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Old 11-27-2009, 09:55 AM   #31
Michael McCaslin
Dojo: aikijujitsu, unaffiliated
Location: New Orleans
Join Date: Aug 2006
Posts: 35
Re: YouTube: Push Test to Nikkyo

Basis Halliop wrote:
No, not really. If I put a book on a table, gravity exerts a force downwards on the table equal to F = -mg where m is the mass of the book. The table exerts an equal and opposite force called the normal force, this is why the book doesn't go through the table. Likewise, the force the table exerts on the floor is now increased by m, and the normal force exerted by the floor on the table is also increased by m. Yet, the table does not move upwards when the book is removed, since the normal force exists only when something is pressing the table. It doesn't continue afterwards.
You know, I almost never post here any more. The signal to noise ratio, agenda trolling, and general personality conflicts conspire to derail conversations. Every now and then I pop in just to make sure I'm not missing anything, LOL.

I feel compelled to chime in because your quote above exactly encapsulates the fundamental idea to me. Make your body transparent to the incoming force, such that the pusher feels like he is pushing on a table. The trick is to arrange your body such that the force flows to the ground, and not add any resistance of your own. That's not what most people naturally do when you try to move them, though. They instinctively dig in and push back.

It sounds so simple, but it's tough to do and there are gradations. I met with Mike S. recently and was surprised to see how much what I was doing differed from what I *thought* I was doing.

I think people discount how much importance there is to this fundamental idea, and your book/table metaphor encapsulates it well. Now, if the book is moving sideways, how do you arrange your "internal table"?


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