Blastrix91

When you say div B = 0 mean that magnetic field lines only forms closed loops, is that in the moment a magnetic field begins and end (if that were to happen) there would be a change in what goes in in relation to what goes out and thus div B wouldn't be 0? That at least makes sense to me.

The B described in Biot Savarts law is the same that is described in div B = 0 right? So from a pure mathematical standpoint div B shouldn't be 0 if it is decreased by r^2 the further in the coordinate system you go. If you get what I'm saying?