Phase Space (Encyclopedia of Science and Religion)
In classical mechanics, the complete state of a particle is given by three components of momentum and three components of position. The phase space of a particle is a six-dimensional space, three axes for momentum and three for position, so that each point of a particle's phase space represents a complete state of the particle, and the entire phase space represents all possible states of the particle. For an N-particle system, the phase space has 6N dimensions, 6 for each particle, and a single point in the phase space represents the simultaneous complete states for each of the N particles.
See also PHYSICS, QUANTUM
W. MICHAEL DICKSON