When physicists talk about forces being carried by virtual particles, it is indeed a concept rooted in the framework of quantum field theory. Virtual particles are not directly observable in the same way as real particles, but they are a useful mathematical tool used to describe and calculate interactions between particles.
In quantum field theory, particles and their interactions are described in terms of fields, which permeate all of space. These fields have associated particles, such as photons for the electromagnetic field or gluons for the strong nuclear force. According to the theory, particles can spontaneously pop into existence for an extremely short time, borrow energy from the vacuum, and then disappear. These short-lived particles are known as virtual particles.
When two particles interact, they can exchange virtual particles, which mediate the interaction between them. For example, in the electromagnetic force, charged particles like electrons can exchange virtual photons. The exchange of these virtual particles can be seen as a transfer of momentum and energy between the interacting particles.
Physically, the concept of virtual particles provides a mathematical framework to understand and calculate the behavior of forces and interactions in quantum field theory. It allows physicists to make predictions and explain experimental observations. However, it's important to note that virtual particles should not be interpreted as real particles in the same sense as particles that are directly detectable.
Virtual particles exist within the context of quantum field theory and are an abstraction used in calculations and mathematical descriptions. They play a crucial role in understanding the behavior of fundamental forces, but their physical interpretation is somewhat different from that of real, observable particles.
In summary, virtual particles are a mathematical convenience within the framework of quantum field theory. They describe the temporary borrowing of energy and momentum during interactions between particles, enabling physicists to explain and calculate the behavior of forces.