For over 80 years, popular culture and cinema have taught us that when it comes to the zombie apocalypse there are always survivors. But according to a journal published this past November by students from the Department of Physics and Astronomy at the University of Leicester, the Earth’s population would be reduced to roughly 100-200 people in just 100 days.The students investigated the spread of a zombie virus using the SIR model, a basic model used to describe the spread of disease throughout a population. Their first investigation explored the zombie outbreak as an epidemic and then adjusted the model to treat it as a pandemic, which considers the geographical separation of Earth’s population. In both cases, the outbreak is started by a single person on day 0 and the virus is twice as contagious as the black death.Ignoring natural birth and death rates and assuming a zombie will turn one person into a zombie each day, the global population would be reduced to just 181 survivors by day 100. Using the pandemic model there would be 273.So if you have a Walking Dead dystopian fantasy for your future, it might not be as awesome as pop culture would lead you to believe. That said, the students did note that the model wasn’t perfect, as it didn’t take into consideration the fact that as time went on and more people were turned, zombies would be less likely to find one person a day to turn. Additionally, the model didn’t take into consideration humans fighting back against the zombies and killing them, giving humans a better chance of survival.
