How far and fast a virus spreads in today’s world is less about physical distance and more about travel patterns of the humans carrying it. In that sense, New York City may be “closer” to London than it is to Rochester, N.Y., based on airline traffic. “The modern transportation network is how infectious diseases get to faraway places,” says Dirk Brockmann, a German physicist and professor at the Institute for Theoretical Biology at Humboldt University of Berlin, who specializes in complex systems. To help public health officials around the world better assess risk, Brockmann developed a system of mapping based on airport connections. His visualization above shows the effective distance of cities globally from the coronavirus outbreak in Wuhan, China.
A version of this article appears in the March 2020 issue of Fortune with the headline “Mapping a Contagion.”
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