Undergrad Are Virtual Exchange Particles a Valid Concept in Understanding Remote Forces?

[planet-75]

TL;DR

What is the concept or idea of this term?

Such particles are virtual, but it should be possible to associate a basic idea with them, as this is the foundation of calculation methods.

I think the concept of vacuum fluctuations in the form of virtual, fluctuating pairs of particles is something else. Is the idea of virtual exchange particles, which allegedly fly back and forth between real particles in order to be able to justify remote forces by impulses, a serious and useful idea, or are there better descriptions for it? That would work, if at all, only for repulsive forces. How, for example, a virtual photon could be used to create an attraction is beyond me.

 

[vanhees71]

The concept is perturbation theory and it's just slang of quantum field theorists. It's better to think in terms of fields to describe interactions than to picture the interaction as the "exchange of virtual particles". The Feynman diagrams are just an ingenious mathematical notation for the formulae that enable you to calculate S-matrix elements via perturbation theory for a given quantum field theory (like the standard model of elementary particles). You find very valuable Insights articles about the use and abuse of "virtual particles" and "vacuum fluctuations" in the Insights Blogs of this forum

https://www.physicsforums.com/insights/what-are-virtual-particles-intro/
https://www.physicsforums.com/insights/vacuum-fluctuation-myth/

 

[Nugatory]

How, for example, a virtual photon could be used to create an attraction is beyond me

https://math.ucr.edu/home/baez/physics/Quantum/virtual_particles.html is a good starting point

 

[vanhees71]

Another simple answer is that you don't need virtual photons at all. The field picture is much more intuitive and even formally more appropriate.