Schrodinger's Cat

Confirmed 109,517

Part of a series on Science. [View Related Entries]

About

Schrödinger's Cat is a thought experiment proposed by Austrian physicist Erwin Schrödinger in 1935 to illustrate a problem with the Copenhagen interpretation of quantum mechanics. In demonstrating its paradox, Schrödinger devised a scenario in which a cat is both alive and dead while inside a closed box containing radioactive material and a volatile substance. Since gaining prominence through the academic community, Schrödinger's thought experiment has also become part of the popular culture lexicon through webcomics, image macros and videos inspired by the idea.

Origin

The idea was conceived in 1935 by Schrödinger during a correspondence^[1] with Albert Einstein regarding the Copenhagen interpretation of quantum mechanics, which posits that two quantum entangled particles are in an indefinite state until measured, in other words, we can only ascertain the probabilities of measuring entities which are nor particles or waves by classic definitions. To illustrate his issue with this notion, he devised a thought experiment in which a cat is placed in a steel container along with a Geiger counter, a tiny amount of a radioactive substance and a flask of hydrocyanic acid that would shatter if one atom of the radioactive substance decays. Based on the Copenhagen interpretation, the cat inside the box would be both dead and alive until someone lifted the lid of the box.

One of the earliest online discussions began among university students and academics on Usenet's sci.physics^[13] group on May 7th, 1990. In the thread, people discussed whether Schrodingers Cat applied to macroscopic environments and received over 22 replies by 13 authors.

Spread

On August 9th, 2000, the Straight Dope Forums^[10] member Bear Nenno started a thread questioning the meaning behind the thought experiment, to which member Or'n'ry Oscar replied with a link to a poem titled "The Story of Schroedinger's Cat."^[11] On August 19th, 2004, the online retailer ThinkGeek^[9] began selling a t-shirt with the words "Schrödinger's Cat Is Dead" screen printed on the front. On January 4th, 2006, the webcomic series Xkcd^[2] published a comic titled "Schrodinger," in which the final panel of the comic is both funny and unfunny until read in its entirety.

On June 2nd, 2007, the Internet humor site I Can Has Cheezburger^[7] published a LOLCat image macro of a cat in a cardboard box with the caption "In ur quantum box… / …maybe" (shown below, left). On August 4th, 2007, a Yahoo Answers^[12] question was submitted by user timbergiant, which asked for an explanation of the thought experiment in layman's terms. On June 1st, 2008, Redditor manixrock submitted a post titled "Wanted: Schroedinger's Cat"^[5], which included a wanted poster of a kitten with the caption "Wanted: Schroedinger's Cat / Dead and Alive" (shown below, right).

On June 23rd, 2010, the viral content site BuzzFeed^[4] published a post titled "Sexy Schrodinger's Cat", which featured a cartoon, bikini-clad woman with a tail and cat ears who was both alive and dead. In the video game Portal 2, released on April 19th, 2011, the robot known as the "Fact Sphere" presents a false interpretation that Schrodinger created the paradox in order to justify killing cats. On August 19th, YouTuber Kalapusa uploaded a Nyan Cat parody video titled "Schrodinger's Nyan Cat", including a pixel art animation of a box with a mathematical equation trail and flashing cat skulls.

On February 18th, 2012, the webcomic Saturday Morning Breakfast Cereal^[3] published a comic titled "What Schrodinger's Cat" Means", which featured a professor explaining the thought experiment juxtaposed with a layman's improper explanation. The meme has continued to spread on I Can Has Cheezburger^[6] under the tag "schrodinger."

On August 12th, 2013, Google observed the 126th birthday of Erwin Schrödinger with a special Google Doodle featuring a cartoon character of the Schrödinger's Cat.