Schrodinger's Cat Paradox

Extracted Attributes

• Type

  Thought Experiment, Paradox

• Field

  Quantum Mechanics

• Deviser

  Erwin Schrödinger

• Critique of

  Niels Bohr and Werner Heisenberg's interpretations of quantum mechanics

• Limitations

  Not meant to be performed literally, technical challenges for macroscopic superposition

• Core Concept

  Cat simultaneously alive and dead until observed

• Significance

  Foundational concept in quantum mechanics discussions, popular culture recognition

• Year Devised

  1935

• Primary Purpose

  Illustrate philosophical problems of quantum superposition

• Related Scientific Concept

  Quantum superposition

Timeline

• Erwin Schrödinger devises the thought experiment in a discussion with Albert Einstein to illustrate problems with quantum mechanics interpretations. (Source: Summary, Wikipedia, Web Search)

  1935

• The paradox survived in correspondence between Albert Einstein and Erwin Schrödinger. (Source: Web Search)

  Early 1950s

• The paradox resurfaced during a conference of physicists and philosophers in Bristol, England. (Source: Web Search)

  1957

• Ursula K. Le Guin features a version of the paradox in her short story 'Schrödinger's Cat'. (Source: Web Search)

  1974

Schrödinger's cat

In quantum mechanics, Schrödinger's cat is a thought experiment concerning quantum superposition. In the thought experiment, a hypothetical cat in a closed box may be considered to be simultaneously both alive and dead while it is unobserved, as a result of its fate being linked to a random subatomic event that may or may not occur. This experiment, viewed this way, is described as a paradox. 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 Niels Bohr and Werner Heisenberg's philosophical views on 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 radiation monitor such as a Geiger counter detects radioactivity (a single atom decaying), the flask is shattered, releasing the poison, which kills the cat. If no decaying atom triggers the monitor, the cat remains alive. Mathematically, the wave function that describes the contents of the box is a combination, or quantum superposition, of these two possibilities. 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. Although originally a critique of Bohr and Heisenberg, Schrödinger's seemingly paradoxical thought experiment became part of the foundation of quantum mechanics. It is often featured in theoretical discussions of the interpretations of quantum mechanics, particularly in situations involving the measurement problem. As a result, Schrödinger's cat has had enduring appeal in popular culture. The experiment is not intended to be actually performed on a cat, but rather as an easily understandable illustration of the behavior of atoms. Experiments at the atomic scale have been carried out, showing that very small objects may exist as superpositions, but superposing an object as large as a cat would pose considerable technical difficulties. Fundamentally, the Schrödinger's cat experiment asks how long quantum superpositions last and when (or whether) they collapse. Different interpretations of the mathematics of quantum mechanics have been proposed that give different explanations for this process.

Web Search Results

• What is Schrödinger's cat theory in simple terms? - Quora

  Schrödinger's cat is a thought experiment, sometimes described as a paradox, devised by Austrian-Irish physicist Erwin Schrödinger. Erwin Schroedinger wrote to Albert Einstein to congratulate him on what is a famous problem in the interpretation of Quantum Mechanics. Soon thereafter, he published what was to become one of the most celebrated paradoxes in quantum theory. [...] Schrödinger's cat is a thought experiment, sometimes described as a paradox, devised by Austrian-Irish physicist Erwin Schrödinger. Erwin Schroedinger wrote to Albert Einstein to congratulate him on what is a famous problem in the interpretation of Quantum Mechanics. Soon thereafter, he published what was to become one of the most celebrated paradoxes in quantum theory. [...] What is the Schrödinger's cat paradox? How does quantum mechanics explain it? What is the significance of Schrödinger's cat in quantum mechanics? Assistant Bot · 1y Schrödinger's cat is a thought experiment in quantum mechanics that illustrates the concept of superposition. In simple terms, it describes a scenario where a cat is placed in a sealed box with a radioactive atom, a Geiger counter, and a vial of poison. Here's how it works:

• What Is Schrödinger's Cat? (Definition, How It Works) | Built In

  Schrödinger’s Cat is a thought experiment devised by the Austrian physicist Erwin Schrödinger, which he designed to illustrate a paradox of quantum superposition wherein a hypothetical cat may be considered both alive and dead simultaneously because its fate is linked to a random event that may (or may not) occur. ## What Is Schrödinger’s Cat in Simple Terms? [...] Schrödinger’s Cat is a thought experiment that illustrates quantum superposition, where a cat in a sealed box is considered both alive and dead until observed. It highlights the paradox of quantum uncertainty and the role of the observer in physics. [...] Schrödinger’s Cat is a thought experiment that illustrates quantum superposition, where a cat in a sealed box is considered both alive and dead until observed. It highlights the paradox of quantum uncertainty and the role of the observer in physics. more

• Schrödinger's Cat: A “Purr-fect” Thought Experiment - Gale Blog

  Made popular by a million memes, the famous Schrödinger’s cat thought experiment (also called the Schrödinger’s cat paradox), devised by physicist Erwin Schrödinger (1887–1961). In 1935, was designed to illustrate the often bizarre implications of quantum mechanics (specifically, superposition and the concept of quantum measurement). [...] Analogous to a radioactive atom that, in the quantum world, is simultaneously decayed and not decayed, Schrödinger’s cat in an unopened box is simultaneously alive and dead (a state of superposition) until the box is opened. When observed (i.e., measured), the quantum superposition collapses into a definite state and we behold either a living or dead cat. [...] In the quantum world, the radioactive atom is in superposition (both decayed and not decayed). Because the atom is in superposition, the cat is equally in superposition (both alive and dead). When the atom decays, it triggers the Geiger counter which triggers the hammer to break the vial of poison which kills the cat. In this entangled system, the state of the cat is determined by the state of the atom. By observing the cat, one can also infer the state of the atom (decayed or not decayed).

• No, Schrödinger's cat is not alive and dead at the same time - Aeon

  In a discussion featured in the conference proceedings, the American physicist David Bohm resurrected Schrödinger’s cat. By this time, the paradox had evolved and was based on a single photon (a ‘particle’ of light) passing (or not passing) through a half-silvered (or ‘one-way’) mirror. Like the radioactive atom, the photon has a 50/50 chance of passing through the mirror or being reflected by it. Passage of the photon triggers a diabolical mechanism in which the cat is killed with a gun. [...] In her short story ‘Schrödinger’s Cat’ (1974), Le Guin presents Bohm’s version of the paradox involving the photon, half-silvered mirror and gun. In a dialogue between the nameless narrator and a dog called Rover, Le Guin wrote: [...] And there the matter rested, for a time. The cat paradox was limited to one paragraph in a lengthy review article, and Schrödinger’s dissent cut little ice with the majority of physicists, including those who spent time pondering on the meaning of quantum theory. It survived in correspondence between Einstein and Schrödinger through to the early 1950s, and resurfaced in 1957, during a conference of physicists and philosophers held in Bristol, England.

• Schrödinger's cat - Wikipedia

  To further illustrate, Schrödinger described how one could, in principle, create a superposition in a large-scale system by making it dependent on a quantum particle that was in a superposition. He proposed a scenario with a cat in a closed steel chamber, wherein the cat's life or death depended on the state of a radioactive atom, whether it had decayed and emitted radiation or not. According to Schrödinger, the position taken by Bohr and Heisenberg would be that the cat remains both alive and [...] A resolution of the paradox is that the triggering of the Geiger counter counts as a measurement of the state of the radioactive substance. Because a measurement has already occurred deciding the state of the cat, the subsequent observation by a human records only what has already occurred. Analysis of an actual experiment by Roger Carpenter and A. J. Anderson found that measurement alone (for example by a Geiger counter) is sufficient to collapse a quantum wave function before any human knows [...] Since Schrödinger's time, various interpretations of the mathematics of quantum mechanics have been advanced by physicists, some of which regard the "alive and dead" cat superposition as quite real, while others do not. Intended as a critique of ideas prevalent in 1935, the Schrödinger's cat thought experiment remains a touchstone "Touchstone (metaphor)") for modern interpretations of quantum mechanics and can be used to illustrate and compare their strengths and weaknesses.[better source