Nine Lives?

“Feline pesematology.” Not exactly a common term, feline pesematology is the name given to the relatively obscure study of the science of falling cats. Believe it or not, due to the large number of cats injured by falls, there has been enough interest in this field to spark a fair amount of research. It is not uncommon for serious studies on absurdly inconsequential matters such as falling cats to attract some attention from the scientific community, but one in particular has created a rather extraordinary level of interest not only for its subject matter but for its seemingly impossible conclusion.

The famous (or infamous) study was conducted by two scientists at the Animal Medical Center in Manhattan who examined the survival rates of some 115 previously airborne cats as a function of the number of stories from which they fell. The cats fell from New York apartments at heights of 2 to 32 stories onto concrete pavement. The first result was interesting if not really unexpected: cats are very good at surviving long falls. In fact, more than 90% of the cats survived their brief flight. The second result was what turned heads. When the height each cat fell was taken into account, it was found that only about 5% of the cats who fell 7 to 32 stories died, while about 10% of the cats who fell from 2 to 6 stories died. Now, in the interests of scientific accuracy, it must be noted that the sample size for this experiment was not really large enough to firmly establish this seemingly paradoxical effect, but the authors of the study did propose a viable explanation.

All falling objects (including cats) will accelerate only up to a particular speed, called the terminal velocity, at which point air resistance becomes strong enough to counter-balance gravity. For a human, terminal velocity is about 130 mph, but for a small furry cat, it is at most 60 mph and is reached after about five stories of free-fall. Now, the well-known sensation of falling, for humans as well as cats, is caused only by

acceleration. After terminal velocity is reached, the sensation disappears. The scientists’ clever explanation for the result of their experiment is that falling cats tend to panic and curl their bodies up – until they reach terminal velocity when they relax and spread out, slowing down and reducing the stress of the crash-landing.

One final thought on this curious subject is the coincidence I noticed last night between the total average survival rate for the cats and the nine lives reputation. Imagine for a moment that cats were like people – certain to lose a life from a fall of several stories. Then, on average, one ninth of the cats that fell would lose their final life, and the survival rate would be just a tad below 90%!