A new study suggests that, in the case of a zombie infection spreading, less than 300 people would be left alive in the world after just 100 days.
The study, from physics students at the University of Leicester, suggested human survivors would be outnumbered a million to one by the undead in just over three months.
The students, from the University of Leicester Department of Physics and Astronomy, worked from the assumption that a zombie could find one person each day and would have a 90% chance of infecting its victim with the virus. Based off this assumption, they found that just 273 humans would remain after the 100 day period.
In order to reach these numbers, the team made use of the SIR mode; an epidemiological model that describes the spread of a disease throughout a population.
The model splits the population into three categories – those susceptible to the infection, those that are infected and those that have either died or recovered. The SIR model then considers the rates at which infections spread and die off as individuals in the population come into contact with each other.
Included in the student’s formula was a consideration of the lifecycle of a zombie, looking at the susceptible population, the zombie population and the dead population. Furthermore, the time frame in which individuals within the population come into contact was examined.
Ignored, however, were natural birth and death rates as they were considered negligible compared to the virus’ impact over such a relatively short time frame.
If populations were equally distributed, and humanity was unable to effectively fight back, calculations showed that humans would be entirely wiped out in less than a year. However, a follow-up study introduced new parameters, such as the rate in which zombies might be killed and people may have children during the epidemic.
According to this more optimistic set of calculations, human survivability became much more feasible. With the notion that survivors may become less likely to be infected over time due to experience fighting zombies also factored in, it was found that humans would not only survive the epidemic but eventually be able to wipe out the zombies and slowly begin the recovery of the population.
The students’ findings were presented as a series of short articles for the Journal of Physics Special Topics, a peer-reviewed student journal run by the University’s Department of Physics and Astronomy. The student-run journal is designed to give students practical experience of writing, editing, publishing and reviewing scientific papers.
Course tutor Dr Mervyn Roy, a lecturer in the University of Leicester’s Department of Physics and Astronomy, said: “Every year we ask students to write short papers for the Journal of Physics Special Topics. It lets the students show off their creative side and apply some of physics they know to the weird, the wonderful, or the everyday.”