# Homework Help: On a basic level why can't monopoles exist?

1. Aug 17, 2014

### needingtoknow

1. The problem statement, all variables and given/known data

If a positive electric charge can create a magnetic field (because all you need to create a magnetic field is a moving charge), how is there 2 poles in this magnetic field created by this positive electric charge. Why isn't the magnetic field created by a single positive electric charge considered a monopole?

2. Aug 17, 2014

### BvU

Are we mixing up things ? In your description, where exactly do you locate the 2 poles you mention ?

3. Aug 17, 2014

### BvU

Other approach: if there were magnetic monopoles, there would be magnetic field lines coming out of e.g. a sphere surrounding such a thingy -- without magnetic field lines going in. But the magnetic field lines from a moving charge are neat circles, all of them. No beginning, no end.

The sophisticated way to express this is $\nabla\cdot{\bf \vec B}=0$, one of the Maxwell equations