I understand that if you move a charged particle, you can create a photon, the basic unit of electromagnetic energy. However, there are static electric and magnetic fields. These fields can extend quite far - the earth's magnetic field for example. Is there any research or theory on what gets the field from point a to point b? Has a charge-on or a magnet-on been discovered or hypothesized? Or is the best explanation at the moment the "virtual photon" thing discussed below? If you look at bubble chamber tracks of elementary particles, the tracks always look smooth, even for little particles like electrons. But as I understand it, the bubble chamber is in an electric field and the particles curve if they are charged - so (using analogy to particles) if something is "hitting" these little electrons, (a) they don't show up as tracks of their own and (b) there must be a lot of them so the electrons and other particle making tracks describe smooth curves as opposed to periodic jerks as something hits them.