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Old 09-20-2006, 05:11 PM   #73
Erick Mead
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Dojo: Big Green Drum (W. Florida Aikikai)
Location: West Florida
Join Date: Jun 2005
Posts: 2,616
Re: What is Weight Transfer(Taijuuidou)??

Mike Sigman wrote:
I'm saying that a linear-forces model is also self-correcting. The idea of "six directions" training, etc., is related to linear/vector directions, not the gyroscopic stability you're talking about. Think of a bead with small bungee strings pulling the bead up, down, forward, back, left, right.

When it comes to the applications of the linear forces, as in "aiki", I think levers and pullies is pretty much all there is to it, in true motion involving jin/kokyu.
"True?" An interesting qualifier. All continuous forces, regardless of curvature, are "linear" but I know what you mean.

Let me first show why that model does not physically answer the equilibrium conditions of known martial positions and ordinary "static" stability, i.e. -- not in overt motion.

The six direction "linear" forces model has gravity and your upright resistance support, that's two directions. Plus it has left and right -- forward and back, all of which can only be created statically by moment lever action of friction against the same ground. Kiba-dachi, kokutsu-dachi and zenkutsu dachi are examples of "braced" postures against the ground, (which BTW have extremely limited hip sway).

On the other hand, I can be perfectly comfortable and balanced with a two hundred pound guy laid across my hip girdle in mid air, standing with my heels together. No large sideways or forward-back bracing is available in this posture, and I am not a kangaroo with an available tripod tail, so something else is obviously working for me.

In fact, using your model we have only three forces acting -- two in direct opposition (up down) at your center of mass, and one (friction) that does NOT act at the center of your bungee bead system. laterla sway would only be opposed by eccentric components of your own bracing support force and the ressitant friction against the ground. In fact, the force couple created by forward motion and opposing friction stopping the foot creates rotation, i.e. -- torque. This looks like potential kuzushi to me. It is also rotary and therefore gyroscopic in form and action.

Your form when standing is a self-supporting pylon fixed at its foot by weight and ground friction. An oscillating pole also obeys gyroscopic principles -- which is why your car antenna, when sprung
and released takes on an elliptical orbit sway, and as it loses momentum its radius of sway decreases and and the orientation of the ellipse travelled by the tip precesses as it slows down and loses momentum -- just like the axis of a slowing top. (Guys, please don't ding the finish with the end button or break it off or your wife will be really mad).

You maintain your bipedal balance by oscillating and active dampening a spring-loaded double universal joint at the center of this pole. Because it is spring loaded and muscle actuated you can wobble this thing back and forth quite fast over a very small radius. You learn as child to make this oscillation dampening very very small, and its frequency therefore very high. We are looking for angular momentum and kinetic energy is proportional to the mass but the square of the velocity, thus high frequency oscillations give a suprisingly large angular moment to use.

The fact of this dynamic oscillation gives the human body true gyroscopic stability, like the wheels of the bike, which from a static perspective (your six-direction equilibrum model is a system of static springs) seems like a violation of conservation laws -- i.e. -- without the wheels spinning the bike will easily topple fall over, so a snap shot of the system statically does not show you the torque energy that provides it stability dynamically, and the faster it turns the more stability it has. For this reason the toddler, whose sway is still too large and his stabilizing oscillation too slow falls over all the time, and usually stands with a very wide stance.

The periodic torque you are experiencing in each hip as you oscillate or walk in dynamic equilibrium is manipulable as I have described.

Mike Sigman wrote:
The "tradition" of the forces stretched between Heaven and Earth and harmonizing with them has never, that I have ever seen, mentioned anything other than sometimes circular application of linear forces.
How is "circular application of linear forces" NOT gyroscopic in nature?


Erick Mead
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