tabby white british shorthair cat jumping

Ever since there have been small children and curious scientists, people have released cats to see what would happen. And that’s exactly how long cats have been on their feet. But how do cats achieve this? The answer to this question has been a scientific quest for hundreds of years.

Do cats always land on their feet?

In his 2019 book Falling cats and fundamental physics, Greg Gber, professor of physics at the University of North Carolina at Charlotte, takes a delightful walk through the history of the science of falling cats (with fascinating digressions into the related history and science). According to Gbur’s accounting, the problem has intrigued and vexed scientists since the 1700s.

By the mid-1800s, the basic laws of motion were established; it was assumed that the law of conservation of angular momentum meant that an object in free fall needed something to push against to give it initial spin. In other words, the cat cannot simply turn around in space after began to fall. It must have been pushed by a tree branch or by the hands of the person who dropped it.

Then in 1882, French scientist Etienne-Jules Marie developed a technique called chrono-photography and used it to photograph a falling cat at 12 frames per second. The resulting images clearly show that the cat can stand up in the air without pushing anything away. When Murray presented his findings at a meeting of the French Academy of Sciences in 1894, the reaction was strong. Murray seemed to have presented evidence that defied the laws of physics.

However, it turns out that the original study of angular momentum was limited to rigid bodies. Cats are anything but. Cats are soft, fluffy and flexible creatures. The flexibility of the cat’s body makes it able to perform these gymnastics in the air.

Find out how cats land when they fall

Scientists quickly realized their mistake, and an explanation was soon offered. The French mathematician Émile Guyou proposed a solution approved by Marey and accepted by most members of the Academy. In a manner similar to skaters pulling their arms to spin faster or extending their arms to slow down, cats use the position of their front and back legs to control their spin.

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

When a cat first falls, Guyou suggests, it extends its hind paws and retracts its front paws. This allows him to twist his upper body without much counter-twisting from his lower body. The cat then retracts its hind paws, extends its front paws, and twists its lower body into the desired position without much counter-twisting from the upper body. Gbur calls this the Tuck and Turn model and it was good as far as it goes.

An ongoing debate about cat gymnastics

Then in 1935 a team of Dutch physiologists, GGJ Rademaker and JWG ter Braak, looked at Murray’s photos again and noticed something others had missed. As the cats begin to fall, they arch their backs, bend their bodies in the middle, then rotate the two halves in opposite directions. The front and rear are essentially two cylinders rotating in opposite directions. The angular momentum of the two rotating parts of the cat’s torso cancel each other out, resulting in essentially zero angular momentum. When the cat rears back, it will have turned around. This is called the Bend and Twist cat flip pattern.

But even that is not the final word. There are many different movements that come into play when a cat falls, Gbur says, and there are many cats with individual personalities. “Every cat probably does their own little twist.”

In addition, there are many scientists, each with an individual personality. Gbur says he sees the “falling cat problem” as something of a Rorschach test for physicists. When you watch movies with falling cats, “everyone sees what they want to see. If you look for Tuck and Turn, you’ll probably notice more limb movement. If you look for Bend and Twist, you’ll probably notice the bending and twisting of the body.”

Despite the slight differences in shape, the physics of the falling cat problem is more or less solved. At this point, Gbur says, the remaining questions are more about the neurosciences involved—how the brain senses the fall and spin.

Don’t try this at home

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

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *