Erick Mead wrote:
As a physical principle, juji depicts the action of perpendicular component forces. In motion in a linear plane, perpendicular forces resolve to linear diagonal forces in proportion to magnitude of the two components. Judo in contrast focuses on using or creating an offsetting pair of opposed forces (a couple) to initiate rotation. In an already rotational or vibrational frame, force perpendicular to the rotational or vibrational plane have resulting perpendicular forces that are not linear, because of the inherent angular momentum, the resultant force depends on where along the radius of rotation/vibration the output is taken. The fact of that momentum also allows the sytem to absorb a great deal of energy withou out readily perceptible change.
Similar to the application of topspin or backspin
Another analogy, is, I suppose the result of what you get when you hit a ball with "english
" on it in pool into another ball.