The speed of sound might just be faster than originally thought, and Assistant Professor of Physics Andrew Steiner has revisited this boundary in “Sound velocity bound and neutron stars,” published in Physical Review Letters. The paper describes how Steiner and his colleague used the speed of sound to investigate the mysteries of matter at high density: one of the outstanding problems in nuclear and astrophysics. As Steiner explained, “the basic motivation [for looking at high-density matter] is that examining extreme forms of matter often gives us insight into what’s going on inside matter on earth. This is generally true: physicists are always looking at the hottest, coldest, densest, spinningest, lightest, heaviest, slowest, fastest, stickiest, or slipperiest things in order to try to figure out how stuff works.” To read more, visit the Department of Physics and Astronomy’s website.