Why do cats always seem to land on their feet?

By doing something that looks impossible. A falling cat has nothing to push against, and physics says you cannot change how much you are spinning without something to push - yet it turns over. The trick is that a cat is not rigid: it bends in the middle, tucks the front legs in and extends the back ones, rotates the light front half one way and the heavy back half a little the other, then swaps. Net rotation, zero net spin. It takes about a third of a second.

It was settled by photography. Étienne-Jules Marey published a sequence in 1894 showing the manoeuvre frame by frame, and the French Academy of Sciences reportedly complained that he had presented a scientific paradox in defiance of mechanics.

The reliability is oversold, though. Cats need height to complete the turn, and a fall of under about a metre can be worse than a longer one. Vets describe high-rise syndrome, and a 1987 study of cats falling from New York buildings found injuries peaking around seven storeys and falling off above that - which may be because they reach terminal velocity, relax and spread out, and may partly be because cats that die on impact are never brought to a vet.