# Precession

Precession is a change in the orientation of the rotational axis of a rotating body. It can be defined as a change in direction of the rotation axis in which the second Euler angle (nutation) is constant. In physics, there are two types of precession: torque-free and torque-induced.

In astronomy, "precession" refers to any of several slow changes in an astronomical body's rotational or orbital parameters, and especially to the Earth's precession of the equinoxes. See Precession (astronomy).

### Other articles related to "precession, precessions":

Apsidal Precession
... In celestial mechanics, perihelion precession, apsidal precession or orbital precession is the precession (rotation) of the orbit of a celestial body ...
Two-body Problem In General Relativity - Historical Context - Apsidal Precession
... See also Apsidal precession and Laplace–Runge–Lenz vector If the potential energy between the two bodies is not exactly the 1/r potential of Newton's gravitational law but differs only slightly, then the ellipse ... This apsidal precession is observed for all the planets orbiting the Sun, primarily due to the oblateness of the Sun (it is not perfectly spherical) and the attractions of the ... (the periapsis and apoapsis, respectively) apsidal precession corresponds to the rotation of the line joining the apsides ...
Lense–Thirring Precession - Derivation
... Therefore the Earth introduces a precession on all gyroscopes in a stationary system surrounding the Earth ... This precession is called the Lense–Thirring precession with a magnitude As an example the latitude of the city of Nijmegen in the Netherlands is used for ... This latitude gives a value for the Lense–Thirring precession of The total relativistic precessions on Earth is given by the sum of the De Sitter precession and the ...
Astronomy - Perihelion Precession
... This is called perihelion precession or apsidal precession ... Discrepancies between the observed perihelion precession rate of the planet Mercury and that predicted by classical mechanics were prominent among the forms of ... See also nodal precession ...
SERF - Typical Operation
... of low noise diode lasers to polarize and monitor spin precession ... An orthogonal probe beam detects the precession using optical rotation of linearly polarized light ... In a typical SERF magnetometer, the spins merely tip by a very small angle because the precession frequency is slow compared to the relaxation rates ...

### Famous quotes containing the word precession:

But how is one to make a scientist understand that there is something unalterably deranged about differential calculus, quantum theory, or the obscene and so inanely liturgical ordeals of the precession of the equinoxes.
Antonin Artaud (1896–1948)