Browse Definitions :
Definition

Schrodinger's cat

Schrödinger's cat is a famous hypothetical experiment designed to point out a flaw in the Copenhagen interpretation of superposition as it applies to quantum theory.

This is a somewhat simplified version of the virtual experiment:

A living cat is placed into a steel chamber along with a hammer, a vial of hydrocyanic acid and a very small amount of radioactive substance. If even a single atom of the radioactive substance decays during the test period, a relay mechanism will trip the hammer, which will in turn, break the vial of poisonous gas and cause the cat to die.

Nobel Prize-winning Austrian physicist Erwin Schrödinger created this mental experiment in 1935 to point out the paradox between what quantum theorists held to be true about the nature and behavior of matter on the microscopic level and what the average person observes to be true on the macroscopic level with the unaided human eye.

The role of the observer in quantum mechanics

The Copenhagen interpretation of quantum physics, which was the prevailing theory at the time, proposed that atoms or photons exist in multiple states that correspond with different possible outcomes and the possibilites , called superpositions, do not commit to a definite state until they are observed.

Edwin Schrodinger

Schrödinger's thought experiment was designed to show what the Copenhagen interpretation would look like if the mathematical terminology used to explain superposition in the microscopic world was replaced by macroscopic terms the average person could visualize and understand. In the experiment, the observer cannot know whether or not an atom of the substance has decayed, and consequently, does not know whether the vial has broken and the cat has been killed.

According to quantum law under the Copenhagen interpretation, the cat will be both dead and alive until someone looks in the box. In quantum mechanics lingo, the cat's ability to be both alive and dead until it is observed is referred to as quantum indeterminacy or the observer's paradox. The logic behind the observer's paradox is the proven ability of observation to influence outcomes.

Schrödinger accepted that superposition exists; during his lifetime, scientists were able to prove its existence by studying interference in light waves. Schrödinger wondered, however, about when the resolution of possibilities actually occurs. His thought experiment was intended to make people ask themselves if it was logical for observation to be the trigger. Wouldn't the cat be either dead or alive, even if not observed?

Throughout the years, Schrödinger's cat analogy has been used to illustrate emerging theories of how quantum mechanics works. In the Many Worlds interpretation of quantum law, for example, the cat is both alive and dead. In this interpretation, the observer and the cat simply exist in two realities -- one in which the cat is dead, and one in which the cat is alive.

What scientists have learned about the nature of matter at the microscopic level and its relationship to what humans observe at the macroscopic level has not yet been fully explored. The role of the observer remains an important question in the study of quantum physics and is an endless source of speculation and conjecture in quantum computing and pop culture. Schrödinger himself is rumored to have said, later in life, that he wished he had never met that cat.

This was last updated in April 2020

Continue Reading About Schrodinger's cat

SearchCompliance
  • smart contract

    A smart contract is a decentralized application that executes business logic in response to events.

  • compliance risk

    Compliance risk is an organization's potential exposure to legal penalties, financial forfeiture and material loss, resulting ...

  • information governance

    Information governance is a holistic approach to managing corporate information by implementing processes, roles, controls and ...

SearchSecurity
  • threat modeling

    Threat modeling is a procedure for optimizing application, system or business process security by identifying objectives and ...

  • social engineering

    Social engineering is an attack vector that relies heavily on human interaction and often involves manipulating people into ...

  • distributed denial-of-service (DDoS) attack

    A distributed denial-of-service (DDoS) attack is one in which multiple compromised computer systems attack a target, such as a ...

SearchHealthIT
SearchDisasterRecovery
  • change control

    Change control is a systematic approach to managing all changes made to a product or system.

  • disaster recovery (DR)

    Disaster recovery (DR) is an organization's ability to respond to and recover from an event that affects business operations.

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

SearchStorage
  • storage security

    Storage security is the group of parameters and settings that make storage resources available to authorized users and trusted ...

  • cloud storage

    Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, ...

  • cloud data management

    Cloud data management is a way to manage data across cloud platforms, either with or instead of on-premises storage.

Close