The Possibility of a Zombie Apocalypse
This post is part of a series of guest posts on GPS by the undergraduate and graduate students in my Science vs. Pseudoscience course. As part of their work for the course, each student had to demonstrate mastery of the skill of “Educating the Public about Pseudoscience.” To that end, each student has to prepare two 1,000ish word posts on a particular pseudoscience topic, as well as run a booth on-campus to help reach people physically about the topic.
The Possibility of a Zombie Apocalypse by Thomas Taylor
(Thomas previously wrote about the history of the zombie)
History aside, there are some people who think that a zombie apocalypse on the scale of Hollywood movies could happen. There have been preparation guides, survival tools, and even mathematical models that have attempted to work out how fast this would destroy the world. If one thinks of how humans are the most effective predators on the planet, it only makes since that if one removes their inhibition and turns them against humans, the result would be catastrophic. The often overlooked issue is that zombies have had everything that makes humans effective worldwide, and has allowed us to prosper, removed. Without the ability to adapt to the environment, an immune system, or even basic reasoning skills, the zombie apocalypse would be short and disappointing.
Humans are often seen as being apex predators, and our tools for maintaining our status on this list are our adaptability and our intelligence. The voodoo version of zombies had to be protected and cared for due to not possessing either of these. Left to their own, zombies would simply stumble into something that will kill them, or they will succumb to predication. Just picture a zombie walking across a subway track; how many would be vaporized by the third rail? The ones that do survive the New York subway would still be stuck as the awkward shuffle displayed by most movie zombies would not be able to circumvent the stairs to get out. In other parts of the world zombies would fair much worse. Being slow and relatively defenseless, they would find themselves on the menu of almost every large predator in existence. Lions, tigers, alligators, and bears would make short work of a zombie after they figure out that it will not react to their advances the same way a normal human would.
Humans have one of the most impressive immune systems on the planet. This may not seem too big of an issue at first, because zombies are not going to suffer from the flu, but protecting from illness is only one of the things our immune system does. In the human body, bacteria outnumber human cells ten to one. These bacteria are largely beneficial to us, aiding in enzyme production, saliva in the mouth, and digestion of food in the gut. All these bacteria are kept in check by our immune system. When zombies shut down the immune system, the microbiome begins the decomposition process. The first thing that happens to the zombie is known as rigor mortis, the contraction of the muscles will make the afterlife very difficult for up to 72 hours after death. During this time, the bacteria reproduce unchecked and produce methane and hydrogen sulfide which attract flies and other animals. These flies lay eggs that hatch into maggots. These maggots can consume up to 60% of the human body within seven days of passing. After some time, the body cavities fill with too much gas from the bacteria buildup causing both the grossest and the funniest ending to a zombie move ever as they pop open and their liquefied remains fall to the ground.
Accounting for both these issues, a long zombie attack would have to be out of the question. So what would happen if somehow zombies were able to gain the critical mass required for a horde at a fairly rapid pace? The timeframe would have to be between the three day mark, where they would not move and the thirty day mark, where they would expire. So for the sake of argument, one day a million ten-day old zombies appeared. If they appear in the winter, it will be a short evasion; lacking the ability to regulate their body temperature or produce their own heat would prove to be a disaster for the zombies. At ten days old, the body temperature will have completely left the zombie; this will result in the water contained in the body to freeze. As half the world is always in its winter season, this leads to an issue with a worldwide epidemic for zombies.
So they can only attack half the world for one month, which could still cause an issue for that half, right? It turns out, probably not. For a living person, an exterior door is fairly easy to get around. Sadly, according to the movies, zombies do not have the balance or the common sense to use this method. Their preferred method is to pound on the door slowly until it caves in. This makes it very unlikely they will ever get through a door with their rotting and broken human hands. Also of note is that, since zombies do not know how to use door knobs, this will happen with almost every exterior door. The next option is for them to use a window. Although they will be able to easily break the glass on the windows, most windows are not on the ground, causing them to have to tumble through in an easily killable fashion.
When they do gain entry into the building, with little to no intelligence, a person would still not be in immediate danger. A good analog for this would be a mouse in a maze. With training, one can get a mouse to run a maze, but it does not take much to trip them up. The inside of a store or office building would only increase this complication, making it highly unlikely that the zombie would ever be able to find a human to bite.
This whole scenario overlooks one of the biggest factors against a zombie apocalypse. Humans are good at killing things. Zombies have their hands and teeth, people have assault rifles and intellect. Before looking at how quick a million zombies would wipe out an area, one needs to look at how fast humans can kill a million zombies. The bloodiest day in recorded history of fighting was the first day of the Somme Offensive where an estimated 30,000 people lost their lives. At this rate, a million zombies would be dead in 33 days; this is probably an underestimate when dealing with mindless zombies.
So now, during the next episode of The Walking Dead or during the repeats of World War Z that are bound to happen on cable TV over the next few years, you can turn to friends and say “Yeaaaaaaah, not gonna happen.”