Erwin Schrödinger posited a thought experiment in 1935 that became known as Schrodinger’s Cat. You put a cat in a box with some equipment and shut it up. Inside, there is a radioactive element that has a 50% chance of decaying in an hour. Any decay will register on a Geiger counter, which trips a device that breaks a poison vial and kills the cat. But the box is closed. At the end of that hour, is the cat dead or alive? You cannot know until you open the box. Therefore, until you observe the cat, he exists as both dead and alive.
To the layman, that seems ridiculous. Schrodinger’s experiment is about quantum mechanics, but it's like philosophy and metaphysics as well. If a tree falls in the forest, and no one is there to hear it, does it make any sound? Of course it does, because believing that nothing exists outside our perception of it is extreme hubris.
Be that as it may, the experiment seems unnecessarily cruel as well as absurd. Schrodinger was a smart man, but that's no excuse to kill a cat. Despite the fact that it was just a thought experiment, Schrodinger's reputation took a hit from both cat lovers and slightly-less-sharp scientists, as you can see in this T-shirt designed by Mike Jacobsen.
The explanation for those somewhat familiar with quantum mechanics reveals that Schrodinger was just trying to make a point among physicists. But the thought experiment lingered on, because we love cats, and would hate to see harm come to one. And the idea of a cat being both dead and alive bends our brains. It’s like a trip into another dimension.
A T-shirt from Wear Viral entitled Schrodinger’s Portal puts the cat into the physics-bending world of the game Portal.
F. Gwynplaine MacIntyre created this illustration for his short story "Schrödinger's Cat-Sitter.” The cat is simultaneously in front of and behind the impossible object, which makes about as much sense as the cat being both dead and alive at once.
Artist Jie Qi saw that the two states of the cat, alive and dead at the same time, were impossible. He illustrated that as an illusion, putting the cat inside an impossible box as well. This drawing is from 2006. He followed that up with two more iterations of the same subject you can see here, and you’ll find the original version from 2004 here.
How can a cat be both dead and alive? DeviantART member Evilkitten3 saw that as a condition that could be desired, even if it’s not possible.
It’s quite a difficult concept, especially when you first hear it. A group of giant robots learn about the Schrodinger’s Cat experiment and decided to investigate the results for themselves, in this Robot Republic video.
Comic artist Hannah Blumenreich considered the entire idea silly, because a cat will let you know when he doesn’t want to be in the box anymore. If he is alive, that is.
Half Dead, Half Alive
Some interpret “both dead and alive” to mean half dead and half alive, because that’s the only way the phrase makes any sense. DeviantART member atoji saw that as a literal way to illustrate the cat. Maybe he's only mostly dead.
DeviantART member RaggedyAnarchist used the same idea, with the cat split down the middle and the “dead” side still holding the poison that killed him. Or half of him. The other side is celebrating life!
When Cecil Adams of The Straight Dope received a rhyming letter asking him to explain Schrodinger’s Cat many years ago, he replied with an epic poem that didn’t clear up anything at all, but it rhymed well. Here the poem appears with Scott Adams’ Dilbert comics featuring Schrodinger’s cat. I have no idea whether Cecil Adams is related to Scott Adams.
The Zombie Cat
But there’s another way to be both dead and alive, as we’ve seen in some George Romero films and the TV series The Walking Dead. The cat could be a zombie! Alive, meaning animated, and dead, meaning he died in the box. DeviantART member pixelat3dLtd illustrated Schrodinger’s zombie cat, who seems to be looking for the one who caused his current state of being.
Taking that idea a step further, DeviantART member Zaleho made Schrodinger’s cat a zombie with one side “deader” than the other, sporting saber-teeth as well!
The Cat’s Revenge
How does the cat feel about being treated in this way? Not happy, as illustrated by Matthew Inman of The Oatmeal. The cat is justified in wanting to turn the tables on the scientist who thought up the experiment.
Animator Chavdar Yordanov tackled the subject in 2012 with a video exploring the wrath of the formerly adorable cat who is subjected to such an inhuman experiment. The mayhem inflicted by the ghost of the wronged feline is rather satisfying.
But we all know how the experiment really would have turned out. The cat is, of course, alive, because cats have nine lives!
See also: The Buttered Cat Paradox