Summary
A Multiverse is a hypothetical collection of universes and serve as the total accumulation of everything that exists, counting the historical universe that people regularly experience. Multiverses can take the form of a set of finite or infinite possible universes that can come into existence such as space, energy, time and matter. It also takes into account the constants and the physical laws that describe those mentioned previously. These universes contained within the multiverse are what people sometimes call “parallel universes". Our universe exists within the fabric of space-time — 3D space combined with time, to create a 4D continuum.
The concept of multiple universes has been discussed throughout history, first appearing in ancient Greek philosophy and eventually evolving into a theory that is widely debating in various fields such as cosmology, physics, and philosophy. The term "multiverse" was first coined William James in 1895, albeit under a different context than cosmology and physics. Over time, the term and concept would become prevalent in fiction, with the first fictional series to use this being DC with the DC comic book titled Flash of Two Worlds and Michael Moorcock's The Sundered Worlds
Hyperverse
A Hyperverse is term created for a verse that contains more than 11 higher dimensional axis. As defined, it's for multiverses that contain dimensions of a higher order than the standard 10 or 11 dimensions that most scientists have theorized to exist out of the total number of spatial dimensions. There isn't a set number of dimensions that a cosmology would need to be considered a "Hyperspace" aside from the minimum of at least 12 higher dimensional axis that exist as higher ordered planes or dimensions as opposed to compacted and curled dimensions
High Hyperversal
In mathematics, there's an idea called Infinite-Dimensional "Hilbert Space" that proposes a countably infinite number of higher dimensions can possibly exist. In literary terms, an Infinite-Dimensional Hilbert Space is the highest level of countable infinite itself and the only thing larger than it is an uncountably infinite amount of dimensions, which would correlate to Low 1-A on this wiki, which means any structure that is just atop of the structure would be considered just another level atop of the countable infinite
Note: The term that's used for this wiki is not found in any other notable work. More often than not, what we define as a "Hyperverse" would be usually described as a universe or multiverse within the retrospective work itself. As long as a cosmology has beyond 11 higher dimensional axis, then it would qualify as a "Hyperverse" by our standard tiering system
- The term "Hyperversal" itself comes from "Hyper", which is theoretical science is used to describe something well beyond our normal level and "Verse" which usually means Universe, but can mean Multiverse even in some cases
Omniverse
Omniverse is a term that is coined by Marvel Comics and is defined all of fiction and reality combined. For our wiki purposes, Omniverse is treated as the total accumulation of all universes, multiverses and everything within a given cosmology. Outside of comics, this term is rarely used and what it can mean is dependent on context. Logically speaking, the definition defined in Marvel Comics is unachievable to any fictional character as all verses are restricted to influencing their own fictional continuity
Mark Gruenwald's Quasar series also defined a "Omniverse" as a infinite collection of multiverses, which is also relevant considering Mark is proposed to have been the one who originally created the term in the first place, meaning this definition can also be just as applicable if one were to assume a "baseline" for what a "Omniverse" is when mentioned in the context of another fictional universe
The definition defined in Mark Gruenwald's Quasar is also notably followed by Chris Claremont's New Exiles where it too is also defined as a collection of infinite multiverses. What this suggests is that an "Omniverse" has no fixed definition of what it can be and this even evident with Marvel itself, with Marvel also embracing this definition as well with their official sources
Types of Multiverse
Max Tegmark and Brian Greene have both proposed many different ideas for what a multiverse would consist of, with there being many levels to what a multiverse could be. This is often referred to as "The Four Levels of the Multiverse" in reference to level I – Beyond our Cosmic Universe, level II multiverse – Other Post Inflation Bubbles, level III – Quantum Many Worlds and level IV - Other mathematical structures
Level I - Beyond Our Cosmic Universe
This is the most basic level of a multiverse. This is the definition highlighted above, with a Level I multiverse containing an infinite amount of universes within it's structure and all universes just being deviations of each other with minimalistically differences and being distributed through quantum superposition and wave function collapse
As far as how the universes function themselves, the laws of physics are the same but due to their different initial conditions, they go through different histories. This means that whatever you can imagine happening, has happened in another universe or could potentially happen under the pretense there's a universe in which that event occurred
Under our system, this would be essentially a 2-A multiverse on the basis that it's a collection of countably infinite amount of Universal Space-Time Continuums. This is considered the textbook definition of what 2-A is as defined on the tiering system
Level II - Other Post Inflation Bubbles
This type of multiverse functions as similarly to a Level I multiverse but there are major differences. Separate universes spring up like bubbles of space-time and essentially undergo its own form of expansion under the laws of inflation theory. This means that laws of physics can potentially vary between different universes and in drastically deviating forms
Similarly to a Level 1 Multiverse, this would also be a 2-A multiverse on a similar basis but can potentially extend to higher levels of 2-A through expansion and other scenarios that would allow it to be arguably "bigger" than 2-A
Level III - Quantum Many Worlds
This variation of a multiverse operates under the principles of quantum physics, proposing that events unfold in every single possible way and they manifest as different, parallel universes. Science fiction tends to utilize this model of multiverse as "alternate history" stories, being the most well-known variation of a multiverse outside of physics
Similarly to both a Level 1 and a Level 2 Multiverse, this would also be a 2-A multiverse on a similar basis but can potentially extend to higher levels of 2-A or even potentially reach into the High 1-B tiering depending on what structures are noting to exist, such as Infinite Dimensional Hilbert Space, which is would qualify for such tier due to being the textbook definition of High 1-B under the tiering system
Level IV - Other Mathematical Structures
This is the ultimate variation of a multiverse, often being called the "Ultimate Ensemble Multiverse" in reference to the idea that it contains all mathematical structures envisioned in all fields and it proposes that all of reality is governed by mathematical equations as structures to allow all possible universes that can be possibly created to exist in tandem.
As Max Tegmark proposes:
| “ | Abstract mathematics is so general that any Theory Of Everything (TOE) which is definable in purely formal terms (independent of vague human terminology) is also a mathematical structure. For instance, a TOE involving a set of different types of entities (denoted by words, say) and relations between them (denoted by additional words) is nothing but what mathematicians call a set-theoretical model, and one can generally find a formal system that it is a model of. | „ |
He argues that all mathematical sets, equations and so on would have a formal system in which exist in and thus the basis for an Ultimate Ensemble Multiverse, which is also explained Andrew Liddle in a way that fully explains the implications of what a Ultimate Ensemble Multiverse:
| “ | The culmination that Tegmark seeks to lead us to is the “Level IV multiverse”. This level contends that the Universe is not just well described by mathematics, but, in fact, is mathematics. All possible mathematical structures have a physical existence, and collectively, give a multiverse that subsumes all others. Here, Tegmark is taking us well beyond accepted viewpoints, advocating his personal vision for explaining the Universe. | „ |
What this all means is that an Ultimate Ensemble multiverse can potentially range in terms of where it scales, with where it sits depending on the context of the verse, what structures are noted to exist and many other factors. At the bare minimum, a Ultimate Ensemble Multiverse would be Low 1-A but can potentially extend into higher tiers such as 1-A or even 1-A α if there's enough evidence to suggest such warranty of a tier