Soft, Fluid, Living Matter (SoFLivMat) Coffee Hour

Hidden order in chaotic crowds

Karol Bacik, MIT

At first glance, a crowd of pedestrians crossing a busy plaza may seem disorderly, but if you look closely, you can discover hidden patterns. For example, two groups moving in opposite directions on a crosswalk spontaneously segregate into contraflowing lanes. In my talk, I will introduce a kinetic theory that gives insight into the physical origin of lane formation and predicts some new dynamical phenomena, such as curved lanes, or order-disorder transition. Mathematically, the discussion will amount to a sequence of stability problems of increasing complexity. To complement the theoretical analysis, I will also discuss a suite of experiments with human crowds - pretty videos of people wearing little paper hats will be provided.

Bio:
Karol Bacik obtained his BSc from Imperial College London in 2016, and an MASt from the University of Cambridge in 2017. Subsequently, he stayed in Cambridge to work on his PhD, which he earned in 2021 after submitting his thesis on sand dune interactions. His doctoral work was also recognized through the APS Andreas Acrivos Dissertation Award in Fluid Dynamics. In 2021-2023 he was a postdoc at the University of Bath, where he worked on a range of problems in crowd modelling and mathematical biology. In Fall 2023, he joined MIT as an Instructor in Applied Mathematics. His research interest include fluid dynamics, active matter, and social complex systems.