Netflix’s retro-inspired sci-fi series, “Stranger Things” tells the story of worlds in collision, and a group of sinister, runaway government scientists who have unintentionally bridged the gap between two parallel universes. While we can be pretty sure our government has not, in fact, opened the portal between our world part of the multiverse, there is compelling scientific inspiration behind this plot premise. So compelling, that the U. S. Department of Energy released a statement explaining that they are not an evil, rogue organization researching monsters and parallel universes.
While it's unlikely that a gooey gray-green “upside-down” world of “Stranger Things” hovers just beneath our own, the idea of parallel or multiple universes is one that has been explored by theoretical physicists for decades. Parallel, though slightly varied worlds have been a theme in theoretical physics, and while there is no evidence that supports their existence, many scientists have attempted to use these ideas to explain quantum mechanics, and natural phenomena like gravity.
“Stranger Things” seems to be taking cues from physicist Hugh Everett’s “many worlds” theory. This theory posits that whenever someone “measures”, or observes something in the universe, such as ordering a cheese pizza instead of pepperoni, two separate realities spring from that moment. This is further evidenced by the fact that the rag tag bunch of boys’ science teacher, Mr. Clarke, references Everett’s theory.
Unlike in “Stranger Things” these parallel universes are entirely separate, and cannot interact. So, no light-flickering monsters and whispers coming out of walls.
In a paper published in 2014, physicist Bill Poirier proposed a different version of this theory, called many interacting worlds theory. According to Poirier, these worlds can talk and interact with each other. Unlike Hawkins Indiana and it’s sinister twin “upside-down” world, our neighboring universes would be pretty similar to our own, and we’d be unable to travel between them. According to Poirier, universes would be layered one on another, with more similar worlds closer together, and more variant universes being farther away. On the off chance you were able to travel to a neighboring universe, it would be pretty similar to our world, probably no demogorgans or weird, fleshy snow.
Unfortunately for fans of “Stranger Things” there is no evidence of any such parallel world, though theoretical physicists are still positing potential theories involving multiple, or parallel universes.
Fortunately, this lack of scientific evidence likely won’t derail the creation of a season 2.