This article or section is in need of attention from an expert on the subject. WikiProject Physics or the Physics Portal may be able to help recruit one. If a more appropriate WikiProject or portal exists, please adjust this template accordingly. The Theory of Everything: The Origin and Fate of the Universe is a popular book disowned by Stephen Hawking although put together with material written by him. ... In philosophy, a theory of everything or TOE is an ultimate, all-encompassing explanation of nature or reality. ... Image File history File links Emblem-important. ...

Beyond the Standard Model

Standard Model Experimental evidence Hierarchy problem • Dark matter Cosmological constant problem Strong CP problem Neutrino oscillation Theories Kaluza–Klein theory Grand Unified Theory Theory of Everything String theory Supersymmetry MSSM • Superstring theory Supergravity Quantum gravity String theory Loop quantum gravity Canonical general relativity Detectors LHC • Super-K

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A theory of everything (TOE) is a hypothetical theory of theoretical physics that fully explains and links together all known physical phenomena. Initially, the term was used with an ironic connotation to refer to various overgeneralized theories. For example, a great-grandfather of Ijon Tichy — a character from a cycle of Stanisław Lem's science fiction stories of 1960s — was known to work on the "General Theory of Everything". Over time, the term stuck in popularizations of quantum physics to describe a theory that would unify or explain through a single model the theories of all fundamental interactions of nature. This article or section seems not to be written in the formal tone expected of an encyclopedia entry. ... Image File history File links No higher resolution available. ... The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ... In theoretical physics, a hierarchy problem occurs when the fundamental parameters (couplings or masses) of some Lagrangian are vastly different (usually larger) than the parameters measured by experiment. ... For other uses, see Dark matter (disambiguation). ... In physical cosmology, the cosmological constant (usually denoted by the Greek capital letter lambda: Λ) was proposed by Albert Einstein as a modification of his original theory of general relativity to achieve a stationary universe. ... CP-symmetry is a symmetry obtained by a combination of the C-symmetry and the P-symmetry. ... Neutrino oscillation is a quantum mechanical phenomenon predicted by Bruno Pontecorvo whereby a neutrino created with a specific lepton flavor (electron, muon or tau) can later be measured to have a different flavor. ... In physics, Kaluza–Klein theory (or KK theory, for short) is a model that seeks to unify the two fundamental forces of gravitation and electromagnetism. ... Grand unification, grand unified theory, or GUT is a theory in physics that unifies the strong interaction and electroweak interaction. ... This page discusses Theories of Everything in physics. ... 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 This box:      String theory is a model of fundamental physics, whose building blocks are one-dimensional extended objects called strings, rather than the zero... This article or section is in need of attention from an expert on the subject. ... // The Minimal Supersymmetric Standard Model (MSSM) is the minimal extension to the Standard Model that realizes supersymmetry (non-minimal extensions exist). ... Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. ... In theoretical physics, supergravity (supergravity theory) refers to a field theory which combines the two theories of supersymmetry and general relativity. ... Quantum gravity is the field of theoretical physics attempting to unify quantum mechanics, which describes three of the fundamental forces of nature, with general relativity, the theory of the fourth fundamental force: gravity. ... 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 This box:      String theory is a model of fundamental physics, whose building blocks are one-dimensional extended objects called strings, rather than the zero... 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. ... The Large Hadron Collider (LHC) is a particle accelerator and collider located at CERN, near Geneva, Switzerland (). Currently under construction, the LHC is scheduled to begin operation in May 2008. ... Super-Kamiokande, or Super-K for short, is a neutrino observatory in Japan. ... The word theory has a number of distinct meanings in different fields of knowledge, depending on their methodologies and the context of discussion. ... Theoretical physics employs mathematical models and abstractions of physics in an attempt to explain experimental data taken of the natural world. ... Ijon Tichy is a fictional character appearing in several novels of Stanisław Lem, for example The Futurological Congress, Peace on Earth, Observation on the Spot, and The Star Diaries. ... StanisÅ‚aw Lem ( , September 12, 1921 – March 27, 2006) was a Polish science fiction, philosophical and satirical writer. ... 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. ... Fig. ... A fundamental interaction or fundamental force is a mechanism by which particles interact with each other, and which cannot be explained in terms of another interaction. ...

