Everything, every-thing, or every thing, is all that exists; it is an

antithesis Antithesis (: antitheses; Greek for "setting opposite", from "against" and "placing") is used in writing or speech either as a proposition that contrasts with or reverses some previously mentioned proposition, or when two opposites are introd ...

of ''

nothing Nothing, no-thing, or no thing is the complete absence of ''anything'', as the opposite of ''something'' and an antithesis of everything. The concept of nothing has been a matter of philosophical debate since at least the 5th century BCE. Ea ...

'', or its complement. It is the totality of things relevant to some subject matter. Without expressed or implied

limits Limit or Limits may refer to: Arts and media * ''Limit'' (manga), a manga by Keiko Suenobu * ''Limit'' (film), a South Korean film * Limit (music), a way to characterize harmony * "Limit" (song), a 2016 single by Luna Sea * "Limits", a 2009 ...

, it may refer to . The

universe The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from s ...

is everything that exists theoretically, though a

multiverse The multiverse is the hypothetical set of all universes. Together, these universes are presumed to comprise everything that exists: the entirety of space, time, matter, energy, information, and the physical laws and constants that describ ...

may exist according to theoretical cosmology predictions. It may refer to an

anthropocentric Anthropocentrism ( ) is the belief that human beings are the central or most important entity on the planet. The term can be used interchangeably with humanocentrism, and some refer to the concept as human supremacy or human exceptionalism. From a ...

worldview A worldview (also world-view) or is said to be the fundamental cognitive orientation of an individual or society encompassing the whole of the individual's or society's knowledge, culture, and Perspective (cognitive), point of view. However, whe ...

, or the sum of human experience, history, and the

human condition The human condition can be defined as the characteristics and key events of human life, including birth, learning, emotion, aspiration, reason, morality, conflict, and death. This is a very broad topic that has been and continues to be pondered ...

in general. Every

object Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Object (abstract), an object which does not exist at any particular time or place ** Physical object, an identifiable collection of matter * Goal, an a ...

and

entity An entity is something that Existence, exists as itself. It does not need to be of material existence. In particular, abstractions and legal fictions are usually regarded as entities. In general, there is also no presumption that an entity is Lif ...

is a part of everything, including all physical bodies and in some cases all

abstract object In philosophy and the arts, a fundamental distinction exists between abstract and concrete entities. While there is no universally accepted definition, common examples illustrate the difference: numbers, sets, and ideas are typically classif ...

Scope

In ordinary conversation, ''everything'' usually refers only to the totality of things relevant to the subject matter. When there is no expressed limitation, ''everything'' may refer to the

, or the

world The world is the totality of entities, the whole of reality, or everything that Existence, exists. The nature of the world has been conceptualized differently in different fields. Some conceptions see the world as unique, while others talk ...

. The universe is most commonly defined as everything that physically exists: the entirety of

time Time is the continuous progression of existence that occurs in an apparently irreversible process, irreversible succession from the past, through the present, and into the future. It is a component quantity of various measurements used to sequ ...

, all forms of

matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic pa ...

energy Energy () is the physical quantity, quantitative physical property, property that is transferred to a physical body, body or to a physical system, recognizable in the performance of Work (thermodynamics), work and in the form of heat and l ...

and

momentum In Newtonian mechanics, momentum (: momenta or momentums; more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. ...

, and the

physical law Scientific laws or laws of science are statements, based on repeated experiments or observations, that describe or predict a range of natural phenomena. The term ''law'' has diverse usage in many cases (approximate, accurate, broad, or narrow) ...

s and

constants Constant or The Constant may refer to: Mathematics * Constant (mathematics), a non-varying value * Mathematical constant, a special number that arises naturally in mathematics, such as or Other concepts * Control variable or scientific const ...

that govern them. However, the term "universe" may be used in slightly different contextual senses, denoting such concepts as the ''

cosmos The cosmos (, ; ) is an alternative name for the universe or its nature or order. Usage of the word ''cosmos'' implies viewing the universe as a complex and orderly system or entity. The cosmos is studied in cosmologya broad discipline covering ...

'', the ''

'', or ''

nature Nature is an inherent character or constitution, particularly of the Ecosphere (planetary), ecosphere or the universe as a whole. In this general sense nature refers to the Scientific law, laws, elements and phenomenon, phenomena of the physic ...

''. According to some speculations, this universe may be one of many disconnected universes, which are collectively denoted as the

. In the bubble universe theory, there are an infinite variety of universes, each with different

physical constant A physical constant, sometimes fundamental physical constant or universal constant, is a physical quantity that cannot be explained by a theory and therefore must be measured experimentally. It is distinct from a mathematical constant, which has a ...

s. In the many-worlds hypothesis, new universes are spawned with every

quantum measurement In quantum physics, a measurement is the testing or manipulation of a physical system to yield a numerical result. A fundamental feature of quantum theory is that the predictions it makes are probabilistic. The procedure for finding a probability ...

