The Nobel committee lauded Yoichiro Nambu, now of the University of Chicago, and Makoto Kobayashi and Toshihide Maskawa of Japan for work that helped show why the universe is made up mostly of matter and not anti-matter via processes known as broken symmetries.
"The fact that our world does not behave perfectly symmetrically is due to deviations from symmetry at the microscopic level," the committee said. This broken symmetry allowed particles of matter to outnumber particles of anti-matter.
This is lucky for all living things—because if the universe were symmetrical, anti-matter would be constantly meeting matter, and exploding.
The work, done in the 1960s and 1970s, predicted the behavior of the tiny particles known as quarks and underlies the Standard Model, which unites three of the four fundamental forces of nature: the strong nuclear force, weak nuclear force and electromagnetic force, leaving out gravity.
"Professor Nambu laid a really theoretical foundation for modern particle physics," Sakue Yamada, emeritus professor of the University of Tokyo, told Kyodo news.
Nambu also influenced the development of quantum chromodynamics, which describes some interactions between protons and neutrons, which make up atoms, and the quarks that make up the protons and neutrons.
Shared Prize
He shared half of the 10 million Swedish crown ($1.4 million) prize with Kobayashi of Japan's High Energy Accelerator Research Organization and Maskawa of Kyoto University.
Kobayashi and Maskawa predicted there were three families of quarks, instead of the two then known. Their calculations played out as predicted in high-energy particle physics experiments and there are now six known types of quarks—up, down, strange, charm, bottom, and top.
Kobayashi said the news of his Nobel prize came as a shock. "It is my great honor and I can't believe this," he said.
Maskawa said he was not surprised.
"There is a pattern to how the Nobel prize is awarded," he was quoted as saying by Kyodo. "I am very happy that Professor Yoichiro Nambu was awarded. I myself am not that happy."
A surprised Nambu greeted reporters and photographers at his three-story brick home. "I don't know about the money yet," Nambu, 87, told Reuters.
Physicists are now searching for the spontaneous broken symmetry, the Higgs mechanism, which threw the universe into imbalance at the time of the Big Bang 13.7 billion years ago.
Scientists at the Large Hadron Collider at the European Organization for Nuclear Research, or CERN, in Switzerland will be looking for the Higgs particle when they restart the collider in spring 2009.
The prize, awarded by the Nobel Committee for Physics at the Royal Swedish Academy of Sciences, was the second of this year's crop of Nobel prizes.
The prizes are given annually for achievements in science, peace, literature and economics. The prizes bearing the name of Alfred Nobel were first awarded in 1901 in accordance with the 1895 will of the Swedish dynamite millionaire.