There have been many theories of everything proposed by theoretical physicists over the last century, but none has been confirmed experimentally. The primary problem in producing a TOE is that the accepted theories of quantum mechanics and general relativity are hard to combine. For a less technical and generally accessible introduction to the topic, see Introduction to quantum mechanics. ... For a less technical and generally accessible introduction to the topic, see Introduction to general relativity. ...

Based on theoretical holographic principle arguments from the 1990s, many physicists believe that 11-dimensional M-theory, which is described in many sectors by matrix string theory, in many other sectors by perturbative string theory is the complete theory of everything. Other physicists disagree. The holographic principle is a speculative conjecture about quantum gravity theories, proposed by Gerard t Hooft and improved and promoted by Leonard Susskind, claiming that all of the information contained in a volume of space can be represented by a theory which lives in the boundary of that region. ... M-theory is a solution proposed for the unknown theory of everything which would combine all five superstring theories and 11-dimensional supergravity together. ... In physics, matrix string theory is the first known set of equations that describe superstring theory in a non-perturbatively complete and consistent framework. ... In theoretical physics, the term dual resonance models refers to the early investigation (1968-1974 or so) on strong interactions of the subject that is currently known as string theory. ...

Historical antecedents

The concept of a "theory of everything" is rooted in the ancient idea of causality, famously expressed by Laplace: Pierre-Simon Laplace Pierre-Simon Laplace (March 23, 1749 – March 5, 1827) was a French mathematician and astronomer, the discoverer of the Laplace transform and Laplaces equation. ...

An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes.

– Essai philosophique sur les probabilités, Introduction. 1814

Although this is usually cited as a statement of determinism, a "single formula" may still exist even if physics is fundamentally probabilistic, as taught by modern quantum mechanics. This article is about the general notion of determinism in philosophy. ... For a less technical and generally accessible introduction to the topic, see Introduction to quantum mechanics. ...

Ancient Greek to Einstein

Since ancient Greek times, philosophers have speculated that the apparent diversity of appearances conceals an underlying unity, and thus that the list of forces might be short, indeed might contain only a single entry. For example, the mechanical philosophy of the 17th century posited that all forces could be ultimately reduced to contact forces between tiny solid particles.^[1] This was abandoned after the acceptance of Issac Newton's long-distance force of gravity; but at the same time, Newton's work in his Principia provided the first dramatic empirical evidence for the unification of apparently distinct forces: Galileo's work on terrestrial gravity, Kepler's laws of planetary motion, and the phenomonenon of tides were all quantitatively explained by a single law of universal gravitation. Note: This article contains special characters. ... The Pre-Socratic philosophers were active before Socrates or contemporaneously, but expounding knowledge developed earlier. ... In philosophy, mechanism is a theory that all natural phenomena can be explained by physical causes. ... In physics, a contact force is a force between two objects (or an object and a surface) that are in contact with each other. ... Sir Isaac Newton FRS (4 January 1643 – 31 March 1727) [ OS: 25 December 1642 – 20 March 1727][1] was an English physicist, mathematician, astronomer, natural philosopher, and alchemist. ... Newtons own copy of his Principia, with handwritten corrections for the second edition. ... Galileo can refer to: Galileo Galilei, astronomer, philosopher, and physicist (1564 - 1642) the Galileo spacecraft, a NASA space probe that visited Jupiter and its moons the Galileo positioning system Life of Galileo, a play by Bertolt Brecht Galileo (1975) - screen adaptation of the play Life of Galileo by Bertolt Brecht... Johannes Kepler Johannes Kepler (December 27, 1571 – November 15, 1630), a key figure in the scientific revolution, was a German astronomer, mathematician and astrologer. ... This article is about tides in the Earths oceans. ... This article covers the physics of gravitation. ...

