This is an excerpt from Terry Pratchett's The Unadulterated Cat. I picked this book up long before I ever got picked by a cat, so it's kinda shaped how I think of them. This bit particularly explains my belief that Honeycat was sent to me from the future, and that Babycat traveled back to ancient Egypt to be worshiped when her mum told her it was time to move out.
All cats are now Schrodinger cats. Once you understand that, the whole cat business falls into place.
The original Schrodinger cats were the offspring of an infamous quantum mechanics experiment of the 1930s (or possibly they weren’t the original ones. Possibly there were no original ones.)
Everyone’s heard of Erwin Schrodinger’s famous thought experiment. You put a cat in a box with a bottle of poison, which many people would suggest is about as far as you need to go. Then you add a little bottle-smashing mechanism which may – or may not – smash the bottle; it all depends on random nuclear thingummies being given off by some radioactive material. This is also in the box. It is a large box. Now, according to quantum theory, the cat in the box is both a wave and a particle… hang on, no. What it is, because of all these quantums, is in a state of not actually being either alive or dead*, but both and neither at the same time, until the observer lifts the lid and, by the act of observation, sort of fixes the cat in space/time etc. He’s either looking at a candidate for the sad patch, or a spitting ball of mildly radioactive hatred with bits of glass in it. The weird part about it is that, before the lid is lifted, not only the cat’s future but also its immediate past are both undecided. It might have had been dead for five minutes, for example.
That’s the story that got into the textbooks, anyway.** Less well know is the work by a group of scientists who failed to realize that Schrodinger was talking about a ‘thought experiment’*** and did it. Box, radioactive source, bottle of poison, everything. And the cat, of course.
They left out one important consideration though. While the observer might not know what is going on, the cat in the box damn well would. We can assume that if the prospect of hanging concentrates the mind, then the inkling that, any minute now, some guy in a white coat is going to lift the lid and there’s a fifty-fifty chance that you are dead already, does wonders for the brain. Spurred by this knowledge, and perhaps by all the quantums floating around the laboratory, the cat nipped around a corner in space-time and was found, slightly bewildered, in the janitor’s cupboard. Evolution is always quick to exploit a new idea, however, and this novel way of getting out of tricky situations was soon passed on to its offspring. It had a large number of offspring. Given its new-found talent, this is not surprising.
The important gene was so incredibly dominant that now many cats have a bit of Schrodinger in them. It is characterised by the ability to get in and out of locked boxes, such as rooms, houses, fridges, the thing you swore you put it in to take it to the vet, etc. if you threw the cat out last night, and this morning it is peacefully asleep under your bed, it is a Schrodinger cat.
Cats make ideal time travelers because they can’t handle guns. This makes the major drawback of time travel – that you might accidently shoot your own grandfather – very unlikely. Of course you might try to become your own grandfather, but having watched a family of farm cats, we can tell you that this is perfectly normal behavior for a cat.
*ie, uncertain. Because of Heisenberg’s Uncertainty Principle.
**If you can believe it. It’s like that one about one twin staying here and the other going off to Sirius at the speed of light and coming back and finding his brother is now a grandfather running a huge vegetable wholesale operation in Bradford. How does anyone know? Has anyone met them? What was it like on Sirius, anyway?
***One that you can’t do, and which won’t work.