Remember Leonhard Euler from the Satan’s Arithmetic post? Of
course you do. Now behold Euler’s Disc – probably the most
hypnotic thing ever. Look into the eyes, look into the eyes, not
around the eyes… and you’re under… The physics behind this
“scientific toy” can be found here, but basically, it comes down
to this: A spinning/rolling disk ultimately comes to rest; and
it does so quite abruptly, the final stage of motion being
accompanied by a whirring sound of rapidly increasing frequency.
As the disk rolls, the point P of rolling contact describes a
circle that oscillates with a constant angular velocity w. If
the motion is non-dissipative, w is constant and the motion
persists forever, contrary to observation (since w is not
constant in real life situations). In fact, precession rate of
the axis of symmetry approaches a finite-time singularity
modeled by a power law with exponent approximately -1/3
(depending on specific conditions). So there you have it.
Obviously, it’s important that you remember that ro