Astrophysics (Index)About

conservation law

(property that remains unchanged by physical phenomena)

Physics has uncovered a number of types of quantities that remain unchanged through physical actions, and the term conservation law indicates the unchanging nature of these values. Such a constant value (per such a law) is often used in analyzing or predicting the results of a physical event, serving as a hint toward what must be happening. They are commonly used in dynamics (e.g., orbits, the motions within galaxies, clouds, etc.) and in quantum mechanics which has a number.

Some relations that are not absolutely universal can still be treated as conservation laws for many purposes: for example, for many purposes, mass and energy can each be treated as constant, but in other cases, they must be treated as interchangeable, i.e., under a single conservation law.

Conserved quantities include momentum, angular momentum, energy, electric charge, and several other quantum numbers.

Further reading:

Referenced by pages:
Jacobi integral
radiation pressure
specific angular momentum (J)