How does quantum field theory account for fundamental forces acting over a distance?
I am not sure as to what the question is asking.
The question is asking how quantum field theory explains the existence of fundamental forces, such as electromagnetism and gravity, which can act over long distances.
In quantum field theory, fundamental forces are understood through the concept of fields. A field is a physical quantity that exists throughout space and time. According to this theory, particles are not considered as isolated entities, but instead are seen as excitations or disturbances in these fields.
Specifically, each fundamental force is associated with a specific type of field. For example, the electromagnetic force is linked to the electromagnetic field, and the gravitational force is associated with the gravitational field. These fields pervade all of space. Particles, such as photons for the electromagnetic field or gravitons for the gravitational field, arise as quantized excitations of their respective fields.
Quantum field theory allows for interactions between these fields and the particles they generate. When two particles interact, they exchange virtual particles, which are transient disturbances in the fields. These virtual particles can carry energy, momentum, and information between the interacting particles.
To explain how fundamental forces act over large distances, quantum field theory introduces the notion of gauge bosons. Gauge bosons are the force-carrying particles associated with each fundamental force. For example, photons are the gauge bosons of electromagnetism. These gauge bosons mediate the interactions between particles, allowing the forces to be transmitted over extended distances.
In summary, quantum field theory explains how fundamental forces act over a distance by postulating the existence of fields pervading all of space. These fields interact with particles and rely on the exchange of force-carrying gauge bosons to transmit the forces between particles, ultimately allowing for long-range interactions.