In 1820, Hans Christian Oersted discovered a connection between electricity and magnetism, triggering decades of work that culminated in James Clerk Maxwell's theory of electromagnetism. Also during the 19th and early 20th centuries, it gradually became apparent that many common examples of forces—contact forces, elasticity, viscosity, friction, pressure—resulted from electrical interactions between the smallest particles of matter. In the late 1920s, the new quantum mechanics showed that the chemical bonds between atoms were examples of (quantum) electrical forces, justifying Dirac's boast that "[t]he underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known".^[2] Hans Christian Ørsted Hans Christian Ørsted (August 14, 1777 in Rudkøbing – March 9, 1851 in Copenhagen) was a Danish physicist and chemist, influenced by the thinking of Immanuel Kant. ... James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and theoretical physicist. ... Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... Elasticity is a branch of physics which studies the properties of elastic materials. ... For other uses, see Viscosity (disambiguation). ... For other uses, see Friction (disambiguation). ... This article is about pressure in the physical sciences. ... For a less technical and generally accessible introduction to the topic, see Introduction to quantum mechanics. ... A chemical bond is the physical process responsible for the attractive interactions between atoms and molecules, and that which confers stability to diatomic and polyatomic chemical compounds. ... Properties For other meanings of Atom, see Atom (disambiguation). ... Dirac is a prototype algorithm for the encoding and decoding (see codec) of raw video and sound. ...

Attempts to unify gravity with electromagnetism date back at least to Michael Faraday's experiments of 1849–50.^[3] After Albert Einstein's theory of gravity (general relativity) was published in 1915, the search for a unified field theory combining gravity with electromagnetism began in earnest. At the time, it seemed plausible that no other fundamental forces exist. Prominent contributors were Gunnar Nordstrom, Hermann Weyl, Arthur Eddington, Theodor Kaluza, Oskar Klein, and most notably, many attempts by Einstein and his collaborators. In his last years, Albert Einstein was intensely occupied in finding such a unifying theory. Yet none of these attempts were successful.^[4] Gravity is a force of attraction that acts between bodies that have mass. ... Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... Michael Faraday, FRS (September 22, 1791 – August 25, 1867) was an English chemist and physicist (or natural philosopher, in the terminology of that time) who contributed to the fields of electromagnetism and electrochemistry. ... “Einstein” redirects here. ... For a less technical and generally accessible introduction to the topic, see Introduction to general relativity. ... This article does not cite any references or sources. ... Gunnar Nordström Gunnar Nordström (12th March 1881, Helsinki – 24th December 1923, Helsinki) was a Finnish theoretical physicist who is best remembered for his theory of gravitation, which was an early competitor of general relativity. ... Hermann Klaus Hugo Weyl (November 9, 1885 – December 9, 1955) was a German mathematician. ... One of Sir Arthur Stanley Eddingtons papers announced Einsteins theory of general relativity to the English-speaking world. ... im a fag! lalalala Headline text KKK ... Oskar Klein (September 15, 1894 - February 5, 1977) was a Swedish theoretical physicist. ...

New discoveries

The search for a unifying theory was interrupted by the discovery of the strong and weak nuclear forces, which could not be subsumed into either gravity or electromagnetism. A further hurdle was the acceptance that quantum mechanics had to be incorporated from the start, rather than emerging as a consequence of a deterministic unified theory, as Einstein had hoped. Gravity and electromagnetism could always peacefully coexist as entries in a list of Newtonian forces, but for many years it seemed that gravity could not even be incorporated into the quantum framework, let alone unified with the other fundamental forces. For this reason, work on unification for much of the twentieth century, focused on understanding the three "quantum" forces: electromagnetism and the weak and strong forces. The first two were unified in 1967–8 by Sheldon Glashow, Steven Weinberg, and Abdus Salam.^[5] The strong and electroweak forces peacefully coexist in the standard model of particle physics, but remain distinct. Several Grand Unified Theories (GUTs) have been proposed to unify them. Although the simplest GUTs have been experimentally ruled out, the general idea, especially when linked with supersymmetry, remains strongly favored by the theoretical physics community. The strong nuclear force or strong interaction (also called color force or colour force) is a fundamental force of nature which affects only quarks and antiquarks, and is mediated by gluons in a similar fashion to how the electromagnetic force is mediated by photons. ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... This article or section does not cite its references or sources. ... Professor Sheldon Lee Glashow (born December 5, 1932) is an American physicist. ... Steven Weinberg (born May 3, 1933) is an American physicist. ... For other uses, see Abdus Salam (disambiguation). ... The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ... For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and... This article or section is in need of attention from an expert on the subject. ...

