Magnetic field lines??? So I'v been taught throughout highschool and now in college that a magnetic field has "lines of force". Also that they aren't just lines, but more like big shells around the magnet. But not one of my professors or teachers could give me a reasonable answer as to why they are there. They dont seem to fit in with other forces that interact on macroscopic scales. Gravity doesn't have field lines, electrostatic forces dont have field lines, why should magnetism have feild lines. I read someplace about virtual particles interacting but that doesn't explain their increased spacing as you move away from the magnet. I expected it was a photon emission because it "can" sort of coerce to look like a interference patter of photons. But that it was bent killed that idea. to be blunt : what is the deal with magnetic field lines?