Tenkan and Centrifugal Force

Ron Ragusa wrote: Forces arise from the relative motions of bodies. Tenkan is not an application of force it is a contributing factor in the generation of force.

No, I'm not going to let you off so easily, Ron, since you deliberately inserted yourself.

Bill said:
Tenkan exploits the power of centrifugal force, for instance.

I then said:
Besides, even if there were a centrifugal force (which there's not), I don't think that's the idea behind tenkan; tenkan still uses the opponent's force.

You then contributed:
Not all tenkan is done just to match uke's body direction. There are numerous techniques that use tenkan as part of the take down or projection of uke during the application of the technique. The tight circular motion executed by nage forces part of uke's body to assume a path with a greater radius; the part of uke's body being held by nage will travel a path more in line with nage's vector.

Tenkan is a turn. It is an entry into an attack. "Relative motions" ain't going to cut it, Ron. Nor is your idea of not matching... that is what "ai ki" means. Nor is your "tight circular motion executed by nage forces uke's body..." stuff. You've just blown the basics of Aikido. You don't get off with the attemped escape of "Tenkan is not an application of force it is a contributing factor in the generation of force." You got some 'splainin' to do, Lucy.

Regards,

Mike Sigman

MJ had some pretty nasty hang time, specially talented or not

quote [MJ had some pretty nasty hang time, specially talented or not] quote

Very true indeed . But I would argue his skills are not supra-human, rather they are the product of natural talent and dedicated work. Like I stated, this is a lame analogy, but I feel the idea is universal.
Moses Jenkins

Mike Sigman wrote: No, I'm not going to let you off so easily, Ron, since you deliberately inserted yourself. Bill said: Tenkan exploits the power of centrifugal force, for instance. I then said: Besides, even if there were a centrifugal force (which there's not), I don't think that's the idea behind tenkan; tenkan still uses the opponent's force. You then contributed: Not all tenkan is done just to match uke's body direction. There are numerous techniques that use tenkan as part of the take down or projection of uke during the application of the technique. The tight circular motion executed by nage forces part of uke's body to assume a path with a greater radius; the part of uke's body being held by nage will travel a path more in line with nage's vector. Tenkan is a turn. It is an entry into an attack. "Relative motions" ain't going to cut it, Ron. Nor is your idea of not matching... that is what "ai ki" means. Nor is your "tight circular motion executed by nage forces uke's body..." stuff. You've just blown the basics of Aikido. You don't get off with the attemped escape of "Tenkan is not an application of force it is a contributing factor in the generation of force." You got some 'splainin' to do, Lucy. Regards, Mike Sigman

Tenkan is not only an entry into an attack. It is any turning motion executed during the application of a technique. I never came up with an idea of not matching, I stated that it is not just executed to match uke's body direction.

Since you don't actually study Aikido, have from what I can see have no rank in Aikido and don't really know anything about the basics of Aikido perhaps you should put 20 or so years in on the mat before you set yourself up as an authority on the subject.

Mike Sigman wrote: There is no "centrifugal force"... what you feel is an object attempting to maintain it's straight-line direction (Newton's First Law, I believe) while you try to contain it in rotational movement.

Correctamundo!
Earn a gold star from most of my maths and science teachers. Except Mr Kugelman: he never gave them out. Just detentions. But anyway...

You seem awfully caught up on that one point (albeit amongst many others of similar importance...). Genuinely caught up? Or just more grist for the mill?

Should I call "Aikido" "that thing"?
Or everything else for that matter? Where, in the Gospel According to Mike, does one draw the line?
Might get confusing. How about I just call it Aikido?

IMNSHO...

Mike Sigman wrote: I don't have a problem with developing the skills you're talking about, Rupert. What I have a problem with is the assertion that "Tenkan" by definition means the application of these forces. It means "turn". It is a form of entering an attack. You can enter an attack with tenkan and apply a kokyu nage without ever applying "centrifugal" or "centripetal" force. Mike Sigman

Tenkan is turning, yes, but if all you do is turn then you have nothing but avoidance. If, however, you start to control uke, as in say irimi-nage, you draw him in with centripetal force and afterwards spit him off with centrifugal force. Ikkyo is a little different - the centripetal force draws him in the whole way to the ground such that he goes down in a spiral. So, may the force be with you, for without it you can only run away (avoid).

It is also possible to avoid tenkan and throw in a straight line with no centripetal/centrifugal force.

Ron Ragusa wrote: Tenkan is not only an entry into an attack. It is any turning motion executed during the application of a technique. I never came up with an idea of not matching, I stated that it is not just executed to match uke's body direction. Since you don't actually study Aikido, have from what I can see have no rank in Aikido and don't really know anything about the basics of Aikido perhaps you should put 20 or so years in on the mat before you set yourself up as an authority on the subject.

