Elementary Tango Physics (22 nov 2008)

In the many lessons I've taken in the course of my tango studies, one recurring concept I've heard is the active use of the energy from the ground. In other words, to think of the ground as containing a vast amount of potential energy that you draw from in order to power your dance and communicate with your partner. Not being a physics student, I always thought of this as being a useful visualization method but having no real world basis. Turns out that it does, in a very literal manner. I realize that I'm a Johnny Come Lately on this one, but it was only very recently that I came across the concept of the normal force. In a nutshell, the normal force is the energy that works counter to forces such as gravity for objects on a surface, I suppose to create equilibrium. However, normal force is variable, while gravity isn't. So I think the trick, for tango dancers, is to take that energy and manipulate it to amplify it and channel it in a specific way. A very direct example of this is in propelling the walk. One digs into the ground in a way that increases the normal force, then uses their muscles to oppose this force, which consequently sends a more substantial sense of weight transference to the partner. Thus, a clearer and stronger communication.

In turn, if I understand correctly, varying the amount of normal force energy stored and released plays a key role in the dynamic of the dance. As such, a dance at a constant velocity will essentially flatten out the normal force, since the constancy allows the normal force to come to a neutral balance against the opposing energy, and the result (when done well) is a kind of floating sensation. Conversely, a dance with varied velocity keeps the normal force shifting and thereby gives the dancers more of a sense of active engagement with their weight, and the result (when done well) is like being on a well designed roller coaster. It's kind of like standing on a train; when the train starts to move there is a sudden instability which requires active compensation to maintain balance (dynamic force), but when it gets to a constant speed it becomes much easier (flat force).

In the past my problem was, I'm guessing, an excessive flattening of this force (which is why, I surmise, teachers often reiterated that I use the ground more). The risk in this is that the partner doesn't feel the intention as clearly as she should. As one person put it, borrowing a phrase from Gertrude Stein, "There's no there there." My tendency was, and perhaps still is, to bring the energy up rather than down. The result is a decrease in normal force, which then translates to less of a sensation of weight to transfer, and so the partner feels less drive. And as a leader, clarity of intention is one of the two main qualities I strive for (the other being mutual comfort). I'd much rather a follower say positive things about my clarity than, say, the number of tricks I know.

Anyway, since I found out about this concept this is how I've been mulling it over. I guess it's not the most romantic way of conceptualizing the dance but I think cold analysis has its uses, as long as we don't get lost in them and forget why we dance in the first place.