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New minor changes:
F = q(E+v×B) ⇄ ∑ici 07:42, 28 May 2012 (UTC)
Not a single mention to Marko Rodin ( http://www.youtube.com/watch?v=RnjW1zROJPc), one way or another - is there a reason for that? 89.153.150.71 ( talk) 13:00, 1 July 2012 (UTC)
The newly added Appendix section is almost exactly copied from http://www.encyclopediaofmath.org/index.php/Magnetic_monopole, on the site that the poster described. It might be relevant material, but it should definitely be presented in a different format. Also, this article does not have anything like this addition in its 2006 history. Nat2 ( talk) 00:22, 31 July 2012 (UTC)
I wonder that an article like this,"Magnetic monopole" in the present form may still exist. In the light of the fact that there do not exist any real particles justified to be called so, it is confusing, and should be revised, rewritten. Caboz ( talk) 14:10, 1 September 2012 (UTC)
The article should inform the reader that no particle of material substance as a source of magnetic field do exist and therefore can not be found. It should make clear, that all phenomena which we call "magnetic" are the consequence of the motion of electric field (charge). And this it does not. 94.113.59.212 ( talk) 16:55, 2 September 2012 (UTC)
Does this drawing help (from field (physics))?
Apart from the one in the lead there are no other diagrams... Maschen ( talk) 08:24, 3 September 2012 (UTC)
It seems to me that the last discussion brings only more confusion and no clarification of the problem. The fact is that there are no "particle-like" magnetic poles, and this fact should be respected anywhere in this article. The first sentence in the present form: "A magnetic monopole is a hypothetical particle in particle physics that is an isolated magnet with only one magnetic pole...." is confusing. It should state: "Magnetic monopole is a misleading technical term inducing the idea of existence of material particles with magnetic properties (magnetic charge)...." The article should be re-written keeping this fact in mind. http://en.wikipedia.org/?title=Talk:Magnetic_monopole&action=edit# — Preceding unsigned comment added by 94.113.59.212 ( talk) 10:34, 13 September 2012 (UTC)
Note to the new drawings:
In the new drawings the depiction of the electric field is OK, but that of the magnetic field is false, - the lines of magnetic induction B are not "product" of "magnetic monopoles N S" but of moving (orbiting) electrical particles (electrons), i.e. electrical current.
So the drawings are not explaining reality but only the false idea of the author.
94.113.59.212 (
talk) 01:37, 14 September 2012 (UTC)
can you please 94.113.59.212 ( talk) 06:12, 14 September 2012 (UTC)explain why should we talk about "hypothetical particles magnetic monopoles" when we know that they do not exist, and all magnetic phenomena can be explained by real effect of moving electrical particles ? 94.113.59.212 ( talk) 06:12, 14 September 2012 (UTC)
I agree that "...hypotheses may be useful for investigating possibilities in the absence of knowledge..." In the case of magnetic phenomena the knowledge is not absent, so why to use hypotheses when the reality is known ? is my question ?
94.113.59.212 (
talk) 11:01, 14 September 2012 (UTC)
I withdraw from this thread...(Maschen). So do I.( 94.113.59.212 ( talk) 08:51, 15 September 2012 (UTC)) Such a "discussion" leads nowhere. 94.113.59.212 ( talk) 13:41, 14 September 2012 (UTC)
I recommend to read also the discussion to the article Magnetischer monopol Ich empfehle auch die Disskusion : Magbetischer Monopol zu lesen. 94.113.59.212 ( talk) 14:05, 14 September 2012 (UTC)
I strongly disagree with the assertion that "magnetic monopoles do not exist" and that they are a "misleading technical term". I agree,we have not found them,many suspect they dont exist,the difficultly in finding them seems to indicate they may not exist,perhaps even they probably dont exist. All of those might be valid statements,but we dont KNOW they dont exist,until for instance,someone finds a charge thats not quantized like it should be. If charges there are magnetic monopoles,then charges have to be quantized in a certain way,therefore if charges are NOT always quantized that way,there must not be any monopoles. No one has found that charge yet either. Finding either that charge or a magnetic monopole gets you a nobel prize,but so far,we just dont KNOW,all we know is that if there ARE magnetic monopoles,they are hard to find. As for it being a misleading technical term,far from it. You might try to say the same thing about the vector potential. But in fact,like monopoles,the vector potential is a very useful thing when solving problems. Similarly,you can solve magnetic field problems by positing monopoles.In the end though,it turns out the vector potential IS physical,as it can affect a particle in places where its curl vanishes. Makes me a little less certain about the monopoles. — Preceding unsigned comment added by 67.2.240.140 ( talk) 07:59, 13 September 2013 (UTC)
References
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Here [1] is a paper (and here [2] are more related) on the covariant form of Maxwell's equations including monopoles (it's not hard to imagine a monopole 4-current and find a second inhomogeneous equation from the Faraday and electric Gauss equations for monopoles, though obviously OR without citations). The equations are:
in more detail the vector set is:
where:
Units | α | β | γ |
---|---|---|---|
SI | 1/ε0 | μ0 | 1 |
Gaussian | 4π | 4π/c | 1/c |
Heaviside-Lorentz | 1 | 1/c | 1/c |
Any objections to inclusion (aside from those who think monopoles are "impossible"!)? Of course we can change the notation for α, β, γ to something less confusing with notation for the Lorentz factor... Maschen ( talk) 06:41, 22 September 2012 (UTC)
Can you please explain how this contribution: "== Covariant form of Maxwell's monopole equations? == can help to explain the question of existence or non-existence of "magnetic monopoles? 94.113.59.212 ( talk) 13:07, 24 September 2012 (UTC)
Very nicely done (by Sbyrnes321), but there seems to be no mention of the U(1) symmetry, if that is the symmetry group... Also maybe it could be a 2nd level section? Maschen ( talk) 19:36, 24 September 2012 (UTC)
I've never worked this before, so I apologize beforehand if I mess this up. I've found these two intriguing articles and moves magnetic monopoles into the realm of reality (albeit not a very practically useful one at present; still better than hypothetical). I'm not qualified to provide any real text submissions/editions to Wikipedia, so if someone would be kind enough to appropriately create and word the new section, it'd be appreciated.
