Phase or phases may refer to:

Science

State of matter In physics, a state of matter is one of the distinct forms in which matter can exist. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma. Many intermediate states are known to exist, such as liquid crystal ...

, or phase, one of the distinct forms in which matter can exist *

Phase (matter) In the physical sciences, a phase is a region of space (a thermodynamic system), throughout which all physical properties of a material are essentially uniform. Examples of physical properties include density, index of refraction, magnetiza ...

, a region of space throughout which all physical properties are essentially uniform *

Phase space In dynamical system theory, a phase space is a space in which all possible states of a system are represented, with each possible state corresponding to one unique point in the phase space. For mechanical systems, the phase space usually ...

, a mathematical space in which each possible state of a physical system is represented by a point — this equilibrium point is also referred to as a "microscopic state" **

Phase space formulation The phase-space formulation of quantum mechanics places the position ''and'' momentum variables on equal footing in phase space. In contrast, the Schrödinger picture uses the position ''or'' momentum representations (see also position and moment ...

, a formulation of quantum mechanics in phase space *

Phase (waves) In physics and mathematics, the phase of a periodic function F of some real variable t (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t. It is denoted \phi(t) and expressed in such a scale that it v ...

, the position of a point in time (an instant) on a waveform cycle **

Instantaneous phase Instantaneous phase and frequency are important concepts in signal processing that occur in the context of the representation and analysis of time-varying functions. The instantaneous phase (also known as local phase or simply phase) of a ''comple ...

, generalization for both cyclic and non-cyclic phenomena * AC phase, the phase offset between alternating current electric power in multiple conducting wires **

Single-phase electric power In electrical engineering, single-phase electric power (abbreviated 1φ) is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when load ...

, distribution of AC electric power in a system where the voltages of the supply vary in unison **

Three-phase electric power Three-phase electric power (abbreviated 3φ) is a common type of alternating current used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires (or four including an optional neutral ...

, a common method of AC electric power generation, transmission, and distribution *

Phase problem In physics, the phase problem is the problem of loss of information concerning the phase that can occur when making a physical measurement. The name comes from the field of X-ray crystallography, where the phase problem has to be solved for the det ...

, the loss of information (the phase) from a physical measurement *

Phase factor For any complex number written in polar form (such as ), the phase factor is the complex exponential factor (). As such, the term "phase factor" is related to the more general term phasor, which may have any magnitude (i.e. not necessarily on the ...

, a complex scalar used in quantum mechanics *in

continuous Fourier transform A Fourier transform (FT) is a mathematical transform that decomposes functions into frequency components, which are represented by the output of the transform as a function of frequency. Most commonly functions of time or space are transformed, ...

, the angle of a complex coefficient representing the phase of one sinusoidal component

Other sciences

Archaeological phase In archaeology, a phase refers to the logical reduction of contexts recorded during excavation to nearly contemporary archaeological horizons that represent a distinct "phase" of previous land use. These often but not always will be a representat ...

, a discrete period of occupation at an archaeological site *

Color phase In biology, polymorphism is the occurrence of two or more clearly different morphs or forms, also referred to as alternative ''phenotypes'', in the population of a species. To be classified as such, morphs must occupy the same habitat at the s ...

, in biology, a group of individuals within a species with a particular coloration *

Gametic phase In genetics, a gametic phase represents the original allelic combinations that a diploid individual inherits from both parents. It is therefore a particular association of alleles at different loci on the same chromosome. Gametic phase is influence ...

, in genetics, the relationship between alleles at two chromosomal loci *

Lunar phase Concerning the lunar month of ~29.53 days as viewed from Earth, the lunar phase or Moon phase is the shape of the Moon's directly sunlit portion, which can be expressed quantitatively using areas or angles, or described qualitatively using the t ...

, the appearance of the Moon as viewed from the Earth *

Planetary phase A planetary phase is a certain portion of a planet's area that reflects sunlight as viewed from a given vantage point, as well as the period of time during which it occurs. Inferior planets The two inferior planets, Mercury and Venus, which ...

, the appearance of the illuminated section of a planet *

Phase separation Phase separation is the creation of two distinct phases from a single homogeneous mixture. The most common type of phase separation is between two immiscible liquids, such as oil and water. Colloids are formed by phase separation, though n ...

, in physical chemistry, the separation of a liquid mixture into two immiscible liquids above and below a meniscus *

Phase (syntax) In linguistics, the minimalist program is a major line of inquiry that has been developing inside generative grammar since the early 1990s, starting with a 1993 paper by Noam Chomsky. Following Imre Lakatos's distinction, Chomsky presents minima ...

, in linguistics, a cyclic domain (proposed by Noam Chomsky) *In biology, a part of the cell cycle in which cells divide (

mitosis In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is mainta ...

) and/or reproduce (

meiosis Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately resu ...

)

Music

Phase (band) Phase is a UK-based rock band formed in Larissa, Greece in 2003. It was founded by Thanos Grigoriou, who was performing and recording with various members until the line-up was completed in 2011, with the addition of Damos Harharidis and Vasili ...

, a Greek alternative rock band *

Phases (band) Phases (formerly known as JJAMZ and pronounced ''juh-jamz'') is an American indie pop band from Los Angeles, California composed of Jason Boesel (Rilo Kiley / Bright Eyes/Conor Oberst and the Mystic Valley Band), Alex Greenwald (Phantom Planet ...

, an indie pop American band, formerly known as JJAMZ * ''Phase'' (album), a debut studio album by an English singer Jack Garratt * ''Phases'' (The Who album), a box set of albums by The Who * ''Phases'' (I See Stars album), 2015 * ''Phase'' (Mildlife album), a 2017 album by Mildlife * ''Phases'' (Angel Olsen album), 2017 *"Phases", a song by English alternative rock band Keane from their 2019 album ''

Cause and Effect Causality (also referred to as causation, or cause and effect) is influence by which one event, process, state, or object (''a'' ''cause'') contributes to the production of another event, process, state, or object (an ''effect'') where the cau ...

Other entertainment

* "Phases" (''Buffy the Vampire Slayer''), a 1998 episode of the TV series ''Buffy the Vampire Slayer'' * Phases (.hack), fictional monsters in the .hack franchise *Phase, an incarnation of the DC Comics character usually known as

Phantom Girl Phantom Girl (Tinya Wazzo) is a superhero appearing in books published by DC Comics, and is a member of the Legion of Super-Heroes in the 30th and 31st centuries. In the Post-'' Zero Hour'' continuity, she is known as Apparition. She has the power ...

Other uses

Phase 10 Phase 10 is a card game created in 1982 by Kenneth Johnson and sold by Mattel, which purchased the rights from Fundex Games in 2010. Phase 10 is based on a variant of rummy known as contract rummy. It consists of a special deck equivalent to ...

, a card game created by Fundex Games * ''Phase'' (video game), a 2007 music game for the iPod developed by Harmonix Music Systems *

Phase (combat) A phase in combat is usually a period within a military operation of a longer duration that is a part of a serial chain of logically connected activities planned to culminate in a defined objective or goal. A phase is usually marked by achieveme ...

, usually a period of combat within a larger military operation *A musical composition using Steve Reich's

phasing A phaser is an electronic sound processor used to filter a signal, and it has a series of troughs in its frequency-attenutation graph. The position (in Hz) of the peaks and troughs are typically modulated by an internal low-frequency oscillat ...

technique

Science

Other sciences

Music

Other entertainment

Other uses

See also