An old friend once defined ki as “mass times acceleration,” which is, of course, the equation used in physics to determine the amount of force applied to an object. (Force = mass x acceleration.) Mass is the weight of an object. Acceleration is its speed at the time of impact.
A bullet has very little weight on the mass side of the equation but tremendous speed on the acceleration side. So it develops deadly force. A steam roller has huge weight on the mass side but low speed on the acceleration side. But because of its huge mass, it develops huge amounts of force and is capable of doing a tremendous amount of damage.
Our goal in a serious, life-threatening encounter is to apply as much force as possible to one of a number of vulnerable body targets in hopes of causing our opponents to either change their minds and want to quit or damage them so badly they can’t continue fighting, regardless of what they would like to do. We do this by applying the equation of force to our actions – accelerating our techniques as quickly as possible, then locking them briefly and allowing the momentum of our entire body mass to be brought to bear on our targets.
Whenever I throw a technique, I do so knowing full well my opponent will try to block it. So I always throw pretty much everything with all the force I can muster and direct each along a path that will best enable it to break through whatever my opponent puts between me and my target (breaking his arm or whatever if necessary) and still possess sufficient force to not only continue on but penetrate deep enough into their bodies to do internal damage. To achieve this, I call into play all the forces at my disposal – mental, physical, and spiritual. For me, one part of the surface or omote bunkai of our kata is discovering these forces and bettering my ability to harness and apply them at the point of contact.
Next time, I’ll discuss more of my thoughts on this, pressure points, and what I think about the theory that our traditional kata were never created to be used against another trained man. Thanks for your continued support. I appreciate it.
I am looking forward to your thoughts on the "trained man" issue.
ReplyDeleteMather Sensei,
ReplyDeleteIf I could humbly add to your reference to the formula for "Force", what is often overlooked is a significant part of this equation, the factor of "time".
The actual formula is "FORCE = MASS × VELOCITY²)/TIME). (FORCE equals MASS times VELOCITY "SQUARE" divided by TIME). As you already mentioned, both mass and velocity are factors effecting the amount of force generated by an action. It is well accepted that a person of greater mass will be assumed to be capable of generating greater force.
In fact, any increase or decrease in "mass" has an "arithmetic" effect on the resulting force, i.e., if a person is 200 lbs., he has double the force potential of someone who is 100 lbs, assuming all other factors remain the same.
However, the significance of Velocity in this equation is that any increase in velocity is "squared", thereby having a "geometric" affect on the resulting force. If the acceleration of the movement is doubled that factor is then squared, i.e., if you change the velocity from 100 mph to 200 mph, each number becomes squared resulting the first factor changing the equation by 1000 and the second by 4000, much more significant than "double"!
Obviously, maximum force would call for a martial artist to attempt to get the most effect from both factors, i.e., get the most mass behind the technique at the fastest acceleration. The contrast between the two factors would leave any knowledgeable person to conclude that if one factor were to be sacrificed for the other, then velocity would be given priority over mass.
With that accepted, my overall point here is the 3rd factor sometimes misunderstood and/or ignored by those examining these principles of physics and applying them if practical usage.
(continued in the next comment due to space)
(continued from last comment)
ReplyDeleteThat third factor is "TIME"and you will note by the equation that "TIME" has an INVERSE relationship to resulting force delivered.
Subsequently, the greater amount of time the lesser amount of resulting force contrasting with the lesser amount of time results in a greater amount of force. The "$64 Question" here is "what do we mean by "TIME" and how does that translate into practical application?
By "TIME", we are referring to the duration of contact/impact, or application of the "FORCE" in this equation. The equation would confirm that the an impact with a shorter duration of contact/application would have a greater resulting force while the longer the duration of impact would result in a lesser amount of force applied.
When reviewing this information one would conclude that a more accurate analogy for examining this phenomenon would be to compare the difference between a pushing/shoving action as contrasted with an explosive, whipping type of action. The same amount of energy can be exerted with a significantly different outcome.
One common experience where we might view to help confirm this is if we were to swing a wet towel to strike someone as compared to if we were to swing and "whip' the towel back at the moment of impact. Most have felt the difference.
An even more prominent example would be with the use of a "bull-whip". Although this is merely a thin light cord,if we simply swing it forward with the greatest speed possible, the result would be minimal. In contrast, if were to do the same, yet pull back quickly, thereby shortening the time of impact, the resulting force would be a much more significant and likely to bruise, cut, or tear depending upon what was struck.
We as martial artist of many "styles" have learned and studied many ways to generate force using all these factors and they are all "good". However, a significant argument can be made for the recognition that there are four critical elements to maximizing "FORCE" when executing and applying our martial arts strikes and/or kicks.
They are "CONCENTRATION OF POWER", "PROPER BODY DYNAMICS", "EXPLOSIVE FORCE", and "ACCURACY".
In conclusion, of these four elements, "EXPLOSIVE FORCE" best occurs when we are able to move the greatest amount of our mass at the most accelerated speed and with the shortest time of impact.
If for any reason we must sacrifice any one of these elements for another, it would be most prudent to give priority to "TIME", first, then "VELOCITY", and last, to "MASS". In my own quest to advance my application, study, and teaching of my own personal martial skills, these revelations have had significant impact on the way we train, practice and apply our striking and kicking techniques in contrast with the more "traditional" way we were taught.
That is the subject for another discussion and I have already taken too much of Master Mather's Blog comment space here. Thank you again for all that you share with us and an opportunity to interact together.
Shihan, fantastic explanation! I tell my students to hit as fast and powerfully as they can but withdraw immediately, as if trying to punch a hole in a very thick sheet of glass. They would want to mobilize all the force they could to break it but wouldn't want their fists passing through the hole, as they would be badly cut. Thanks, as always, for sharing your great knowledge with us.
ReplyDeleteShihan Pascetta, what a great post. Thank you for taking time to share with us all. While it is sometimes nice to keep things simple (Hit here. It hurts.) I, for one, enjoy the detailed explanations now and then. It reminds me of a time I was in Boston for a computer convention for work (at the time I was a programmer.) and on a whim I went to MIT and looked up karate in their library only to discover a Masters thesis on the physics of a karate punch that is used to break a cinder block.
ReplyDelete