Today's Google Doodle honors Erwin Schrödinger, the Austrian physicist whose thought experiment demonstrated the absurdity of conventional ideas in quantum mechanics.
What if you penned a cat in a steel chamber and then affixed to that chamber a small amount of radioactive substance? And what if, over the course of one hour, one of the atoms in that substance might – or, in equal probability, might not – decay? What if, in the 50/50 chance that the substance did decay, it deployed a hammer that shatters a flask of hydrocyanic acid that then poisons the cat?
So, after an hour, is the cat alive or dead?
It’s both, said Erwin Schrödinger, the Austrian physicist who revolutionized how quantum mechanics is understood and who is honored today in a Google Doodle.
It’s an absurd idea, ripe for riffs and jokes: "If they don't ever open the box to feed it, it'll eventually just be two different kinds of dead,” observes a character in Neil Gaiman’s novel "American Gods."
Plus, what sadistic person would ever want to do that to a cat? Who has ambiguously radioactive solutions lying around their home?
Well, Schrödinger meant it to be absurd.
Schrödinger’s simultaneously alive and dead cat is a reaction to Niels Bohr's and others’ interpretation of quantum mechanics (the Copenhagen Interpretation). That idea holds that matter has both wave-like and particle-like properties, and that subatomic particles can be in multiple places at once, until an observation is made and the object assumes just one value. Until then, the atom is represented by a mathematical formulation called a wave function that covers all the possibilities of what the object could be.