I’m generally a sucker for anything cat-related on the internet (hilarious videos of cats surprising babies notwithstanding), though it’s rare that I find something Damn Interesting enough to share with the blogosphere-at-large. Today, however, I’ve got some news cat lovers (and, potentially, haters) can use. Did you know? Cats and high-rises don’t mix. Check it out:

Among the feline’s numerous predatory gifts is the capacity to fixate on his prey–a skill useful when chasing a shrew through the grass, but a serious disadvantage in the urban world. People living in tall buildings often allow their cats to sit on window ledges and fire escapes, unaware that the traits which allow cats to clamber through trees aren’t nearly as effective with metal railings, window panes, and brick. Cats have been known to fixate on something outside and leap or fall from high-rise ledges, an occurrence frequent enough that urban veterinarians have coined a phrase for it: High-Rise Syndrome.

If you must live in a high-rise with a cat, feline physics advisors counsel, then live on the sixth floor or higher. It seems that cats who tumble from great heights have a better shot at survival — much better, in fact — than those who fall from five floors or lower. Six floors is the magic number. (Brief digression: ten years ago a good friend of mine’s dad was working construction, and fell off the top of a six-story building. He landed on his feet, and survived. (Needless to say, he’s got some joint problems.) Every year on the anniversary, he has a “fall party,” and his family bakes him a six-story-building-shaped cake. Six stories, apparently, is the magic number for people, too.) The record for a cat surviving a fall is forty-three stories. How do they pull it off?

It takes a normal cat about a two and a half feet of free-fall to orient himself to feet-down, and it wasn’t until the advent of high-speed cameras that the acrobatics were fully understood. Much like an ice skater controls her rate of spin by pulling in or extending her arms, the cat first tucks in his front legs and splays out his rear legs, allowing him to quickly situate his forequarters with the feet down. He then reverses the procedure, extending his front legs and tucking in the rear legs, allowing the hindquarters to rapidly twist into position while the forequarters turn only slightly. Rear legs re-extend when in place, and he’s fully deployed. This position is ready for landing, but it also lends the cat a limited aerodynamic–much like the flying squirrel. The ability to increase drag slows a cat’s average terminal velocity from a person’s 130mph to a much happier 60mph.