Talk:Magnetic monopole

From reading this article, I don't understand why protons and electrons do not count as magnetic monopoles. Could someone give a definition that clearly to a beginner does not include the charged particles we are familiar with?

An idea from a post further down: The protons and electrons would be electric, not magnetic, monopoles, and those are known to exist.  — Sverdrup (talk) 14:24, 18 Dec 2003 (UTC)

Ah, that's helping a little bit. The magnetic monopole article has a link to charge in the first sentence, referring to "magnetic charge", but there is only an article on "electric charge". I still don't quite know what the difference is between those two things.

IMO, this is abt the dipole article not being helpful enuf, and i am really hesitant to tackle that bcz of limited expertise; wish someone else would, and add some stuff in this article as well. But:

An electric monopole is simply a point charge, and a charged particle is a very good approximation to a point charge. I may never have heard the expression "magnetic charge" before, but let it stand; i suspect it could be just a metaphor based on analogy between

• electric dipoles that sometimes are made up of two equal and opposite charges or electric monopoles, and
• the hypothetical magnet (not based on motion of charges, but a dipole composed of two magnetic monopoles), that would act like the magnets we know, except that when "broken in half", the two equal and opposite magnetic charges, or magnetic monopoles, could be manipulated separately. --Jerzy 20:48, 2003 Dec 19 (UTC)

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stray text from another page; anything not already on article needs to be merged in:

Magnets exert forces on one another; similarly to electric charges, like poles will repel each other and unlike poles will attract. There is one big difference between magnets and electric charges, though - magnetic poles always exist in north-south pairs! If you take a magnet and cut it in half, you don't wind up with just a north pole and just a south pole; you wind up with two smaller magnets, each with its own north and south poles. An isolated magnetic pole is called a magnetic monopole; it has been theorized that such things might exist in the form of tiny particles similar to electrons or protons, but no such particles have ever been found.

Merged looxix 18:32 Feb 21, 2003 (UTC)

From "Talk:Magnetic monopole (crackpot)":

Until now, no magnetic monopoles have ever been discovered. Nonetheless, if such monopoles could actually exist, they would cause an unprecedented revolution in electrical engineering. For instance, if one could replace the iron core of a transformer with an identical core that would be made of a substance containing free magnetic monopoles, in other words, of a 'magnetic conductor', this transformer could work as well on direct current as on alternating current, perhaps better on DC,judging from the latest theories claiming that magnetic monopoles are much heavier than electrically charged elementary particles.

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Have included a reason for the Kuhne theory being mentioned. I'm not convinved that the theory is well enough accepted to deserve a mention, but seeing the whole area is speculative I think it may deserve a place. EddEdmondson 12:50 Dec 16, 2003.

Other thoughts

This article doesn't cover all the views on this. For example, Maxwell's equations tells us that no monopoles exist. Or is that irrelevant?  — Sverdrup (talk) 15:58, 17 Dec 2003 (UTC)

It may be worth mentioning this, but I think this is in Maxwell's Equations because no-one's ever seen a monopole rather than any more fundamental reason. EddEdmondson 12:50 Dec 16, 2003.

Now I don't know about the math of all this, I'm just posting so that better-knowing can answer my thinking. If it is stated in Maxwell's equation, then ain't it fundamental of the reason that commonly accepted fundamental theories are derived from the Maxwell equations?  — Sverdrup (talk) 14:01, 18 Dec 2003 (UTC)

Well, actually Maxwell's equations could easily be fixed to accomodate magnetic monopoles. Just like the first equation (<math>\nabla \cdot \mathbf{D} = \rho <math>) accounts for electric monopoles, the second equation could be rewritten <math>\nabla \cdot \mathbf{H} = <math>"magnetic charge density". In the absence of magnetic monopoles, this would of course predict the same behaviour as today. Rasmus Faber 14:19, 18 Dec 2003 (UTC)

Aha, I see. So the article is all about wheter Maxwell's postulate that they do not exist is true or not? Thanks.  — Sverdrup (talk) 14:24, 18 Dec 2003 (UTC)

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I am moving the following 'graph out of the article Magnetic monopole for work:

However, there is a theory by Rainer W. Kühne from 1997 in which he predicts a second kind of photon, the "magnetic photon", which if found would provide indirect evidence for Dirac monopoles. This magnetic photon may have been observed by Kundt. New experiments to test Kühne's theory appear to confirm the magnetic photon rays.

It is so tenuous in the first sentence, and so vague in the second, as to merely confuse things.

IMO it could be the beginning of a longer 'graph or two that would enhance the article, but now its not yet ready for prime time. --Jerzy 19:41, 2003 Dec 18 (UTC)

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Similarly, the sentence abt DC transformers resulting (which could itself badly use some explanation & references!) ended

perhaps better on DC, judging from the latest theories claiming that magnetic monopoles are much heavier than electrically charged elementary particles.

Put it back, IMO, when "the latest theories" have names and authors, and when "much heavier" is clear enough that, e.g., we know a magnetic monopole would still be light enough to be mobile in these "magnetic conductors". --Jerzy 21:44, 2003 Dec 19 (UTC)

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"This creates a problem, because it predicts that the monopole density today should be about the times the critical density of our Universe, according to the Big Bang model."

(I have little idea about this subject, but that doesn't look right to me Motor 23:58, 15 Jan 2004 (UTC)

At first glance one would thing they meant "three", but according to [1] (http://superstringtheory.com/cosmo/cosmo4a.html) it's 10¹¹. -- Tim Starling 00:04, Jan 16, 2004 (UTC)

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I have just written Eric Laithwaite and was surprised to find a link in this article. Could somebody tie a bow round this please? I've also added Felix Ehrenhaft whose claims are better known (to me) Cutler 13:19, 11 Feb 2004 (UTC)

Plz clarify yr request. --Jerzy(t) 08:26, 2004 Mar 4 (UTC)

Ah, i see: no mention except in link. But the link was added in the edit described as

. 20:21, 2003 Dec 19 . . The Anome (* Eric Laithwaite)

at the page history (http://en.wikipedia.org/w/wiki.phtml?title=Magnetic_monopole&action=history); it may be worth consulting User:The Anome or inspecting their other edits that hour or the next day. --Jerzy(t) 08:41, 2004 Mar 4 (UTC)

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The following reference from the article & section Magnetic monopole#External links may be of interest to specialists, but IMO is not worth the distraction it has been presenting to more typical readers:

• A review of monopole search experiments (http://pdg.lbl.gov/2003/s028.pdf) (presented as a table in Adobe pdf format)

--Jerzy(t) 08:26, 2004 Mar 4 (UTC)

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vector magnetic monopole?

What about a source of vector magnetic potential, rather than magnetic field lines? That's technically different from a magnetic monopole, right?

Adding a function with no curl (but some divergence) to the vector potential has no physical effect. So a source of vector potential isn't a meaningful physical concept. This is explained in Griffiths 3rd ed. section 5.4, ISBN 0-13-919960-8 -- Tim Starling 01:44, Oct 12, 2004 (UTC)

Single magnetic monopole in the universe

Referring to [2] (http://en.wikipedia.org/w/wiki.phtml?title=Magnetic_monopole&diff=6097857&oldid=6097851): it's not necessary for even a single magnetic monopole to be present in the universe, there only needs to be the potential for one to exist. The argument is that charge quantisation is required for renormalisation of the magnetic monopole wavefunction. -- Tim Starling 01:39, Nov 30, 2004 (UTC)