This may at first seem like a very stupid question, but I can't seem to get to the root of magnetism. As we all know, all charges exert electric forces on each other, and point charges obey the inverse-square law. I know how a moving charge generates a magnetic field according to Ampere's law. But how is the magnetic field actually generated? Why should a magnetic field be generated in this form? Also, how do you show that both electric and magnetic forces are both aspects of the same force?. Is relativity the only way to explain it?