The Schroedinger's Cat thought experiment was directly based off of the Copenhagen Interpretation, so it is necessary to know something about the Copenhagen Interpretation. The Copenhagen Interpretation was one of the many interpretations of Quantum Physics such as The Many Worlds Interpretation and Relational Quantum Physics. The Many Worlds Interpretation states that the world lines of objects split into unobservable little histories, universes within another. Relational Quantum Physics states that a number of observers of a state may have different views of it: for some, a state may be collapsed, or it may be in superposition.

The Copenhagen Interpretation of Quantum Physics was the first interpretation of Quantum Physics ever created and was the first general attempt to understand the microscopic world. It was started by Neils Bohr, Werner Heisenberg, Max Born, and several other physicists [7]. The two leaders of the Copenhagen Interpretation, Neils Bohr and Werner Heisenberg, did not agree on the mathematical description of Quantum Physics: the Copenhagen Interpretation was just a tie between their different ideas. Heisenberg’s interpretation followed a stricter set of rules than Bohr’s, which was opposed by Bohr.

The Copenhagen Interpretation is composed of five elements: the Heisenberg’s Uncertainty Principle which was published in 1927, Born’s Statistical Interpretation of quantum physics from 1926 which states what is typical and what is not, Bohr’s Complementary Concept from 1928 which says that a single quanta can act as a wave or a particle, but not both, Heisenberg’s Identification of the State Vector with “Knowledge of the System” which describes the viewed states of an object in space and Heisenberg’s Positivism which states that the only knowledge is based on what has been measured [10]. The Copenhagen Interpretation has been highly criticized, and there is no full statement describing it [2].

One very important fact that should be observed is that all of the concepts of the Copenhagen Interpretation include wave function collapse, which means a break in superposition by measuring whatever is in superposition [7]. The Copenhagen Interpretation was the interpretation of quantum mechanics that Austrian Physicist Erwin Schroedinger opposed in his famous thought experiment, Schroedinger's Cat.