Quantum mechanics is inherently probabilistic. It provides a mathematical framework for describing the behavior of particles and systems at the microscopic scale, such as atoms and subatomic particles. In contrast to classical mechanics, where the properties of particles are deterministically determined, quantum mechanics introduces the concept of wave-particle duality and uncertainty.
According to quantum mechanics, the state of a particle or system is described by a wave function, which contains all the relevant information about its properties. However, the wave function does not directly provide deterministic predictions of specific outcomes. Instead, it provides probabilities for various possible outcomes of measurements or observations.
When a measurement is performed on a quantum system, the wave function "collapses" to one of the possible measurement outcomes with a probability determined by the wave function itself. The probabilistic nature of quantum mechanics arises from the inherent uncertainty in the behavior of particles at the quantum level.
While individual measurements are probabilistic, the statistical behavior of a large number of identical quantum systems can be predicted with great accuracy. This is known as the statistical interpretation of quantum mechanics, which states that the probabilities calculated from the wave function accurately describe the distribution of measurement outcomes over a large ensemble of systems.
So, in summary, quantum mechanics is fundamentally probabilistic, providing statistical predictions for the outcomes of measurements on individual systems while exhibiting precise statistical behavior for ensembles of systems.