Why Do Cats Always Land on Their Feet?

 

Well, have you ever taken a closer look to a cat jumping off a wall, or a bookshelf, or a coffee table or literally anywhere? If you have, you must have noticed them ALWAYS landing on their feet. It's almost like, "Hey, you throw me down the Wonderland rabbit hole and I'll still be on my feet." 

Obviously, you must have heard that cats have nine lives, but really, how does something this vague even come into the picture? So, here's the thing: a cat can fall from a building, nope, not your two-storey building, I'm talking of skyscrapers, floors numbering in their 30s and 40s, and still land on their feet. 

Throw the cat upside down from a height and you will see it rotate mid-air like one of those natural athletes off a giant circus and land... yep, on its feet.

But how does this actually happen? How does this little, adorable, furry animal defy the laws of physics?

THE CAT-REFLEX

I don't know about us, but for cats, that's totally their motto. They're like: "Ah, gravity, old friend." and will start defying it like teeny tiny superheroes. Or humans in zero gravity. Except, of course, they can't fly. But hey! Throw them in any orientation, and they will ALWAYS land on their feet. Perfectionists, ugh.

I read this Scientific American article recently and that talked about how cats basically looked at a law of Physics, stared directly into its soul, scanned its nitty gritty and smirked, "Aha!". 

Their inner ear has this incredible balance system, which is kind of surprising, but it tells them which is the right way up. So, first, the cat would move its head to reorient itself. Then, they put their front paws close to their bodies, reducing their moment of inertia, which is something that resists an object from rotating around its axis. Moment of inertia is like a chain around your ankles and hands holding you to the wall. You can move, sure, but can you rotate around like a spider? Not really. 

With their hind legs, the cats then employ the opposite effect. When they stretch their legs, they create as large a moment of inertia as possible. So basically, the upper body is free to rotate and the lower body... not so much. As a result, the upper body rotates through a large angle, while the legs rotate less in the opposite direction. But how does this happen? Well, cats have 30 vertebrae in their spine (humans have 24), so you can imagine how flexible they must be. If they ever choose to be acrobats, they will surely give Cirque de Soleil a run for money. 

Once the upper body is now in the correct position, with head aligned upright above the ground, cats can extend their front paws, tighten their hind legs and perform the pepper-mill-like movement in the opposite direction so that their hind paws are also aligned above the ground. 

This is their Righting Reflex. It's the one thing that involuntarily just comes to them, so whenever they're going to fall, there's going to be a voice saying "Sorry, not today!" that will make them land right onto their feet. 

AND THERE WE GO AGAIN: CATS OUTSMART US... AGAIN!

Let me give you a scenario. A cat jumps out of a window on the second storey VS the same cat jumping out of a window on the 10th storey. Which should be more injured?

The 10th storey cat? Piiiing! You're wrong. It's the second storey cat.

Okay, before you raise your eyebrows and say "The joke is over." listen to me. Cats reach terminal velocity at around five storeys. That is when their weight is balanced by air resistance. After 5 storeys, the air resistance has enough time to increase and make them land slowly and perfectly on all fours like some sort of Barbie Cat (except the heels, of course). 

To all those confused, I am referring to the concept of free fall. Initially, when you fall, your weight is the dominant force, because obviously YOU'RE FALLING! The acceleration is around 9.81ms⁻². As you accelerate, your speed increases, so air resistance increases and suddenly this opposing resistance slows you down. When your weight equals air resistance, terminal velocity is reached. 

And cats use this to their own advantage. 

GRAVITY'S WORST NIGHTMARE

Before you attempt to jump from a 10 storey building, hear me out! Cats have another quality that works to their advantage. 3 guesses. 

For those who got it, yes! It's their small size. They weigh SO LITTLE, gravity does not pull on them as hard as they pull on us. A ten pound cat falling from 10 storeys is NOT the same as even a hundred pound human. 

It's Physics 101. Imagine a feather and a brick. Which do you think will break? (This is not a trap question, I promise.)

Yep, it's the brick.

Same way, the cats are lighter, and hence, will suffer minor injuries, while a human... well, let's not talk about that. 

CAT PARKOUR

So, the next time you see another video on 'Cat Parkour' with a disclaimer 'DO NOT DO THIS ON YOUR OWN KIDS' remember, that cats have a Righting Reflex, an awesomely flexible spine that could even leave the world's best gymnast gaping AND a very light weight.

Do you still want to risk it?