Take the 2-minute tour ×  When you spin an asymmetrically
weighted, 2D disk-shaped top, the heavy part actually rises to
the top. Why is this?    1.
http://www.youtube.com/watch?v=h0SZZTBQmEs    2.
http://www.youtube.com/watch?v=tDr26U49_VA  In the second video
it shows that this is because of friction but trying this on a
frictionless surface won't do much: The disk will go up and down
and still the heavy part will be on the top.  share|improve this
question  2 Answers 2  up vote 8 down vote accepted  I think the
solution has more to do with the tennis racket effect (see:
http://physics.stackexchange.com/a/17507/392).  Let me clarify
the disk with hole in it has two stable axes of rotation and one
unstable one. The unstable one is through the hole and the
stable one is across (below in green) and normal to the disk.
Axes Def  I have confirmed that without friction (and from the
videos in the link above) when the disk is spun on the unstable
axis, it will perdiodically flip. This is what caused it to flip
wh