# Quicky on (div)B

1. May 16, 2007

### robousy

Hey there,

can someone give me a nice explanation as to why (div)B = 0 implies there are no magnetic monopoles?

If you could explain mathematically and or intuitively I'd be really grateful as I've 'known' this fact for years, but never really understood.

2. May 16, 2007

### Staff: Mentor

3. May 16, 2007

### robousy

Ok, I'll take a look, thanks!

4. May 17, 2007

### Repetit

To answer that question you would need to rewrite Div B into an integral using gauss' law. The integral you get is the magnetic flux through a closed surface, and this then implies that the magnetic flux through any closed surface is always equal to zero. In other words, there is always a balance between magnetic southpole and magnetic northpole which exactly cancels out, so that there cannot be a surplus of one or the other inside a closed surface. This again means that there can be no magnetic monopoles.