NationMaster - Encyclopedia: Multiverse (science)

A multiverse (or meta-universe) is the hypothetical set of multiple possible universes (including our universe) that together comprise all of physical reality. The different universes within a multiverse are called parallel universes. The structure of the multiverse, the nature of each universe within it and the relationship between the various constituent universes, depend on the specific multiverse hypothesis considered. Universe is a word derived from the Old French univers, which in turn comes from the Latin roots unus (one) and versus (a form of vertere, to turn). Based on observations of the observable universe, physicists attempt to describe the whole of space-time, including all matter and energy and... Reality in everyday usage means the state of things as they actually exist. ... Parallel universe or alternate reality in science fiction and fantasy is a self-contained separate reality coexisting with our own. ...

Multiverses have been hypothesized in cosmology, physics, philosophy, theology, and fiction, particularly in science fiction and fantasy. The specific term "multiverse", which was originally coined by William James, was popularized by science fiction author Michael Moorcock. In these contexts, parallel universes are also called "alternate universes", "quantum universes", "parallel worlds", or "alternate realities". Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Fantasy is a genre of art that uses magic and other supernatural forms as a primary element of plot, theme, or setting. ... For other people named William James see William James (disambiguation) William James (January 11, 1842 â€“ August 26, 1910) was a pioneering American psychologist and philosopher. ... Michael John Moorcock (born December 18, 1939) is a prolific English writer primarily of science fiction and fantasy who has also published a number of literary novels. ...

The possibility of many universes raises various scientific, philosophical, and theological questions.

Multiverse hypotheses in physics

Classification

According to Max Tegmark,^[1] the existence of other universes is a direct implication of cosmological observations. Tegmark describes the set of related concepts which share the notion that there are universes beyond the familiar observable one, and goes on to provide a taxonomy of parallel universes organized by levels.^[2] In order to clarify terminology, George Ellis, U. Kirchner and W.R. Stoeger recommend using the term "the Universe" for the theoretical model of the whole of the causally connected space-time in which we live, universe domain for the observable universe or a similar part of the same space-time, "universe" for a general space-time, either our own "Universe" or another one disconnected from our own, multiverse for a set of disconnected space-times, and multi-domain universe to refer to a model of the whole of a single connected space-time in the sense of chaotic inflation models.^[3] Max Tegmark Max Tegmark born 1967 in Sweden to Karin Tegmark and Harold S Shapiro, is a cosmologist formerly at the University of Pennsylvania and now at the Massachusetts Institute of Technology as an Associate Professor. ... George Ellis is the Distinguished Professor of Complex Systems at the University of Cape Town (South Africa), in the Department of Mathematics and Applied Mathematics. ... A MÃ¶bius strip, a surface with only one side and one edge; such shapes are an object of study in topology. ... In mathematics, a set can be thought of as any collection of distinct things considered as a whole. ... The theory created by Andrei Linde that states that our universe could have come from nothing more than hundred-thousandth of a gram of matter. ...

The levels according to Tegmark's classification and using Ellis, Koechner and Stoeger's terminology are briefly described below.

Multi-domain universes (Ellis, Koechner and Stoeger sense):

Level I: (Open multiverse) A generic prediction of cosmic inflation is an infinite ergodic universe, which, being infinite, must contain Hubble volumes realizing all initial conditions - including an identical copy of a given person about $10^{10^{29}}$ meters away. In physical cosmology, cosmic inflation is the idea that the nascent universe passed through a phase of exponential expansion that was driven by a negative-pressure vacuum energy density. ... This article or section is not written in the formal tone expected of an encyclopedia article. ... In physics and thermodynamics, the ergodic hypothesis says that, over long periods of time, the time spent in some region of the phase space of microstates with the same energy is proportional to the volume of this region, i. ... A Hubble volume refers to a volume of space, usually defined as a cube where each axis is approximately 13. ...