Modern physics

In current mainstream physics, a Theory of Everything would unify all the fundamental interactions of nature, which are usually considered to be four in number: gravity, the strong nuclear force, the weak nuclear force, and the electromagnetic force. Because the weak force can transform elementary particles from one kind into another, the TOE should yield a deep understanding of the various different kinds of particles as well as the different forces. The expected pattern of theories is: A fundamental interaction or fundamental force is a mechanism by which particles interact with each other, and which cannot be explained in terms of another interaction. ... Gravity is a force of attraction that acts between bodies that have mass. ... The strong nuclear force or strong interaction (also called color force or colour force) is a fundamental force of nature which affects only quarks and antiquarks, and is mediated by gluons in a similar fashion to how the electromagnetic force is mediated by photons. ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... In physics, the electromagnetic force is the force that the electromagnetic field exerts on electrically charged particles. ... In particle physics, an elementary particle is a particle of which other, larger particles are composed. ...

In addition to the forces listed here, modern cosmology might require an inflationary force, dark energy, and also dark matter composed of fundamental particles outside the scheme of the standard model. The existence of these has not been proven and there are alternative theories such as modified Newtonian dynamics. Gravity is a force of attraction that acts between bodies that have mass. ... The electronuclear force is the unification of the strong nuclear force and the electroweak force (itself a unification of weak nuclear force and electromagnetic force). ... For the album, see Grand Unification (album). ... The strong interaction or strong force is today understood to represent the interactions between quarks and gluons as detailed by the theory of quantum chromodynamics (QCD). ... In mathematics, the special unitary group of degree n, denoted SU(n), is the group of n×n unitary matrices with unit determinant. ... In physics, the electroweak theory presents a unified description of two of the four fundamental forces of nature: electromagnetism and the weak nuclear force. ... In mathematics, the special unitary group of degree n, denoted SU(n), is the group of n×n unitary matrices with unit determinant. ... In mathematics, the unitary group of degree n, denoted U(n), is the group of n×n unitary matrices with complex entries, with the group operation that of matrix multiplication. ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... In mathematics, the special unitary group of degree n, denoted SU(n), is the group of n×n unitary matrices with unit determinant. ... Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. ... In mathematics, the unitary group of degree n, denoted U(n), is the group of n×n unitary matrices with complex entries, with the group operation that of matrix multiplication. ... Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ... In physics, magnetism is a phenomenon by which materials exert an attractive or repulsive force on other materials. ... Cosmology, from the Greek: κοσμολογία (cosmologia, κόσμος (cosmos) order + λογια (logia) discourse) is the study of the Universe in its totality, and by extension, humanitys place in it. ... Inflation is the idea—first proposed by Alan Guth (1981)—that the nascent universe passed through a phase of exponential expansion (the inflationary epoch) that was driven by a negative pressure vacuum energy density. ... In physical cosmology, dark energy is a hypothetical form of energy that permeates all of space and tends to increase the rate of expansion of the universe. ... For other uses, see Dark matter (disambiguation). ... In physics, Modified Newtonian dynamics (MOND) is a theory that proposes a modification of Newtons Second Law of Dynamics, to explain the galaxy rotation problem. ...

