you usually do end up having to teach body flight, because that which was natural in non-dance walking gets lost in the years when the developing dancer tried to learn the degree of control on which his teachers insist.

Anonymous. Ever since I went to a lecture by a former World Finalist. I beleive that body flight will occur naturaly if as we were asked to take our shoes off and do a few steps in our stocking feet. He was more concerned with the very first step in a walk forward. We must use the whole of the foot right to the tip of the toe on the rear foot.That is were the body flight comes from. Think about it for a minute. Where does the moving of the body come from. It can only come from the standing leg. Keep that still and we will fall forward. I saw a ridiculous situation a while back. This pair were having a lesson. Every time the male went to do a heel lead the teacher pushed him hard in the back. How stupid was that. I saw only a few days later the couple in a low grade competition, and what do you think the man was trying to do. He was lunging forward as if he was pushed. It looked a mess as you can imagine.

"We must use the whole of the foot right to the tip of the toe on the rear foot.That is were the body flight comes from."

You have it backwards. You can only use the whole departing foot if you have sufficient body flight. Body flight is not created from the standing foot, instead it is something preserved from the preceding step or gained from converting energy freed up by loosing altitude.

You are mistaking drive for body flight...

Anonymous.I say again that body flight comers from the correct lowering , use of the feet. Posture and so on. Do that right and the correct use of the body will follow. If you know anything about the Rumba just as an example. The body moves before the foot, but at the point of overbalancing the foot catches the body arriving first. Nobody is going to call that flighting the body. Mainly because we start on straight knees. In the Waltz and Foxtrot we start with a 46 degree flex, or shin to floor angle .
Take note that this is in your setup before the first step is taken. Not to wait untill 1 before the knee is bent. Big mistake that one. For thoes who like to dabble in maths might like to work out how much a 6 foot person will lower before stepping off. Then in the Waltz on step 3 we are up on the toes. Theres another 3 to 4 inches, before the heel will touch the floor on an (and)count. Plus the 46 degree bending of the knee. Must not forget we start off in a lowered position on step one. Do all of this and body flight will come. Open to comments.

You're still completely missing the point. Body flight is not a result of leg action, but of carrying momentum across multiple steps. You can fake the right leg action, and still not have body flight, unless you have a continuity of momentum across steps. Likewise, if you have a continuity of momentum, you can have body flight even with the wrong leg action (you will just have other problems)

As a child, the Nobel Prize-winning physicist Richard Feynman asked his father why a ball in his toy wagon moved backward whenever he pulled the wagon forward. His father said that the answer lay in the tendency of moving things to keep moving, and of stationary things to stay put. "This tendency is called inertia," said Feynman senior. Then, with uncommon wisdom, he added: "But nobody knows why it is true."

Accelerating forward pushes the ball backward.
Accelerating backward pushes the ball forward.
Decelerating pushes the ball forward.
Curving pushes the ball sideways to opposite direction of turning.

The word ball can be replaced with the word body.

Pushing forward with the supporting foot accelerates the mass of the body and a force tends your body to bend backward, because of inertia. Body flight can be demonstrated in slow motion by asking somebody to push you against your chest while you are taking first forward step. The pushing will hold your moving foot not to fall on the floor. On walking the push of the supporting feet accelerates your body and the mysterious inertia takes care to push against your chest and other accelerating parts of the body to let your body to flight.

Deceleration is decreasing of velocity, ex. by braking. When the pushing of the supporting foot ends and the moving foot hits the floor, decelerates the mass of the body causing by inertia a forward force witch pushes the body on the new supporting foot.

When turning the body tends to fall to the opposite direction and must be balanced by the sway, like a cyclist does while curving.

Momentum is mass x velocity. Momentum must be increased by impulse to keep moving continuously. Impulse is force x time. Impulse accelerates the velocity. It should be interesting to discuss at what moment of the step and time of the beat the impulse takes place. I think during the beat one if the step takes two beats, in some dances.

Interesting points SQQ, but not really relevant.

Body Flight is essentially the opposite of impulse. The total movement is the sum of a contribution from impulse and one from body flight - for a good dancer, the impulse contribution is quite small.

In terms of acceleration from the legs causing the upper body to move backwards, this is not really going to occur. The legs won't start to produce any acceleration until the weight has already overbalanced beyond the point of support in the foot. The body would pitch forward, except that the push from the legs accelerates the lower body forward faster. But in the body flight dances, this is the minor component of the motion - the major component is the already existing body flight.

Anonymous. Yes it does get interesting.Now look at it from the ladies steps. She bends the knee towards the man and provides a bit of resistance. The left leg is way behind right on the tip of the toe. Exactly where does this body flight come into play. It is simply move the body onto the now standing leg, what else can it do. If we were to measure the distance between the body at its starting point and to its final destination and divided this into thousand parts, then the body will have a thousand different positions on its move to the standing leg . I don't think any dancer will do it any other way.As Shakespeare wrote. " Much Ädo About Nothing ".

"The left leg is way behind right on the tip of the toe."

A classic mistake! The left LEG is not way behind the right, the left FOOT is. The legs are still quite close together, until the point when the body flight has carried the body halfway through the new step. Only then will the legs be - quite briefly - apart.

As for much ado about nothing, the widespread and obvious failures to make good use of body flight prove that to be nonsense. It's a quite serious issue - look where the lack of it causes trouble on some of the videos here.

Would you please give me more teaching tip about the 46 degree fex or shin to floor angle ?
Which one is the angle you mentioned : 1. the angle formed by shin and instep
2. the angle against the shin bone. (the two sides are extending from the thigh to floor and floor ).( sit up postion when body journeys from heel to ball )
thanks.
ylchen