi, with High Energy Accelerator Research Organization (KEK), in Tsukuba, Japan, and Toshihide Maskawa, with the Yukawa Institute for Theoretical Physics (YITP) at Kyoto University, for discovering the origin of the broken symmetry that predicts the existence of at least three families of quarks in nature.

Nambu formulated a mathematical description of spontaneous broken symmetry in elementary particle physics in 1960. Spontaneous broken symmetry explains how nature's order hides beneath a surface that appears jumbled. Nambu's theories permeate the Standard Model of elementary particle physics. The Model blankets the smallest building blocks of all matter and three of nature's four forces to cover them under one theory.

Kobayashi and Maskawa describe different spontaneous broken symmetries, which scientists believe existed when the universe began. They came as a surprise when they first appeared in particle experiments in 1964. In 1972, Kobayashi and Maskawa explained broken symmetry within the framework of the Standard Model but they extended the Model to include three families of quarks.

Recent physics experiments have demonstrated their hypothesis surrounding the new quarks. In 2001, two particle detectors, BaBar at Stanford and Belle at Tsukuba, Japan, independently detected broken symmetries with results that Kobayashi and Maskawa predicted 29 years earlier.

Scientists are still trying to understand how broken symmetry allowed the universe to survive the Big Bang an estimated 14 billion years ago. They believe that if equal amounts of matter and antimatter appeared, they would have annihilated each other. Scientists believe that a deviation of one extra particle of matter for every 10 billion antimatter particles could have allowed the cosmos to survive. Just how that happened is unclear. Researchers at the Large Hadron Collider in Geneva hope to shed light on the process.