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Evidence of Magnetic Monopoles Found?
TheMatt writes "As reported on PhysicsWeb and published in Science (subscription required), researchers at AIST and co-workers believe they have
found evidence of magnetic monopoles. They observed an anomalous Hall effect in a ferromagnetic crystal that they say can only be explained via magnetic monopoles. To refresh your memory, magnetic monopoles are the magnetic analogue of electrons and other charged particles--a "north" or "south" pole only.
Dirac in 1931 showed that the existence of a magnetic monopole naturally leads to the quantization of electric and magnetic charge. Thus, showing the existence of just one magnetic monopole would be quite profound for physics, but their mass (> 10^16 GeV) has made searches for them difficult."
From the later parts of your post it's obvious that you're now talking about *special relativity*. It is not in any way at odds with quantum mechanics; in fact, the fusion of relativity and quantum mechanics (something called "quantum field theory") is *the most succesful theory of physics ever developed* (at least when success is measured by how well the theory fits with experiment).
What we don't have is a quantum theory of gravity. We have a very well working *classical* theory of gravity, called "general relativity", which is obviously as much at odds with quantum mechanics as any classical theory is.
Now, when Einstein devised relativity, he based it very heavily on Maxwell's Laws. The Laws are a set of four equations which describe pretty much all electromagnetic phenomena out there. It was the world's first Grand Unified Theory (GUT), in that it unified electricity and magnetism into one package.
That would not be a _GUT_.
And one of Maxwell's Laws ("the divergence of the magnetic field equals zero") has, as a direct consequence, an absolute law: NO MAGNETIC MONOPOLES EXIST.
This is certainly true, but it is trivial to fix this law to handle magnetic monopoles. Remember, you have one Maxwell equation basically stating that
div E = electric charge density
and another, the one that states that no magnetic monopoles exist,
div B = 0
(for the completely unprepared reader: here E and B are the electric and magnetic fields and "div" is a certain sort of an operator that acts on vectors) If you compare these two equations, you'll see *why* the divergence of B is zero: by analogy, div B should just equal the "magnetic charge density", but since there are no magnetic monopoles, the magnetic "charge" density is always zero and div B = 0. In other words, there is no *theoretical* reason why you couldn't write
div B = magnetic charge density
but since the *experiments* tell us that this is always zero, we don't usually bother talking about magnetic charges at all and just set this to zero. If the experiments ever tell us that magnetic monopoles exist, then we'll just have to include these magnetic charge/current terms (which are normally set to zero) in Maxwells equations as well.
So if Maxwell's Laws are wrong and relativity is built heavily on Maxwell's Laws, then there's a tantalizing chance relativity is wrong.
No, there isn't. First of all, including magnetic monopoles the way I outlined above won't make Maxwells theory of electromagnetism in any way incompatible with special relativity. This would be a very minor modification of electodynamics. Second of all, special relativity isn't *based* on electrodynamics at all - ED was an inspiration for Einstein (basically, Maxwells ED is at odds with Newtonian mechanics; Einstein saw this and decided to seek an alternative theory of mechanics that wouldn't be in conflict with it - and found one). If electodynamics ever turned out to be wrong, it wouldn't yet say anything at all about the validity of special relativity.
Warning: I'm not a professional physics geek.
Well, I am. Trust me, I know what I'm doing. :-)