An infinite hierarchy of quantities with this property arises from the Korteweg–de Vries (“COR-tuh-veg-duh-VREEZ”) equation because it is fully integrable. In most scenarios, the Poisson bracket of the Hamiltonian with quantities with this property equals zero. Quantities conjugate to “cyclic” (0[1])or “ignorable” coordinates of a Lagrangian (“luh-GRONZH-ee-un”) have this property. (20[1])The correspondence of quantities with this property to differentiable symmetries of the action (20[1])is described by (*) Noether’s (10[1])theorem (10[3]0[1])(“NUR-turz”). By definition, (10[1]0[1])kinetic energy (10[1])has this property (10[2])in elastic (10[2])collisions. (10[11])In the absence (10[4])of (10[1])external forces, (10[1])momentum has this property because its time derivative equals zero. For 10 points, name this property of quantities that do not change as a (10[1])system (10[1])evolves. (10[1])■END■ (10[3])