Apparently, whilst falling upside down, a cat can right itself faster than the eye can see. How fast is that?

Friar Tuck

The lore that cats always land on their feet may not be strictly true, but it's also more than just talk. To right themselves while falling, cats rotate while keeping their angular momentum constant at zero. A cat falling with its back to the ground thrusts its back legs straight out behind its body. It simultaneously tucks its front legs. Extending the rear legs increases their rotational inertia and their tendency to stay straight and resist spinning. This shift of the hind legs creates a small torque that is transmitted through the cat's body. Because the front legs are tucked, their rotational inertia is relatively {small;} it takes only a small torque to rotate them. The result, very useful for the cat, is that the torque traveling through the cat's torso twists its front legs down toward the ground. Using its muscles to stop the front legs' rotation when pointing closer toward the ground, the cat generates torque that can travel back through its body and help bring the hind legs around, too. With enough falling time, a cat can ratchet itself around by repeating these opposing twist motions, until both sets of feet are pointed down for the landing. Basically this means that it would take some time for the cat to achieve all this so 'faster than the eye can see' is rather an exaggeration Mar 10 02, 11:01 PM