In the most general sense, '''symmetry''' can be defined as a property that an entity has whereby it preserves some of its aspects under certain actual or possible transformations. A sphere is symmetrical because a rotation about its axis preserves its shape. A crystal [[structure]] is symmetrical with respect to certain translations in [[space]]. The existence of symmetries in natural [[phenomena]] and in human artifacts is pervasive. However, nature also displays important violations of symmetry: Some organic molecules come only or predominantly in left-handed varieties; the bilateral symmetry of most organisms is at best only approximate. | In the most general sense, '''symmetry''' can be defined as a property that an entity has whereby it preserves some of its aspects under certain actual or possible transformations. A sphere is symmetrical because a rotation about its axis preserves its shape. A crystal [[structure]] is symmetrical with respect to certain translations in [[space]]. The existence of symmetries in natural [[phenomena]] and in human artifacts is pervasive. However, nature also displays important violations of symmetry: Some organic molecules come only or predominantly in left-handed varieties; the bilateral symmetry of most organisms is at best only approximate. |