11. See precession as well as nutation . 12. It includes librations but no nutations . 13. Simple nutation occurs in dorsiventral organs, such as flat leaves, both foliage and floral. 14. Finally, the top can wobble up and down; the inclination angle is the nutation angle. 15. They are also called nutations , except for the slowest, which is the precession of the equinoxes. 16. However, the combined effects of precession and nutation will cause the coordinates to change slightly over time. 17. Changes in temperature cause flowers to open or close by movements which resemble the simple nutation of dorsiventral organs. 18. Nutation is one of the corrections which must be applied to obtain the apparent place of an astronomical object.19. Its axial tilt does undergo nutation ; a slight, irregular motion with a main period of 18.6 years. 20. An example of precession and nutation is the variation over time of the orientation of the axis of rotation of the Earth.
