| 词条 | Gyration |
| 释义 |
In geometry, a gyration is a rotation in a discrete subgroup of symmetries of the Euclidean plane such that the subgroup does not also contain a reflection symmetry whose axis passes through the center of rotational symmetry. In the orbifold corresponding to the subgroup, a gyration corresponds to a rotation point that does not lie on a mirror, called a gyration point.[1] For example, if you have a sphere rotating about any point that is NOT the center of the sphere, the sphere is gyrating. If it was rotating about its center, the rotation would be symmetrical and it would not be considered gyration. References1. ^{{cite book|last=Liebeck, Saxl |title=Groups, Combinatorics & Geometry|url=https://books.google.com/books?id=5h84AAAAIAAJ&lpg=PA439&ots=-E28qsV2GB&dq=%22gyration%20point%22%20-actual%20group&pg=PA439#v=onepage&q&f=false|publisher=Durham|accessdate=7 August 2010}} {{geometry-stub}} 1 : Euclidean geometry |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。