Electroweak unification is a broken symmetry: the electromagnetic and weak forces appear distinct at low energies because the particles carrying the weak force, the W and Z bosons have a mass of about 100 GeV, whereas the photon, which carries the electromagnetic force, is massless. At higher energies Ws and Zs can be created easily and the unified nature of the force becomes apparent. Grand unification is expected to work in a similar way, but at energies of the order of 10¹⁶ GeV, far greater than could be reached by any possible Earth-based particle accelerator. By analogy, unification of the GUT force with gravity is expected at the Planck energy, roughly 10¹⁹ GeV. Broken symmetry is a concept used in mathematics and physics when an object breaks either rotational symmetry or translational symmetry. ... In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... Matter creation is process inverse to annihilation. ... For the DC Comics Superhero also called Atom Smasher, see Albert Rothstein. ... The Planck energy is the natural unit of energy, denoted by EP. 1. ...

It may seem premature to be searching for a TOE when there is as yet no direct evidence for an electronuclear force, and while in any case there are many different proposed GUTs. In fact the name deliberately suggests the hubris involved. Nevertheless, most physicists believe this unification is possible, partly due to the past history of convergence towards a single theory. Supersymmetric GUTs seem plausible not only for their theoretical "beauty", but because they naturally produce large quantities of dark matter, and the inflationary force may be related to GUT physics (although it does not seem to form an inevitable part of the theory). And yet GUTs are clearly not the final answer. Both the current standard model and proposed GUTs are quantum field theories which require the problematic technique of renormalization to yield sensible answers. This is usually regarded as a sign that these are only effective field theories, omitting crucial phenomena relevant only at very high energies. Furthermore, the inconsistency between quantum mechanics and general relativity implies that one or both of these must be replaced by a theory incorporating quantum gravity. Hubris or hybris (Greek ), according to its modern usage, is exaggerated self pride or self-confidence (overbearing pride), often resulting in fatal retribution. ... Quantum field theory (QFT) is the quantum theory of fields. ... Figure 1. ... In physics, an effective field theory is an approximate theory (usually a quantum field theory) that contains the appropriate degrees of freedom to describe physical phenomena occurring at a chosen length scale, but ignores the substructure and the degrees of freedom at shorter distances (or, equivalently, higher energies). ... Quantum gravity is the field of theoretical physics attempting to unify quantum mechanics, which describes three of the fundamental forces of nature, with general relativity, the theory of the fourth fundamental force: gravity. ...

Unsolved problems in physics: Is string theory, superstring theory, or M-theory, or some other variant on this theme, a step on the road to a "theory of everything", or just a blind alley?

The mainstream theory of everything at the moment is superstring theory / M-theory; current research on loop quantum gravity may eventually play a fundamental role in a TOE, but that is not its primary aim. These theories attempt to deal with the renormalization problem by setting up some lower bound on the length scales possible. String theories and supergravity (both believed to be limiting cases of the yet-to-be-defined M-theory) suppose that the universe actually has more dimensions than the easily observed three of space and one of time. The motivation behind this approach began with the Kaluza-Klein theory in which it was noted that applying general relativity to a five dimensional universe (with the usual four dimensions plus one small curled-up dimension) yields the equivalent of the usual general relativity in four dimensions together with Maxwell's equations (electromagnetism, also in four dimensions). This has led to efforts to work with theories with large number of dimensions in the hopes that this would produce equations that are similar to known laws of physics. The notion of extra dimensions also helps to resolve the hierarchy problem, which is the question of why gravity is so much weaker than any other force. The common answer involves gravity leaking into the extra dimensions in ways that the other forces do not. Image File history File links No higher resolution available. ... This is a list of some of the unsolved problems in physics. ... 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 This box:      String theory is a model of fundamental physics, whose building blocks are one-dimensional extended objects called strings, rather than the zero... Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. ... M-theory is a solution proposed for the unknown theory of everything which would combine all five superstring theories and 11-dimensional supergravity together. ... Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. ... M-theory is a solution proposed for the unknown theory of everything which would combine all five superstring theories and 11-dimensional supergravity together. ... 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. ... In theoretical physics, supergravity (supergravity theory) refers to a field theory which combines the two theories of supersymmetry and general relativity. ... In physics, Kaluza-Klein theory (or KK theory, for short) is a model that seeks to unify the two fundamental forces of gravitation and electromagnetism. ... For thermodynamic relations, see Maxwell relations. ...