Lame, Ron. Now we see what "universal love" is when it's scratched.

Mike

Stuart Norton wrote: Correctamundo! Earn a gold star from most of my maths and science teachers. Except Mr Kugelman: he never gave them out. Just detentions. But anyway... You seem awfully caught up on that one point

Pardon me, but if you look at who started this thread, it wasn't me. Or did you notice that?

Should I call "Aikido" "that thing"? Or everything else for that matter? Where, in the Gospel According to Mike, does one draw the line? Might get confusing. How about I just call it Aikido?IMNSHO...

Why do I care what you call it? Shouldn't you be concerned what it is recognized as? As I've said a few times... are you trying to convince the beginners and your peers, or are you trying to convince the experts?

Regards,

Mike Sigman

Mike Sigman wrote: Lame, Ron. Now we see what "universal love" is when it's scratched. Mike

Universal love??????????????

In any event, you still haven't presented your Aikido credentials.

I am not a physics student or an engineer, so I'm not going to get too hung up on the semantics. Whether it's centrifugal or centripetal, etc. is not of primary interest to me.

Example: When I pivot (I'm Yoshinkan) and enter into Kote Gaeshi, I can feel some extra energy forming as my center of gravity nears uke's. I have been visualizing this energy concentrating and being released again as I bring uke around and I feel that this has improved my performance. To me, it now feels more like I am pulling uke back into the wrist return like a yo yo. It's a very subtle thing, but also it feels very powerful.

I'm interested in the physics involved, because if I can understand it and apply it more effectively, I think IT's the extra power (that appears to be present beyond the exertion of normal human strength).

IMHO, O-Sensei was equally as clever as Einstein and Hawking- He was able to perceive and utilize the forces of nature, but he explained it and applied it in a different way. If anything gave him 'his power', this was it.

My view is that all the major waza owe their effectiveness to their exploitation of the various natural forces. This seems to fit the definition of Ai Ki Do.

Bill Danosky wrote: I am not a physics student or an engineer, so I'm not going to get too hung up on the semantics. Whether it's centrifugal or centripetal, etc. is not of primary interest to me. Example: When I pivot (I'm Yoshinkan) and enter into Kote Gaeshi, I can feel some extra energy forming as my center of gravity nears uke's. I have been visualizing this energy concentrating and being released again as I bring uke around and I feel that this has improved my performance. To me, it now feels more like I am pulling uke back into the wrist return like a yo yo. It's a very subtle thing, but also it feels very powerful. I'm interested in the physics involved, because if I can understand it and apply it more effectively, I think IT's the extra power (that appears to be present beyond the exertion of normal human strength). IMHO, O-Sensei was equally as clever as Einstein and Hawking- He was able to perceive and utilize the forces of nature, but he explained it and applied it in a different way. If anything gave him 'his power', this was it. My view is that all the major waza owe their effectiveness to their exploitation of the various natural forces. This seems to fit the definition of Ai Ki Do.

Excellent.

Mike Sigman wrote: Pardon me, but if you look at who started this thread, it wasn't me. Or did you notice that?

Yep, noticed that. Thanks for the tip.
You were the one going on about how by God, it just shouldn't be called "centrifugal force", because it just wasn't. Noticed that too. Hence the comment. You seem to enjoy getting everyone caught up on minutae.

Mike Sigman wrote: Why do I care what you call it? Shouldn't you be concerned what it is recognized as? As I've said a few times... are you trying to convince the beginners and your peers, or are you trying to convince the experts? Regards, Mike Sigman

Nah, I'm concerned what it is.
Nice try though. ;-)

Mike Sigman is correct. Tenkan is a turning entry into (actually alongside or behind) the line of attack, without interfering with the movement in an inertiaI frame of reference. This is "aiki"! It has nothing to do with centripetal or centifugal (which is a pseudo!) force.

The "tenkan takedown techniques" Ron refers to is more the result of gravity and Newton's 2nd Law of motion - NOT centripetal force.

Larry Camejo wrote: Reminds me of the progression from Nanahon no Kuzushi to the Ura Waza of the Nage no Kata in Shodokan. It starts off as kuzushi training and then develops into application of kuzushi to throw using the weak lines and then turning while breaking balance along the weak lines. This is not only the ability to utilise inertia in a circular fashion, but targeted application of force to manipulate the arcs, circles and spirals while keeping Uke off balance imho. LC

I agree. That kata is a good example.

Ron Ragusa wrote: Universal love?????????????? In any event, you still haven't presented your Aikido credentials.

