Embodied intuition in physics

2019. Used Java and Python. Some of the code was built at the 2019 McGill Physics Hackathon.

A big thank you to Dr. Anita Parmar (McGill) and Dr. Sha Xin Wei (Synthesis Centre, Arizona State University).

As a dancer, I often feel restricted working through problems in physics, as if I needed to put my physical reality in a box and retreat to some abstract headspace. As a physicist, I am fascinated by Laban dance notation theory's ability to swiftly characterize the shape and intention of complex human motion. This project sought to explore embodied intuition in physics through quantized Laban notation, using the double pendulum as a toy model. See my full report here.

While its equations of motion may seem mundane, this system features a beauty that anyone can appreciate. When I asked non-physicists to describe what they saw in the swinging double pendulum, people pointed out the rods' mesmerizing relationship to each other, as if entangled in a slow dance.

It is clear that while the equations of motion may completely describe the system, they fail to capture our own embodied knowledge of the motion. While our physical intuition and appreciation for abstract movement is often neglected in the context of physics, they are absolutely worth further investigating. This motivated me to build a Python program that extracts four Laban's efforts of a double pendulum's movement. These Laban efforts are simple scalars that are capable of efficiently summarizing intention of human movement. Could calculating the "intention" of pendulum movement provide us with better physical intuition for this basic classical system?

Each effort takes in basic Cartesian position/velocity data and output a scalar describing magnitude of effort.

I extracted both rods' efforts for both chaotic and non-chaotic conditions. Using Fourier analysis, I demonstrated that Laban's Time effort, even in chaotic conditions, is mainly periodic. This quantifies the beautiful harmonies that a human's (especially a trained dancer's) eye immediately notices in the system. Amongst the chaos, there is a consistent time effort that our bodies naturally recognize.

Fourier analysis of the chaotic rods' time efforts. They are clearly more periodic than their generalized coordinates (rotational angles).

Moving on, I also found that the rods' Laban Flow efforts agreed with the non-physicist's interpretation. At any given time, the bottom rod (rod 2) exemplifies a more pronounced flow effort. That is to say, its motion is smoother than rod 1. In a dance choreography, this would mean rod 1 is being tugged around by the long strides of rod 2, and does not follow through on its own movement. For instance, this sort of dance occurs in the Nutcracker ballet's Waltz of the Flowers. The ballerinas are swung up, over, and around the male dancers, with just barely enough time to fully extend their legs.

Flow efforts of the rods in calm context, and then in chaotic context. Notice that in both cases, flow effort is harmonically damped over time, an effect I do not understand yet.