In physics, a conservation law states that a particular measurable property of an isolated physical system does not change as the system evolves. The following is a partial listing of conservation laws that have never been shown to be inexact. The willingness to question previously held truths and search for new answers resulted in a period of major scientific advancements, now known as the Scientific Revolution. ...

• conservation of energy
• conservation of momentum
• conservation of angular momentum
• conservation of electric charge
• conservation of color charge
• CPT symmetry

There are also approximate conservation laws. These are approximately true in particular situations, such as low speeds, short time scales, or certain interactions. Conservation of energy, also known as the first law of thermodynamics, is possibly the most important, and certainly the most practically useful of several conservation laws in physics. ... In physics, momentum is a physical quantity related to the velocity and mass of an object. ... In physics, angular momentum intuitively measures how much the linear momentum is directed around a certain point called the origin; the moment of momentum. ... Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interactions. ... In quantum chromodynamics (QCD), color or color charge refers to a certain property of the subatomic particles called quarks. ... CPT-symmetry is a fundamental symmetry of physical laws under transformations that involve the inversions of charge, parity and time simultaneously. ...

• conservation of baryon number (See chiral anomaly)
• conservation of flavor (violated by the weak interaction)
• conservation of mass (only in nonrelativistic theories)
• conservation of parity
• CP symmetry.

Noether's theorem expresses the equivalence which exists between conservation laws and the invariance of physical laws with respect to certain transformations (typically called "symmetries") for systems which obey the Principle of least action and hence having a Lagrangian and a Hamiltonian (See Classical mechanics, Hamiltonian mechanics for details). For instance, time invariance implies that energy is conserved, translation invariance implies that momentum is conserved, and rotation invariance implies that angular momentum is conserved. In particle physics, the baryon number is an approximate conserved quantum number. ... Chiral anomaly is the anomalous nonconservation of charge in a quantized theory of chiral fermions coupled to a background gauge field. ... In particle physics, flavor is a property of a fermion that identifies it, a label that specifies the name of the particle. ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... The law of conservation of mass/matter states that the mass of a system of substances is constant, regardless of the processes acting inside the system. ... Albert Einsteins theory of relativity is a set of two scientific theories in physics: special relativity and general relativity. ... In physics, a parity transformation (also called parity) is the simultaneous flip in the sign of all spatial coordinates: A 3×3 matrix representation of P would have determinant equal to -1, and hence cannot reduce to a rotation. ... CP-symmetry is a symmetry obtained by a combination of the C-symmetry and the P-symmetry. ... Noethers theorem is a central result in theoretical physics that expresses the one-to-one correspondence between the symmetries and the conservation laws. ... Invariant may have meanings invariant (computer science), such as a combination of variables not altered in a loop invariant (mathematics), something unaltered by a transformation invariant (music) invariant (physics) conserved by system symmetry This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the... Square with symmetry group D4 Symmetry is a characteristic of geometrical shapes, equations, and other objects; we say that such an object is symmetric with respect to a given operation if this operation, when applied to the object, does not appear to change it. ... The principle of least action was first formulated by Pierre-Louis Moreau de Maupertuis, who said that Nature is thrifty in all its actions. See action (physics). ... A Lagrangian of a dynamical system, named after Joseph Louis Lagrange, is a functional of the dynamical variables which concisely describes the equations of motion of the system. ... In physics, Classical mechanics is one of the two major sub-fields of study in the science of mechanics, which is concerned with the motions of bodies, and the forces that cause them. ... Hamiltonian mechanics is a re-formulation of classical mechanics that was invented in 1833 by William Rowan Hamilton. ...

Philosophy of conservation laws

• Things that remain unchanged, in the midst of change

The idea that some things remain unchanging throughout the evolution of the universe has been motivating philosophers and scientists alike for a long time.

In fact, quantities that are conserved, the invariants, seem to preserve what some would like to call some kind of a 'physical reality' and seem to have a more meaningful existence than many other physical quantities. These laws bring a great deal of simplicity into the structure of a physical theory. They are the ultimate basis for most solutions of the equations of physics. In physics, invariants are usually quantities conserved (unchanged) by the symmetries of the physical system. ... The willingness to question previously held truths and search for new answers resulted in a period of major scientific advancements, now known as the Scientific Revolution. ...