This is sooooo trite and typical of New Agers.... when they screw up they look for some reason to attack personally. All you need to know, Ron, is that I have credentials but I don't claim to be an Aikido teacher. Now see if you can BS your way out of the fact that you don't seem to know what tenkan is and you just revealed it to all the world. Quit worrying about me and see if you can throw in enough hurried posts on topic that everyone forgets! Back to tenkan.

Regards,

Mike Sigman

Bill Danosky wrote: I am not a physics student or an engineer, so I'm not going to get too hung up on the semantics. Whether it's centrifugal or centripetal, etc. is not of primary interest to me. Example: When I pivot (I'm Yoshinkan) and enter into Kote Gaeshi, I can feel some extra energy forming as my center of gravity nears uke's. I have been visualizing this energy concentrating and being released again as I bring uke around and I feel that this has improved my performance. To me, it now feels more like I am pulling uke back into the wrist return like a yo yo. It's a very subtle thing, but also it feels very powerful. I'm interested in the physics involved, because if I can understand it and apply it more effectively, I think IT's the extra power (that appears to be present beyond the exertion of normal human strength). IMHO, O-Sensei was equally as clever as Einstein and Hawking- He was able to perceive and utilize the forces of nature, but he explained it and applied it in a different way. If anything gave him 'his power', this was it. My view is that all the major waza owe their effectiveness to their exploitation of the various natural forces. This seems to fit the definition of Ai Ki Do.

OK, I see where you're coming from, but I think you're missing the point. When you "pivot", that's the tenkan, which has the point of moving out of the line of attack and placing your body in a position to go somewhat with the attack ("aiki"). As you begin to "lead", in the technique you're mentioning, you are indeed making use of "centrifugal force".... that's what you're saying. I don't have a problem with that, but as you lead into a technique (the lead into kote gaeshi, in this example), you are already past the tenkan. That's why I pointed out that a tenkan can just as easily lead into a kokyu throw as into a throw that uses "centrifugal force". The tenkan is the turn that initially allows you to avoid the line of attack... all else is the lead and then the technique. Even if I choose to go into Sayu Nage at that point there is a slight lead/entry (not really involving centrifugal force) into an off-balance direction and then the consummation of technique. But the tenkan was the "pivot" that took me off the line of attack, Bill, not the lead or the actual technique.

Insofar as the physics goes, you can see that it's not the centrifugal force.... however, the physics is indeed interesting. Tohei actually does a pretty good job of trying to explain the application of forces through his Ki paradigm, but he's not clear enough so that it's obvious what he's saying. The essential "force" in Aikido that is always spoken of in relation to "Ki" is the force of "kokyu ryoku", or "jin" (sometimes spelled "jing") in Chinese. It's the resisting force that Tohei exhibits when he is standing on one leg (or both legs, or lying down, or from behind, etc.... you can manifest this one force in any direction, but it's too complicated for this post).

The main idea is that you can manifest this force at will in the direction you want it to be in. For example, if someone pushes against my chest, I may want to manifest this kokyu force at my chest so he can't push me over, thereby impressing onlookers. In real Aikido, of course, we would never deliberately resist the force, but would immediately move offline or go immediately with the force and begin a technique into a direction where the pusher has no power (there are a number of these). BTW, please forgive the pedantry... I actually have a point I'm working toward.

So when an opponent grabs my wrist, I enter while turning (that's the tenkan) and I must manifest this basic kokyu force of Aikido into a direction that suitably begins the lead-into-technique. The lead into the technique of kote gaeshi involves you forming the kokyu force into one direction, up, then over (every bit of the movement is powered by kokyu force). It often looks like a sudden, straight technique but if you analyze the directional changes the kokyu forces go through (if you did it correctly), those forces make a circle. You may have included another circle horizontally (here's your beloved centrifugal force ), but the leading force you use to effect putting your partner into a centrifugal arc is also part of the kokyu power you must manifest throughout the technique.

In other words, the importance of entry and technique is just as much your ability to manifest kokyu power in relation to the opponent as it's important to do the technique. This is true of ALL techniques involving Ki/Kokyu as O-Sensei, Tohei, et al mean it, and it is considered quite different from the normal use of strength and just "technique" involving centrifugal force. Most people practicing Aikido use normal force and focus on "technique" while never developing useable kokyu force throughout all directions of movement. The Aiki Taiso at the beginnings of classes are originally meant to warm you up in the use of kokyu power throughout the entire range of various movements.

The lead into Sayu Nage (as another example) from tenkan is the same universal idea... you move off-line, immediately match your "ki" to the opponent's grab as you begin the "lead" of up and over (another circle!!!) with your kokyu power, driven by your hips and hara (the hara actually controls the direction of the kokyu force).

That's more the intriguing part of the physics, IMO, Bill.

Regards,

Mike Sigman

Mike Sigman wrote: This is sooooo trite and typical of New Agers.... when they screw up they look for some reason to attack personally. All you need to know, Ron, is that I have credentials but I don't claim to be an Aikido teacher.

Well, if you correct others and present your opinion, it's just that -- some opinion. Just the same as some opinion from Joe Random I just met on the street. If you want people to actually respect your opinion, you have to give it a certain "weight" or foundation. That means either making it clear that you indeed do know something about the topic (e.g. by presenting your credentials or at least telling where and how long you've trained) or by quoting someone who is known as knowledgeable on the subject.

As to the "centrifugal force not being a real force" -- that's of course correct. And pretty much irrelevant. The term is a good and well-known shorthand and it is a nice term for something that's clearly observable. Physics people use it all the time. But if you prefer to say "the pseudoforce (caused by the object's inertia and perpendicular to its direction of movement) counter-acting the effects of the centripetal force in a bound circular motion" you're of course free to do so . Just don't force that on others.

No comment on tenkan, because we usually don't use that term...

Update: The "centrifugal force" comment was based on your earlier insisting on the term not being used. Which I found pretty annoying. But it seems my above comment was unnecessary after all...

You're still flat out wrong about tenkan Mike. In your own words, 'It means "turn".' ; when the turn occurs during the application of technique isn't part of the definition of the word. Maruyama sensei uses tenkan to describe any turn during the execution of a technique not just the initial move.

Bill Danosky wrote: I think Tai Chi and Aikido have an apeal to new agers because there is a mystical element within them. That's to say that there appears to be a power at work that's beyond the exertion of normal human strength. I'm intrigued by this, too, but I explain that there is at least a solid working theory of physics behind every technique. Tenkan exploits the power of centrifugal force, for instance.

Surely tenkan uses centripetal force?

They are drawn into the centre, not thrown out from it.

Christian Reiniger on Ron Ragusa wrote: [snip]If you want people to actually respect your opinion, you have to give it a certain "weight" or foundation. That means either making it clear that you indeed do know something about the topic (e.g. by presenting your credentials or at least telling where and how long you've trained) or by quoting someone who is known as knowledgeable on the subject.

Christian, Ron was not trying to ascertain my credentials to verify any information... he was obviously trying to turn toward a pissing contest. What you're saying wide of the mark.

As to the "centrifugal force not being a real force" -- that's of course correct. And pretty much irrelevant.

For something irrelevant and which I said only light-heartedly to distract from having to say that that force was not part of tenkan, it seems to be a big topic. Why not accept that yes, what I said was true, and then grow up enough to realize I only said it to take the sting out of the remainder of the sentence?

Regards,

Mike Sigman

To say there are not Centripetal Force in Aikido is ridiculous. Whether it happens with a Tenkan movement is debatable depending on the speed, attack reaction and technique.

p.s. I'm not a new ager.

Tim Jester wrote: To say there are not Centripetal Force in Aikido is ridiculous. Whether it happens with a Tenkan movement is debatable depending on the speed, attack reaction and technique. p.s. I'm not a new ager.

Who said "there are not Centripetal Force in Aikido"? If you'll go back and read, you're mixing your comments, Tex. And no, I doubt I'd think of you as a New Ager.

Mike Sigman

When I tenkan, I think that the initial movement (kai ten maybe) is going have some forces acting inside my body acting towards center, and as I complete that rotational movement (stepping back so to speak) that movement is going to have some forces acting inside my body going away from center (my foot resulting in stepping back away from my center for one).

I totally agree that semantics are important if they are actually causing a misunderstanding as opposed to using them to put someone down just to try to establish/assert dominance. Everyone makes mistakes. I wouldn't consider the usage of that term a mistake since everyone knew what was meant - which is the purpose of having a common language. Some people consistantly make the mistake of trying to put themselves on pedastols at the expense of others. The bottomline is that no one has rank in a forum.

Rob

IMHO, I accept that all theories are simply cognitive models to explain what is observed in nature. I also accept that those theories are useful no matter what label you put on them.

Entering and blending without resisting or interfering with the inertia and momentum of an approach or attack is useful. Redirect by utilizing the centrifugal force to pull the head into the center of the circular motion while using centripetal force to let the feet try to keep up on the circumference of the circular motion is useful to take balance (kuzushi). In a downward spiral motion it become a useful take down.

While this may not make sense or appear useful to some, it sure helped me get my head around it. And, wherever the head goes, the body tends to follow.

Rob Liberti wrote: When I tenkan, I think that the initial movement (kai ten maybe) is going have some forces acting inside my body acting towards center, and as I complete that rotational movement (stepping back so to speak) that movement is going to have some forces acting inside my body going away from center (my foot resulting in stepping back away from my center for one).

So in the example of a same-side wrist grab to kote gaeshi, how about giving us some idea of your forces, Rob?

Mike