Everything is the concept of all that exists.^[1] Every entity, physical body, and abstract object is part of everything. Everything is the opposite of nothing.^{[citation needed]} This article is about the concept of an entity. ... A physical body is an object which can be described by the theories of classical mechanics, or quantum mechanics, and experimented upon by physical instruments. ... In philosophy it is commonly considered that every object is either abstract or concrete. ... This article is about nothing in the abstract sense. ...

World

Main article: World

The World is a proper noun for the planet Earth envisioned from an anthropocentric or human worldview, as a place inhabited by human beings. It is often used to signify the sum of human experience and history, or the 'human condition' in general.^[2] For other uses, see World (disambiguation). ... This article is about Earth as a planet. ... Anthropocentrism (Greek άνθρωπος, anthropos, man, human being, κέντρον, kentron, center) is the practice, conscious or otherwise, of regarding the existence and/or concerns of human beings as the central fact of the universe. ... This article is about modern humans. ... This article is about the radio show. ... Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ... Look up Experience in Wiktionary, the free dictionary This article discusses the general concept of experience. ... For other uses, see History (disambiguation). ... For other uses, see Human condition (disambiguation). ...

Especially in a metaphysical context, World may refer to everything tat constitutes reality and the Universe: see World (philosophy). Plato (left) and Aristotle (right), by Raphael (Stanza della Segnatura, Rome) Metaphysics is the branch of philosophy investigating principles of reality transcending those of any particular science. ... For other uses, see Reality (disambiguation). ... For other uses, see Universe (disambiguation). ... The world is, in a philosophical sense, everything that is seen and percieved by human intellect and human senses, even though some branches of philosophy may refer to different worlds, making a reference to the different realms of philosophy (such as the mathematical world, the intelligible world, the world of...

Universe

Main article: Universe

The Universe is most commonly defined as everything that physically exists: the entirety of space and time, all forms of matter, energy and momentum, and the physical laws and constants that govern them. However, the term "universe" may be used in slightly different contextual senses, denoting such concepts as the cosmos, the world or Nature. For other uses, see Universe (disambiguation). ... This article is about the idea of space. ... This article is about the concept of time. ... This article is about matter in physics and chemistry. ... This article is about momentum in physics. ... For a list of set rules, see Laws of science. ... A physical constant is a physical quantity that is generally believed to be both universal in nature and constant in time. ... The Ancient and Medieval cosmos as depicted in Peter Apians Cosmographia (Antwerp, 1539). ... The world is, in a philosophical sense, everything that is seen and percieved by human intellect and human senses, even though some branches of philosophy may refer to different worlds, making a reference to the different realms of philosophy (such as the mathematical world, the intelligible world, the world of... This article is about the physical universe. ...

Experiments suggest that the universe has been governed by the same physical laws and constants throughout its extent and history. The dominant force at cosmological distances is gravity, and general relativity is currently the most accurate theory of gravitation. The remaining three fundamental forces and the particles on which they act are described by the Standard Model. The universe has at least three dimensions of space and one of time, although extremely small additional dimensions cannot be ruled out experimentally. Spacetime appears to be a simply connected smooth manifold, and space has very small mean curvature, so that Euclidean geometry is accurate on the average throughout the universe. Gravity is a force of attraction that acts between bodies that have mass. ... For a generally accessible and less technical introduction to the topic, see Introduction to general relativity. ... A fundamental interaction is a mechanism by which particles interact with each other, and which cannot be explained by another more fundamental interaction. ... The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ... 2-dimensional renderings (ie. ... In physics, compactification plays an important part in string theory. ... For other uses of this term, see Spacetime (disambiguation). ... A geometrical object is called simply connected if it consists of one piece and doesnt have any circle-shaped holes or handles. Higher-dimensional holes are allowed. ... Informally, a differentiable manifold is a type of manifold (which is in turn a kind of topological space) that is locally similar enough to Euclidean space to allow one to do calculus. ... Though actual perceptible space-time is a 4-dimensional Minkowski space (see special relativity), human beings usually perceive space as a three-dimensional space as long they dont notice anything with high relative velocity. ... In differential geometry, the Riemann curvature tensor is the most standard way to express curvature of Riemannian manifolds, or more generally, any manifold with an affine connection, torsionless or with torsion. ... Euclid Euclidean geometry is a mathematical system attributed to the Greek mathematician [[Euclid]] of Alexandria. ...

According to some speculations, this universe may be one of many disconnected universes, which are collectively denoted as the multiverse. In one theory, there is an infinite variety of universes, each with different physical constants. In another theory, new universes are spawned with every quantum measurement. By definition, these speculations cannot currently be tested experimentally. For other uses, see Multiverse (disambiguation). ... It has been suggested that this article or section be merged with Chaotic inflation theory. ... A physical constant is a physical quantity that is generally believed to be both universal in nature and constant in time. ... The framework of quantum mechanics requires a careful definition of measurement, and a thorough discussion of its practical and philosophical implications. ...

In theoretical physics

Main article: Theory of everything

In theoretical physics, a theory of everything (TOE) is a hypothetical theory 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 page discusses Theories of Everything in physics. ... Theoretical physics employs mathematical models and abstractions of physics in an attempt to explain experimental data taken of the natural world. ... The word theory has a number of distinct meanings in different fields of knowledge, depending on their methodologies and the context of discussion. ... 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 have 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 generally accessible and less technical introduction to the topic, see Introduction to quantum mechanics. ... For a generally accessible and less technical 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. ...

In philosophy

Main article: Theory of everything (philosophy)

In philosophy, a theory of everything or TOE is an ultimate, all-encompassing explanation of nature or reality.^[3][4][5] Adopting the term from physics, where the search for a theory of everything is ongoing, philosophers have discussed the viability of the concept and analyzed its properties and implications.^[3][4][5] Among the questions to be addressed by a philosophical theory of everything are: "Why is reality understandable?" "Why are the laws of nature as they are?" "Why is there anything at all?"^[3] In philosophy, a theory of everything or TOE is an ultimate, all-encompassing explanation of nature or reality. ... This article is about the physical universe. ... For other uses, see Reality (disambiguation). ... This page discusses Theories of Everything in physics. ...

References