An American physicist and two Japanese physicists won the Nobel Prize on Tuesday for their work on understanding the breakdown of symmetries in the laws of nature.
Most people intuitively know what symmetry is; they see it in people's faces and in snowflakes. But theoretical physicists think about symmetry as it relates to the fundamental workings of the universe.
Yoichiro Nambu, 87, was woken up early this morning by a phone call — a call he'd pretty much given up on. It was Sweden's Royal Academy of Sciences, telling him he had won the Nobel Prize for a paper he wrote on something called spontaneous broken symmetry in subatomic physics. Nambu's paper helped explain some of the fundamental forces of nature, and why different particles have different masses.
"My paper came out 1960, I believe. It was a long, long time ago," says Nambu. He added that he's honored and happy to get the prize, but that he didn't expect it after so many years had passed.
He shares the prize, and $1.4 million, with two researchers in Japan. Makoto Kobayashi and Toshihide Maskawa explored another kind of symmetry breaking. Their work in the 1970s led to the prediction that physicists should eventually find new types of the subatomic particles known as quarks. And experiments have proved them right.
"These three gentlemen provided theories that explain one of the most fundamental aspects of existence. How symmetric is the universe?" says Philip Schewe, a spokesperson for the American Institute of Physics.
"We sort of instinctively want the universe to be symmetric, we want it to be regular, and the fact that it's not is kind of interesting."
Experts say that understanding asymmetries is important because they are at the heart of what makes life possible.
For example, when the Big Bang created the cosmos some 14 billion years ago, it didn't create equal amounts of matter and antimatter. That's a good thing, because they would have cancelled each other out. Scientists are still trying to understand why there was just a tiny bit of extra matter created, a little asymmetry that was the seed of our whole universe. The person who figures that one out might someday win a Nobel of their own.
Nambu came to the United States from Japan in 1952 and is now a citizen. He's worked at the University of Chicago for decades. Some of his colleagues in Chicago say the honor is long overdue.
"We'd been talking about it for years that he deserved it. He's such a shy and humble man; those kinds of people don't always win the prize," says Joe Lykken, a particle physicist at Fermilab in Illinois.
"But the Nobel committee has finally wised up and done the right thing for him," Lykken says of the man he calls one of his personal heroes.
Kobayashi and Maskawa's research, Lykken says, was built on the work of an Italian physicist named Nicola Cabibbo.
"These three people — Cabibbo, Kobayashi, and Maskawa — are mentioned so often together that we usually just say C-K-M rather than saying all three of their multisyllabic names," says Lykken.
Some scientists might wonder why Cabibbo wasn't honored by the committee. But the rules state that the Nobel can go to only three scientists.