By admin 
Anxo Biasi, with his cat Eme, who inspired him to develop the equation. Credit: Anxo Biasi
In the age of social media, there is little doubt who is the star of the animal kingdom. Cats rule the screens, just as their cousins, the lions, rule the savannah. Thanks to Erwin Schrödinger, this feline also has a place of honor in the history of physics. And it was Eme the cat who inspired Anxo Biasi, researcher at the Instituto Galego de Física de Altas Enerxías (IGFAE), to create a article in the American Journal of Physics.
In this article, Anxo presents the cat exercise comparison. “This article aims to bring physics closer to non-experts and provides a pleasant example with which it is possible to understand various concepts of classical mechanics. To do this, an equation has been constructed that describes the behavior of a cat in the presence of a cat models person, considering the former as a point particle moving in a potential created by man,” he summarizes.
Explaining physics with cats
Anxo recently joined the IGFAE, a joint center of the University of Santiago de Compostela (USC) and the regional government of Galicia (Spain), through the Junior Leader program of La Caixa, of the Physics Department of the École Normale Superior de Paris.
At the IGFAE, where he has already completed his training thesishe will develop his line of research in non-linear evolution equations, at the intersection between physics and mathematics, and join the team of String Theory and related fields.
The idea for the article came about to “communicate physics in a fun way, making it more attractive to students,” he says. And so what seemed to some extent a joke gradually took on an academic form.
“This started as a playful idea for Fool’s Day, inspired by some researchers’ funny papers. However, I soon realized that this story I created could be a great help to physics students. The story is very conceptually loaded, but it introduces in a fun way using an example that arouses great curiosity: a cat!”
And how is the comparison of cat movements constructed?
Anxo starts from seven dynamics, or patterns, drawn from his daily experience with Eme, and uses the hypothesis that ‘cats behave as if they sense a force around a person’.
In this way, the paper argues that the seven dynamics mentioned above can be modeled, as a first approximation, by considering the cat as a point particle following Newtonian mechanics.
The cat experiences a “force” related to an external potential (induced by the presence of a person) where x
Comparison of cat movement. Credit: Anxo Biasi
Starting from this formula, and through the analysis of the movement of cats, it is possible to show how the equations themselves are constructed.
“The work entertainingly demonstrates the mental process followed in the construction of physical models, which is rarely described in books. For example, it analyzes movement patterns (or non-movements), derived from the fact that cats tend not to come when called, are easily distracted or tend to stay on their favorite person’s lap longer.”
All these calculations are approached in an interesting and fun way. “We don’t always have to tackle the deepest and most challenging mysteries of the universe; sometimes we can just relax and use the power of physics to explain everyday life – it’s really funny!” says Anxo.
In this way, it brings cat-human interaction model physics closer to non-experts, demonstrating through a curious and familiar situation the reasoning behind the construction of physical models,” he summarizes.
Description of the cat movement equation. Credit: American Journal of Physics
Spiders and zoomies analysis
The article focuses on the analysis of the characteristic purring of cats. His proposal is that this response is a stabilization mechanism, fed back by the interaction between the cat and its human companion.
“It is proposed that when a cat is petted and starts to purr, people tend to feel the impulse to continue petting it, reinforcing the stability of the process.”
This stabilization is further enhanced because the exchange of affection between purring and stroking temporarily strengthens the bond between cat and human.
The study also takes into account periods of frenetic random activity, known as FRAP or ‘zoomies’, when cats move at full speed from one place to another, usually at night. The article discusses how in this case the equation requires an arbitrary component to model these periods, built into the formula as an external ‘forcing’. This adds a certain amount of randomness needed to model these ‘cat outbursts’, which can be tailored to everyone’s particularities to some extent.
Educational use
In addition to the playful approach, Anxo emphasizes that this article is “intended for use in introductory courses in classical mechanics, to demonstrate how apparently complex and unrelated behavior can be explained by simple laws.”
It does this by “showing a range of dynamics that are easy to visualize, reducing the need for abstraction,” and by presenting “a multi-term equation that covers the fundamentals of classical mechanics.”
More information:
On the interaction between cat and human from the point of view of physics: an equation of motion, American Journal of Physics (2024). DOI: 10.1119/5.0158200
Delivered by
Galician Institute for High Energy Physics
Quote: A physicist and his cat ‘reveal’ the equation of cat motion (2024, November 4) retrieved on November 4, 2024 from
This document is copyrighted. Except for fair dealing purposes for the purpose of private study or research, no part may be reproduced without written permission. The content is provided for informational purposes only.