## Tech & Science dictionary

# Schrödinger’s cat

or Schrodinger's cat
[**shroh**-ding-erz kat]

#### What does **Schrödinger's cat **mean?

*Schrödinger’s cat* is a famous physics thought experiment, which presents a paradox in which a cat in a box is somehow simultaneously both alive and dead.

## Where does Schrödinger’s cat come from?

Austrian physicist Erwin Schrödinger won the 1933 Nobel Prize in Physics for his work in quantum mechanics, a branch of physics that studies the nature and behavior of subatomic particles. In 1935 Schrödinger came up with a famous thought experiment, now referred to as *Schrödinger’s cat*, as a criticism of the Copenhagen interpretation of quantum mechanics. The Copenhagen theory stated, essentially, we can’t know what state or place an atomic particle is in until it’s observed, and so that particle could hypothetically be in all possible states or places until then.

Schrödinger found this theory flawed, and to demonstrate why, he asked his colleagues to imagine a “ridiculous case” where a cat, a tiny bit of radioactive material, a Geiger counter, a hammer, and a glass vial of poison were all locked inside a single box. The hammer, the scenario continues, is programmed to smash open the vial of poison—and thus, kill the cat with its fumes—if the Geiger counter detects the radioactive material over the course of the hour. But, the amount of radioactivity is tiny enough that there is a chance the Geiger counter will not pick up on it before the hour is up.

Now, if we scale up the Copenhagen theory from the quantum level all the way up Schrödinger’s scenario, then all outcomes simultaneously exist in all possible configurations until one opens the box, which, according to the complex mathematics of quantum mechanics, forces only one outcome: The cat is either alive or dead. The problem is that this would mean that until the very last moment before someone opens the box, the cat is somehow both alive and dead at the same time.

Obviously, a cat can’t be both alive and dead—vampire cats excluded—which was exactly Schrödinger’s point. The Copenhagen theory is a paradox. At what precise moment do the mathematical probabilities give over to physical reality?

Complex scientific theories don’t tend to become online memes, but *Schrödinger’s cat* is an exception, perhaps due to its rather visceral nature. References to *Schrödinger’s cat *have been featured in webcomics, images, YouTube videos, in poems, and t-shirts saying that “*Schrödinger’s cat *is dead” (as some physicists like to joke). The popularity of the LOLcats meme, which depicts house cats in various cute or amusing poses, has also inspired into humorous depictions of *Schrödinger’s cat*, with many images of cats in cardboard boxes serving as a chance to reference the famous theory. For example, there is an image of a cat angrily clawing its way out of a cardboard box, with the caption “*Schrödinger’s cat* is alive… and very pissed off.”

On August 12, 2013, which would have marked Erwin Schrödinger’s 126th birthday, Google celebrated by marking its homepage with a cat-themed doodle.

## Examples of Schrödinger’s cat

*The Mudflats*, August 2013

*Junkee*, April 2017

## Who uses Schrödinger’s cat?

While the thought experiment itself is still discussed and taught in schools today, online references to *Schrödinger’s cat *are often more for the amusement of those who know and appreciate the thought experiment. Often these take the form of cats clawing their way out of cardboard boxes with various allusive captions, but *Schrödinger’s cat *has also made a lot of appearances in webcomics, which often riff on the complicated nature of quantum theory and its tendencies towards simplification and misinterpretation.

Sometimes, *Schrödinger’s cat*, or even simply *Schrödinger*, is used as a way to reference something as a paradox, unfeasible, or working against itself. For example, when India started issuing all its citizens unique 12-digit identity numbers known as Aadhaar, a meme circulated referring to the situation as *Schrödinger’s Aadhaar*, because the ID system was confusingly presented as both optional and mandatory at the same time.

Whatever I believe is the reality, or will be the reality. Schrödinger’s Cat applies to everything in the world. I will get whatever I want ❤️ #lawofattraction #Manifest #visualization #positive #witch #witchcraft #coven #cat #aura #secret #universe #吸引力法則 #心想事成 #超能力 pic.twitter.com/BsPHea40j7

— Hélène 카블리🌟晴海 (@tvxqmilk) August 7, 2019

## Note

This is not meant to be a formal definition of Schrödinger’s cat like most terms we define on Dictionary.com, but is rather an informal word summary that hopefully touches upon the key aspects of the meaning and usage of Schrödinger’s cat that will help our users expand their word mastery.