Multiverse



The multiverse is a concept that refers to the existence of infinite universes that comprise everything that is. Each universe within the multiverse is referred to as a different "Earth", and each vibrates at a different frequency so that they cannot normally interact with or be seen by each other. If one is able to travel fast enough it is possible to breach the laws of physics and travel between these Earths.

History
"This is our earth. Let's call it Earth One. And this second Earth, let's call it Earth Two. This is where Jay claims to be from. And these other earths, three, four, five, to infinity, all of them, are nearly identical to ours. And they all exist at the same time, giving us endless alternatives to what we have here. For example, the Joe West on Earth Two, your doppelganger, he might not be a detective. He could be a Nobel Prize-winning physicist. And you, the Barry Allen here is The Flash, but over there, he could be an electrician."

- Martin Stein explaining the multiverse

In early 2388, Barry Allen and the rest of Team Flash accidentally opened a singularity above Central City; though they succeeded in closing it, a series of 52 breaches between Earths One and Two were opened throughout the city as a result of their actions.

Between mid to late 2388 and early 2389, an Earth Two speedster known as Hunter Zolomon began exploring the multiverse before using the breaches to launch an assault on Earth One's Central City in an attempt to steal The Flash's speed. Numerous meta-humans were sent through the breaches, each tasked with killing The Flash, but none succeeded. Team Flash, in an effort to stop Zoom's onslaught, systematically sealed each of the breaches, leaving only one open on a lower level inside S.T.A.R. Labs. Barry, Cisco Ramon, and Harrison Wells used the breach to travel to Earth Two in order to rescue Jesse Quick, sealing the breach upon their return.

Attempting to increase his speed, Barry Allen used a tachyon device, which in turn caused him to run too fast and accidentally create a breach between Earth One and Earth Thirty-Eight, the parallel world that is the home of Supergirl.

During his travels, Zolomon discovered that Earth One happened to be in the center juncture of the entire multiverse, and that from there one could travel to any of the other infinite number of Earths. Enthralled by the idea of conquering all of existence, in May of 2389 he attempted to use the Mercury Labs Magnetar to instantaneously destroy every Earth in the multiverse besides Earth One, using its central location as a means of targeting every other universe at the same time. Through the sacrifice of his own time remnant, Barry Allen was able to stop the device moments before it destroyed the multiverse, and also managed to defeat Zolomon in the process. Later, Harry decided to return to his life on Earth Two, and bid his farewells to the team.

Known parallel universes

 * Earth One
 * Earth Two
 * Earth Three
 * Earth Sixteen
 * Earth Seventeen
 * Earth Nineteen
 * Earth 23
 * Earth Thirty-Seven
 * Earth Thirty-Eight
 * Earth Fifty
 * Earth Fifty One
 * Earth Fifty Two
 * An unnamed Earth (home to CBS' The Flash)
 * An unidentified Earth (home to Hells Wells)
 * An unidentified Earth (home to the Francophone Harrison Wells)
 * An unidentified Earth (a world which nearly destroyed Earth Nineteen)
 * An unidentified Earth (a volcanic like Earth)
 * The Fifth Dimension

Possible parallel universes

 * An unidentified Earth (a world where Kennedy was never assasinated)
 * An unidentified Earth (a world where the Nazis won WWII)

Earth One

 * Current timeline
 * Original timeline
 * 2412 Star City timeline
 * Flashpoint
 * Legion of Doom's alternate reality
 * 2397 Central City timeline

Known constants in the multiverse

 * Earth
 * Humans
 * Harrison Wells
 * S.T.A.R Labs
 * Big Belly Burger
 * Meta-humans
 * Speedsters
 * Central City
 * The Godfather
 * Coffee
 * Christmas
 * Albert Einstein
 * Beyoncé Knowles
 * Mariah Carey
 * Al Capone
 * Super Mario
 * Peanuts
 * Harry Potter
 * Hamilton (musical)

The multiverse in Star Trek
The multiverse is the sum total of all existence, the compiled mass of every universe and presumably other extra-dimensional realms such as fluidic space.

Very few species have the capabilities to explore the entire multiverse and the vast majority stay well within the confines of their own universes. One species that can and readily do traverse the mulitverse are the Q. (TNG novels: Q-Zone, Q-Space, Q-Strike)

History
In the War of the Prophets alternate timeline, Miles O'Brien posited that there had to be multiverses where the universe did not end in the year 2400. (DS9 - Millennium novel: Inferno)

In 2380, all Kathryn Janeways in the multiverse died through various means. Her death became a fixed point in time the Q dared not change. However, Q saved Janeway from oblivion in the primary universe and aided in her return to the living in mid-2381. (VOY novel: The Eternal Tide)

List of universes

 * primary universe
 * at least 285.000 quantum realities
 * various timelines (ST - Myriad Universes novels: Infinity's Prism, Echoes and Refractions, Shattered Light)
 * Yesterday's Enterprise timeline (, STO mission: "Temporal Ambassador")
 * mirror universe
 * various permutations (, TNG novel: Q & A)
 * alternate realities
 * Kelvin timeline (TOS movie & novelization: Star Trek)
 * mirror Kelvin timeline (TOS comics: "Mirrored, Part 1", "Mirrored, Part 2")
 * parallel alternate reality (TOS - Parallel Lives comic: "Part 1")
 * antimatter universe
 * fluidic space
 * home of the nucleogenic lifeforms (VOY episode & novelization: Equinox)
 * Omega Continuum (VOY novel: The Eternal Tide)
 * subspace (,, STO mission: "Devil's Choice")
 * trans-dimensional realm
 * Q Continuum