The Japanese–American particle physicist Yoichiro Nambu died on 5 July at the age of 94. Nambu shared one half of the 2008 Nobel Prize for Physics, with the other half split between Makoto Kobayashi and Toshihide Maskawa. Nambu won his half of the prize for realizing in 1960 how to apply spontaneous symmetry breaking to particle physics.

Nambu achieved his breakthrough while working on how spontaneous symmetry violation can cause substances to become superconducting. His work inspired Peter Higgs, François Englert and others in the 1960s to develop the theoretical mechanism for the Higgs boson, which was discovered by CERN’s Large Hadron Collider (LHC) in 2012. A year later, Higgs and Englert shared the 2013 Nobel Prize for Physics for building on Nambu’s ideas to predict the existence of the Higgs boson.

In an interview with Physics World in 2004, Higgs acknowledged Nambu’s influence: “Although my name gets thrown around in this context, it was Nambu who showed how fermion masses would be generated in a way that was analogous to the formation of the energy gap in a superconductor.”

“Nambu’s work was an act of imagination that was way ahead of its time”
Frank Wilczek, Massachusetts Institute of Technology

Commenting on Nambu’s Nobel prize, Frank Wilczek of the Massachusetts Institute of Technology told Physics World that “Nambu’s work was an act of imagination that was way ahead of its time”. Wilczek, who shared the 2004 Nobel Prize for his work on the strong interaction, added that “It introduced the idea that what we perceive as empty space is, to a deeper vision, a medium that complicates the motion of matter we observe.”

Nambu was born on 18 January 1921 in Tokyo and studied physics at the Imperial University of Tokyo from 1940 to 1942. Like many physicists of his generation, he then worked on military applications of radar. He completed a PhD at the University of Tokyo in 1952 and then worked briefly at Osaka City University before moving to the Institute for Advanced Study in Princeton, US. In 1954 Nambu arrived at the University of Chicago, where he spent the rest of his career and became an American citizen in 1970.