出典:Wikipedia
出典:『Wikipedia』 (2011/07/04 19:09 UTC 版)
The screw axis (helical axis or twist axis) of an object is a line that is simultaneously the axis of rotation and the line along which a translation occurs. Chasles' theorem shows that each Euclidean displacement in three dimensional space has a screw axis, and the displacement can be decomposed into a rotation about and a slide along this screw axis.