Abstract

I will introduce the phenomenon of turbulence and discuss where it happens (everywhere!), why we might care (intellectually and pragmatically), and how to theorise about it — this will contain a very informal outline of Kolmogorov’s theory of homogenous, isotropic turbulence. I will then show how these simple ideas can be extended to predict the structure of turbulence in a rotating fluid — the new physical elements being the system’s anisotropy and its ability to support wave propagation. These features turn out to be ubiquitous in natural turbulent systems, not only on Earth but also across the Universe, whose visible contents mostly consist of turbulent plasma. I will touch on two rather different examples: why turbulent transport affects performance of fusion devices and how universality of Kolmogorov turbulence helped X-ray astronomers understand the thermodynamics of galaxy clusters.