The claim that quantum mechanics is a complete theory is based on several factors and interpretations within the framework of the theory. However, it's important to note that there are different viewpoints and debates within the physics community regarding the completeness of quantum mechanics. Here are some of the reasons why some physicists argue that quantum mechanics is a complete theory:
Experimental Success: Quantum mechanics has been remarkably successful in describing and predicting the behavior of particles and systems at the microscopic scale. Its predictions have been rigorously tested and confirmed by numerous experiments. The experimental verification of quantum phenomena, such as the double-slit experiment, quantum entanglement, and the behavior of atoms and subatomic particles, supports the view that quantum mechanics is a complete and accurate theory for describing those phenomena.
Mathematical Consistency: Quantum mechanics provides a mathematically consistent framework that allows for precise calculations and predictions. It is based on a set of well-defined mathematical principles, such as wave functions, operators, and probabilistic interpretations. The mathematical formalism of quantum mechanics has proven to be highly accurate and self-consistent, further supporting the claim of its completeness.
No Discrepancies or Experimental Violations: To date, no experimental observations have conclusively shown any discrepancies or violations of quantum mechanics at its core. Despite ongoing research and tests, quantum mechanics has remained robust and consistent in its predictions. This absence of empirical evidence for deviations from quantum mechanics reinforces the notion that it is a complete theory within its applicable domain.
Application to Diverse Physical Systems: Quantum mechanics has been successfully applied to a wide range of physical systems, including atoms, molecules, nuclei, and elementary particles. It has also found applications in condensed matter physics, quantum information theory, and other fields. The ability of quantum mechanics to describe and explain such diverse phenomena suggests its completeness in capturing the underlying principles governing quantum behavior.
It's important to recognize that while quantum mechanics is widely accepted and highly successful, there are ongoing debates and open questions within the field. For example, the interpretation of quantum mechanics and its relationship to other theories, such as general relativity, remain areas of active research and exploration. These debates reflect the continuous progress and evolution of scientific understanding.
Ultimately, whether a theory is considered complete is not something that can be definitively proven or disproven in an absolute sense. It relies on the consensus of the scientific community based on empirical evidence, mathematical consistency, and the ability to make accurate predictions within a given domain.