Erick Mead wrote:
By what physical mechanism then, you do you say that Master Sum is transmitting the dantien/hara movements that we see in the video?
This is a thread about baseline skills, Erick. The mechanisms Master Sum are using are above that baseline and they involve conditioning the body in unusual ways (in comparison with current western sports physiology) and coordinating a couple of odd approaches. What he does will naturally conform to the laws of physics, just as all card-tricks do.... but like all card-tricks unless you know the secret you're not going to be able to replicate it very well. If you look in post #6, I said, "So we've got Sum using a very clever set of mechanics (and yeah, Ignatius, I'm not going to say what they are on a public forum)".
So Sum is using some clever mechanical and physiological tricks... on top of the baseline skills. Ueshiba is using a little bit of one himself that is on top of the baseline skills (Sum is using it, too).
I've delineated what I think would be a good starting point for a must-have skill level in all Aikido dojo's. If you want to make a side topic and try and guess what the secondary skills are, make a go at it... I'll tell you if you're right, but I'm not going to get into a comprehensive side-issue.
Other than that, I don't want to get into another argument about gyrational movement.... certainly Tohei and Ueshiba are not using gyrational movement when they do a static display of this sort of power. Even in the simple bouncing they're using, the mechanics are more adequately described by elastic potentials and vector forces (although the tricks I mentioned get too complex for that simple model).
Why not just stick to baseline skills of static and simple-movement descriptions of kokyu/ki skills for use in Aikido dojos?