Full Idea
In QED an electron constantly emits and reabsorbs virtual photons and these photons constantly create and reabsorb pairs of virtual electrons and positrons, and so on.
Gist of Idea
Electron emit and reabsorb photons, which create and reabsorb virtual electrons and positrons
Source
Brian R. Martin (Particle Physics [2011], 06)
A Reaction
'And so on'! These virtual particles have energy, and hence mass.
Book Reference
Martin, Brian R.: 'Particle Physics' [One World 2011], p.91
Related Idea
Idea 21210 Virtual particles surround any charged particle [Martin,BR]