astronomy

Parallel universes in fiction

Parallel universes in fiction is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Parallel universes in fiction rather than just read about it. In short: A parallel universe, also known as an alternate universe, world, or dimension, is a plot device in fiction which uses the notion of a hypothetical universe co-existing with another, typically to enable alternative narrative possibilities. The sum of all potential parallel universes that constitute reality is often called the "multiverse".

Key takeaways

Parallel universes in fiction belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Parallel universes in fiction to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Parallel universes in fiction from memory before moving on to harder problems.

Reference excerpt

A parallel universe, also known as an alternate universe, world, or dimension, is a plot device in fiction which uses the notion of a hypothetical universe co-existing with another, typically to enable alternative narrative possibilities. The sum of all potential parallel universes that constitute reality is often called the "multiverse". The device serves several narrative purposes. Among them, parallel universes have been used to allow stories with elements that would ordinarily violate the laws of nature, to enable characters to meet and interact with alternative versions of themselves or others from their home universe, thus enabling further character development, and to serve as a starting point for speculative fiction, particularly alternate history.

History

Early examples One of the first science-fiction examples of a parallel universe is Murray Leinster's short story Sidewise in Time, published in 1934. Although Leinster's story was not the first example of parallel universes, it is credited with popularizing the concept. The use of parallel universes as a device in superhero fiction was popularized with the publication of the 123rd issue of The Flash, "Flash of Two Worlds", in 1961. In the issue, the Flashes of Earth-One and Earth-Two, Barry Allen and Jay Garrick, meet, establishing the concept of the DC Comics multiverse.

Modern examples The multiverse has seen much usage in popular media in the late 2010s and early 2020s, particularly in superhero films, such as the Marvel Cinematic Universe (MCU) and the animated Spider-Verse franchise, as well as the 2022 film Everything Everywhere All at Once. Some filmmakers and critics, including MCU director Joe Russo, have expressed concern that film studios may be embracing multiverse-centric plotlines to capitalize on characters and intellectual property with pre-existing popularity, ultimately to the detriment of originality and creativity in filmmaking.

Associated genres

Isekai

Isekai is a subgenre of Japanese fantasy light novels, manga, anime, and video games revolving around a normal person being transported to or trapped in a parallel universe. Often, this universe already exists in the protagonist's world as a fictional universe, but it may also be unbeknownst to them.

Fan fiction In fan fiction, parallel universes are commonly used as a setting for a story that departs from the canon of the fictional universe that the fan work is based on. Such works are usually referred to as "alternate universe" works, often abbreviated to "AU". Common motivations for writing such stories are to either explore alternative narrative possibilities not depicted in the original media, or to "fix" plot points which were disliked by the fandom. Different types of AU's (and examples) include, but are not limited to:

Swap AU's. A swap AU has every character be swapped (normally in pairs) with another character. A popular example of a swap AU is "Underswap" (an AU of Toby Fox's Undertale). Fell AU's. A fell AU (also known as Evil AU's) is where character's that are normally on the protagonists side, are now on the antagonists side, and vice versa. Popular examples of Fell AU's are "The Mirror Universe" (an AU of Star Trek), and "Underfell" (an AU of Toby Fox's Undertale). Dust AU's. A dust AU (also known as Desperation or Maddness AU's) is where a normally courageous hero is told something that mentally breaks them, and to protect their loved ones, they must kill everyone else, inlcuding their allies. A popular example of a Dust AU is "Dusttale" (an AU of Toby Fox's Undertale).

Whilst the list above uses certain name's for types of AU's, many AU's also use different names.

See also Alternate history List of fictional works featuring parallel universes The Long Earth (series)

References

External links Media related to Multiverse (science fiction) at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with Parallel universes in fiction

Start with the simplest possible case. Write down what Parallel universes in fiction claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Parallel universes in fiction before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Parallel universes in fiction ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Parallel universes in fiction

In research: Parallel universes in fiction appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Parallel universes in fiction in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Parallel universes in fiction is common in secondary-school and first-year university syllabi. It links to neighbouring topics Fiction about parallel universes, Multiverse, Science fiction genres, so understanding it makes those chapters shorter.
In everyday life: Look for Parallel universes in fiction outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Parallel universes in fiction in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Parallel universes in fiction means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Parallel universes in fiction out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Parallel universes in fiction in simple terms?

Why does Parallel universes in fiction matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Parallel universes in fiction?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Parallel universes in fiction.