A character explains Time Travel, Faster-Than-Light Travel, Teleportation, or wormholes by folding a sheet of paper (or something similar) in half to illustrate the theory of an Einstein-Rosen Bridge. Usually they indicate two points at opposite ends of the sheet, then fold the sheet so that the points touch. If they really want to get their audience's attention, they might create their metaphorical wormhole by stabbing a pen through the two points.
Truth in Television: the piece of paper explanation has become so ubiquitous that it turns up in many real-world scientific explanations of wormholes and space/time.
- Happens in Déjà Vu when Doug demands a Layman's Terms explanation for how the scientists established a live feed connection to a timeline four days in the past. Denny holds up a blank sheet of paper and then folds it to explain how they folded space and time to create a wormhole into the past.
- In Event Horizon, the ship's designer William Weir (Sam Neill), demonstrates the concept with the centerfold page from a magazine.
- On the way to the wormhole in Interstellar, Romilly does some exposition talk to explain the wormhole idea to Cooper. Interestingly, the movie refers to the hole as a sphere rather than a tunnel, which seems scientifically correct.
Romilly: So they say you want to go from here, to there. [holds up a blank sheet] But this is too far. So a wormhole bends space like this so you can take a shortcut through a higher dimension. [folds paper and pierces it with a pen]'' Okay so, to show that they've turned three-dimensional space into two dimensions, which turns a wormhole in two dimensions? ... A circle. What's a circle in three dimensions?
Cooper: A sphere.
Romilly: Exactly. A spherical hole.
- In the My Teacher Is an Alien series, a random alien explains the ship's movement using a noodle-like alien food. The book also makes a point that said alien knows the general theory but can't explain the mechanics of how it works, because he's not actually an engineer, much as how most people have only a vague idea of how an internal combustion engine works.
- Subverted in The Restaurant at the End of the Universe, in which Ford Prefect starts with a napkin, and subsequently completely fails to explain to Arthur Dent why Milliways is protected from the destruction of the Universe.
- In The Wheel of Time, Rand uses this with a cloth to explain his method of Thinking Up Portals to a female channeler. Since the Mars-and-Venus Gender Contrast is hard-coded into the magic system, she's quite disturbed by the notion of distorting and puncturing the fabric of reality, while he's equally confused by her own method of somehow turning the destination and origin points into the same location.
- In A Wrinkle in Time, the protagonists are shown an ant walking across a cloth, how it has to travel such a far distance to get from one side to the other. But, by folding the cloth so that the two ends are right beside each other, the ant can travel the whole distance by only going a few steps.
- Skeleton Crew: Not physically demonstrated but the analogy is made in "Mrs Todd's Shortcut". Homer discovers evidence that Mrs Todd's shortcuts are taking fewer miles than are in a straight line between the trip origin and its destination, something that would be impossible in reality. Mrs. Todd compares the shortcuts to folding a map to bring two points closer together, suggesting she has discovered a warped version of reality, akin to a wormhole.
- In Quantum Leap Sam uses the term "string theory" to explain his leaping. Imagine your life as a piece of string, with one end (birth) and the other end (death). If you ball the string up, every day of your life touches every other day out of order, so you can jump from one to another, therefore time-travelling within your own lifetime.
- Mentioned in the Stargate SG-1 episode "Enigma". When Daniel takes Omoc outside to send a FTL transmission to the Nox, he asks Omoc to explain how his message can cross interstellar distances in an instant. At first reluctant (due to the Tollan rule about not giving technology to younger races), Omoc takes a branch and bends it, so that the ends touch, explaining that the distances seem to be far away, until you merge the points together (paraphrasing). Daniel assumes he's talking about space folding, causing Omoc to shake his head in disappointment and shut up on the subject.
- In Episode 5 of Stranger Things, the science teacher uses this method to explain to our kid heroes how they could create a doorway to the "Upside Down" dimension. He takes a paper plate, folds it and pierces it with a pen.
- In Lighthouse: The Dark Being, Dr. Jeremiah Krick used his titular lighthouse to create a portal device. His theory follows this trope to the letter, but when he gets it working, it instead creates a portal to a Parallel Universe, which he perceives as his portal crumpling a second sheet of paper against ours.