nonmovement

Nonmovement denotes the absence of motion in a physical system or object. In everyday use it can refer to a temporary state in which an entity has zero velocity relative to a chosen frame of reference. Because motion is relative, nonmovement is also frame-dependent and carries the same caveats as the broader concept of rest.

Within classical physics, nonmovement is usually described in terms of rest or being stationary. An object at nonmovement may still experience forces; if the forces balance, the object is in static equilibrium. Conversely, a body can be moving in one frame and nonmoving in another, illustrating that there is no absolute state of motion.

In biology and medicine, nonmovement describes immobility or akinesia, a depletion or absence of voluntary movement. It is a symptom in several neurological disorders and can be studied in contexts such as Parkinsonian syndromes, where reduced movement is a key feature. Immobility also has practical implications for rehabilitation and patient care.

In philosophy and the arts, nonmovement or stillness is examined as a qualitative condition: a deliberate relinquishment of activity, a discipline of attention, or an aesthetic choice. In cognitive science, the perception of nonmovement contrasts with motion perception and can influence how motion cues are processed.

See also: motion, rest, stationary, inertia, akinesia.