Biology

• Equilibrioception
  Equilibrioception
  Equilibrioception or sense of balance is one of the physiological senses. It helps prevent humans and animals from falling over when walking or standing still. Balance is the result of a number of body systems working together: the eyes , ears and the body's sense of where it is in space ideally...
  
  , the sense of a balance present in human beings and other animals
• Equilibrium unfolding
  Equilibrium unfolding
  In biochemistry, equilibrium unfolding is the process of unfolding a protein or RNA molecule by gradually changing its environment, such as by changing the temperature or pressure, adding chemical denaturants, or applying force as with an atomic force microscope tip. Since equilibrium is...
  
  , the process of unfolding a protein or RNA molecule by gradually changing its environment
• Genetic equilibrium
  Genetic equilibrium
  A genetic equilibrium is at hand for an allele in a gene pool when the frequency of that allele is not changing . For this to be the case, evolutionary forces acting upon the allele must be equal and opposite. The only basic requirement is that the population be large enough that the effects of...
  
  , theoretical state in which a population is not evolving
• Homeostasis
  Homeostasis
  Homeostasis is the property of a system that regulates its internal environment and tends to maintain a stable, constant condition of properties like temperature or pH...
  
  , the ability of an open system, especially living organisms, to regulate its internal environment
• Punctuated equilibrium
  Punctuated equilibrium
  Punctuated equilibrium is a theory in evolutionary biology which proposes that most species will exhibit little net evolutionary change for most of their geological history, remaining in an extended state called stasis...
  
  , theory in evolutionary biology
• Sedimentation equilibrium
  Sedimentation equilibrium
  Sedimentation equilibrium in a solution or suspension of different particles, such as molecules, exists when the rate of transport of each material in any one direction due to sedimentation equals the rate of transport in the opposite direction due to diffusion...
  
  , analytical ultracentrifugation method for measuring protein molecular masses in solution
• Equilibrium Theory (Island biogeography
  Island biogeography
  Island biogeography is a field within biogeography that attempts to establish and explain the factors that affect the species richness of natural communities. The theory was developed to explain species richness of actual islands...
  
  ), MacArthur-Wilson theory explaining biodiversity character of ecological islands

Physics

• Equilibrium figure
  Hydrostatic equilibrium
  Hydrostatic equilibrium or hydrostatic balance is the condition in fluid mechanics where a volume of a fluid is at rest or at constant velocity. This occurs when compression due to gravity is balanced by a pressure gradient force...
  
  s of Earth and planets (physical geodesy)
• Equilibrium mode distribution
  Equilibrium mode distribution
  The equilibrium mode [power] distribution of light travelling in an optical waveguide or fiber, is the distribution of light that is no longer changing with fibre length or with input modal excitation. This phenomenon requires both mode filtering and mode mixing to occur in the fibre to produce a...
  
  , the state of fiber optic or waveguide transmission in which the propagation mode does not vary with distance along the fiber or changes in the launch mode
• Hydrostatic equilibrium
  Hydrostatic equilibrium
  Hydrostatic equilibrium or hydrostatic balance is the condition in fluid mechanics where a volume of a fluid is at rest or at constant velocity. This occurs when compression due to gravity is balanced by a pressure gradient force...
  
  , the state of a system in which compression due to gravity is balanced by a pressure gradient force
• Hyperbolic equilibrium point
  Hyperbolic equilibrium point
  In the study of dynamical systems, a hyperbolic equilibrium point or hyperbolic fixed point is a fixed point that does not have any center manifolds. Near a hyperbolic point the orbits of a two-dimensional, non-dissipative system resemble hyperbolas. This fails to hold in general...
  
  , a mathematical concept in physics
• Mechanical equilibrium
  Mechanical equilibrium
  A standard definition of static equilibrium is:This is a strict definition, and often the term "static equilibrium" is used in a more relaxed manner interchangeably with "mechanical equilibrium", as defined next....
  
  , the state in which the sum of the forces, and torque, on each particle of the system is zero
• Radiative equilibrium
  Radiative equilibrium
  Radiative equilibrium is one of the several requirements for thermodynamic equilibrium, but it can occur in the absence of thermodynamic equilibrium. There are various types of radiative equilibrium, which is itself a kind of dynamic equilibrium....
  
  , the state where the energy radiated is balanced by the energy absorbed
• Secular equilibrium
  Secular equilibrium
  In nuclear physics, secular equilibrium is a situation in which the quantity of a radioactive isotope remains constant because its production rate is equal to its decay rate.-Secular equilibrium in radioactive decay:...
  
