Neutron Star Provides Direct Evidence for Bizarre Type of Nuclear Matter

For more than 50 years, astrophysicists have speculated that inside a superdense neutron star, nuclear matter might flow without any resistance whatsoever—much like electricity does in earthy materials known as superconductors. Now, two teams say they have direct evidence of such bizarre "superfluidity" in a neutron star, and other researchers seem convinced. "I think it's a defensible claim," says theorist Krishna Rajagopal of the Massachusetts Institute of Technology in Cambridge. "The only explanation [of the observation] that I'm aware of is the one presented in papers."