Zombie outbreak? Statistical mechanics reveal the ideal hideout

February 25, 2015
Zombie outbreak? Statistical mechanics reveal the ideal hideout
Zombies as portrayed in the movie Night of the Living Dead. Credit: Wikipedia

A team of Cornell University researchers focusing on a fictional zombie outbreak as an approach to disease modeling suggests heading for the hills, in the Rockies, to save your 'braains' from the 'undead.'

Reading World War Z, an oral history of the first zombie war, and a graduate class inspired a group of Cornell University researchers to explore how an "actual" zombie outbreak might play out in the U.S.

During the 2015 American Physical Society March Meeting, on Thursday, March 5 in San Antonio, Texas, the group will describe their work modeling the statistical mechanics of zombies—those thankfully fictional "undead" creatures with an appetite for human flesh.

Why model the mechanics of zombies? "Modeling zombies takes you through a lot of the techniques used to model real diseases, albeit in a fun context," says Alex Alemi, a graduate student at Cornell University.

Alemi and colleagues' work offers a nice introduction to disease modeling in general, as well as some techniques of statistical physics for measuring second-order phase transitions. "It's interesting in its own right as a model, as a cousin of traditional SIR [susceptible, infected, and resistant] models—which are used for many diseases—but with an additional nonlinearity," points out Alemi.

All told, the project was an overview of modern epidemiology modeling, starting with differential equations to model a fully connected population, then moving on to lattice-based models, and ending with a full U.S.-scale simulation of an outbreak across the continental U.S.

It involved a lot of computational results generated from simulations the researchers wrote themselves. "At their heart, the simulations are akin to modeling chemical reactions taking place between different elements and, in this case, we have four states a person can be in—human, infected, zombie, or dead zombie—with approximately 300 million people," Alemi explains.

The project's large-scale simulations are stochastic in nature, meaning that they have an element of randomness. "Each possible interaction—zombie bites human, human kills zombie, zombie moves, etc.—is treated like a radioactive decay, with a half-life that depends on some parameters, and we tried to simulate the times it would take for all of these different interactions to fire, where complications arise because when one thing happens it can affect the rates at which all of the other things happen," he says.

In most films or books, "if there is a zombie outbreak, it is usually assumed to affect all areas at the same time, and some months after the outbreak you're left with small pockets of survivors," explains Alemi. "But in our attempt to model zombies somewhat realistically, it doesn't seem like this is how it would actually go down."

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.

"A lot of modern research can be off-putting for people because the techniques are complicated and the systems or models studied lack a strong connection to everyday experiences," Alemi adds. "Not that zombies are an everyday occurrence, but most people can wrap their braains around them."

What's next for Alemi and colleagues? "Given the time, we could attempt to add more complicated social dynamics to the simulation, such as allowing people to make a run for it, include plane flights, or have an awareness of the zombie outbreak, etc.," he notes.

Explore further: UK brains under threat?

More information: meeting.aps.org/Meeting/MAR15/Session/S48.8

Related Stories

UK brains under threat?

October 26, 2011

The British appetite for zombies is becoming a growing trend. From computer games and films to organised zombie walks though Britain's cities, the proliferation of zombies seems to be everywhere. Yet, this high interest in ...

The zombie-ant fungus is under attack, research reveals

May 2, 2012

A parasite that fights the zombie-ant fungus has yielded some of its secrets to an international research team led by David Hughes of Penn State University. The research reveals, for the first time, how an entire ant colony ...

Zynga unleashes zombies on smartphones

May 24, 2012

Zombies stalked San Francisco streets on Thursday as social game maker Zynga ghoulishly introduced a game that lets iPhone or iPod Touch users slash and hack the undead.

Zombie bacteria in tuberculosis

January 26, 2015

"Living-dead" bacteria exist in limbo: biologically active but not proliferating. Buried in this zombie state, disease-causing bacteria could come back from the dead to re-infect patients. Researchers at EPFL have produced ...

1st 'zombie' bees on East Coast found in Vt. (Update)

January 28, 2014

Vermont beekeepers say they face mite infestations, extreme temperature swings and the possibility of colony collapse. But a San Francisco State University professor says a new threat has arrived in Vermont: zombie bees.

Recommended for you

9 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

HeloMenelo
not rated yet Feb 25, 2015
Hey hey do the zombi stomp...hey..... hey.... do the zombi... Zombi Stomp!
mndaffy
not rated yet Feb 25, 2015
So these were our shovel ready jobs?
Doug_Huffman
not rated yet Feb 25, 2015
So these were our shovel ready jobs?

Oh Bummer, dead men walking.
antialias_physorg
5 / 5 (3) Feb 25, 2015
Well, it's not just fluff if you think in terms of biological warfare scenarios.
(The down side is that such a scenarios tell you where to use those weapons in addition to the obvieous population centers...so as to get the best 'coverage' of the entire area, leaving no retreat)
wolfdaddy74701
not rated yet Feb 25, 2015
In the book Zone One, Colson Whitehead writes of a scenario that probably mirrors what is being described here. New York City falls almost immediately, but Buffalo manages to hold out to become a staging ground for an organized attempt to reclaim NYC. Haven't finished it yet, but it's a compelling read.
nkalanaga
5 / 5 (2) Feb 25, 2015
Not just biological warfare, but any new easily transmitted disease with a short incubation period.
Doug_Huffman
5 / 5 (2) Feb 25, 2015
Not just biological warfare, but any new easily transmitted disease with a short incubation period.
A suicide bomber with fully developed Ebola EVD.
nkalanaga
not rated yet Feb 26, 2015
Nasty, but since Ebola is spread through bodily fluids that would work.
Steelwolf
not rated yet Mar 01, 2015
Well, the poor zombies would starve to death around WA DC, that Might be a safe place to go, unless the politicians are amongst the zombies, that is.

Can just see a zombie singing "If I Only Had A Brain..."

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.