In quantum field theory, particles are described as excitations or quanta of underlying quantum fields. According to this framework, particles are not viewed as independent entities moving through space like classical objects, but rather as manifestations of field oscillations.
In this perspective, the fundamental entities are the quantum fields, which permeate all of spacetime. Each type of particle is associated with a specific field, such as the electron field or the electromagnetic field. These fields are quantized, meaning that they can be in different energy states or configurations.
When a quantum field is in its lowest energy state, it is said to be in its "vacuum state," which corresponds to the absence of particles. However, when the field is excited or perturbed, it can undergo oscillations and generate particle-like excitations.
These excitations, often referred to as particles, can be visualized as localized disturbances or waves in the field. These waves propagate and interact with other fields, giving rise to the behaviors and interactions we observe as particles in experiments.
It's important to note that the interpretation of particles as waves in fields is a theoretical framework used in quantum field theory. The nature of particles and their relation to fields can be complex and abstract, and it may not align precisely with our everyday intuitions based on classical physics. However, this framework has been highly successful in describing and predicting the behavior of particles and their interactions at the quantum level.
So, while particles can be understood as wave-like excitations of quantum fields, it is crucial to recognize that this description is rooted in the framework of quantum field theory and does not directly correspond to classical waves trapped in a container.