Fajin is not from a "coiled spring" in Classical Tai Chi

To quote an ARTICLE by Tim Chan:  "We live in a different world today. We are more restrained and much less inclined, for various reasons, to using the same approach as these masters.  That said, we should be looking for a less violent and more structured approach to understanding the art. And I find we can achieve this objective by expounding Chinese wisdom through Western science such as relying on the discipline of physiology and mechanics."

Tim Chan continues: "Let’s consider a spring coil that is compressed tightly as depicted in the diagram below. An inward force from the wall equally balances the inward force from the compression. This creates inertia within the coil. When the spring is released, acceleration creates a net outward ‘explosive’ force. This is shown in the diagram where the coil springs forward.
There are quite a few  Youtube videos on the subject of Fajin, Fajing, Fa-Jing, etc. Like the Tai Chi itself, the word "internal" is spoken of in those demonstrations. Usually what we see is the solid rooting of feet in order to generate power from the legs and push or punch something. I did this for years in both Yang Style and Wu's Style Tai Chi "large frame" forms. On the contrary, the Compact Form of Classical Tai Chi as passed on from Wu Chien Chuan to Young Wabu to Stephen Hwa and his students uses the compression and decompression of the torso to generate Fa Jing power.  

There is also discussion in books and articles about the use of a "reaction force". Said reaction force uses the legs to transmit power from the ground as a solid base. Some of these same documents have even attempted to show the "physics" of Fa Jing. One sees this in many demonstrations where a Master pushes against the outstretched arms of his disciple and sends them flying..." Fa Jing".

There is an excellent video and explanation of Fajin by Master Stephen Hwa at   Besides the fact that Master Stephen Hwa demonstrates with Tom Kostusiak that Fa Jing can be done with a less than "solid base" to use his terminology. His technique reflects a fa jing that can move in both a 2 dimensional and 3-dimensional fashion as he demonstrates. He had a slight upward force which then lifted Tom and then drove him back. I do not recall ever seeing this lifting and driving of the opponent in Boxing where one sees knockouts most of the time.  Which brings up the next point of how Classical Tai Chi might design a scientific "diagram" that illustrates this. It seems that what his diagrams demonstrate is at best a fa jing of longer duration. They do not demonstrate a burst such as he did with Tom. In his scheme, one has to be pushed in order to effect a rebound by using the ground aka the spring is compressed before it can fa jing. 

How one might design such a spring to reflect the internal energy of Classical Tai Chi is beyond my drafting capabilities at this point.  Such a spring would have to reflect itself in more than 2 dimensions. It would have to reflect how internal energy is generated from inside the spring itself.  It would have to show that it is not entirely dependent on a "solid base".  It would have to show however that a "solid base" is necessary to fulfill Newton's law of action and reaction since there is still a brace needed at times. 

Further: We, of course, have the inevitable referral to the "Tai Chi Classics" as the final authority of what the old Masters required. It is interesting to note however that those same old Masters had to rely on fighting in order to prove their arts.  Many, to this day,  still feel that fighting is the only way to prove the effectiveness.  Yet how does this hold up in today's world?  For one thing, most of today's "combat" in Tai Chi is done under controlled conditions.  Safety equipment, gloves, footpads, rings, antibiotics, timers for "rounds" and more are required. If that same "combat" is not adhering to "tucking", being "upright", etc. how is it showing the "effectiveness"?  In my humble opinion, it looks more like flailing with no glimpse of a tuck to be had. If the old masters had no technology to prove or refine the art, what does it say if it is not being refined or proven in this era of overwhelming technology?