Multiverse
The multiverse is the set of all universes, and an alternate reality — equally called an alternate universe or parallel universe — is one member of that set. The vocabulary is unstable on both sides of the physics: the Stanford Encyclopedia of Philosophy entry on the many-worlds interpretation notes that Everett's "branch" is "world" in its usage, that "world" is "universe" in Deutsch, and that "universe" is "multiverse." Named cosmologists and physicists publishing in peer-reviewed venues affirm the multiverse and others reject it, so its standing is an open dispute among specialists. A large body of contactee, insider and channeled literature goes further and treats other realities as experientially real and traversable, and describes the reported acts of moving between them as Inter-reality travel and reality shifting. Corey Goode relays a confirmation that the Mandela Effect is real and tied to merging timelines, and Jason Reza Jorjani offers it as an empirical precondition for a history that time travellers can overwrite. That traversability is where this literature parts from the physics, in which the branches of the many-worlds interpretation are dynamically decoupled from one another.
Two things are called a "dimension" in this literature and are best held apart. A reality is a member of the multiverse and lies beside other realities; a density or plane is a level within a reality. The neighbouring concept of alternate timelines concerns a branch of history rather than a coexisting universe, and the simulation hypothesis concerns the reading on which the members are computed.
Vocabulary
The members of the multiverse are called worlds or universes in the physics literature, with "multiverse" used for the whole. In the contactee literature the phrase is "alternate reality" in one witness's words and "fixed timelines" in another's. Arkheim Ra describes being taken to "an alternate reality" through jump gates, and elsewhere in the same interview calls a branch in which Hillary Clinton was president a "timeline."
The same vocabulary split runs through the other accounts. Dan Burisch, describing Project Looking Glass, speaks of going "in two different directions at the same time" and of the "path" a probability took, not of realities. Swaruu of Erra speaks of fixed "timelines" and of frequency "addresses," each a specific still image on the film reel. David Icke describes a "simulation field" of frequency information that the five senses pick up and that "the brain decodes... into a sense of reality." Elena Danaan relays Thor Han Eredyon's description of the Koldasii as long-standing residents of the solar system who have always been there "in a parallel dimensional plane." Of these, Arkheim Ra alone is quoted using the phrase "alternate reality," and in the same interview he uses "reality" and "timeline" for the same class of experience.
The multiverse in physics
The concept has several independent routes in physics. Tegmark sorts them into four levels: regions of space beyond the horizon of the observable universe (Level I), regions with different physical constants produced by eternal inflation or a string-theory landscape (Level II), the branches of the many-worlds interpretation of quantum mechanics (Level III), and every mathematically consistent structure (Level IV).
- Inflation and the landscape. Alan Guth describes eternal inflation as producing "pocket universes," Andrei Linde argues for the multiverse from inflationary cosmology, and Bousso and Polchinski derived a large "discretuum" of string vacua from four-form fluxes. Leonard Susskind draws the anthropic conclusion from that landscape.
- The many-worlds interpretation. Hugh Everett III's relative-state formulation of quantum mechanics is read by David Deutsch as a multiverse in which the branches are physically real, and Sean Carroll and David Wallace defend it as the straightforward reading of quantum theory.
Whether the multiverse can be tested
George Ellis and Joe Silk hold that multiverse proposals slide away from empirical testing and that the practice of physics is being bent to accommodate them. Ellis, Kirchner and Stoeger had earlier argued that the physical cosmology supporting a multiverse cannot be observationally established, and Ellis wrote in Scientific American in 2011 that "I do not believe the existence of those other universes has been proved—or ever could be." In 2017 Paul Steinhardt, an original architect of inflation, joined Anna Ijjas and Abraham Loeb in Scientific American to argue that inflationary cosmology "cannot be evaluated using the scientific method"; a reply signed by Guth, David Kaiser, Linde and Yasunori Nomura, with other cosmologists, disputed the charge.
Many-worlds itself is a respectable minority position and not the consensus: six of the 33 participants in a 2013 poll at a conference on quantum foundations endorsed it (about 18%), and 15% of more than 1,100 respondents to a 2025 Nature survey selected it, against 36% for the Copenhagen interpretation and 7% for Bohmian mechanics. Single-world alternatives — Bohmian mechanics, objective-collapse theories, relational quantum mechanics and QBism — remain in the peer-reviewed literature.
Two axes: across and up
The literature that speaks of multiple realities uses "dimension" for two different things.
| Axis | What it orders | An alternate reality is... | Sources that use it |
|---|---|---|---|
| Lateral (multiverse) | Universes or realities coexisting beside one another | a member of the set | Tegmark, Deutsch, Wallace, Mensky; Swaruu on parallel fixed timelines[5] |
| Vertical (density or plane) | Levels of vibration or consciousness within a reality | not the same thing; a reality contains the levels | the Law of One material on densities[29]; Swaruu on numbered densities[30]; the Michael Teachings on the seven planes[9] |
The Michael Teachings describe the seven planes as layers of one universe and state that "the Tao has created many universes, or overall experiments," adding "(I am not speaking here of parallel universes)." The Law of One material sets out densities as successive levels of conscious evolution, and Swaruu calls the numbered densities concepts humans came up with in an attempt to understand something bigger than themselves. The interdimensional and ultraterrestrial accounts of beings carry their own vocabulary for the vertical axis.
Traversal
Michael Mensky of the Lebedev Physical Institute proposed, in a peer-reviewed physics paper, an Extended Everett Concept in which the separation of the alternatives is identified with consciousness, so that consciousness "at the edge" — in sleep or trance — gains access to "other alternative classical realities" (other Everett's worlds). The theory both affirms a multiverse and holds that reports of unusual experience are consistent with it.
The reports themselves come from other quarters. Swaruu of Erra describes uncountable parallel fixed timelines, each a written "film reel," between which a person jumps by decision and by shifts of frequency, with the lines to one side progressively lower in frequency and those to the other progressively higher. Dan Burisch, discussing Project Looking Glass, describes going "in two different directions at the same time," with the path decided by the direction one looks, and Arkheim Ra describes being taken through jump gates to an alternate reality. Timeline branching carries these accounts in full, and Inter-reality travel carries the reported means of crossing.
Open questions
References
Source ratings:
(
[1 Wikipedia-grade]
·
[2 Questionable]
·
[3 Reporting/Analysis]
·
[4 Speculative/Hearsay]
·
[5 Ungrounded]
). (To change source ratings,
edit this page
.)