Ever wonder how a cat always lands on its feet? For over a hundred years this puzzle has been catnip for physicists – leaving many chasing their tails.
In this episode of Tumble we unpack the mystery.
We enlisted the help of Greg Gbur is a professor of physics at the University of North Carolina in Charlotte to explain how falling cats have actually contributed to modern science.
In addition to being a physicists, Greg is an owner of multiple cats, an expert skydiver, and the author of a blog Skulls in the Stars – where he writes about the history of science.
“One thing I’ve learned from studying the history of science is that scientists are human beings. Often incredibly weird, weird human beings,” he writes. “In the mid-to-late-1800s, an exciting era in which the foundations of electromagnetic theory were set and the electromagnetic nature of light was discovered, a number of the greatest minds in physics were also preoccupied with a rather different problem.
“Cat-turning” or the “Cat-Righting Reflex” is the cat’s ability to flip over from rest in free fall. Greg says, scientists thought falling cats were defying the laws of physics. So they started to dropping them to learn more. When dropped from upside down, the cats were able to turn super fast without any outside force. But how could this be?
To the average person these moves may look impressive, but to a physicists it is mind blowing. To a trained eye, the cats appear to violate Newton’s Laws of angular momentum and inertia! This had many reputable scientists hooked on dropping cats, but also stumped.
It wasn’t until the development of high-speed photography that they started to make heads or tails of the kitty gymnastics.
The first high speed photographs of a cat flipping over were done by a Frenchman named Étienne-Jules Marey. Marey’s photos are really cool. They are a black and white timeline of a cat flipping. In 1894, he made a film of the experiment. It is the first video EVER of a cat.
And yes, it is on YouTube:
Marey’s video was the first, but definitely not the last, video of a falling cat!
As you might imagine the internet is full of them:
Even cats in space!
Caption: NASA studying cats in Zero-G – hoping to learn more about how cats move to help astronauts move better in space.
So how does a cat do it?? The key, says Greg, is the V shape the cat makes when falling. You need to think of the cat as two segments, rather than one straight body.
When the cat bends, it essentially is able to turn its body against itself, keeping the laws of physics intact.
Greg recommends Smarter Every Day’s “Slow Motion Flipping Cat Physics” video as a great explanation and to see the breakdown of the movement more clearly: