In Japan long ago friends gathered at night in an exquisite garden to admire the light of the moon. They basked in it, delighted in it, wrote poems, philosophized, fell in love, strolled and mused and set aside the cares and concerns of daily life.
They looked up and saw what looked to them like a rabbit on the moon. Each one of those people saw this from his or her own perspective, and it meant something unique to each one, even though there was one moon, and one rabbit on it.
What they never suspected, not one of them, was that the moon was trying to get away. It was trying go in a straight line. The whole time. Every time they saw it. It was held in place, in its orbit, by the gravity of the earth. The moon kept trying to fly away into space, on a straight line, along its own tangent, perpendicular to the radius of its orbit. It had plenty of energy, but it was held fast in the steady embrace of the earth. And, perhaps to the moon’s delight, it would never let go.
The forces operating between the earth and the moon resemble the rock and the sling that David used to stop Goliath.
David got a rock from a riverbed and put it in a sling, a leather rectangle, and folded the rectangle over to hold the rock, in a kind of pocket. Attached to each end of the leather rectangle was a leather strap. David wrapped one strap around his wrist and held the other strap tight in his fist.
He began to swing the rock in the sling over his head. He swung it around in a circle, faster and faster, increasing its angular momentum, its potential energy, with every revolution. The whole time the rock was trying to fly away. But it was held fast by the leather sling.
Then David let go.
The rock took off. All that high speed angular momentum was instantly converted into linear motion. The rock flew through the air and the energy it had accumulated was transmitted into Goliath’s head.
David did not just pick up a rock and throw it at Goliath. He magnified the power he could produce with his muscles by rotation, as angular momentum, and released his projectile directly at the target.
Anything but a straight path to the target would have transmitted less power. You could loop the trajectory to the target or send it up into a parabolic arc, but it would have less power than sending it on a straight line.
That is why we use the whipping action of the koshi rotation transmitted to a deep-chambered straight-line punch – with elbows in against the ribs and the rotation of the forearm delayed until full extension, any time we turn and strike, turn and block, or turn and throw.
We commonly step 180°, 225° and 270° in our kata. In these stepping techniques we maximize power by converting angular momentum to linear force.
Keeping the arms close in to the body on the initial phase of the turn increases our speed during rotation. We make use of the same mechanics as a ballet dancer or figure skater who, to accelerate their spin, draw their arms and one leg in toward the axis of rotation.
In our case we achieve maximum speed this way and then suddenly expand, converting rotation to linear force, to execute our throw, block or strike. We maximize our speed and power using the same mechanics as ballerinas, ice skaters, satellites and slings.
A sling was used for hunting and fighting throughout the ancient world. It was primitive, not an advanced technology like a catapult. It was what regular people used at stand off distance as a deadly weapon. It was a farm tool. Like the kama or the tonfa or the nunchaku.
It is worth noting that David was not just spontaneously overcome by the will to win. He had used the sling frequently. He practiced. In his day job, as a shepherd, he relied on it when his life was on the line and it was his responsibility to act.
As the story goes he killed lions and bears who were attacking his flock, using a rock and sling. He pulled the lost and terrified sheep out of the mouths of the predators, at risk to his own life.
He trained to be skillful. He was motivated to be courageous. He was accustomed to taking responsibility.
Facing piracy, fraud or robbery in ports across the world, the coastal and island peoples of east Asia understood what it takes for a small force to prevail despite the odds, despite what is reasonable.
They knew very well that the way to produce a sudden effect is to spin and let go. The way to endure was to revolve and hold on. It was true in politics, war, commerce, the arts, the natural world and even in the movement of heaven.
When you do it that way you can maintain your center and choose your path.
Then, at the end of the day, the training, the battle, you are free to enjoy the light of the moon on an evening in a garden with your friends, to appreciate the reflection of the moon in the water, and to appreciate all of it, and each of them, in everything else.
Post by Jeff Brooks
Photo by George Desipris