Scientists in the STAR collaboration at the Relativistic Heavy Ion Collider (RHIC)—an atom smasher at the U.S. Department of Energy's Brookhaven National Laboratory—have published a comprehensive analysis aimed at determining which factors most influence fluctuations in the flow of particles from heavy ion collisions. The results, published in Physical Review Letters, will help the scientists zero in on key properties of a unique form of matter that mimics the early universe.