“symmetry”的概念、定义、翻译、参考文献-科学参考

symmetry

Physics

The set of invariances of a system. Upon application of a symmetry operation on a system, the system is unchanged. Symmetry is studied mathematically using group theory. Some of the symmetries are directly physical. Examples include reflections and rotation for molecules and translation in crystal lattices. Symmetries can be discrete (i.e. have a finite number), such as the set of rotations for an octahedral molecule, or continuous (i.e. do not have a finite number), such as the set of rotations for atoms or nuclei. More general and abstract symmetries can occur, as in CPT invariance and in the symmetries associated with gauge theories. See also broken symmetry; supersymmetry.

Chemistry

The property of an object that enables it to undergo certain manipulations, called symmetry operations, such that its new state is indistinguishable from its original state. Examples include inversion through a point, reflection through a plane, and rotation about an axis. The geometrical feature of the object with respect to which the symmetry operation is carried out is termed a symmetry element. In the above examples, a point through which inversion can be performed, a plane of reflection, and an axis of rotation are the symmetry elements. See also molecular symmetry.

Biology

Regularity in the arrangement of the parts of an organism. See bilateral symmetry; radial symmetry.

单词	symmetry
释义	symmetry Physics The set of invariances of a system. Upon application of a symmetry operation on a system, the system is unchanged. Symmetry is studied mathematically using group theory. Some of the symmetries are directly physical. Examples include reflections and rotation for molecules and translation in crystal lattices. Symmetries can be discrete (i.e. have a finite number), such as the set of rotations for an octahedral molecule, or continuous (i.e. do not have a finite number), such as the set of rotations for atoms or nuclei. More general and abstract symmetries can occur, as in CPT invariance and in the symmetries associated with gauge theories. See also broken symmetry; supersymmetry. Chemistry The property of an object that enables it to undergo certain manipulations, called symmetry operations, such that its new state is indistinguishable from its original state. Examples include inversion through a point, reflection through a plane, and rotation about an axis. The geometrical feature of the object with respect to which the symmetry operation is carried out is termed a symmetry element. In the above examples, a point through which inversion can be performed, a plane of reflection, and an axis of rotation are the symmetry elements. See also molecular symmetry. Biology Regularity in the arrangement of the parts of an organism. See bilateral symmetry; radial symmetry.
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