tabby white british shorthair cat jumping

For as long as there have been little kids and curious scientists, people have dropped cats to see what would happen. And for just as long, cats have landed on their feet. But how do cats achieve this? The answer to that question has been a scientific query for hundreds of years.

Do cats always land on their feet?

In his 2019 book Feline Fall and Fundamental Physics, Greg Gbur, professor of physics at the University of North Carolina Charlotte, gives a delightful tour of the history of the science of falling cats (with fascinating detours into related history and science). According to Gbur’s accounting, the problem has intrigued and puzzled scientists since the 18th century.

In the mid-19th century, the basic laws of motion were established; the law of conservation of angular momentum was supposed to mean that a freely falling object needed something to push against to give it the initial rotation. In other words, a cat couldn’t just turn around in space. after began to fall. He must have been pushed from a tree branch or the hands of the person who dropped him.

Then, in 1882, the French scientist Étienne-Jules Marey developed a technique called chrono-photography and used it to photograph a cat falling at 12 frames per second. The resulting images clearly showed that the cat could right itself in the air. without pushing anything. When Marey presented his findings at a meeting of the French Academy of Sciences in 1894, the reaction was intense. It seemed that Marey had presented evidence that contradicted the laws of physics.

However, it turns out that the initial study of angular momentum was limited to rigid bodies. Cats are the complete opposite. Cats are soft, cuddly, flexible things. The flexibility of a cat’s body makes it capable of performing this gymnastics in the air.

Find out how cats land when they fall

The scientists quickly realized their mistake and an explanation was soon offered. The French mathematician Émile Guyou proposed a solution supported by Marey and accepted by most members of the Academy. Similar to ice skaters pulling their arms in to spin faster or stretching them out to slow them down, the cats used the position of their front and hind legs to control their spin.

(Credit: Étienne-Jules Marey, Public Domain, via Wikimedia Commons/) {{PD-US}}

When a cat falls for the first time, Guyou suggested, it spreads its hind legs and tucks in its front legs. This allows you to twist your upper body without much lower body counter-twist. The cat then bends its hind legs, extends its front legs, and twists its lower body into the desired position without turning its upper body too much. Gbur calls this the Tuck and Turn model, and it was fine as far as it went.

Ongoing debate on feline gymnastics

Then, in 1935, a team of Dutch physiologists, GGJ Radiator and J.W.G ter BraakHe took another look at Marey’s photos and noticed something others had missed. When cats begin to fall, they arch their backs, bend their bodies in half, and then turn the two halves in opposite directions. The front and rear are essentially two cylinders that rotate in opposite directions. The angular momenta of the two rotating parts of the cat’s torso offset each other, resulting in essentially zero angular momentum. When the cat straightens up, it will have turned over. This is called the Bend and Twist pattern of turning the jack.

But even that is not the last word. There are many different movements that come into play when a cat is falling over, says Gbur, and there are many cats with individual personalities. “Each cat probably puts their own spin on it.”

And there are also many scientists, each with an individual personality. Gbur says that he sees the “falling cat problem” as something like a Rorschach test for physicists. When watching tumbling cat movies, “everyone sees what they want to see. If you’re looking for Tuck and Turn, you’ll probably notice more limb movement. If you’re looking for Bend and Twist, you’ll probably notice body folding and twisting.” “.

Despite minor differences in form, the physics of the falling cat problem is more or less resolved. At this point, Gbur says, the remaining questions are more about the neuroscience involved: how the brain detects fall and rotation.

don’t try this at home

Gbur offers some advice to amateur scientists who are interested in the physics of falling cats: “Please don’t drop your cats. All cats are supposed to have this reflex, but not all are very good at it.” that. And there are plenty of videos online of falling cats that you can watch and study.”