  , a state of radioactive elements in which the production rate of a daughter nucleus is balanced by its own decay rate
• Thermal equilibrium
  Thermal equilibrium
  Thermal equilibrium is a theoretical physical concept, used especially in theoretical texts, that means that all temperatures of interest are unchanging in time and uniform in space...
  
  , a state where an object and its surroundings cease to exchange energy in the form of heat, i.e. they are at the same temperature.

Chemistry

• Chemical equilibrium
  Chemical equilibrium
  In a chemical reaction, chemical equilibrium is the state in which the concentrations of the reactants and products have not yet changed with time. It occurs only in reversible reactions, and not in irreversible reactions. Usually, this state results when the forward reaction proceeds at the same...
  
  , the state in which the concentrations of the reactants and products have no net change over time
• Diffusion equilibrium, when the concentrations of the diffusing substance in the two compartments are equal
• Donnan equilibrium, the distribution of ion species between two ionic solutions separated by a semipermeable membrane or boundary
• Dynamic equilibrium
  Dynamic equilibrium
  A dynamic equilibrium exists once a reversible reaction ceases to change its ratio of reactants/products, but substances move between the chemicals at an equal rate, meaning there is no net change. It is a particular example of a system in a steady state...
  
  , the state in which two reversible processes occur at the same rate
• Equilibrium constant, a quantity characterizing a chemical equilibrium in a chemical reaction
• Partition equilibrium
  Partition equilibrium
  The most common chemical equilibrium systems involve reactants and products in the same phase - either all gases or all solutions. However, it is also possible to get equilibria between substances in different phases, such as two liquids that do not mix...
  
  , a type of chromatography that is typically used in GC
• Quasistatic equilibrium
  Quasistatic equilibrium
  Quasistatic equilibrium is the quasi-balanced state of a thermodynamic system near to thermodynamic equilibrium in some sense or degree...
  
  , the quasi-balanced state of a thermodynamic system near to equilibrium in some sense or degree
• Schlenk equilibrium
  Schlenk equilibrium
  The Schlenk equilibrium is a chemical equilibrium named after its discoverer Wilhelm Schlenk taking place in solutions of Grignard reagents.The process described is an equilibrium between two equivalents of an alkyl or aryl magnesium halide on the left of the equation and on the right side, one...
  
  , a chemical equilibrium named after its discoverer Wilhelm Schlenk taking place in solutions of Grignard reagents
• Solubility equilibrium
  Solubility equilibrium
  Solubility equilibrium is a type of dynamic equilibrium. It exists when a chemical compound in the solid state is in chemical equilibrium with a solution of that compound. The solid may dissolve unchanged, with dissociation or with chemical reaction with another constituent of the solvent, such as...
  
  , any chemical equilibrium between solid and dissolved states of a compound at saturation
• Thermodynamic equilibrium
  Thermodynamic equilibrium
  In thermodynamics, a thermodynamic system is said to be in thermodynamic equilibrium when it is in thermal equilibrium, mechanical equilibrium, radiative equilibrium, and chemical equilibrium. The word equilibrium means a state of balance...
  
  , the state of a thermodynamic system which is in thermal, mechanical, and chemical equilibrium
• Vapor-liquid equilibrium
  Vapor-liquid equilibrium
  Vapor–liquid equilibrium is a condition where a liquid and its vapor are in equilibrium with each other, a condition or state where the rate of evaporation equals the rate of condensation on a molecular level such that there is no net vapor-liquid interconversion...
  
  , where the rates of condensation and vapourization of a material are equal

Other

• Social equilibrium
  Social equilibrium
  In sociology, a system is said to be social equilibrium when there is a dynamic working balance among its interdependent parts . Each subsystem will adjust to any change in the other subsystems and will continue to do so until an equilibrium is retained...
  
  , a system in which there is a dynamic working balance among its interdependent parts
• Equilibration, the means of cognitive development in Jean Piaget
  Jean Piaget
  Jean Piaget was a French-speaking Swiss developmental psychologist and philosopher known for his epistemological studies with children. His theory of cognitive development and epistemological view are together called "genetic epistemology"....
  
  's cognitive developmental theory

Economics

• Competitive equilibrium
  Competitive equilibrium
  Competitive market equilibrium is the traditional concept of economic equilibrium, appropriate for the analysis of commodity markets with flexible prices and many traders, and serving as the benchmark of efficiency in economic analysis...
  
  , economic equilibrium when all buyers and sellers are small relative to the market
• Economic equilibrium
  Economic equilibrium
  In economics, economic equilibrium is a state of the world where economic forces are balanced and in the absence of external influences the values of economic variables will not change. It is the point at which quantity demanded and quantity supplied are equal...
  
  , a condition in economics
• Equilibrium price
  Economic equilibrium
  In economics, economic equilibrium is a state of the world where economic forces are balanced and in the absence of external influences the values of economic variables will not change. It is the point at which quantity demanded and quantity supplied are equal...
  
