"A liquid is traditionally defined as a material that adapts its shape to fit a container. Yet under certain conditions, cats seem to fit this definition. This somewhat paradoxical observation emerged on the web a few years ago and joined the long list of internet memes involving our feline friends. When I first saw this question it made me laugh, and then think. I decided to reformulate it to illustrate some problems at the heart of rheology, the study of the deformations and flows of matter." Marc-Antoine Fardin's research on the rheology of cats won him the 2017 Ig Nobel Prize in Physics. The goal of the organization that awards these prizes is "to highlight scientific studies that first make people laugh, then think." Read on for Fardin's response to the question, "Are cats liquid?"
