for illustration, if a physical system behaves the same, regardless of how it is oriented in space, the physical laws that govern it are rotationally symmetric; from this symmetry, noether's theorem shows the angular momentum of the system must be conserved. the physical system itself need not be symmetric; a jagged asteroid tumbling in space conserves angular momentum despite its asymmetry. rather, the symmetry of the "physical laws" governing the system is responsible for the conservation law. as another example, if a physical experiment has the same outcome at any place and at any time, then its laws are symmetric under continuous translations in space and time; by noether's theorem, these symmetries account for the conservation laws of linear momentum and energy within this system, respectively.