In the late 1990s, it was noted that one problem with several of the candidates for theories of everything (but particularly string theory) was that they did not constrain the characteristics of the predicted universe. For example, many theories of quantum gravity can create universes with arbitrary numbers of dimensions or with arbitrary cosmological constants. Even the "standard" ten-dimensional string theory allows the "curled up" dimensions to be compactified in an enormous number of different ways (one estimate is 10⁵⁰⁰) each of which corresponds to a different collection of fundamental particles and low-energy forces. This array of theories is known as the string theory landscape. In physical cosmology, the cosmological constant (usually denoted by the Greek capital letter lambda: Λ) was proposed by Albert Einstein as a modification of his original theory of general relativity to achieve a stationary universe. ... In string theory, a model used in theoretical physics, a compact dimension is curled up in itself and very small (Planck length). ... The string theory landscape or anthropic landscape refers to the large number of different false vacua in string theory. ...

A speculative solution is that many or all of these possibilities are realised in one or another of a huge number of universes, but that only a small number of them are habitable, and hence the fundamental constants of the universe are ultimately the result of the anthropic principle rather than a consequence of the theory of everything. This anthropic approach is often criticised in that, because the theory is flexible enough to encompass almost any observation, it cannot make useful (as in original, falsifiable, and verifiable) predictions. In this view, string theory would be considered a pseudoscience, where an unfalsifiable theory is constantly adapted to fit the experimental results. In physics and cosmology, the anthropic principle states that we should take into account the constraints that our existence as observers imposes on the sort of universe that we could observe. ... A typical 18th century phrenology chart. ...

With reference to Gödel's incompleteness theorem

A small number of scientists claim that Gödel's incompleteness theorem proves that any attempt to construct a TOE is bound to fail. Gödel's theorem states that any non-trivial mathematical theory that has a finite description is either inconsistent or incomplete. In his 1966 book The Relevance of Physics, Stanley Jaki pointed out that, because any "theory of everything" will certainly be a consistent non-trivial mathematical theory, it must be incomplete. He claims that this dooms searches for a deterministic theory of everything.^[6] In mathematical logic, Gödels incompleteness theorems are two celebrated theorems proven by Kurt Gödel in 1931. ... The Reverend Father Professor Stanley L. Jaki OSB (b. ...

Freeman Dyson has stated that Freeman John Dyson FRS (born December 15, 1923) is an English-born American theoretical physicist and mathematician, famous for his work in quantum mechanics, solid-state physics, nuclear weapons design and policy, and for his serious theorizing in futurism and science fiction concepts, including the search for extraterrestrial intelligence. ...

Stephen Hawking was originally a believer in the Theory of Everything but, after considering Gödel's Theorem, concluded that one was not obtainable. Stephen William Hawking, CH, CBE, FRS, FRSA, (born 8 January 1942) is a British theoretical physicist. ...

This view has been argued against by Solomon Feferman,^[7] among others. Douglas S. Robertson offers Conway's game of life as an example:^[8] The underlying rules are simple and complete, but there are formally undecidable questions about the game's behaviors. Analogously, it may (or may not) be possible to completely state the underlying rules of physics with a finite number of well-defined laws, but there is little doubt that there are questions about the behavior of physical systems which are formally undecidable on the basis of those underlying laws. Solomon Feferman is a mathematician and philosopher at Stanford University. ... Gospers Glider Gun creating gliders. The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. ...

