Why this rotation occurs is not entirely clear yet.

The rotation occurs in the up motion of the wing.

It will be at once obvious that a rotation has occurred, round an identifiable centre.

The rotation occurs in the sense prescribed by the right-hand rule.

In general, the larger the angle, the more reversible rotation occurs.

On skis, the foot is pointed in the direction of travel, and the rotation onto the edge occurs by moving the leg to the side.

Therefore at most one rotation will occur within this loop.

The major rotation will occur in early January, but the exact date has not been set.

As the liquid never spills, the rotation can all occur within the same plane.

Thus no rotation occurs in this system as well.