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Taijitu Magazine

is published by

Phosphene Publishing Co.

All material © 2016

A magazine of martial and movement arts, with a focus on the internal style of Tai Chi Chuan

Toying with Tai Chi

Figure 10 Various examples of Newton's Cradle. Click any of the images to see the animations. (6)

Figure 11 Snap the Whip by Winslow Homer (1872) (7)

by Christopher Dow

© 2017






Concluding our look at toys that exhibit Tai Chi qualities.



Newton’s Cradle


Next, we’ll look at Newton’s Cradle, also called Collision Balls and Executive Desk Balls. (Figure 10) The former name comes from it’s creator, Isaac Newton, the middle name is obvious, and the last one comes, presumably, because 1) only executives can afford to waste money on frivolous items that occupy valuable desk space that they’re not using because executives do so little real work, 2) executives have so little to do that they have time to play with such frivolities, 3) executives have so little real creativity that they can easily become mesmerized by a simple mechanical device, 4) executives like to give housekeeping staff difficult objects to dust, or 5) executives perpetually study the middle ball which remains static when two end balls are set in motion, demonstrating the chief tactic of the middleman: Do absolutely nothing but transfer something one way or another and reap profits off the efforts and energy of others.


Okay, I’ll stop, though it’s easy to be cynical these days. Back to Newton’s Cradle. This from Wikipedia:


"Newton’s cradle…is a device that demonstrates conservation of momentum and energy using a series of swinging spheres. When one on the end is lifted and released, it strikes the stationary spheres; a force is transmitted through the stationary spheres and pushes the last one upward…. A typical Newton’s cradle consists of a series of identically sized metal balls suspended in a metal frame so that they are just touching each other at rest. Each ball is attached to the frame by two wires of equal length angled away from each other. This restricts the pendulums’ movements to the same plane.

         If one ball is pulled away and is let to fall, it strikes the first ball in the series and comes to a nearly dead stop. The ball on the opposite side acquires most of the velocity and almost instantly swings in an arc almost as high as the release height of the first ball. [In the absence of friction or other external forces besides gravity, the opposite ball would swing exactly the same height.] This shows that the final ball receives most of the energy and momentum that was in the first ball. The impact produces a compression wave that propagates through the intermediate balls. Any efficiently elastic material such as steel will do this as long as the kinetic energy is temporarily stored as potential energy in the compression of the material rather than being lost as heat.

         With two balls dropped, exactly two balls on the opposite side swing out and back. With three balls dropped, three balls will swing back and forth, with the central ball appearing to swing without interruption." (6)


I’ve quoted the Wikipedia entry at length since the presentation was pretty succinct and I’d waste time paraphrasing it. There’s some fancy mathematics involved in the details of the motions of the balls, such as whether or not the balls at rest actually touch or not and other factors that I don’t dare attempt to go into. But I think at least one Tai Chi lesson is clear from the motion of Newton’s Cradle.


Most of us Tai Chi folks have seen, have demonstrated, or been pushed by a trick Tai Chi application. This is when the demonstrator holds a Press posture and has one person push against his raised arm while several other people line up behind, all pushing, too. As they push, the demonstrator gives a pop of peng energy from his Press posture, and all the people who are pushing move slightly backward except for the last person in line, who is jolted back farther, often several feet. Clearly this is the same conservation of momentum and energy shown by Newton’s Cradle.


In this demonstration, peng energy can easily be seen propagating through the line of people and finally manifesting in the last person in line. But the more important propagation is less visible because it happens inside the Tai Chi Chuanist’s body. We often think of bouncing our energy down into our feet then back up through the legs and torso, into the arms and hands. This movement of internal energy, combined with physical compression and release, acts very similarly to the energy system demonstrated by Newton’s Cradle.

At it's base, this demonstration recalls the idea from the Tai Chi Classics that one should learn to “pass a thread through the nine-channel pearl.” Apparently, the nine-channel pearl was a of game in which Chinese girls attempted to push a thread through a ball with nine caddywampus holes drilled in it. In Tai Chi, the nine-channel pearl is the human body, the channels are the major joints that must be aligned correctly to give the exponent’s uncoiling force and energy a proper path to follow. The idea is that the Tai Chi Chuanist must learn to consciously lead the energy sequentially through every joint—ankle, knee, hip, shoulder, elbow, wrist, and the three joints of the phlanges—and all the way to the fingertips. When considered like this, Cheng Man-ching advocating the use of Ladylike Wrist during form practice makes perfect sense because that hand form allows the chi to flow unimpeded to the fingertips.


