Phase

Phase or phases may refer to:

In science

Phase (matter), a physically distinctive form of a substance, such as the solid, liquid, and gaseous states of ordinary matter
- Phase transition is the transformation of a thermodynamic system from one phase to another
Phase (separation science)
- Mobile phase and Stationary phase in chromatography
- Aqueous phase and organic phase in liquid-liquid extraction
Phase (waves), the initial angle of a sinusoidal function at its origin
Polyphase system, a means of distributing alternating current electric power in multiple conducting wires with definite phase offsets
- Single-phase electric power
- Three-phase electric power
  - Three-phase, the mathematics of three-phase electric power
Phase problem, the loss of information (the phase) from a physical measurement
Phase factor, a complex scalar used in quantum mechanics
Continuous Fourier transform, the angle of a complex coefficient representing the phase of one sinusoidal component
Instantaneous phase, generalization for both cyclic and non-cyclic phenomena

Archaeological phase, a discrete period of occupation at an archaeological site
Lunar phase, the appearance of the Moon as viewed from the Earth
Planetary phase, the appearance of the illuminated section of a planet
In biology, a part of the cell cycle in which cells divide and reproduce
Color phase, in biology, a group of individuals within a species with a particular coloration

Phase (band), an alternative rock band
"Phases" (Buffy episode), an episode of the TV series Buffy the Vampire Slayer
Phases (.hack), fictional monsters in the .hack franchise
Phase IV, a 1974 science fiction movie directed by Saul Bass
Phase, an incarnation of the DC Comics character usually known as Phantom Girl
Phaze, an alternate world in Piers Anthony's Apprentice Adept series

Phase (syntax), a syntactic domain hypothesized by Noam Chomsky
Phase 10, a card game created by Fundex Games
Phase (video game), a music game for the iPod developed by Harmonix Music Systems
Phase (combat) usually a period of combat within a larger military operation
A musical composition using Steve Reich's phasing technique