ACMS Abstracts: Spring 2022
Geoffrey Vasil (Sydney)
Title: The mechanics of a large pendulum chain
Abstract: I’ll discuss a particular high-dimensional system that displays subtle behaviour found in the continuum limit. The only catch is that it formally shouldn’t, which raises a few questions. When is a discrete system large enough to be called continuous? When are approximate (broken) symmetries good enough to be treated like the real thing? When and why does a fluid approximation work as well as we like to assume? What does all this say about observables and the approach to equilibria? The particular system I have in mind is a large ideal pendulum chain, and it’s cousin the continuous flexible string. I propose that the pendulum chain is a perfect model system to study notoriously difficult phenomena such as vortical turbulence, waves, cascades and thermalisation, but with many fewer degrees of freedom than a three-dimensional fluid.