  , the price at which quantity supplied equals quantity demanded
• General equilibrium theory, a branch of theoretical microeconomics
• Intertemporal equilibrium
  Intertemporal equilibrium
  Intertemporal equilibrium is a notion of economic equilibrium conceived over many periods of time. The term has a different meaning in contemporary macroeconomics from its earlier meaning in Austrian economics....
  
  , an equilibrium concept over time
• Lindahl equilibrium
  Lindahl equilibrium
  A Lindahl tax is a form of taxation in which individuals pay for the provision of a public good according to their marginal benefits. So each individual pays according to his/her marginal benefit derived from the public good. eg...
  
  , a method proposed by Erik Lindahl for financing public goods
• Partial equilibrium
  Supply and demand
  Supply and demand is an economic model of price determination in a market. It concludes that in a competitive market, the unit price for a particular good will vary until it settles at a point where the quantity demanded by consumers will equal the quantity supplied by producers , resulting in an...
  
  , the equilibrium price and quantity which come from the cross of supply and demand in a competitive market.
• Radner equilibrium
  Radner equilibrium
  Radner equilibrium is an economic concept defined by economist Roy Radner in the context of general equilibrium. The concept is an extension of the Arrow-Debreu equilibrium and the base for the first consistent incomplete markets framework....
  
  , an economic concept defined by economist Roy Radner in the context of general equilibrium
• Recursive competitive equilibrium
  Recursive competitive equilibrium
  In macroeconomics, recursive competitive equilibrium is an equilibrium concept. It has been widely used in exploring a wide variety of economic issues including business-cycle fluctuations, monetary and fiscal policy, trade related phenomena, and regularities in asset price co-movements...
  
  , an economic equilibrium concept associated with a dynamic program
• Static equilibrium (economics)
  Economic equilibrium
  In economics, economic equilibrium is a state of the world where economic forces are balanced and in the absence of external influences the values of economic variables will not change. It is the point at which quantity demanded and quantity supplied are equal...
  
  , the intersection of supply and demand in any market
• Sunspot equilibrium
  Sunspots (economics)
  In economics, the term sunspots usually refers to an extrinsic random variable, that is, a random variable that does not directly affect economic fundamentals...
  
  , an economic equilibrium in which nonfundamental factors affect prices or quantities
• Underemployment equilibrium
  Underemployment equilibrium
  In Keynesian economics, underemployment equilibrium refers to a situation with a persistent shortfall relative to full employment and potential output so that unemployment is higher than at the NAIRU or the "natural" rate of unemployment. This situation is not seen as solvable via laissez-faire...
  
  , a situation in Keynesian economics with a persistent shortfall relative to full employment and potential output

Game theory

• Correlated equilibrium
  Correlated equilibrium
  In game theory, a correlated equilibrium is a solution concept that is more general than the well known Nash equilibrium. It was first discussed by mathematician Robert Aumann . The idea is that each player chooses his/her action according to his/her observation of the value of the same public...
  
  , a solution concept in game theory that is more general than the well-known Nash equilibrium
• Nash equilibrium
  Nash equilibrium
  In game theory, Nash equilibrium is a solution concept of a game involving two or more players, in which each player is assumed to know the equilibrium strategies of the other players, and no player has anything to gain by changing only his own strategy unilaterally...
  
  , a solution concept in game theory involving two or more players
  • Quasi-perfect equilibrium
    Quasi-perfect equilibrium
    Quasi-perfect equilibrium is a refinement of Nash Equilibrium for extensive form games due to Eric van Damme. Informally, a player playing by a strategy from a quasi-perfect equilibrium takes observed as well as potential future mistakes of his opponents into account but assumes that he himself...
    
    , a refinement of Nash Equilibrium for extensive form games due to Eric van Damme
  • Sequential equilibrium
    Sequential equilibrium
    Sequential equilibrium is a refinement of Nash Equilibrium for extensive form games due to David M. Kreps and Robert Wilson. A sequential equilibrium specifies not only a strategy for eachof the players but also a belief for each of the players...
    
    , a refinement of Nash Equilibrium for extensive form games due to David M. Kreps and Robert Wilson
• Symmetric equilibrium
  Symmetric equilibrium
  In game theory, a symmetric equilibrium is an equilibrium where both players use the same strategy in the equilibrium. In the Prisoner's Dilemma game pictured to the right, the only Nash equilibrium is . Since both players use the same strategy, the equilibrium is symmetric.Symmetric equilibria...
  
