why does the monopoles not exist

Vanadium 50

The statement that field lines have no ends is identical to the statement that there are no monopoles. It's not an explanation.

Furthermore, all at Tris_d has shown is that in the situation he describes there are no monopoles, not that there are no monopoles anywhere.

jtbell

Ultimately the question is an experimental one. We can construct theories in which magnetic monopoles and monopole-type magnetic fields exist (for which ##\nabla \cdot \vec B \ne 0##). However, to date nobody has actually found such particles or fields. Maybe next February 14 someone will actually detect them convincingly, and then we will have to rewrite Maxwell's equations etc.

tris_d

Actually, magnetic field due to moving charge looks like monopole to me. I see only one pole there and it certainly does not look like a dipole. I've been saying that for quite a few years now, but people are dismissing it and I never got any reasonable response. Could it be too simple to be believed, right under everyone's nose?

What do you think it is, a dipole?

ZapperZ

What does it mean that it looks like a monopole to you? Do you mean that you can show that the magnetic field here has a non-zero divergence?

Note that we have already seen situations that mimic a magnetic monopole from a spin ice system.

http://news.sciencemag.org/scienceno.../09/04-01.html

So we do know what it should look like if it occurs.

Zz.

tris_d

It means that it does not look like a dipole, so what else could it be? Why would you expect anything, why not simply count? Just tell me, if you mean to say that it is not monopole, what is it then, is it a dipole?

ZapperZ

Er.... This isn't based on a matter of TASTES! The distinction of something being a monopole will require a non zero divergence. You simply can't argue "oh it looks like a monopole to me". That is NOT a physics reason.

So I take it from your response that you had NEVER checked if the magnetic field divergence is zero? That is a very simple question that will say a lot.

Zz.

jtbell

The field lines continue through the magnet to form closed loops. See for example Fig. 27.13(a) here:

http://www.physics.sjsu.edu/becker/p.../mag_field.htm