By Hamish Johnston

It’s been a very difficult week for some UK-based physicists for reasons that you can read about here. Therefore I thought this week’s Red Folder should be a bit of a tonic, so here’s a combination that’s guaranteed to put smile on even the glummest face: cats, physics and the Internet.

“Cats seem to grasp the laws of physics,” at least according to Saho Takagi and colleagues at Kyoto University in Japan. It seems that our feline friends have a firm understanding of causality, as shown by their ability to recognize that an effect (an object falling out of an overturned container) is preceded by its cause (the noisy shaking of the object in the upright container). The cats quickly realized that a noisily shaken container would yield an object, but the silent shaking of an empty container would not.

Although the cats weren’t using special relativity and light cones to analyse the situation, they did appear genuinely surprised when tricked by a recorded rattling sound to think that an object would drop from an empty container. If you, or your cat, want to know more, here is a paper describing the experiments: “There’s no ball without noise: cats’ prediction of an object from noise”.

Not everyone, however, is convinced. “But before you rename your cat Isaac Mewton, you may want to take a step back and examine the study a little more closely,” writes Hilary Hanson in the Huffington Post. She points out that several cat-behaviour experts are poking holes in the study. You can read her critique in “Wait, do cats really understand physics?”.