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nutation
[ noo-tey-shuhn, nyoo- ]
noun
- an act or instance of nodding one's head, especially involuntarily or spasmodically.
- Botany. spontaneous movements of plant parts during growth.
- Astronomy. the periodic oscillation observed in the precession of the earth's axis and the precession of the equinoxes.
- Mechanics. the variation of the inclination of the axis of a gyroscope to the vertical.
nutation
/ njuːˈteɪʃən /
noun
- astronomy a periodic variation in the precession of the earth's axis causing the earth's poles to oscillate about their mean position
- physics a periodic variation in the uniform precession of the axis of any spinning body, such as a gyroscope, about the horizontal
- Also calledcircumnutation the spiral growth of a shoot, tendril, or similar plant organ, caused by variation in the growth rate in different parts
- the act or an instance of nodding the head
nutation
/ no̅o̅-tā′shən /
- A small, cyclic variation of the Earth's axis of rotation with a period of 18.6 years, caused by tidal forces (mostly due to the gravity of the Moon). Nutation is a small and relatively rapid oscillation of the axis superimposed on the larger and much slower oscillation known as precession . Although discovered in 1728 by the British astronomer James Bradley (1693–1762), nutation was not explained until two decades later.
- A slight curving or circular movement in a stem, as of a twining plant, caused by irregular growth rates of different parts.
Derived Forms
- nuˈtational, adjective
Other Words From
- nu·tation·al adjective
Word History and Origins
Word History and Origins
Origin of nutation1
Example Sentences
Why did he not continue in the same spot, except for the slow change caused by the nutation or nodding of Venus?
It is affected by the motions of Precession and Nutation, of which the former has been known since the time of Hipparchus.
These two motions are defined with greater detail in the articles Precession of the Equinoxes and Nutation.
Many growing stems have also a movement of Nutation, that is, of nodding successively in different directions.
In the case of nutation the North Pole remains in the same geographical position, but points to a different part of the heavens.
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