Earth's rotation Foucault in 1851, which consisted of a lead-filled brass sphere suspended from the top of the Panthéon in Paris. Because of the Earth's rotation under the swinging pendulum, the pendulum's plane of oscillation appears to rotate at a rate depending on latitude. At the latitude of Paris the predicted and observed shift was about clockwise per hour. Foucault pendulums now swing in museums around the world. Earth's rotation period relative to the Sun (solar noon to solar noon) is its "true solar day" or "apparent solar day". It depends on the Earth's orbital motion and is thus affected by changes
Kapitza's pendulum become stable in Kapitza's pendulum. The rotating solutions of the Kapitza's pendulum occur when the pendulum rotates around the pivot point at the same frequency that the pivot point is driven. There are two rotating solutions, one for a rotation in each direction. We shift to the rotating reference frame using formula_59 and the equation for formula_39 becomes: Again considering the limit in which formula_5 is much higher than the proper frequency formula_38, we find that the rapid-formula_5 slow-formula_65 limit leads to the equation: The effective potential is just that of a simple pendulum equation. There is a stable equilibrium