Editing Multiverse (section)

=== Brian Greene's nine types ===
{{anchor|Brian Greene's nine types of multiverses}}The American [[theoretical physicist]] and [[Super-string theory|string theorist]] [[Brian Greene]] discussed nine types of multiverses:<ref>Greene, Brian. ''[[The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos]]'', 2011.</ref>

;Quilted
:The quilted multiverse works only in an [[infinity|infinite]] universe. With an infinite amount of space, every possible event will occur an infinite number of times. However, the speed of light prevents us from being aware of these other identical areas.

;Inflationary
:The [[Eternal inflation|inflationary multiverse]] is composed of various pockets in which inflation fields collapse and form new universes.
[[File:Brane theory.ogg|thumb|upright=1.6|Animation showing the multiple brane universes in the bulk]]
;Brane
:The [[Brane cosmology|brane multiverse]] version postulates that our entire universe exists on a membrane ([[brane]]) which floats in a higher dimension or "bulk". In this bulk, there are other membranes with their own universes. These universes can interact with one another, and when they collide, the violence and energy produced is more than enough to give rise to a [[Big Bang]]. The branes float or drift near each other in the bulk, and every few trillion years, attracted by gravity or some other force we do not understand, collide and bang into each other. This repeated contact gives rise to multiple or "cyclic" [[Big Bang|Big Bangs]]. This particular hypothesis falls under the string theory umbrella as it requires extra spatial dimensions.
[[File:Cosmos-animation Friedmann-closed.gif|thumb|upright=0.8|Cosmos animation of a cyclic universe]]
;Cyclic
:The [[cyclic model|cyclic multiverse]] has multiple [[brane]]s that have collided, causing [[Big Bang]]s. The universes bounce back and pass through time until they are pulled back together and again collide, destroying the old contents and creating them anew.

;Landscape
:The [[String theory landscape|landscape multiverse]] relies on string theory's [[Calabi–Yau manifold|Calabi–Yau]] spaces. Quantum fluctuations drop the shapes to a lower energy level, creating a pocket with a set of laws different from that of the surrounding space.

;Quantum
:The [[Many-worlds interpretation|quantum multiverse]] creates a new universe when a diversion in events occurs, as in the real-worlds variant of the [[many-worlds interpretation]] of quantum mechanics.

;Holographic
:The [[Holographic principle|holographic multiverse]] is derived from the theory that the surface area of a space can encode the contents of the volume of the region.

;Simulated
:The [[Simulated reality|simulated multiverse]] exists on complex computer systems that simulate entire universes. A related hypothesis, as put forward as a possibility by astronomer [[Avi Loeb]], is that universes may be creatable in laboratories of advanced technological civilizations who have a [[theory of everything]].<ref>{{cite web |last1=Loeb |first1=Avi |title=Was Our Universe Created in a Laboratory? |url=https://www.scientificamerican.com/article/was-our-universe-created-in-a-laboratory/ |website=Scientific American |date=December 2021 |access-date=12 July 2022 |language=en}}</ref> Other related hypotheses include [[brain in a vat]]<ref>{{cite web |title=What if we're living in a computer simulation? |url=https://www.theguardian.com/technology/2017/apr/22/what-if-were-living-in-a-computer-simulation-the-matrix-elon-musk |work=The Guardian |access-date=12 July 2022 |language=en |date=22 April 2017}}</ref>-type scenarios where the perceived universe is either simulated in a low-resource way or not perceived directly by the virtual/simulated inhabitant species.{{additional citation needed|date=July 2022}}

;Ultimate
:The [[Mathematical universe hypothesis|ultimate multiverse]] contains every mathematically possible universe under different laws of physics.