|Posted by Mark Cantrell on April 1, 2017 at 4:30 PM|
Scientists don't rate our chances once the undead bite
Scientists at Leicester University don't rate humanity's chances in the event of a zombie apocalypse, writes Mark Cantrell; so, it's probably just as well there's no such thing outside of fiction... er, right?
AS many a horror aficionado knows, there's just no living with zombies, but the popularity of this necrotic presence in popular genre fiction suggests we can't quite live without them either.
Now a team of scientists at the University of Leicester, UK, has applied a little epidemiological thinking to a potential walker apocalypse – and they don't rate our chances.
In a real-life zombie outbreak, they calculate, that 100 days after a peckish patient zero took a bite out of victim number one, there'd be a mere 275 human survivors – outnumbered a million-to-one by zombies. Talk about a short, sharp descent from the top of the food chain.
The study makes the assumption that a zombie can find one person each day, with a 90% chance of infecting the victim; from then on it’s exponential mayhem, according to the team from the university's Department of Physics & Astronomy.
Hang on, physics and astronomy? That's an odd combination for the study of a hypothetical zombie outbreak; surely you'd expect medical experts, epidemiologists, biologists, those kinds of specialisms to be taking a bite of the problem, not stargazers and quantum mechanics?
Well, you might say that astronomy and physics are number-crunching games, and in a way that's just what this little epidemiological exercise is – a mental work-out. It's a bit of pop-culture fun with a serious intent. You see the scientists behind the study aren't full-fledged white-coats just yet: no, they're students. So relax, we're not likely to get bitten out of existence any time soon, at least not by zombies.
“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 the physics they know to the weird, the wonderful, or the everyday,” said Dr Mervyn Roy, a course tutor and lecturer at the university department.
The journal is a peer-reviewed publication designed to provide a practical taste of writing, editing, publishing and reviewing scientific papers; essentially a foretaste of what is to come as working scientists. So that's all right, then.
Back to the study. The student scientists investigated the spread of the hypothetical zombies virus using the SIR model. This is an epidemiological model that describes the spread of 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.
As part of the formula, the students looked at S (the susceptible population), Z (the zombie population) and D (the dead population), suggesting that the average life-cycle of a zombie would be S to Z to D.
They also examined the time frame over which individuals in the population encounter one another.
However, the initial study did not factor in natural birth and death rates, since the hypothetical epidemic took place over 100 days, resulting in natural births and deaths being negligible compared to the impact of the zombie virus over a short time frame.
Without the ability for humankind to fight back against the undead hordes, the students’ calculations suggest that if global populations were equally distributed then in less than a year the human race might be wiped out.
Grim tidings indeed, but there's an obvious flaw in the thinking; humans are a rowdy lot. As we known from zombie fiction, we're not going to take the undead lying down. Regardless of the odds, people will fight to survive and put the shambling dead in the grave for good.
This was acknowledged in a rather more hopeful follow-up study. In this scenario, the students introduced new parameters, such as the rate in which zombies might be killed, and people having children, within the nightmare scenario. This made human survival more feasible, they found.
The team factored in how over time survivors may also be less likely to become infected after having experience of avoiding or fending off zombies.
They found that it would be possible for the world’s human population to survive the zombie epidemic under these conditions. Eventually the zombie population would be wiped out and the human population would recover.
All's well that ends well, then; except for those poor souls bitten and left for dead. Still, that's a zombie apocalypse for you.
Find the two papers here: