Title: Schrödinger's cat - Wikipedia
Headings: Schrödinger's cat
Schrödinger's cat
Contents
Origin and motivation
Thought experiment
Interpretations of the experiment
Copenhagen interpretation
Many-worlds interpretation and consistent histories
Ensemble interpretation
Relational interpretation
Transactional interpretation
Zeno effects
Objective collapse theories
Applications and tests
Extensions
See also
References
Further reading
External links

Content: Nobody really doubts that the presence or absence of the cat is something independent of the act of observation. Note that the charge of gunpowder is not mentioned in Schrödinger's setup, which uses a Geiger counter as an amplifier and hydrocyanic poison instead of gunpowder. The gunpowder had been mentioned in Einstein's original suggestion to Schrödinger 15 years before, and Einstein carried it forward to the present discussion. Interpretations of the experiment
Since Schrödinger's time, other interpretations of quantum mechanics have been proposed that give different answers to the questions posed by Schrödinger's cat of how long superpositions last and when (or whether) they collapse. Copenhagen interpretation
Main article: Copenhagen interpretation
A commonly held interpretation of quantum mechanics is the Copenhagen interpretation. In the Copenhagen interpretation, a system stops being a superposition of states and becomes either one or the other when an observation takes place. This thought experiment makes apparent the fact that the nature of measurement, or observation, is not well-defined in this interpretation. The experiment can be interpreted to mean that while the box is closed, the system simultaneously exists in a superposition of the states "decayed nucleus/dead cat" and "undecayed nucleus/living cat", and that only when the box is opened and an observation performed does the wave function collapse into one of the two states. One of the main scientists associated with the Copenhagen interpretation, Niels Bohr, offered an interpretation that is independent of a subjective observer-induced collapse of the wave function, or of measurement;