Gyroscopes have always fascinated me. Even after taking engineer
physics classes and learning the principles, I still find it amazing that the momentum of a spinning,
stationary object will resist an attitudinal perturbance. This video demonstrates the ability of a gyro
to hold up a relatively heavy mass, and the resulting precession. It is the same phenomenon that causes
the Earth's 26k-year cycle of the precession of the equinoxes.
Also demonstrated is nutation, which is the same kind of wobble that occurs with our moon that causes
a slight variation in the lines between the light and dark sides. It has the period of a lunar orbit.
The Earth also experiences nutation, but its period of 18.6 years is barely noticeable.