1. The problem statement, all variables and given/known data Consider two charged particles 1 and 2, each of them able to translate (move from place to place) and to spin. 2. Relevant equations I can not completely think of relevant equations at the moment. 3. The attempt at a solution I am a bit confused on how charged particles can create magnetic fields. and if there is magnetic interaction between particle 1 and 2. I know that when a charged particle has a velocity, it creates a magnetic field. In class, we covered Special Relativity, but I'm still a bit confused on what velocity of a charged particle means. (As in, if particle 1 translates pass particle 2 with a velocity, does that create a magnetic field, since both particles have a velocity in either reference frame?) Translating (moving) I am pretty sure means a charged particle has a velocity, but what about if one particle 1 is spinning while particle 2 is at rest, would that be considered the charged particle having a velocity?