How does precession work?

1 Answer
Nov 19, 2016

See explanation


The primary cause for the precession motion of the polar axis is

gravitational torque ( rotation causing force ) of interactive

attractions from the nearer Luna and the farther Sun, upon the


In this revolutionary motion the polar axis revolves like a double

conical pendulum over a mildly corrugated surface of a double

right cone. The vertex of this cone is near the center of the Earth.

The semi angle of this cone is the Earth's obliquity ( axial tilt angle )


The poles describe small lateral oscillations ( due to nodding (

nutation) ), while moving along a small circle on the surface of the


The period of the precession revolution is great and is befittingly

called Great Year that is nearly 258 centuries.

The incognizant ( not easily perceived ) backward shift of either

equinox on the equator, wherein it is annual right overhead noon,

makes the total for about 258 centuries as 24 hours. This is a work

of this precession

For graphical depiction with animation, see the gyroscopic

precession in