People Particles: Physics Based Modelling of Crowd Dynamics

Synopsis

Across all fields of physics, we often study the motion of individual particles as well as their collective dynamics. However, most of the particles we tend to focus on, from protons in an accelerator to orbiting moons and planets, share at least one common trait: they don’t have minds of their own. In this talk, the particle I will be talking about is the human pedestrian. I will first describe three general categories of models for crowd dynamics. We will go through the math behind each model, some of the common variations within each category, and where each model’s strengths and weaknesses lie. Next, I will focus on a particular study on pairwise interactions between pedestrians. We will see how in this 2021 Ig Nobel prize winning paper, the authours were able to conduct experiments on how pedestrians avoid collisions with each other, and we will see how they overcame a huge data analysis problem to model this behaviour using physics. By the end of this talk, I hope to show how a physics point of view can lead to solving problems that may seem purely within the realm of other fields such as sociology.