It's important to understand that the transition from a particle-based description to a field-based description in physics was not a mere arbitrary choice made by theoretical physicists, but rather a result of careful analysis and empirical evidence. The development of quantum field theory (QFT) emerged as a more comprehensive framework that better accounted for the behavior of particles and their interactions.
While the concept of particles has a long history in physics, the advent of quantum mechanics revealed that the behavior of particles could not be fully understood solely through classical notions. Quantum mechanics introduced wave-particle duality, where particles exhibit both particle-like and wave-like properties. This duality was not adequately captured by the classical particle model.
Quantum field theory, on the other hand, incorporates both particle and wave aspects through the notion of fields. Fields are continuous quantities that pervade all of space and time, and particles arise as localized excitations or disturbances in their respective fields. In QFT, particles are treated as quanta of these fields.
The shift from particle-based models to field-based models was driven by experimental observations and the need for theoretical consistency. Field theory provided a more coherent framework for describing the interactions and behavior of particles, particularly in the realm of quantum phenomena. It successfully explained phenomena like particle creation and annihilation, the behavior of particles in scattering experiments, and the conservation laws associated with various quantities.
It's important to note that theoretical physicists do not claim that their models represent reality in an exact sense. Models and theories in physics are developed to provide accurate descriptions and predictions of natural phenomena based on available data and empirical evidence. The transition from particle-based models to field-based models was a necessary step in developing a more comprehensive and consistent understanding of quantum behavior.
Scientists continuously refine and update their models as new experimental data and theoretical insights emerge. The field-based approach of quantum field theory has been highly successful in describing a wide range of phenomena and has been extensively tested through experimental verification. However, it is always subject to further investigation and refinement as our understanding of the natural world progresses.