Definitions for "Phase transition"
In physics, a change from one state of matter to another. In dynamical systems theory, a change from one mode of behavior to another.
In dynamical systems, a change from one mode of behavior to another, such as from continuous to chaotic behavior.
A large, global change occurs quickly in a system with little or no intermediate forms. Often, the global change occurs through small, local, gradual changes. Example: water goes through a phase transition when heated to steam.
Keywords:  junctures, sleep, wake, cycle, major
One of the two junctures of the major sleep and wake phases in the 24 hour sleep-wake cycle.