Decades ago, astronomers estimated that “ordinary” matter (basically everything that isn’t dark matter or dark energy) makes up 5% of the universe. There was just one problem—they had no idea where most of it was. Astronomers from the Center for Astrophysics Harvard & Smithsonian (CfA) and the California Institute of Technology (Caltech) have tracked down the universe’s “missing” matter. Fast radio bursts (FRBs) indicate that over three-quarters of ordinary matter, officially called baryonic mat...