. By definition, these speculations cannot currently be tested experimentally, yet, if multiple universes do exist, they would still be part of everything. Especially in a

metaphysical Metaphysics is the branch of philosophy that examines the basic structure of reality. It is traditionally seen as the study of mind-independent features of the world, but some theorists view it as an inquiry into the conceptual framework of h ...

context, ''World'' may refer to everything that constitutes

reality Reality is the sum or aggregate of everything in existence; everything that is not imagination, imaginary. Different Culture, cultures and Academic discipline, academic disciplines conceptualize it in various ways. Philosophical questions abo ...

and the

: see World (philosophy). However, world may only refer to ''

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

'' envisioned from an

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

, as a place by

human beings Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are great apes characterized by their hairlessness, bipedalism, and high intellige ...

In theoretical physics

theoretical physics Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict List of natural phenomena, natural phenomena. This is in contrast to experimental p ...

, a ''theory of everything'' (TOE) is a hypothetical

theory A theory is a systematic and rational form of abstract thinking about a phenomenon, or the conclusions derived from such thinking. It involves contemplative and logical reasoning, often supported by processes such as observation, experimentation, ...

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 Ijon Tichy () is a fictional character who appears in several works of the Polish science fiction writer Stanisław Lem: initially in '' The Star Diaries'', later in '' The Futurological Congress'', '' Peace on Earth'', '' Observation on the Spot' ...

—a character from a cycle of

Stanisław Lem Stanisław Herman Lem (; 12 September 1921 – 27 March 2006) was a Polish writer. He was the author of many novels, short stories, and essays on various subjects, including philosophy, futurology, and literary criticism. Many of his science fi ...

science fiction Science fiction (often shortened to sci-fi or abbreviated SF) is a genre of speculative fiction that deals with imaginative and futuristic concepts. These concepts may include information technology and robotics, biological manipulations, space ...

stories of the 1960s—was known to work on the "General Theory of Everything". Over time, the term stuck in popularizations of

quantum physics Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is ...

to describe a theory that would unify or explain through a single model the theories of all

fundamental interaction In physics, the fundamental interactions or fundamental forces are interactions in nature that appear not to be reducible to more basic interactions. There are four fundamental interactions known to exist: * gravity * electromagnetism * weak int ...

s in nature. 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 Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is ...

general relativity General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the differential geometry, geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of grav ...

, and

special relativity In physics, the special theory of relativity, or special relativity for short, is a scientific theory of the relationship between Spacetime, space and time. In Albert Einstein's 1905 paper, Annus Mirabilis papers#Special relativity, "On the Ele ...

are hard to combine. Theories exploring quantum mechanics and string theory are easier to combine. Based on theoretical holographic principle arguments from the 1990s, many physicists believe that 11-dimensional

M-theory In physics, M-theory is a theory that unifies all Consistency, consistent versions of superstring theory. Edward Witten first conjectured the existence of such a theory at a string theory conference at the University of Southern California in 1 ...

, which is described in many sectors by matrix string theory, and in many other sectors by perturbative string theory, is the complete theory of everything. Other physicists disagree.

In philosophy

In philosophy, a ''theory of everything'' or ''TOE'' is an ultimate, all-encompassing explanation of

.Rescher, Nicholas (2006a). "Holistic Explanation and the Idea of a Grand Unified Theory". Collected Papers IX: Studies in Metaphilosophy.Rescher, Nicholas (2006b). "The Price of an Ultimate Theory". Collected Papers IX: Studies in Metaphilosophy.Walker, Mark Alan (March 2002)
"Prolegomena to Any Future Philosophy"
Journal of Evolution and Technology Vol. 10. Adopting the term from physics, where the search for a

theory of everything A theory of everything (TOE), final theory, ultimate theory, unified field theory, or master theory is a hypothetical singular, all-encompassing, coherent theoretical physics, theoretical framework of physics that fully explains and links togeth ...

is ongoing,

philosophers Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, value, mind, and language. It is a rational and critical inquiry that reflects on ...

have discussed the viability of the concept and analyzed its properties and implications. Among the questions to be addressed by a

philosophical theory A philosophical theory or philosophical positionBothamley, Jennifer (1993), ''Dictionary of Theories'', Canton, MI: Visible Ink Press is a view that attempts to explain or account for a particular problem in philosophy. The use of the term "theory ...

of everything are: "Why is reality understandable?", "Why are the laws of nature as they are?", and " Why is there anything at all?".

References

{{reflist Perception Ontology Quantity

Scope

In theoretical physics

In philosophy

See also

References