Level II: (Andrei Linde's bubble theory) In chaotic inflation, other thermalized regions may have different effective physical constants, dimensionality and particle content. (Surprisingly, this level includes Wheeler's oscillating universe theory as well.) Andrei Linde is an American physicist and professor of Physics at Californias Stanford University. ... The bubble universe model is a variant of the inflationary model of the big bang. ... The theory created by Andrei Linde that states that our universe could have come from nothing more than hundred-thousandth of a gram of matter. ... // ... The oscillatory universe is the hypothesis, attributable to Richard Tolman, that the universe undergoes an infinite series of oscillations, each beginning with a big bang and ending with a big crunch. ...

Multiverses (Ellis, Koechner and Stoeger sense)

Level III: (Hugh Everett III's many-worlds interpretation) An interpretation of quantum mechanics that proposes the existence of multiple universes, all of which are "identical", but exist in possibly different states. It is widely believed that Everett's interpretation (considered as a formal theory) is a conservative extension of standard quantum mechanics -- that is, as far as results expressible in the language of ordinary quantum mechanics is concerned, it leads to no new results. This, according to Tegmark, "is ironic given that this level has historically been the most controversial". Hugh Everett III (November 11, 1930 â€“ July 19, 1982) was an American physicist who first proposed the many-worlds interpretation of quantum physics, which he called his relative state formulation. ... The many-worlds interpretation of quantum mechanics or MWI (also known as the relative state formulation, theory of the universal wavefunction, many-universes interpretation, Oxford interpretation or many worlds), is an interpretation of quantum mechanics that claims to resolve all the paradoxes of quantum theory by allowing every possible outcome... Fig. ... // Definition A logical theory T2 is a conservative extension of theory T1 if any consequence of T2 involving symbols of T1 only is already a consequence of T1. ...

Level IV: (The ultimate "Ensemble theory" of Tegmark) Other mathematical structures give different fundamental equations of physics. This level considers "real" any hypothetical universe based on one of these structures. M-theory might be placed here. Since this subsumes all other possible ensembles, it brings closure to the hierarchy of multiverses: there cannot be a Level V. The Ultimate Ensemble is a speculative possible feature of theories of everything (TOEs), suggested by Max Tegmark. ... M-theory is a solution proposed for the unknown theory of everything which would combine all five superstring theories and 11-dimensional supergravity together. ...

Open multiverse

Some physicists believe that the universe is spatially unbounded. The theory of relativity places a firm upper limit on the speed at which information can travel, effectively dividing this infinite space into "local" universes. Our observable universe, for example, is a sphere centered on the Earth (centered, that is, on whoever's doing the calculating), currently about 46.5 billion light years in radius, called the Hubble volume. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Two-dimensional analogy of space-time distortion described in General Relativity. ... The observable Universe is a term used in cosmology to describe a ball-shaped region of space surrounding the Earth that is close enough that we might observe objects in it. ... A light-year or lightyear (symbol: ly) is a unit of measurement of length, specifically the distance light travels in vacuum in one Julian year. ... A Hubble volume refers to a volume of space, usually defined as a cube where each axis is approximately 13. ...

Thus, there are an infinite number of regions of space the same size as our observable universe -- an infinite number of observable universes, that is. This infinite set (which must contain, among other things, an infinite number of identical copies of you,^[4] the nearest of which is about $10^{10^{29}}$ meters away, and an equally infinite number of not-quite-identical copies) comprises the level-I multiverse. By the Bekenstein bound there are only a finite number of configuration possible within any region, hence exact duplication is possible. Space has been an interest for philosophers and scientists for much of human history. ... The observable Universe is a term used in cosmology to describe a ball-shaped region of space surrounding the Earth that is close enough that we might observe objects in it. ... In set theory, an infinite set is a set that is not a finite set. ... In physics, the Bekenstein bound imposes a limit on the entropy S or information that can be contained within a three-dimensional volume. ...

