In quantum mechanics, Schrödinger’s cat is a thought experiment that illustrates a paradox of quantum superposition. In the thought experiment, a hypothetical cat may be considered simultaneously both alive and dead, while it is unobserved in a closed box, as a result of its fate being linked to a random subatomic event that may or may not occur. This thought experiment was devised by physicist Erwin Schrödinger in 1935 in a discussion with Albert Einstein to illustrate what Schrödinger saw as the problems of the Copenhagen interpretation of quantum mechanics.
In Schrödinger’s original formulation, a cat, a flask of poison, and a radioactive source are placed in a sealed box. If an internal monitor (e.g. a Geiger counter) detects radioactivity (i.e. a single atom decaying), the flask is shattered, releasing the poison, which kills the cat. The Copenhagen interpretation implies that, after a while, the cat is simultaneously alive and dead. Yet, when one looks in the box, one sees the cat either alive or dead, not both alive and dead. This poses the question of when exactly quantum superposition ends and reality resolves into one possibility or the other. 1
Recently I heard about a rather interesting situation. The task is in a done state but is not done. Is it finished? No, but it’s done for now. Now that means when? Now, not now … Is it finished? No. But when it will be finished nobody knows.
What does this mean for Schrödinger’s Cat?
For a furry, there were only two states - alive or dead. Thus, if it turns out that we have a nano box with a nano cat inside, then until the measurement is made, in this case, a glance inside, all signs in the sky and earth would clearly indicate that the cat is alive and dead.
Only opening the box causes us to break the wave function, i.e. we
force the tested object to assume a given state. Another example would be water in a bucket, which, until we put our hand inside, would be liquid, vapor, and a block of ice at the same time - retaining all the properties of a given state of aggregation until we break its wave function.
It seems that it is precisely because all of this defies common sense that almost every time the adjective
quantum echoes through the labs of science fiction movies when the uncreated happens on the screen.
From Wikipedia. ↩