Re: Why does a spinning school class ring flip over?

The spinning class ring is an example of the famous "tippy top"
problem.  A list of references which explain the details of how this works
is given in the book "The Flying Circus of Physics" by Jearl Walker.

In order to find the solution to the equations of motion in which the top
(or the ring) flips over, it is essential to include the frictional force
of the table on the top.  Perhaps saying that "If you solve the equations
of motion, that's what happens." is not the type of answer you wanted.
However, the equations of motion are a set of coupled non-linear
differential equations, and seeing how they work is not simple!  Because
friction is an essential element of this effect, the energy and the
angular momentum of the top are not conserved by the equations.
Of course, the total system consisting of the top plus the table must obey
all the usual conservation laws. 

It is claimed that this trick can also be done with a hard-boiled egg.
(A raw egg will not work, because the insides will slosh around as the
egg is spun.)