  , in game theory, an equilibrium where all players use the same strategy
• Trembling hand perfect equilibrium
  Trembling hand perfect equilibrium
  There are two possible ways of extending the definition of trembling hand perfection to extensive form games.* One may interpret the extensive form as being merely a concise description of a normal form game and apply the concepts described above to this normal form game. In the resulting perturbed...
  
   assumes that the players, through a "slip of the hand" or tremble, may choose unintended strategies
  • Proper equilibrium
    Proper equilibrium
    Proper equilibrium is a refinement of Nash Equilibrium due to Roger B. Myerson.Proper equilibrium further refines Reinhard Selten's notion of atrembling hand perfect equilibrium by assuming that more costly trembles are made with...
    
     due to Roger B. Myerson, where costly trembles are made with smaller probabilities

Film and television

• Equilibrium (film)
  Equilibrium (film)
  Equilibrium is a 2002 American science fiction action film written and directed by Kurt Wimmer. It stars Christian Bale as John Preston, a warrior-priest and enforcement officer in a future dystopia where both feelings and artistic expression are outlawed and citizens take daily injections of drugs...
  
  , a 2002 science-fiction film
• Equilibrium, alternate title of the 1953 film The Story of Three Loves
  The Story of Three Loves
  The Story of Three Loves, also known as Equilibrium, is a 1953 romantic anthology film made by MGM. It consists of three stories, "The Jealous Lover", "Mademoiselle", and "Equilibrium". The film was produced by Sidney Franklin. "Mademoiselle" was directed by Vincente Minnelli, while Gottfried...
  
  
  • title of one of the three segments of the film
• "Equilibrium" (seaQuest 2032 episode), episode of seaQuest 2032
• "Equilibrium" (DS9 episode), an episode of Star Trek: Deep Space Nine

Music

• Equilibrium (band)
  Equilibrium (band)
  Equilibrium is a Folk metal band from Germany. The band's music combines elements of folk and symphonic metal with various instruments including electric guitars, strings and flutes. Their riffs reflect traditional Germanic melodies....
  
  , a folk metal band from Germany
• Equilibrium (Fergie Frederiksen album), released in 1999
• Equilibrium (Crowbar album), released in 2003
• Equilibrium (Erik Mongrain album)
  Equilibrium (Erik Mongrain album)
  Equilibrium is the second album of the Canadian guitarist Erik Mongrain.- Description :Equilibrium is an acoustic guitar album by Erik Mongrain recorded at Paul Reed Smith's Dragon Crossing Studios during August 2008...
  
  , released in 2008
• IX Equilibrium
  IX Equilibrium
  -Credits:*Ihsahn – vocals, lead guitars, synthesizers, bass guitar*Samoth – rhythm guitars*Trym – drums, percussion...
  
  , an album by the Norwegian band Emperor

Other

• Equilibrium (puzzle)
  Equilibrium (puzzle)
  Equilibrium, also known as "Equi-librium" is an interlocking puzzle in the shape of a sphere. Copyrighted in 1974 by Reiss Games, Inc., it consists of 6 closed arch pieces, 5 of which have pegs on their straight center. The two pegs block the other pieces from being shifted back or forth, only the...
  
  , a 3D interlocking type puzzle
• Equilibrium moisture content
  Equilibrium moisture content
  The moisture content of wood below the fibre saturation point is a function of both relative humidity and temperature of surrounding air. The equilibrium moisture content is the moisture content at which the wood is neither gaining or losing moisture; this however, is a dynamic equilibrium and...
  
  , the moisture content at which the wood is neither gaining nor losing moisture
• Equilibrium point, node in mathematics
• Reflective equilibrium
  Reflective equilibrium
  Reflective equilibrium is a state of balance or coherence among a set of beliefs arrived at by a process of deliberative mutual adjustment among general principles and particular judgments. Although he did not use the term, philosopher Nelson Goodman introduced the method of reflective equilibrium...
  
  , the state of balance or coherence among a set of beliefs arrived at by a process of deliberative mutual adjustment

See also

• Balance (ability)
  Balance (ability)
  In biomechanics, balance is an ability to maintain the center of gravity of a body within the base of support with minimal postural sway. When exercising the ability to balance, one is said to be balancing....
  
  
• Disequilibrium (disambiguation)
• Equilibristics
  Equilibristics
  Equilibristics is a blanket term for a number of circus skills which involve balancing or maintaining equilibrium. The term applies equally to acts in which the performer balances on a prop, and acts in which the performer balances or spins a prop....
  
  , e.g. juggling
• Stability (disambiguation)
• Steady state (disambiguation)
  Steady state (disambiguation)
  Steady state may refer to:*Steady state an operating condition in thermodynamic and other systems or processes when variables stay constant as time passes.**Steady state economy, a stable economy maintained at a sustainable equilibrium....