An international team of researchers has developed a new mathematical tool that could help scientists to deliver more accurate predictions of how diseases, including COVID-19, spread through towns and cities around the world. Rebecca Morrison, an assistant professor of computer science at CU Boulder, led the research. CU says that for years, she has run a repair shop of sorts for mathematical models—those strings of equations and assumptions that scientists use to better understand the world around them, from the trajectory of climate change to how chemicals burn up in an explosion.  As Morrison put it, “My work starts when models start to fail.”