# Tag Info

• 3,642

### Maximum $B$-field at the surface of a permanent magnet

If you stay at the surface of the magnet, your $r=R$ the radius of the magnet. If you want to maximize $B$, you need to be careful, because you have a second term that isn’t aligned so you could have ...
• 1,145

### Why are magnetic monopoles "incompatible" with quantum mechanics?

For your first question, on the link between quantum mechanics and potentials is that currently, there is no formulation of QM without these potentials and only in terms of the gauge invariant EM ...
• 1,145
Accepted

### Why are magnetic monopoles "incompatible" with quantum mechanics?

The argument here is supposed to go something like this: Classical electrodynamics, as long as you don't insist on a Lagrangian formulation, is fully described by Maxwell's equations in terms of the ...
• 105k
Magnetic monopoles are incompatible with $\nabla \cdot B=0$ hence with $B = \nabla \times A$. They are incompatible with the Maxwell equations and with the electromagnetic potential. The ...