I have just returned from a thought experiment.

Specifically, I heard a thump somewhere inside the house and went downstairs to the spare room to check it out.

Why downstairs? Why specifically the spare room? Because we have a house guest. We’re cat-sitting our daughter’s newly adopted kitten while she’s away for a few days for work and travel.

We can’t let the kitty have the run of the house. For one thing, it’s been a long time since we had a pet; the house is no longer cat-proofed. Second, I’m being treated for an allergy to cats; especially on a day when I’m having the shots, it’s important that I stay away from them.

All’s quiet in the spare room. Thus the curious thought experiment.

The cat’s out of the bag

I’m not the first to attempt such an experiment. Back in 1935, Austrian physicist Erwin Schrödinger used one to reduce an interpretation of quantum mechanics to absurdity. According to that interpretation, subatomic objects do not have definite properties until they are observed and measured. Until that happens they can only be predicted using probability.

Schrödinger said that was like sealing a cat in a cylinder with a poison that would be released when an atom of radioactive substance decayed. Without knowing whether the trigger had been activated, it’s impossible to determine whether the cat is alive or dead, even using probability. Open the cylinder and observe the cat, and you have the answer. Until then, you don’t — although clearly the cat is either alive or dead. It can’t be both.

Hypothetical-animal cruelty issues aside, it’s clear that more than eight decades later, Schrödinger’s theoretical cat would be no spring kitty. Yet I suspect our guest kitten is a distant relation.

Is the cat alive or dead? Or less macabre: Is she sleeping or is she in trouble? If she’s sleeping, I don’t want to disturb her. If she’s in trouble, I want to rescue her.

To complicate matters, unlike the dead-or-alive scenario, there are other possibilities. She could be playing quietly. She could be waiting to pounce on me or to escape when I open the door. She could be about to get into trouble.

The only way to find out is to open the door.

…She was in her bed, but her head popped up when she heard the latch click. No kitty rescue required.

This time, anyway…