Overtly or not, physicists often use the idea of an Open Multiverse when evaluating theories. For example, Max Tegmark writes: Max Tegmark Max Tegmark born 1967 in Sweden to Karin Tegmark and Harold S Shapiro, is a cosmologist formerly at the University of Pennsylvania and now at the Massachusetts Institute of Technology as an Associate Professor. ...

Bubble theory

Bubble theory posits an infinite number of open multiverses, each with different physical constants. (The set of bubble universes is thus a Level II multiverse.) Counterintuitively, these universes are farther away than even the farthest universe in our open multiverse, which is itself infinitely far from us. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... // ...

The formation of our universe from a "bubble" of a multiverse was proposed by Andre Linde. This Bubble universe theory fits well with the widely accepted theory of inflation. The bubble universe concept involves creation of universes from the quantum foam of a "parent universe." On very small scales, the foam is frothing due to energy fluctuations. These fluctuations may create tiny bubbles and wormholes. If the energy fluctuation is not very large, a tiny bubble universe may form, experience some expansion like an inflating balloon, and then contract and disappear from existence. However, if the energy fluctuation is greater than a particular critical value, a tiny bubble universe forms from the parent universe, experiences long-term expansion, and allows matter and large-scale galactic structures to form. Andrei Linde is an American physicist and professor of Physics at Californias Stanford University. ... The bubble universe model is a variant of the inflationary model of the big bang. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Analogy to a wormhole in a curved 2D space (see Embedding Diagram) Artists impression of a wormhole as seen by an observer crossing the event horizon of a Schwarzschild wormhole, which is similar to a Schwarzschild black hole but with the singularity replaced by an unstable path to a...

Big bounce

According to some quantum loop gravity theorists, the Big Bang was merely the beginning of a period of expansion that followed a period of contraction. In this oscillatory universe hypothesis (originally attributable to John Wheeler), the universe undergoes an infinite series of oscillations, each beginning with a big bang and ending with a big crunch. After the big bang, the universe expands for a while before the gravitational attraction of matter causes it to collapse back in and undergo a Big bounce. Although the model was abandoned for a time, the theory has been revived in brane cosmology as the cyclic model. Loop quantum gravity (LQG), also known as loop gravity and quantum geometry, is a proposed quantum theory of spacetime which attempts to reconcile the seemingly incompatible theories of quantum mechanics and general relativity. ... According to the Big Bang theory, the universe emerged from an extremely dense and hot state (singularity). ... The oscillatory universe is the hypothesis, attributable to Richard Tolman, that the universe undergoes an infinite series of oscillations, each beginning with a big bang and ending with a big crunch. ... John Archibald Wheeler (born July 9, 1911) is an eminent American theoretical physicist. ... In physical cosmology, the Big Crunch is the hypothesis that the universe will collapse upon itself after its expansion eventually stops â€” a counterpart to the Big Bang. ... According to one version of the Big Bang theory of cosmology, in the beginning the universe had infinite density. ... Brane cosmology is a protoscience motivated by, but not rigorously derived from, superstring theory and M-theory. ... The cyclic model is a brane cosmology model of the creation of the universe, derived from the earlier ekpyrotic model. ...

