The Atlantic is making vital coverage of the coronavirus available to all readers in a guide to understanding COVID-19 Find the collection here. And read this fascinating piece on A New Understanding of Herd Immunity The portion of the population that needs to get sick is not fixed. We can change it... just as barely predictable meteorological events arise from totally predictable laws of physics, the complex dynamics of a pandemic center on an extremely limited set of concepts in basic viral biology. Early failures to test and shut down in the U.S. have been amplified through the butterfly effect. Current decisions will be as well.When phenomena appear chaotic, mathematical modelers make it their job to find the underlying order. Once models can accurately describe the real world, as some now do, they gain the predictive power to give clearer glimpses into likely futures.'