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Comment by ada1981 | Hacker News Reader

ada1981

I didnt know that below a certain size, gravity won’t kill you.

The idea a mouse can survive a fall into a thousand foot mineshaft is quite wonderful.

For cats it's better to fall off a higher floor than a lower one because they have more time to turn feet down and increase their air drag thus getting under the terminal velocity and allow them to survive the fall.

For humans a jump from the third floor is where safe ticket to afterlife start, though head first will end it just as fine from the second or even first floor.

For an adult, a fatal fall is possible from the standing position, it's just most of the time people are able to break the fall in some way when they do fall and not land on their head.

So true. Especially: don't push drunkards.

> For cats it's better to fall off a higher floor than a lower one because they have more time to turn feet down and increase their air drag thus getting under the terminal velocity and allow them to survive the fall.

True, and there's been at least one, probably many, actual study done that came to that conclusion.

Small nitpick (I'm sorry, I couldn't stop myself!), their action doesn't get them "under the terminal velocity," it lowers what their terminal velocity is. It's just the speed at which the wind resistance is enough to prevent further acceleration by gravity. It's terminal as in the end of something (acceleration), not terminal as in the predicted death of the something.

Thanks for the nitpicking, English isn't my native tongue.

Also because getting their feet facing down allows them to use their legs as shock absorbers. Watch a cat as it lands on a flat surface from a 1 meter high jump, you will see it in action.

Also because cat legs are very good shock absorbers. The hind legs are impressively springy, which is why cats can leap four or five feet into the air without a run-up.

Human legs aren't as flexible. Beyond bent-knee heights, the choice is between learning how to tuck and roll - which takes practice for most people - or having dislocated hips on landing.

This inspires a high school physics test problem:

You are sitting in an apartment building and your cat sees a mouse on the window sill.

The mouse jumps out the window and lands on the ground unscathed.

The cat, seeing the mouse made the leap safely, and hoping for lunch, makes the same jump and suffers no injury.

You worried about your cat escaping, need to decide if you’ll jump as well.

Based on seeing the tiny mouse make it and even your bigger cat, can you assume you’ll be safe? Why or why not?

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