Many worlds interpretation of quantum physics

Hugh Everett's many-worlds interpretation (MWI) is one of several mainstream interpretations of quantum mechanics. Other interpretations include the Copenhagen and the consistent histories interpretations. The multiverse proposed by MWI has a shared time parameter. In most formulations, all the constituent universes are structurally identical to each other and though they have the same physical laws and values for the fundamental constants, they may exist in different states. The constituent universes are furthermore non-communicating, in the sense that no information can pass between them. The state of the entire multiverse is related to the states of the constituent universes by quantum superposition, and is described by a single universal wavefunction. Related are Richard Feynman's multiple histories interpretation and H. Dieter Zeh's many-minds interpretation. Hugh Everett III (November 11, 1930 â€“ July 19, 1982) was an American physicist who first proposed the many-worlds interpretation of quantum physics, which he called his relative state formulation. ... The many-worlds interpretation of quantum mechanics or MWI (also known as the relative state formulation, theory of the universal wavefunction, many-universes interpretation, Oxford interpretation or many worlds), is an interpretation of quantum mechanics that claims to resolve all the paradoxes of quantum theory by allowing every possible outcome... It has been suggested that Quantum mechanics, philosophy and controversy be merged into this article or section. ... The Copenhagen interpretation is an interpretation of quantum mechanics formulated by Niels Bohr and Werner Heisenberg while collaborating in Copenhagen around 1927. ... In quantum mechanics, the consistent histories approach is intended to give a modern interpretation of quantum mechanics, generalising the conventional Copenhagen interpretation and providing a natural interpretation of quantum cosmology. ... Quantum superposition is the application of the superposition principle to quantum mechanics. ... The Universal Wavefunction is a term introduced by Hugh Everett in his Princeton PhD Thesis[1], entitled The Theory of the Universal Wavefunction and forms a core concept in the relative state interpretation[2][3] or many-worlds interpretation[4][5] of quantum mechanics. ... Richard Phillips Feynman (May 11, 1918 â€“ February 15, 1988; surname pronounced ) was an American physicist known for expanding the theory of quantum electrodynamics, the physics of the superfluidity of supercooled liquid helium, and particle theory. ... The concept of multiple histories is closely related to the many-worlds interpretation of quantum mechanics. ... This article needs to be cleaned up to conform to a higher standard of quality. ... The many-minds interpretation of quantum mechanics extends the many-worlds interpretation by proposing that the distinction between worlds should be made at the level of the mind of an individual observer. ...

M-theory

A multiverse of a somewhat different kind has been envisaged within the 11-dimensional extension of string theory known as M-theory. In M-theory our universe and others are created by collisions between membranes in an 11-dimensional space. Unlike the universes in the "quantum multiverse", these universes can have completely different laws of physics—anything may be possible. Interaction in the subatomic world: world lines of pointlike particles in the Standard Model or a world sheet swept up by closed strings in string theory String theory is a model of fundamental physics whose building blocks are one-dimensional extended objects called strings, rather than the zero-dimensional point... M-theory is a solution proposed for the unknown theory of everything which would combine all five superstring theories and 11-dimensional supergravity together. ... The many-worlds interpretation of quantum mechanics or MWI (also known as the relative state formulation, theory of the universal wavefunction, many-universes interpretation, Oxford interpretation or many worlds), is an interpretation of quantum mechanics that claims to resolve all the paradoxes of quantum theory by allowing every possible outcome... Universe is a word derived from the Old French univers, which in turn comes from the Latin roots unus (one) and versus (a form of vertere, to turn). Based on observations of the observable universe, physicists attempt to describe the whole of space-time, including all matter and energy and...

String landscape

Another proposal for a multiverse in string theory has received considerable attention lately. It is called the string landscape and asserts that, roughly speaking, there are a very large number of ways to go from ten dimensional string theory down to the four-dimensional low-energy world we see, and each one of these corresponds to a radically different universe. The string theory landscape or anthropic landscape refers to the large number of different false vacua in string theory. ...

Criticisms of multiverse theories

It's not science.

Critics claim that these theories lack empirical correlation and testability, and without hard physical evidence are unfalsifiable; outside the methodology of scientific investigation to confirm or disprove; and therefore more mathematically theoretical and metaphysical than scientific in nature. In philosophy generally, empiricism is a theory of knowledge emphasizing the role of experience. ... This page is a candidate to be copied to Wiktionary. ... In science and the philosophy of science, falsifiability, contingency, and defeasibility are roughly equivalent terms referring to the property of empirical statements that they must admit of logical counterexamples. ... Scientific method is a body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting and integrating previous knowledge. ... Plato and Aristotle (right), by Raphael (Stanza della Segnatura, Rome). ...

Tegmark notes that improved measurements of the microwave background radiation and of the large-scale distribution of matter may fortify or knock down two pillars of the multiverse -- the infinitude of space and the theory of chaotic inflation -- so at least part of the theory may be testable. However, chaotic inflation is not the only version of cosmic inflation that can lead naturally to the multiverse hypothesis, as "new inflation" is also eternal and offers a scientific justification of the anthropic principle. Furthermore, not all models of inflation are eternal. In cosmology, the cosmic microwave background radiation (most often abbreviated CMB but occasionally CMBR, CBR or MBR, also referred as relic radiation) is a form of electromagnetic radiation discovered in 1965 that fills the entire universe. ... In physical cosmology, cosmic inflation is the idea that the nascent universe passed through a phase of exponential expansion that was driven by a negative-pressure vacuum energy density. ...

It’s bad science.

Some have argued that the job of the scientist is to provide fundamental explanations for observed phenomena, without making reference to observers. Resorting to anthropic principles constitutes a "lazy way out" of accounting for features such as the apparent fine-tuning of parameters in relation to the existence of life.

Leonard Susskind claims, however, that some form of multiverse is unavoidable, given the current state of physics, and that observer effects are inevitable and have to be taken into account in other sciences. Lenny Susskind at Stanford University Leonard Susskind is a theoretical physics professor at Stanford University in the field of string theory and quantum field theory. ...

Alternate universes violate Occam's Razor.

To postulate an infinity of unseen and unseeable universes just to explain the one we do see seems like a case of excess baggage carried to the extreme.

Tegmark answers:"A common feature of all four multiverse levels is that the simplest and arguably most elegant theory involves parallel universes by default. To deny the existence of those universes, one needs to complicate the theory by adding experimentally unsupported processes and ad hoc postulates: finite space, wave function collapse and ontological asymmetry. Our judgment therefore comes down to which we find more wasteful and inelegant: many worlds or many words."^[5] Thus, according to Tegmark, paradoxically the multiverse scenario is more parsimonious than that of a single universe. In certain interpretations of quantum mechanics, wavefunction collapse is one of two processes by which quantum systems apparently evolve according to the laws of quantum mechanics. ...

There is only one possible universe.

It is sometimes argued that the observed universe is the unique possible universe, so that talk of “other” universes is ipso facto meaningless. Einstein raised this possibility when he wondered whether the universe could have been otherwise, or non-existent altogether. This possibility is also expressed in theories such as determinism and chaos theory. The hope is sometimes expressed that once a grand unified theory of everything is achieved, it will turn out to have a unique “solution” corresponding to the observed universe. Albert Einstein ( ) (March 14, 1879 â€“ April 18, 1955) was a German-born theoretical physicist who is widely considered to have been one of the greatest physicists of all time. ... Determinism is the philosophical proposition that every event, including human cognition, decision and action, is causally determined by an unbroken chain of prior occurrences. ... A plot of the trajectory Lorenz system for values r = 28, Ïƒ = 10, b = 8/3 In mathematics and physics, chaos theory describes the behavior of certain nonlinear dynamical systems that under certain conditions exhibit a phenomenon known as chaos. ... This article or section is in need of attention from an expert on the subject. ...

Measures of fine-tuning are meaningless.

The principle observational support for the multiverse hypothesis comes from the Anthropic Principle: the universe we observe is bio-friendly, or we would not be observing it. While this is a truism, when the sensitivity of biology to the form of the laws of physics and the cosmological initial conditions is considered, it has some apparent credence; but on the other hand, many key parameters of physics do not seem to be very strongly constrained by biology. In physics and cosmology, the anthropic principle is an umbrella term for various dissimilar attempts to explain the structure of the universe by way of coincidentally balanced features that are necessary and relevant to the existence on Earth of biochemistry, carbon-based life, and eventually human beings to observe such... A truism is a claim that is so obvious or self-evident as to be hardly worth mentioning, except as a reminder or as a rhetorical or literary device. ... This article or section does not cite its references or sources. ...

Another criticism of the fine-tuning argument is that, as far as we know, there could be a more fundamental law under which the parameters of physics must have the values they do: that the values of the various physical constants aren't really "tunable" and thus couldn't have been "set" to anything other than the values we find any more than the ratio of a circle's diameter to its circumference could be anything other than π. Thus, given such a law, it is not improbable that the known parameters of physics fall within the life-permitting range. Fine Tuning is the name of XM Satellite Radios eclectic music channel. ...

Multiverses merely shift the problem up one level.

Multiverse proponents are often vague about how the parameter values are selected across the defined ensemble. If there is a “law of laws” or meta-law describing how parameter values are assigned from one universe to the next, then we have only shifted the central problems of cosmology up one level, because we need to explain where the meta-law comes from. Moreover, the set of such meta-laws is infinite, so we have merely replaced the question “why this universe?” with “why this meta-law?”. There would seem to be little point in invoking an infinity of universes when it would be simpler to postulate a single universe with a single principle.

Tegmark maintains that in his extreme multiverse theory this problem is circumvented, because in that case all possible meta-laws (or all possible unified theories) are in force and describe really-existing multiverses. However, his ultimate ensemble is still restricted to mathematical (or mathematically describable) laws, processes and structures. If it is in any way possible for something non-mathematical to exist, his ensemble is not ultimate, and relies on a contingent meta-law law excluding the non-mathematical from actual existence. The Ultimate Ensemble is a speculative possible feature of theories of everything (TOEs), suggested by Max Tegmark. ...

The fake universe problem.

Most scientists are prepared to entertain the possibility of conscious machines, and some artificial intelligence advocates even claim we are not far from producing conscious computers. It is then but a small step to the point where the engineered conscious beings inhabit a simulated world. For such beings, their “fake” universe will appear indistinguishable from reality. So should we include these simulated universes in the ensemble that constitutes the multiverse? Is it meaningful to assign equal ontological status to our own, observed, universe and universes that are virtual? If it is not then is it meaningful to assign equal ontological status to our own, observed, universe and universes that can never be observed by any sentient being? Hondas humanoid robot AI redirects here. ... Digitalism may refer to: Digital philosophy Digitalism, a New Rave duo from Hamburg, Germany ... Simulated reality is the idea that reality could be simulated â€” usually computer-simulated â€” to a degree indistinguishable from true reality. ... In philosophy, ontology (from the Greek , genitive : of being (part. ...

Incidentally, this of course assumes that our observed universe is 'real' and not virtual; at least one philosopher, Nick Bostrom, has proposed that this may not be the case (for more information see Simulated reality, or the Simulation Argument page). Nick Bostrom (Boström in the original Swedish) is a philosopher at the University of Oxford, and known for his work on the anthropic principle. ... Simulated reality is the idea that reality could be simulated â€” usually computer-simulated â€” to a degree indistinguishable from true reality. ...

Why stop there?

The last objection to the existing multiverse theories is a challenge to the criteria for defining universes. In most multiverse theories, universes are labeled by laws of physics and initial conditions. It might be objected that these terms are narrow and chauvinistic; there may be criteria for categorization that lie completely beyond the scope of human comprehension. In mathematics, boundary conditions are imposed on the solutions of ordinary differential equations and partial differential equations, to fit the solutions to the actual problem. ...

