The lore of Stranger Things is inextricably tied with Dungeons & Dragons, the popular tabletop RPG that was practically a household name in the early eighties (having procured millions of devoted players by the time the series begins.) Aside from the concepts of the Demogorgon and the Mind Flayer, the story also incorporates the Upside Down — known as the Vale of Shadows in D&D.
According to the kids, it is "a dimension that is a dark reflection, or echo, of our world." A fitting description for the version displayed in the story, but is it completely watertight in of history, structure, and physics? The list given here will elucidate a few confusing aspects of the Upside Down in Stranger Things.
How Was It Created?
The first time it is discovered is when Eleven tears open a "wound" or portal into the dimension, while in the process of counter-espionage against Soviet agents. Once this happens, the Mind Flayer and Demogorgons begin verging on the real world, causing havoc in the once-sleepy town of Hawkins, Indiana.
However, absolutely nothing is known about its creation — Is it as old as our cosmos? Did it emerge spontaneously or was it formed by some kind of intelligence? What function does its existence even serve?
Is It Sci-fi Or Fantasy?
The Duffer brothers have claimed that they have purposefully withheld specifics about the Upside Down in order to create a tense atmosphere, packed with mystery and looming threats hidden behind the shadows. The problem is that the shadows themselves are rather unclear in their nature.
The Demogorgons have biological bodies, but they are referred to by their Dungeons & Dragons counterparts, mostly because the kids have no other information about these creatures. Also, the Mind Flayer is said to have absolute control over the Upside Down, which isn't really solid science, to be honest.
Shouldn't There Be Others?
Scott Clarke, the local science teacher, mentions that "parallel universes" are a possibility (according to the Many-Worlds hypothesis postulated by the quantum physicist, Hugh Everett.) Therefore, why would the Upside Down be the only alternate dimension?
If there are an infinite number of them, there could also be one where the stars are made of cotton candy and everyone lives happily with rainbow unicorns? If this is the case, then why does Eleven unlock such a horrible dimension?
The Inverse Of Hawkins
Right, so the Upside Down entered by the characters is noticeably similar to Hawkins, except covered in weird gloop and glowing evil. This is confirmed by the fact that Will finds his little tent in there, where he hides from Demogorgons and other beasts that probably stalk the land.
Further, most people are taken to a Demogorgon "nest" in the Upside Down, which is nothing more than the Hawkins Public Library. Does this mean that every place on earth has a mucus-coated reflection? Or is it just Hawkins? Why does everything bad happen to that poor town, anyway?
Are There No Recognizable Creatures?
It's been established that this dark space is identical to the real world, but then why aren't there any plants/animals similar to those found here? There are buildings, roads, and other hints that humans have been there, but no actual humans except those that are forcibly dragged in?
The atmosphere contains the right proportions of oxygen, which explains why Nancy and Will don't die instantly, but on the other hand it is supposedly toxic to spend too much time in there, none of which makes sense.
What Does The Mind Flayer Want?
Eleven breaks into the Upside Down by total accident, opening a "Gate" that allows the Mind Flayer to begin its manipulative schemes. For all intents and purposes, it seems like the antagonist wants to take control of the entire world, but why? What will it gain from doing so?
Does it run around capturing innocent dimensions and converting them into habitats for its minions? This answer clashes with the nature of the Upside Down itself, because it implies that there aren't any others available for invasion. More importantly, has the Mind Flayer completely absorbed its own dimension?
The Fundamental Forces Of The Universe Apply
If the Upside Down is truly different, then it shouldn't behave according to the rules of the characters' universe. Nonetheless, the universal constants have not changed — light works the same way, gravity exists, stuff is composed of atoms and molecules (differently arranged but still the building blocks of matter), and so on.
According to physics, this strongly implies that the Upside Down and the Stranger Things universe are one and the same, which makes the whole argument counterintuitive.
Sound Can Be Transmitted To The Real World
Sound travels through the Upside Down, which is not shocking because it has some kind of atmosphere to allow for air vibrations. But how is sound, specifically the plaintive cries of lost boys trapped in a mirror dimension, able to transmit itself all the way into Hawkins, specifically the home of aforementioned lost boy?
It functions in the reverse as well, as Will can perceive the sound of his mother's voice when they are separated. This could be some kind of portal magic, because Nancy and Jonathan converse across interdimensional space while being in proximity to one of the minor "gates", but something about it doesn't add up.
The Connection With Electricity
The only reason for the Upside Down to impact electrical fields in Hawkins is a narrative one: it is incorporated so that Will can send Christmas light messages to his mom, explaining his situation. Similarly, he successfully triggers the Byers' landline in a bid to prove his survival.
Why is it always electricity that is affected when supernatural connections are made? Even ghosts have been depicted as being capable of influencing the flow of current. Enough with the blinky lights, already.
What's With All The Spores?
The Upside Down contains countless spores of an unidentified essence, thickly suspended in the air like filthy snowflakes. They also enter the human world when the first portal is created, and in one scenario, a living tentacle-y protrusion generates an aerosolic version of the same.
These minute objects are quite poisonous to humans, shown when Chief Hopper instantly crumples when he is hit by the spray. What is their objective, if any? Are they sent by the Mind Flayer to "spy" on Hawkins?