Criticality may refer to:

Physics terms

Critical phenomena In physics, critical phenomena is the collective name associated with the physics of critical points. Most of them stem from the divergence of the correlation length, but also the dynamics slows down. Critical phenomena include scaling relations ...

, the collective name associated with the physics of critical points **

Critical point (thermodynamics) In thermodynamics, a critical point (or critical state) is the end point of a phase Equilibrium (thermodynamics), equilibrium curve. One example is the liquid–vapor critical point, the end point of the pressure–temperature curve that designat ...

, the end point of a phase equilibrium curve **

Quantum critical point A quantum critical point is a point in the phase diagram of a material where a continuous phase transition takes place at absolute zero. A quantum critical point is typically achieved by a continuous suppression of a nonzero temperature phase t ...

, a special class of continuous phase transition that takes place at absolute zero

Nuclear-physics terms

Criticality (status) In the operation of a nuclear reactor, criticality or critical state is the state in which a nuclear chain reaction is self-sustaining but not growing. Subcriticality or subcritical state is the state in which a nuclear chain reaction is not sel ...

, the state in which a

nuclear chain reaction In nuclear physics, a nuclear chain reaction occurs when one single nuclear reaction causes an average of one or more subsequent nuclear reactions, thus leading to the possibility of a self-propagating series or "positive feedback loop" of thes ...

is self-sustaining **

Prompt criticality In nuclear engineering, prompt criticality is the criticality (the state in which a nuclear chain reaction is self-sustaining) that is achieved with prompt neutrons alone (without the efforts of delayed neutrons). As a result, prompt supercri ...

, the criticality that is achieved with prompt neutrons alone **

Critical mass In nuclear engineering, critical mass is the minimum mass of the fissile material needed for a sustained nuclear chain reaction in a particular setup. The critical mass of a fissionable material depends upon its nuclear properties (specific ...

, the minimum

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

of the nuclear reactor's fissionable material that can achieve criticality *

Criticality accident A criticality accident is an accidental uncontrolled nuclear fission chain reaction. It is sometimes referred to as a critical excursion, critical power excursion, divergent chain reaction, or simply critical. Any such event involves the uninten ...

, an uncontrolled nuclear chain reaction * Nuclear criticality safety, the prevention of nuclear and radiation accidents resulting from an inadvertent, self-sustaining nuclear chain reaction

Other terms

Critical thinking Critical thinking is the process of analyzing available facts, evidence, observations, and arguments to make sound conclusions or informed choices. It involves recognizing underlying assumptions, providing justifications for ideas and actions, ...

, in education * Criticality index, in risk analysis * Criticality matrix, a representation (often graphical) of failure modes along with their probabilities and severities * Self-organized criticality, a property of (classes of) dynamical systems which have a critical point as an attractor {{disambiguation