Precession (disambiguation)

Not to be confused with Procession.

Precession refers to a specific change in the direction of the rotation axis of a rotating object, in which the second Euler angle (angle of nutation) is constant

Precession may specifically mean:

• Precession is the name of one of the Euler rotations
• Axial precession (astronomy) — the precession of the Earth's axis of rotation (also known as the "precession of the equinoxes"), or similar
• de Sitter precession — a general relativistic correction to the precession of a gyroscope near a large mass such as the Earth
• Larmor precession — the precession of the magnetic moments of electrons, atomic nuclei, and atoms about an external magnetic field
• Lense-Thirring precession — a general relativistic correction to the precession of a gyroscope near a large rotating mass such as the Earth
• Precession (mechanical) — the process of one part rotating with respect to another due to fretting between the two
• Thomas precession — a special relativistic correction to the precession of a gyroscope in a rotating non-inertial frame

Precession can also refer to change in the direction of an axis other than an axis of rotation:

• Apsidal precession, perihelion precession, or orbital precession, the rotation of the orbit of a celestial body

See also

• Axial tilt, also called axial inclination or obliquity, is the inclination angle of a planet's rotational axis in relation to a perpendicular to its orbital plane
• Conventional International Origin is a conventionally defined reference axis of the pole's average location over the year 1900
• Great year, also known as a Platonic year or Equinoctial cycle, is the time required for one complete cycle of the precession of the equinoxes
• Nutation is a slight irregular motion (etymologically a "nodding") in the axis of rotation of a largely axially symmetric object
• Polar motion is the movement of Earth's rotation axis across its surface