The second major advantage cats have when falling is their unique ability to right themselves midair, while people tend to tumble uncontrollably (and quite uncivilized like, a cat might comment) as they fall. This requires a use of, if perhaps not an understanding of, the concept of angular momentum. Cats have a superb internal gyroscope located in their inner ear which very quickly detects their orientation as hey falls. As can be seen below, a cat rotates its body in one direction and tail in the opposite direction as it falls (conserving angular momentum in the process), and then stretches its legs out and reverses the process. The outstretched legs keep the cat from twisting all the way back to its original orientation. The cat then reverts back to the first motion and continues the process until rotation is complete. Tail-less cats use one of their hind legs extended in place of a tail. The rotation takes a mere two to three feet of descent.
**This is a series of photographs of a cat being dropped upside down (fortunately it landed on its feet). For more information on this check out "The tail-less cat in free-fall".