The physics of the walking dead: the scientists studying the spread of zombies

03 May 2016 alisonhadley
Physics World May issue cover

Science writer Stephen Ornes talks with the physicists who mixed modelling with science fiction to predict the success of a zombie invasion, available in May’s issue of Physics World magazine, online now!

Zombies, with their appetite for the living and their ability to transcend the boundaries of life and death, have captured the imagination of audiences for centuries, and it seems that even physicists can’t resist the appeal of these reanimated corpses.

In this month’s Physics World, Stephen Ornes delves into the science of the walking dead, and talks to a team of researchers whose work into simulating the next zombie apocalypse even led to a paper in a leading peer-reviewed scientific journal.

Graduate physicists Alex Alemi, Matt Bierbaum and a team of researchers at Cornell University, USA, have taken mathematical models commonly used to understand traditional disease outbreaks and added a supernatural twist.

Their findings, published in Physical Review E, introduce parameters such as the probability of a zombie biting a human, versus the probability of a human managing to immobilise a zombie (which any zombie enthusiast would know is only possible by removing or shooting it in the head).

Talking to Physics World, Alemi and Bierbaum explain that the idea for the research came from Alemi reading popular fiction books about zombies whilst taking a statistical-mechanics class at Cornell University.

Using existing models that simulate disease spread, they developed their own series of zombie outbreak equations.

“Eventually it got to the point where we’d done some cool calculations and got some interesting results,” says Alemi.

Adding to the mix principles from network science, computational chemistry and 2010 census data from the US, the team successfully modelled potential outbreaks of a zombie apocalypse across mainland USA, and saw some surprising patterns.

Veteran zombie outbreak enthusiast and mathematician Robert Smith? [the question mark is part of his name], who first published research on zombie outbreaks back in 2009 and is a fan of Alemi and Bierbaum’s findings, spoke to Physics World about the value of combining the supernatural with the mathematical:

“Now we’ve got people reading math papers with equations in them – people who would never normally read such a thing and would run a million miles to get away,” says Smith?

“You add zombies, and suddenly it’s interesting.”

Want to read on?

IOP members can access the May issue digitally.

Also in this issue:
Something from nothing – the pros and cons of publishing “null results”
Profit and loss – the true benefit of CERN’s Large Hadron Collider