Blog #3: Is dancing Lindy Hop pure physics?

Sometimes teachers talk about physics in Lindy Hop classes and I never know how serious it is. Is it just a metaphor or is there something real about it? An article in The Guardian claims that dance = physics. Let’s dive deeper into this.

The title of this article is: The science and magic of Lindy Hop.
And you can read the full article here

A part that caught my attention as a dancer, was this paragraph:

Great partner dancers may not know it, but they are masters of space, time and Newton’s laws of motion. When Fred Astaire and Ginger Rogers danced cheek-to-cheek in a close turn their two bodies achieved a beautiful line impossible for any individual. Dancing like this is a conversation in physics, where the bodies of both dancers are required to master the forces involved.”

The article then continues about dancing in closed position, where Newton’s Third Law of Motion is applied:

In close hold, bodies are joined at the hip and hand. The follow exerts an equal and opposite force through arms and body in response to the lead. These equal and opposite forces, in accordance with Newton’s Third Law of Motion, allow the follow to dance in synchrony with the lead: as a mirror image. This symmetry can only be broken if the pairs of forces become unbalanced, causing one or both of the dancers to accelerate away from the other.”

Momentum

The writer, Andy Connelly, also dives deeper into the physics behind momentum. A subject we talk a lot about in class:

“This, and all forces, cause a transfer of momentum (which is the product of mass and velocity). So, when the lead applies a net force, momentum is transferred to the follow. The more of the lead’s mass (body) moves as the force is applied, the greater the transfer of momentum and so the more the follow’s mass will move. Also, the longer it takes to transfer that momentum the smoother the ride. This is the difference between the slow gentle acceleration and deceleration of a careful driver, and the painful jarring of rapid acceleration or an emergency stop. The constant contact and gentle tension between the bodies of dancers means that momentum can be transferred at any time and over any time period.”

Lindy Hop physics research: busted or confirmed?

So, what is nice about science, is that you don’t have to believe everything other people say.  In the article “Optimization and Pose Selection for a Lindy Hop Partnered Spin”, three physicists tried to test the hypothesis that good dancers optimize their Lindy Circle better than less experienced dancers. Read the article here.

Swing dancers often talk about using the laws of physics in performing their physically rigorous jumps, lifts, and spins. Do expert swing dancers physically optimize their pose for a partnered spin?”

And this is their conclusion:

We did not find a difference between the fraction of optimality achieved by beginners and expert dancers. The rotational acceleration achieved by the dancers was roughly a factor of ten less than the predicted optimal acceleration.”

So, maybe dance = physics, but maybe it is just magic. What do you think?