Multiverse hypotheses in philosophy

Hindu universes

The concept of a multiverse was first expressed in ancient Hindu cosmology, in texts such as the Puranas. They expressed the idea of an infinite number of universes, each with its own gods, inhabitants and planets, and an infinite cycle of births, deaths, and rebirths of a universe, with each cycle lasting 8.4 billion years. The belief is too that the number of universes are infinite.^[6] // The Rig Veda describes the origin of the universe as: Then was not non-existence nor existence: there was no realm of air, no sky beyond it. ... Purana (Sanskrit: à¤ªà¥à¤°à¤¾à¤£ , meaning ancient or old) is the name of a genre (or a group of related genres) of Hinduism literature (as distinct from oral literature). ...

Anthropic principle

The concept of other universes has been proposed to explain why our universe seems to be fine-tuned for conscious life as we experience it. If there were a large number (possibly infinite) of different physical laws (or fundamental constants) in as many universes, some of these would have laws that were suitable for stars, planets and life to exist. The anthropic principle could then be applied to conclude that we would only consciously exist in those universes which were finely-tuned for our conscious existence. Thus, while the probability might be extremely small that there is life in most of the multiverses, this scarcity of life-supporting universes does not imply intelligent design as the only explanation of our existence. In physics and cosmology, the anthropic principle is an umbrella term for various dissimilar attempts to explain the structure of the universe by way of coincidentally balanced features that are necessary and relevant to the existence on Earth of biochemistry, carbon-based life, and eventually human beings to observe such... The deepest visible-light image of the cosmos. ... For other uses, see Life (disambiguation), Lives (disambiguation) or Living (disambiguation), Living Things (disambiguation). ... A teleological argument (or a design argument) is an argument for the existence of God or a creator based on perceived evidence of order, purpose, design and/or direction in nature. ...

The entire range of multiverse hypotheses, with specific emphasis on Hugh Everett's many-worlds interpretation, have been criticised by proponents of intelligent design. William Dembski in particular, derides it as inflating explanatory resources without evidence or warrant, and terms such concepts "inflatons".^[7] Intelligent design (ID) is the concept that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection. ... William Dembski Dr William Albert Bill Dembski (born July 18, 1960) is an American mathematician, philosopher and theologian known for advocating the controversial idea of intelligent design. ... The inflaton is the generic name of the unidentified scalar field (and its associated particle), that may be responsible for an episode of inflation in the very early universe. ...

Modal realism

Additionally, possible worlds are a way of explaining probability, hypothetical statements and the like, and some philosophers such as David Lewis believe that all possible worlds non-actually exist, and yet are just as real as the actual world (a position known as modal realism). This thesis is one of the central tenets of his book.^[8] In philosophy and logic, the concept of possible worlds is used to express modal claims. ... David Kellogg Lewis (September 28, 1941 â€“ October 14, 2001) is considered to have been one of the leading analytic philosophers of the latter half of the 20th century. ... Modal realism is the view, notably propounded by David Lewis, that possible worlds are as real as the actual world. ...

Trans-world identity issues

A metaphysical issue that crops up with multiverse schema that posit infinite identical copies of any given universe is that of the notion that there can be identical objects in different possible worlds.

The problem lies in the tension between classical notions of identity and quantum indeterminacy. In short, quantum reality does not allow classical - radically mechanical - 'identities' due to the Heisenberg Uncertainty Principle. However, in an infinite set of possible universes such a correspondence is presumed to exist. The question then becomes whether one can claim a distinction between entities that vary only in terms of some arbitrary dimensional metric in De Sitter space. In philosophy, identity is whatever makes an entity definable and recognizable, in terms of possessing a set of qualities or characteristics that distinguish it from entities of a different type. ... Quantum indeterminacy is the apparent necessary incompleteness in the description of a physical system, that has become one of the characteristics of the standard description of quantum physics. ... In quantum physics, the Heisenberg uncertainty principle is a mathematical limit on the accuracy with which it is possible to measure everything there is to know about a physical system. ... In mathematics and physics, n-dimensional de Sitter space, denoted , is the maximally symmetric, simply-connected, Lorentzian manifold with constant positive curvature. ...

