constant of the motion پایای ِ جنبش pâyâ-ye jonbeš Fr.: constante de mouvement Classical mechanics: A variable X whose total rate of change dX/dt
along the path of a → dynamical system is zero. In other words,
a function of an object’s position, velocity, or both that does not change even as the
object moves. For example, the total energy of a
→ simple harmonic oscillator is a constant of the motion.
Quantum mechanics: An → observable
that remains constant in time. As an example, the energy
is a constant of the motion of all systems whose → Hamiltonian
does not depend explicitly upon time.
See also: → constant; → motion. |
