Nuclear physicists are known for their atom-smashing explorations of the building blocks of visible matter. At the Relativistic Heavy Ion Collider (RHIC), a particle collider at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, and the Large Hadron Collider (LHC) at Europe’s CERN laboratory, they steer atomic nuclei into head-on collisions to learn about the subtle interactions of the quarks and gluons within.