Cities would fall quickly, but it would take weeks for zombies to penetrate into less densely populated areas, and months to reach the northern mountain-time zone.

“Given the dynamics of the disease, once the zombies invade more sparsely populated areas, the whole outbreak slows down–there are fewer humans to bite, so you start creating zombies at a slower rate,” he elaborates. “I’d love to see a fictional account where most of New York City falls in a day, but upstate New York has a month or so to prepare.”

If you somehow happen to find yourself in the midst of a fictional zombie outbreak and want to survive as long as possible, Alemi recommends making a run for the northern Rockies. While not an entirely practical implication, it’s “fun to know,” he says, and points out the benefits of applying hard science to fun topics–especially to help make learning more entertaining and enjoyable.