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Cats are amongst the easiest pets to take care of - They clean themselves, are easy to litter train and most important of all, don't splatter liquid the way dogs do. This talent apparently also extends to bigger felines like lions and cheetahs - Now, researchers have figured out why and believe it or not, it involves some laws of physics!
The lapping research began about three years ago, when MIT researcher Roman Stocker, was watching his cat Cutta Cutta (stars in an Australian aboriginal language), drinking milk and thought it was interesting that she did not splatter one drop - Being a scientist he decided to find out what was going on from a scientific perspective.
Joined by researchers from Virginia Tech and Princeton University, the team started by observing reduced speed videos of domesticated and wild cats drinking and then created a robotic tongue that mimicked the movement - What they discovered, is quite fascinating.
It is a well-known fact that cats drink liquids with the tip of their extended tongues curled backwards like a capital J, so that it's the first thing to touch the liquid. However, when the scientists observed the tapes in slow motion, they realized that unlike dogs who insert their tongues into the liquid and use them like a ladle, cats merely skim the surface of the liquid with the tip of their tongues, before pulling them back in again.
That simple motion, results in a column of liquid that forms between the cat's moving tongue and the surface of the liquid. The cat then closes its mouth, drawing in with it the liquid that is at the top of the column - This not only results in a nice sip, but also, helps keep its chin dry.
How does the liquid defy gravity and get drawn up? That is where the principals of physics come in.
When the tip of the cat's tongue touches surface of the liquid, some of it sticks to the tongue, just like water sticks to our bodies when you come in contact. The cat however, pulls its tongue back so rapidly, that just for one second, inertia - the tendency of the moving liquid to follow the tongue, overcomes the forces of gravity, which are trying to pull the liquid back into the bowl.
The cat it seems, knows exactly when this will happen and shuts its mouth at the right time, capturing some of the liquid. If for some reason it delayed shutting its mouth, all the liquid would fall right back into the bowl and it would be left hi and dry!
The researchers estimated that while domesticated cats average about four laps a second, larger cats lap more slowly, since their tongues are much longer. However, for all the cats, the ratio between gravity and inertia is exactly one - indicating perfect balance! Who would have guessed that the mere act of drinking would require such perfect technique and utilize the laws of physics?