Magnetic Monopoles

[Rev. Green]

How could we detect a magnetic monopole, and why is it said that if a single magnetic monopole exists then all the electrons in the Universe must have the same rest mass?

[Flonska]

Does this link help?

https://en.wikipedia.org/wiki/Magnetic_monopole

[jim360]

I can't say I've ever done much thinking about either of these questions but magnetic monopoles could be detected easily enough assuming they exist, I reckon, because naturally they'd interact with electric circuits in a unique way (eg because they violate Gauss's Law, and the modification if magnetic monopoles exist has already been extensively studied).

I'd have to do a little digging to answer the second question.

[jim360]

If it's not too much trouble can you let me know where you heard it said that "if a single magnetic monopole exists then all the electrons in the Universe must have the same rest mass"?

[nescio]

It was Dirac who showed that if a single magnetic monopole exists, then the charge on the electron is quantised. Nothing to do with the mass.

[Rev. Green]

Thanks Flonska, the wikipedia article shows that it is electric CHARGES, not masses, that would be equal. I'd be grateful if Jim could dig a bit and explain monopoles in terms I can understand without resurrecting my meagre tensor knowledge.

[jim360]

Ah, thanks for clearing that up -- I was puzzling for a while about how the mass might come into it. Not that there may not be a link but if there were then it would be exceedingly complicated for sure!

I'll have to get back to you Rev.