Are cats both liquid and solid?

The Conversation

Physics and psychology of cats – an (improbable) conversation

Marc-Antoine Fardin: I was on the internet a few years ago, and I saw this set of webpages that were discussing whether cats are liquid. And then they had the definition of a liquid. And usually the definition of a liquid is material that takes the shape of its container. [For example,] if I pour liquid into a mug, the liquid is going to take the shape of the mug, and if I pour it into a wine glass it is going to take the shape of the glass.

If you look at a bunch of different cats, there are many different pictures and experiments that have been run by many people around the world where you see the cats taking the shape of the container [they are in], like a box or a sink. People were asking this question. And so I took this question and put it into the modern lingo of rheology.

Our problem with communicating with cats is that you can try to train cats, but [they are very stubborn]. For instance, cats who take part in psychology studies frequently … just leave. The cats do not hang around for the rest of your study.