The reconciliation of different views of particles in quantum field theory (QFT) can be understood by recognizing that these views are complementary descriptions of the same underlying physics. In QFT, particles can be described in two different but interrelated ways: as excitations of fields and as independent entities.
Excitations of Fields: According to the principles of QFT, elementary particles are viewed as excitations of underlying quantum fields that permeate all of space. These fields are defined at every point in spacetime and are associated with specific particle types (e.g., electron field, photon field). The particles are understood as quantized disturbances or fluctuations in these fields. They arise from the interactions of these fields and carry the corresponding properties, such as mass, charge, and spin.
Independent Entities: On the other hand, particles can also be treated as independent entities with well-defined properties, such as position, momentum, and energy. This perspective is often employed in experimental settings, where particles are detected as discrete entities with definite trajectories, interactions, and measurements.
The reconciliation between these two views can be achieved by recognizing that particles emerge as localized, quantized excitations of their respective fields. The field description emphasizes the underlying continuous nature of the fields and their interactions, while the particle description focuses on the discrete nature of particle detections and measurements.
In practice, both descriptions are used in different contexts. When calculating interactions and predicting outcomes in QFT, the field description is often more convenient and mathematically tractable. It provides a unified framework for understanding the behavior of particles and their interactions. However, when dealing with experimental observations and measurements, the particle description is often employed to analyze and interpret the results.
It is important to note that both the field and particle descriptions are approximations and idealizations of the underlying quantum reality. QFT is a complex and sophisticated framework that combines the principles of quantum mechanics and special relativity, and it allows for a consistent description of particle physics phenomena.