In Ursula K. Le Guin’s “Schrödinger's Cat”, she explains in a Pynchonesque manner the infamous thinking experiment (Gedankenexperiment) proposed by Erwin Schrödinger in 1935.  Although Le Guin does an exemplary job at explaining the actual process of the experiment, the purpose is generally left out—perhaps to keep the story as interesting as it is.  Quantum mechanics isn’t the sort of topic that everyday people discuss, nor is it light reading.  Thus, to get the full understanding of “Schrödinger's Cat”, one is forced to delve into the basics (or not so basics) of quantum theory.

Quantum mechanics came into existence in the early part of the 20th century through the work of notable physicists like Einstein and Bohr.  It is a theory of mechanics similar and extending that of Newtonian mechanics where atomic and even subatomic (think electrons) properties are given a predicted measurement based on observations (eigenstates).  Erwin Schrödinger’s work on quantum mechanics involved defining a way to predict the wave function of an eigenstate as time passes.  However, during this development, he pointed out a rather interesting, contradictory part of quantum mechanics when transferring it to a macroscopic level (the level at which humans perceive, as opposed to the atomic level of quantum mechanics).  He used the “cat in a box” thinking experiment to illustrate this.

Le Guin explains the experiment in plenty of detail; however, some of the specifics differ from Schrödinger’s original.  He proposed that a cat be put in box with a diabolical device in a way that the cat could not interfere with the device.  The device would include a Geiger counter or similar apparatus that would be able to tell when a radioactive atom decayed.  The half-life of this atom was exactly an hour, so that it had a 50% chance of decaying within an hour.  If it did decay, the device would shatter a vial of hydrocyanic acid that would kill the cat.  Thus if the cat was placed in the box for an hour, it would have a 50% chance of being dead and a 50% chance of being alive when the box is opened.  Differences aside, the idea is the same.

The principle point to be made by the experiment is only briefly touched on by Le Guin.  She examines it in “Schrödinger's Cat” with, “until you lift the lid of the box, the cat has neither been shot nor not been shot?”  What this says is that while the cat is in the box, it is in a seemingly paradoxical state of being both dead and alive.  Such a superposition (mixture of observable states) is fine on the quantum level but not so at the macroscopic level.  Then, the apparent question is:  when is the cat’s state either dead or alive if it is unknown until the box is opened?

Le Guin goes on to relate the experiment to other points like quantum decoherence and God playing dice with the world.  The fact that the cat in the story is not dead or alive when the box is opened but rather lost is perhaps a portrayal of quantum decoherence as well as a great, mysterious ending.  Nevertheless, Le Guin makes Schrödinger’s thinking experiment exactly what it was intended to be while providing a delightful story in which to realize it.