The probability interpretation of quantum mechanics, also known as the Copenhagen interpretation, is one of the fundamental interpretations of quantum theory. It was developed primarily by Niels Bohr, Werner Heisenberg, and other physicists associated with the Copenhagen school in the 1920s and 1930s.
The probability interpretation arises from the mathematical formalism of quantum mechanics, which uses wave functions to describe the behavior of quantum systems. According to this interpretation, the wave function provides a complete description of a quantum system, but it only allows predictions of probabilities for the outcomes of measurements.
In the Copenhagen interpretation, it is postulated that before a measurement is made, a quantum system exists in a superposition of multiple possible states, and it is not in a definite state until the measurement is performed. When a measurement is made, the wave function "collapses" into one of the possible measurement outcomes, with the probability of each outcome determined by the squared magnitude of the corresponding term in the wave function.
The probabilistic nature of quantum mechanics reflects the inherent uncertainty at the microscopic level. The interpretation suggests that it is fundamentally impossible to predict with certainty the outcome of a single measurement on a quantum system; instead, we can only determine the probabilities of different outcomes.
It is important to note that there are alternative interpretations of quantum mechanics, such as the many-worlds interpretation and the pilot-wave theory, which offer different perspectives on the nature of quantum reality and the role of probabilities. However, the Copenhagen interpretation remains one of the widely taught and applied interpretations in the field of quantum mechanics.