The dogs may be man's best friend, but the cat, on the other hand, is happy to be cool. Afterall, it has a lot in its arsenal to be that way. First, you may have heard about the proverbial nine lives of the cat. A mythical number of lives which was something people say due to its incredible agility and quick reflexes to jump out of harm's way. Without letting the cat out of the bag (pun intended), we may we may partly blame the English proverb- "A cat has nine lives. For three he plays, for three he strays, and for the last three he stays", for lending credence to the myth of nine lives of a cat, a cat only has a life.
Image credits: Pxhere Commons]
The oldest living cat, Creme Puff died at a ripe old age of 38 years plus 3 days (August 3, 1967, to August 6, 2005) and made into the hall of fame of the Guinness World Records. Sadly, cats are like us and have only one life to live. But we should not to be too sad for the cat, it is a fascinating animal, one which the physicists have taken a liking to it. And no, their liking has nothing to do with a cat's purr or smooth fur. It has to do with its incredible ability to always land on its feet when released from a height irrespective of the orientation of the feet at the moment of such a release.
This is not the first time physicists have something to do with a cat. Remeber the Schrödinger’s Cat thought experiment? If you don't, I would quickly do a short summary of it. It was a paradox because there's an element of conflict, inconsistency, and of course, contradictory proposition. It was named after the Austrian physicist, Erwin Schrodinger. The thought experiment takes a look on quantum mechanic's superposition which Schrödinger believe is a flawed assertion. The quantum superposition theory states that an object can possibly exist in multiple states until someone checks in on it. Using a simple analogy, Greenrun can be a bot, an alien, or a human, until you met me and found out I am truly a bot. So your checking in to verify just reduces the possibility to a single outcome.
But what has that got to do with a cat? Well, let's us imagine a cat in an enclosed box away from prying eyes. The box was in a room that has a Geiger counter, a device that can detect and measure ionization from radiating substance or environment, and a radioactive material which may or may not decay. If it does, the Geiger counter can measure it and the poisonous fumes released will kill the cat.
If a person closes the door of the room where this box was, the Schrodinger's cat is now both alive and dead, or in a quantum state of superposition. The only way to find out us to interfere via opening the door to check on the cat. The outcome will be either a dead or live cat. The opening of the door is where the paradox sets in, the observation (measurement) has affected the outcome which beforehand was not there.
If you have ever had a cat, you will notice about from being quite agile with quick reflex, that they always tend to land on their feet when they fall from a height. This reflex has some interesting science behind it. It is one that scientists have not only found interesting but also very fascinating in past centuries.
[From the 1894 movie, Falling Cat
Image credits: Wikipedia Commons]
Some notable scientists also caught the bug of the cat-dropping craze. One of them is no other than James Clerk Maxwell popular for Maxwell's equations; an important equation in the electromagnetism and optics.
The Maxwell got in on this cat-throwing fest for the love of science; he wanted to verify that the cat can turn and land on its feet while keeping the concept of conservation of angular momentum.
During his residence in Cambridge he endeavoured to investigate the process by which a cat is enabled invariably to alight on her feet. The mode of conducting the experiments and the impression they left on the mind of the College will appear from the following extract from a letter written to Mrs Maxwell, from Trinity, on January 3d, 1870, when Professor Maxwell was examining for the Mathematical Tripos :
There is a tradition in Trinity that when I was here I discovered a method of throwing a cat so as not to light on its feet, and that I used to throw cats out of windows. I had to explain that the proper object of research was to find how quick the cat would turn round, and that the proper method was to let the cat drop on a table or bed from about two inches, and that even then the cat lights on her feet. Archive Text of The life of James Clerk Maxwell : with a selection from his correspondence and occasional writings and a sketch of his contributions to science*
If we closely examine the process, we will come up with three stages of how the cat accomplishes the feat of always nailing the landing on feet.
[image credits: Wikipedia Commons]
First, due to the flexibility of the cat's muscle, it curls up (folds). At the point, the angular momentum is at zero as the body of the cat is moving in opposite directions during the folding process.
As it moves on to the next stage, each of the now folded body moves in opposing direction. Again, there is zero angular momentum- the two halves rotation was in the opposing direction.
Finally, we got to when the cat almost hits the floor, it unfolds its body landing on the four feet. Due to the same reason encountered on the first stage, the angular moment is also zero here. This is an extremely simplified version of the process which paints the picture of the process.
The "cat dynamics" of body rotation "cancel out" any angular momentum of movement ensuring it is at zero.
The studies of how cat land may not just be something a bored physicist who needs something to spice up his evening came up with. It has some real-life applications. The process has application in satellites via attitude control when a space vehicle's sensors help in orientation and avoidance of obstacles and redirection of an antenna for optimum communication with the Earth station.
Also, the study was put to use in astronauts training to develop a safer free fall. A $60,000 research grant was given to Thomas R. Kane a Professor emeritus of applied mechanics of the Stanford University in the 1960s by NASA to help develop a cat-like manoeuver falls for astronauts.
No cat was harmed during the making of this post :)
Thank you for reading.