Since most physicists would consider the statement of the underlying rules to suffice as the definition of a "theory of everything", these researchers argue that Gödel's Theorem does not mean that a TOE cannot exist. On the other hand, the physicists invoking Gödel's Theorem appear, at least in some cases, to be referring not to the underlying rules, but to the understandability of the behavior of all physical systems, as when Hawking mentions arranging blocks into rectangles, turning the computation of prime numbers into a physical question.^[9] This definitional discrepancy may explain some of the disagreement among researchers. In mathematics, a prime number (or a prime) is a natural number which has exactly two distinct natural number divisors: 1 and itself. ...

Potential status of a theory of everything

No physical theory to date is believed to be precisely accurate. Instead, physics has proceeded by a series of "successive approximations" allowing more and more accurate predictions over a wider and wider range of phenomena. Some physicists believe that it is therefore a mistake to confuse theoretical models with the true nature of reality, and hold that the series of approximations will never terminate in the "truth". Einstein himself expressed this view on occasions.^[10] On this view, we may reasonably hope for a theory of everything which self-consistently incorporates all currently known forces, but should not expect it to be the final answer. On the other hand it is often claimed that, despite the apparently ever-increasing complexity of the mathematics of each new theory, in a deep sense associated with their underlying gauge symmetry and the number of fundamental physical constants, the theories are becoming simpler. If so, the process of simplification cannot continue indefinitely. Gauge theories are a class of physical theories based on the idea that symmetry transformations can be performed locally as well as globally. ... In physics, fundamental physical constants are, in the strictest sense, physical constants that are independent of systems of units and hence are dimensionless numbers. ...

There is a philosophical debate within the physics community as to whether or not a theory of everything deserves to be called the fundamental law of the universe.^[11] One view is the hard reductionist position that the TOE is the fundamental law and that all other theories that apply within the universe are a consequence of the TOE. Another view is that emergent laws (called "free floating laws" by Steven Weinberg), which govern the behavior of complex systems, should be seen as equally fundamental. Examples are the second law of thermodynamics and the theory of natural selection. The point being that, although in our universe these laws describe systems whose behaviour could ("in principle") be predicted from a TOE, they would also hold in universes with different low-level laws, subject only to some very general conditions. Therefore it is of no help, even in principle, to invoke low-level laws when discussing the behavior of complex systems. Some argue that this attitude would violate Occam's Razor if a completely valid TOE were formulated. It is not clear that there is any point at issue in these debates (e.g. between Steven Weinberg and Philip Anderson) other than the right to apply the high-status word "fundamental" to their respective subjects of interest. Reductionism in philosophy describes a number of related, contentious theories that hold, very roughly, that the nature of complex things can always be reduced to (explained by) simpler or more fundamental things. ... A termite cathedral mound produced by a termite colony: a classic example of emergence in nature. ... Steven Weinberg (born May 3, 1933) is an American physicist. ... There are many definitions of complexity, therefore many natural, artificial and abstract objects or networks can be considered to be complex systems, and their study (complexity science) is highly interdisciplinary. ... The second law of thermodynamics is an expression of the universal law of increasing entropy. ... For other uses, see Natural selection (disambiguation). ... For the House television show episode called Occams Razor, see Occams Razor (House episode) Occams razor (sometimes spelled Ockhams razor) is a principle attributed to the 14th-century English logician and Franciscan friar William of Ockham. ... Steven Weinberg (born May 3, 1933) is an American physicist. ... Philip Warren Anderson (born December 13, 1923) is an American physicist. ...

Although the name "theory of everything" suggests the determinism of Laplace's quote, this gives a very misleading impression. Determinism is frustrated by the probabilistic nature of quantum mechanical predictions, by the extreme sensitivity to initial conditions that leads to mathematical chaos, and by the extreme mathematical difficulty of applying the theory. Thus, although the current standard model of particle physics "in principle" predicts all known non-gravitational phenomena, in practice only a few quantitative results have been derived from the full theory (e.g. the masses of some of the simplest hadrons), and these results (especially the particle masses which are most relevant for low-energy physics) are less accurate than existing experimental measurements. The true TOE would almost certainly be even harder to apply. The main motive for seeking a TOE, apart from the pure intellectual satisfaction of completing a centuries-long quest, is that all prior successful unifications have predicted new phenomena, some of which (e.g. electrical generators) have proved of great practical importance. As in other cases of theory reduction, the TOE would also allow us to confidently define the domain of validity and residual error of low-energy approximations to the full theory which could be used for practical calculations. For other uses, see Chaos Theory (disambiguation). ... In particle physics, a hadron is a subatomic particle which experiences the strong nuclear force. ... This article is about machines that produce electricity. ...

