Polhode


Also found in: Wikipedia.

polhode

[′pä‚lōd]
(mechanics)
For a rotating rigid body not subject to external torque, the closed curve traced out on the inertia ellipsoid by the intersection with this ellipsoid of an axis parallel to the angular velocity vector and through the center.

Polhode

 

in astronomy, the locus of the points of intersection of the earth’s surface by the earth’s instantaneous axis of rotation, that is, the path of the earth’s instantaneous pole. The polhode resembles a spiral whose loops alternately wind and unwind.