Threading the nine-channel pearl can be thought of as an unfolding process or even a pneumatic process in which the body sort of inflates in a wave that progresses from foot to hand, but in a sense, the dynamics also are similar to those of Newton’s Cradle. The joints are like the places where the balls of Newton’s Cradle touch, and the body parts are like the balls themselves. Chi in the foot bounces through the ankle joint to the fibia. Then it bounces through the knee joint to the femur, through the hip joint into the pelvis/torso, through the shoulder joint into the humerus, and so forth down the arm and through the last joints of the fingers.


But there is an important difference. In an idealized Newton’s Cradle (without friction), the energy propagates through the several balls then knocks the final ball into the air. This ball then falls back with equal velocity, strikes the first of the lined-up balls, and transmits its energy through the line to the ball on the other end. This one reacts by bouncing into the air exactly as high as its initial fall, and so on, each strike imparting only the energy with which it was endowed. In the Tai Chi exponent, however, the initial impetus of the energy surge going down the leg terminates at the foot. Because the surface on which the foot rests is solid, the foot, unlike the end ball, has no space into which it can move.


In a way, Earth itself has become the final ball, and clearly Earth is too heavy to move much by pushing your foot down on it. So, instead of swinging out then falling back to retransmit itself back along the path from which it came, the energy instantly rebounds back into the foot. It’s almost as if the energy makes a 180° turn inside the Earth, making the foot not just the ball that acts against the ball of the Earth, but also the next ball in line as the energy reemerges into the foot. And because the human body is flexible and mind-directed, the rebounding energy can be tremendously augmented by the strength of the uncoiling leg muscles and tendons as it surges up the leg, through the hips and waist, and into the torso.


This augmented energy propagates through the intervening body segments (the balls) and arrives at its terminus (hand, say, but it could be an elbow, shoulder, etc.) in a very powerful state because it has built up momentum and power over a distance of about ten feet (through the body, into the ground, then back up through the body) in a very rapid fashion. So, unlike the end balls in Newton’s Cradle, which each receive and transmit exactly the same amount of energy, the end ball in the Tai Chi Chuanist’s train of balls—often the hand—receives a seriously amplified pulse of energy.


In the case of the Peng demonstration describe above, the energy doesn’t go all the way through the arm to the fingertips. Instead, it goes only as far as the demonstrator’s jolting palm, then through the space between the palm and the demonstrator’s forearm, then through the space between the back of the forearm and the palms of the first person in the pushing line. Thereafter, each person in line is like a ball that is subsequently jolted through the places where they touch until the jolt terminates, with full force, at the final person in line.


Crack the Whip


Okay, you don’t need a toy to play Crack the Whip. But it is play, and this particular game amply demonstrates Tai Chi’s whipping power. (Figure 11) It's also kind of the yin to the yang of Newton's Cradle: a stretching, flexible, pulling energy rather than a compressive and concussive energy.


For those of you out there who don’t know what Crack the Whip is all about, it’s when a bunch of kids stand in a line in a big field, sequentially holding hands. Then the person at the head of the line begins hauling backwards, dragging the next person along, who drags the next person, and so forth down the line. Pretty soon, the whole train of kids is snaking around across the surface of the field as the head person turns this way and that, sinuously weaving his followers along behind him.


The pace and turning of the head might appear leisurely and gradual, but as the snaking effect works its way down the line and becomes more sinuous, the people toward the tail end of the line find themselves whipped back and forth as they run along, dragged by the person in front of them. The last person in the line receives the most violent snaking effect and eventually is “cracked” off the end of the line at the apex of a whipping turn and sent rolling and tumbling across the grass. But even as the last person is cracked off and tumbles, the person at the head of the line—the handle of the whip—continues to maintain a leisurely pace. You can see the same sort of effect in bullwhip, of course, but it’s also present in other scenarios, such as a roller coaster. The people in the front car experience the most stable ride, while the people in the tail car are more violently whipped and thrown around in their seats.



Well, I guess it’s time to stop toying around with these ideas and go play Tai Chi. While I do, though, I might not think back to my childhood toy box and the Tai Chi toys it held. Instead, I’ll try to concentrate on my Tai Chi form, which has become the biggest and best toy box I could imagine. It might be finite in external size—bigger than a breadbox but smaller than a room—but the whole of reality seems to be in there. It’s like Felix the Cat’s magic bag of tricks or an infinite store where playthings, tools, and insights line the shelves of secrets I didn’t even know existed. To discover those secrets, all I have to do is start playing.





1  Top images:

Hand-thrown top:

Spindle top:

Device-activated top:

Mechanical top:


2  Wikipedia entry: "Gyroscope"




4  ​




6  Wikipedia entry: "Newton’s Cradle"

7  Wikipedia entry: "Snap the Whip"


Images not otherwise attributed are my own illustrations or photos.

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