(This intermission is all about what people from Earth think about the Multiverse. All words that have been written here are real, so don't doubt their credibilty.)
The multiverse, also known as a maniverse, megaverse, metaverse, omniverse, or meta-universe, is a hypothetical group of multiple universes.
Together, these universes comprise everything that exists: the entirety of space, time, matter, energy, information, and the physical laws and constants that describe them.
The different universes within the multiverse are called "parallel universes", "other universes", "alternate universes", or "alterverses".
***********
Multiple universes have been hypothesized in cosmology, physics, astronomy, religion, philosophy, transpersonal psychology, music and all kinds of literature, particularly in science fiction, comic books and fantasy.
Laszlo, Ervin (2003). The Cennectivity Hypothesis: Fountations of an Integral Science of Quantum, Cosmos, Life, and Consciousness, p.108. State University of New York Press, Albany. ISBN 0791457850
"Planck reveals an almost perfect Universe".
"Space in Images".
"Multiple universes".
"Multiple universes principle".
"Multiverses: Do Other Universes Exist?".
"Split the Universe".
"Hidden Portals in Earth's Magnetic Field".
"Erwin Schrödinger and the Quantum Revolution by John Gribbin: review".
James, William, The Will to Believe, 1895; and earlier in 1895, as cited in OED's new 2003 entry for "multiverse": James, William (October 1895), "Is Life Worth Living?", Internat. JRNL. Ethics, 6: 10, doi:10.1086/205378, Visible nature is all plasticity and indifference, a multiverse, as one might call it, and not a universe.
Kragh, H. (2009). "Contemporary History of Cosmology and the Controversy over the Multiverse". Annals of Science. 66 (4): 529–551. doi:10.1080/00033790903047725.
Ellis, Georg; Silk, Joe (16 December 2014). "Scientific Method: Defend the Integrity of Physics". Nature. 516 (7531): 321–323. Bibcode:2014Natur.516..321E. doi:10.1038/516321a. PMID 25519115.
"Feynman on Scientific Method". YouTube. Retrieved 28 July 2012.
Davies, Paul (12 April 2003). "A Brief History of the Multiverse". New York Times. Retrieved 16 August 2011.
Ellis, George F. R. (1 August 2011). "Does the Multiverse Really Exist?". Scientific American. Vol. 305 no. 2. New York City: Nature Publishing Group. pp. 38–43. Bibcode:2011SciAm.305a..38E. doi:10.1038/scientificamerican0811-38. ISSN 0036-8733. LCCN 04017574. OCLC 828582568. Retrieved 16 August 2011.
Tegmark, Max (May 2003). "Parallel Universes". Scientific American. Vol. 288. pp. 40–51. arXiv:astro-ph/0302131. Bibcode:2003SciAm.288e..40T. doi:10.1038/scientificamerican0503-40. PMID 12701329.
Tegmark, Max (23 January 2003). Parallel Universes (PDF). Retrieved 7 February 2006.
"Parallel universes. Not just a staple of science fiction, other universes are a direct implication of cosmological observations.", Tegmark M., Sci Am. 2003 May;288(5):40–51.
"First Second of the Big Bang". How The Universe Works 3. 2014. Discovery Science.
Nomura, Yasunori; Johnson, Matthew C.; Mortlock, Daniel J.; Peiris, Hiranya V. (2012). "Static quantum multiverse". Physical Review D. 86 (8): 083505. arXiv:1205.5550. Bibcode:2012PhRvD..86h3505N. doi:10.1103/PhysRevD.86.083505.
Tegmark, Max (2014). Our Mathematical Universe: My Quest for the Ultimate Nature of Reality. Knopf Doubleday Publishing Group. ISBN 9780307599803.
J. Schmidhuber (1997): A Computer Scientist's View of Life, the Universe, and Everything. Lecture Notes in Computer Science, pp. 201–208, Springer: IDSIA – Dalle Molle Institute for Artificial Intelligence
Schmidhuber, Juergen (2000). "Algorithmic Theories of Everything". Sections In: Hierarchies of Generalized Kolmogorov Complexities and Nonenumerable Universal Measures Computable in the Limit. International Journal of Foundations of Computer Science ():587-612 (2002). Section 6 In: The Speed Prior: A New Simplicity Measure Yielding Near-Optimal Computable Predictions. In J. Kivinen and R. H. Sloan, Editors, Proceedings of the 15th Annual Conference on Computational Learning Theory(COLT 2002), Sydney, Australia, Lecture Notes in Artificial Intelligence, Pages 216-228. Springer, 2002. 13 (4): 1–5. arXiv:quant-ph/0011122. Bibcode:2000quant.ph.11122S.