Theory of everything and philosophy

Main article: Theory of everything (philosophy)

The status of a physical TOE is open to philosophical debate. For instance, if physicalism is true, a physical TOE would coincide with a philosophical theory of everything. Some philosophers (Aristotle, Plato, Hegel, Whitehead, Karl Marx, et al) have attempted to construct all-encompassing systems. Others are highly dubious about the very possibility of such an exercise. In philosophy, a theory of everything or TOE is an ultimate, all-encompassing explanation of nature or reality. ... Philosophy (from the Greek words philos and sophia meaning love of wisdom) is understood in different ways historically and by different philosophers. ... The term physicalism was coined by Otto Neurath, in a series of early 20th century essays on the subject, in which he wrote According to physicalism, the language of physics is the universal language of science and, consequently, any knowledge can be brought back to the statements on the physical... For other uses, see Aristotle (disambiguation). ... For other uses, see Plato (disambiguation). ... Georg Wilhelm Friedrich Hegel (August 27, 1770 - November 14, 1831) was a German philosopher born in Stuttgart, Württemberg, in present-day southwest Germany. ... Alfred North Whitehead, OM (February 15, 1861, Ramsgate, Kent, England – December 30, 1947, Cambridge, Massachusetts, U.S.) was an English-born mathematician who became a philosopher. ... Karl Heinrich Marx (May 5, 1818 – March 14, 1883) was a 19th century philosopher, political economist, and revolutionary. ...

See also

• An exceptionally simple theory of everything

An Exceptionally Simple Theory of Everything[1] is a physics paper submitted to the arXiv library on Nov. ...

References

Further reading

• John D. Barrow, Theories of Everything: The Quest for Ultimate Explanation (OUP, Oxford, 1990) ISBN 0-099-98380-X
• Stephen Hawking 'The Theory of Everything: The Origin and Fate of the Universe' is an unauthorized 2002 book taken from recorded lectures (ISBN 1-893224-79-1)
• Stanley Jaki OSB, 2005. The Drama of Quantities. Real View Books (ISBN 1-892548-47-X)
• Abraham Pais Subtle is the Lord...: The Science and the Life of Albert Einstein (OUP, Oxford, 1982). ISBN 0-19-853907-X
• Steven Weinberg Dreams of a Final Theory: The Search for the Fundamental Laws of Nature (Hutchinson Radius, London, 1993) ISBN 0-09-1773954

John David Barrow FRS (born November 29, 1952, London) is an English cosmologist, theoretical physicist, and mathematician. ... Stephen William Hawking, CH, CBE, FRS, FRSA, (born 8 January 1942) is a British theoretical physicist. ... The Theory of Everything: The Origin and Fate of the Universe is a popular book disowned by Stephen Hawking although put together with material written by him. ... The Reverend Father Professor Stanley L. Jaki OSB (b. ... Abraham (Bram) Pais (May 19, 1918, Amsterdam, The Netherlands — July 28, 2000, Copenhagen, Denmark) was a Dutch-born American physicist and science historian. ... Steven Weinberg (born May 3, 1933) is an American physicist. ...

External links

• The Elegant Universe-Nova online — a 3 hour PBS show about the search for the Theory of everything and string theory.
• 'Theory of Everything' Freeview video by the Vega Science Trust and the BBC/OU
• 'An Exceptionally Simple Theory of Everything' A. Garrett Lisi
• Theory of Everything based on Music