September 2010

What Color Is Your Cat's Parachute?

I recently listened to an episode of Radiolab which was dedicated to the concept of falling.  One segment covered the topic of falling cats. 

As everyone knows, a cat always lands on its feet.  (Not to mention the buttered cat paradox: if toast always lands butter side down, and cats always land on their feet, what happens if butter the top of a cat?)  But the physics involved in this maneuver are truly impressive.

In order to right itself as quickly as possible, a falling cat relies on a fairly sophisticated use of physics.  It twists its front half around to face the ground, and then its rear half. 

But it doesn't do this the usual way; instead, the cat conserves the angular momentum created by its fall, by sticking out its back feet to create drag (so that the front can swing around more easily), then sticking out its front feet (to bring the rear around).