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Cats are mysterious creatures, and among their many secrets is how the heck they always manage to land on their feet. It’s a phenomenon that has interested scientists for as long as both cats and scientists have co-existed. We’re getting close to figuring it all out, but the physics of the falling cat is surprisingly complex.
Before the advent of high-speed photography, the general consensus was that cats would push off of the dropper when they felt themselves beginning to fall. That would give them the necessary momentum to flip over in mid-air. Then in 1894, French scientist Etienne Jules Marey took a sequence of 34 photos that showed a cat dropping and “tumbling” to land on its feet (above). No one could figure out the physics of it, but comparisons were made to figure skaters accelerating a spin by pulling their arms inward.
The next step in our understanding of falling cats came in 1934 when Dutch physiologists G.G.J. Rademaker and J.W.G. Ter Braak came up with a mathematical drawing to describe the movement of a cat in freefall. They said the cat’s front and back halves rotated like cylinders in opposite directions. This canceled out its angular momentum and brought the feet down first. They called this “bend and twist.” In the 1960s, some of the same physics was applied to the study of how astronauts could rotate in freefall. Here’s SmarterEveryDay with a good overview.
More recently, physicists have looked at cat movements as an example of what’s known as “geometric phase.” This has connections to very deep, cutting edge quantum mechanics. The bottom line is: cats do weird things with their bodies that are really hard to describe with physics. Researchers will keep trying, though.