Trans-world identity is also considered in depth in possible worlds concepts.^[9]^[10] The identity of indiscernibles is an ontological principle that states that if there is no way of telling two entities apart then they are one and the same entity. ... In quantum physics, a quantum fluctuation is the temporary change in the amount of energy in a point in space, arising from Werner Heisenbergs uncertainty principle. ... Hermeneutics may be described as the development and study of theories of the interpretation and understanding of texts. ... In philosophy and logic, the concept of possible worlds is used to express modal claims. ...

The simulation theory

Some recent philosophers, including Nick Bolstrom of the University of Oxford, have brought a somewhat different perspective to the idea of a "multiverse", that is based upon the hypothesis that the each multiverse's universe is a computer simulated reality, similar to a virtual reality, or in other words a metaverse. This theory is radically different than others related to the multiverse, as it is bringing back physical and astrophysical matters on their fundamental sensorial basis of perception; thus the universe being perceived only through senses and an intellectual interpretation of sensorial data, the universe as we are allowed to see it might very well be only an artificial filter, or screen, hiding a deeper, and perhaps more genuine universe beyond. In the multiverse, two or more simulated universes could be more or less linked together through a state transition system. Virtual reality (VR) is a technology which allows a user to interact with a computer-simulated environment, be it a real or imagined one. ... The Metaverse, a phrase coined by Neal Stephensons science fiction novel Snow Crash (1992) constitutes Stephensons vision of how a virtual reality-based Internet might evolve in the near future. ... In psychology and the cognitive sciences, perception is the process of acquiring, interpreting, selecting, and organizing sensory information. ... In theoretical computer science, a state transition system is an abstract machine used in the study of computation. ...

The facts that we can only perceive a particular spectrum of light, sound and smell of the universe, as well as the general physical paradox of the density of matter at microscopic levels are among the evidences brought in support of this theory. Moreover, the simulation theory is profoundly rooting the multiverse idea back to a fundamentally philosophical nature, and is therefore rejecting the scientific pretense of absolute knowledge of the universe without the recognition of subjective human perception. It is also regarded by some as providing a potential interpretation scheme for the understanding of the true nature of the mysterious "dark matter" that occupies a substantial space in the universe, leading to the idea that dark matter could be part of the unperceived multiverses existing beyond this very universe. In astrophysics and cosmology, dark matter is matter, not directly observed and of unknown composition, that does not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence can be inferred from gravitational effects on visible matter. ...

Fictional multiverses

The concept of the multiverse figures prominently in many science fiction and fantasy novels. For some it serves primarily as a plot device, a means to put characters into an unfamiliar situation, or a framework that usually lies in the background for continuity purposes. For others it is a major theme and focus of the work. It is sometimes used as the basis for exploring "what if" scenarios, such as in alternate history stories. The TV show Sliders from the 1990's first popularized the concept through the TV entertainment medium. The film The One (2002) starring Jet Li carried the same idea to the action film medium. The popular MYST computer game franchise uses concepts of describing a world and then linking to that world, which is part of a multiverse of infinite possible and concurrently existing universes, matching the descriptions. The Michael Crichton novel Timeline featured a method for what appeared to be time travel by traveling to parallel universes that are identical except for the moment of their birth, thus rendering off-set yet parallel time. Parallel universe or alternate reality in science fiction and fantasy is a self-contained separate reality coexisting with our own. ... Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Alternate history (fiction) - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... This article is about the sci-fi television show. ... The One can refer to several things: The Absolute The Downbeat is the first beat in the bar. ... Jet Li (born Li Lianjie on April 26, 1963 in Beijing, China) is a Chinese martial artist, actor and action star. ... Myst (or MYST) is a graphic adventure computer game designed and directed by the brothers Robyn and Rand Miller. ... John Michael Crichton (born October 23, 1942, pronounced [1]) is an American author, film producer, film director, and television producer. ... Timeline is a science fiction novel by Michael Crichton that was published in November 1999. ...

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