Spin a Go stone
1)Place a stone on a goban.
2)Give it a good spin.
3)Observe the stone as it spins and eventually rises in a vertical position.
Note: This was observed by spinning a glass go stone on a wooden floor goban. Could you replicate it? :)
togo: The physical explanation probably is the loss in rotational energy correlated with this transition (The mass is distributed nearer to the axis, if the axis is in the plane defined by the "sharp" edges of the stone. This is equivalent to have less rotational energy for the same
angular momentum.). The shape obviously would allow a
monotonic transfer from short axis respectively wide distribution to long axis respectively near distribution. Not so obvious is, that the gain of
gravitational energy never exceeds the loss of rotational energy. There the shape has some relevance, too; but more important is to simply have enough rotational energy. So spin fast enough!