http://www.nature.com/news/2009/090903/full/news.2009.881.html http://www.sciencedaily.com/releases/2009/09/090903163725.htm http://arxiv.org/abs/0908.3568v2 — Preceding unsigned comment added by 111.68.108.82 ( talk) 05:02, 1 March 2013 (UTC)
"Nearly 85 years after pioneering theoretical physicist Paul Dirac predicted the possibility of their existence, an international collaboration led by Amherst College Physics Professor David S. Hall '91 and Aalto University (Finland) Academy Research Fellow Mikko Möttönen has created, identified and photographed synthetic magnetic monopoles in Hall's laboratory on the Amherst campus. The groundbreaking accomplishment paves the way for the detection of the particles in nature, which would be a revolutionary development comparable to the discovery of the electron." http://phys.org/news/2014-01-physicists-synthetic-magnetic-monopole-years.html Thangalin ( talk) 10:17, 30 January 2014 (UTC)
Here we have a demonstration of monopoles being created; and here is a more thorough demonstration of their monopole nature (a compass is circulated completely around the object, showing that it has only a south pole and no north).
Is it the opinion of the editors of this article that these videos are a hoax? 71.219.201.182 ( talk) 20:59, 18 May 2013 (UTC)
It must be a hoax, as no "magnetic monopoles" do exist ! I shall try to find out where the dupery is. 62.245.107.32 ( talk) 13:30, 13 July 2013 (UTC)
The video seemingly demonstrating the "creation south poles" on one drip tray, and "north poles" on the other by passing the drops of melted metal through two coils of wire is nothing but fake abusing the visual similarity with Lord Kelvin Generator (see Wikipedia). Prove of the fake: 1. In "the demonstration" video no connection of the coils to electric current source is shown, so no magnetic field which should influence the melted metal passing through the coils exists. 2. The fact, that the needle of the compass when moved under the tray points always in the direction to the tray is no proof of "monopole". Such an effect has a small permanent magnet pasted to the bottom underneath the tray.(notice, that the compass was moved only under the tray, not also above it, where the magnetic field has opposite direction). The video is nothing but poor fake. 62.245.107.32 ( talk) 07:05, 14 July 2013 (UTC)
Many years ago this article had an "In popular culture" section. It was entirely deleted, which is a pretty common fate for these kinds of sections -- See WP:POPCULTURE! But now it has been recreated and is steadily growing.
For what it's worth, here is the old version, immediately before it was deleted: [3].
I personally think that these sections can be nice when they are done well (not a list), but they tend to get flooded with trivia, and it's so much trouble to maintain that it's better to delete the section altogether. -- Steve ( talk) 17:11, 12 November 2013 (UTC)
The new paper is: Observation of Dirac monopoles in a synthetic magnetic field
in Nature
http://www.nature.com/nature/journal/v505/n7485/full/nature12954.html
This is just... they exist?? arghhhhhhhh — Preceding unsigned comment added by Waylah ( talk • contribs) 14:11, 30 January 2014 (UTC)
Should the article perhaps contain a brief explanation of why monopoles are not possible within normal matter? Perhaps with reference to magnetic domains, and/or to magnetic moment as an extensive property? (Please forgive any vocabulary glitches; my degree is in chemistry, not physics) DS ( talk) 14:57, 18 February 2014 (UTC)
This article is currently the target of a redirect of Magnetricity, and yet does not appear to be mentioned, let alone defined, explained, or bolded as a redirect. I found a layman's description of this term (which has apparently been gracing the headlines of both science and pop-sci articles for years) as "the magnetic equivalent of electricity", which sounds fascinating without being at all illuminating.
Someone apparently believes that "magnetricity" or its related concepts are discussed here. Could that someone or other informed party make this connection explicit? Thank you in advance. ~ Jeff Q (talk) 22:33, 12 March 2014 (UTC)
I wonder how the evident nonsenses about nonexisting "magnetic monopoles" can be "upgraded" by new expressions, like "magnetricity". All "electromagnetic phenomenon" in the universe are explaned by properties of electrons. Exisitence of "magnetic monopoles" as elelemntary particles is not "needed", so why are they supposed to exist and searched for? Can someone explaine ?
14:14, 18 November 2014 (UTC) 94.113.58.149 ( talk)
Hello Steve. here I am again with my doubts about any sense of looking for "magnetic monopoles" or "magnetricity". May be it is so because I am not, and I even do not want to be, a theoretical physicist, looking for something the nature did not find to be necessary for the existence of the universe. And so it is with the "magnetic monopoles". Evidentaly the nature does with electrones, without "magnetrons". It makes without the kind help of theoretical physicists living on a planet in the universe. Nevertheless they, the physicists, should be thanked for their good will. 94.113.58.149 ( talk) 10:53, 4 December 2014 (UTC)
A magnetic monopole is a hypothetical elementary particle in particle physics that is an isolated magnet with only one magnetic pole (a north pole without a south pole or vice versa).[1][2] In more technical terms, a magnetic monopole would have a net "magnetic charge". In fact, all electro-magnetic phenomena are the result of natural properties of electrons, depending on their relative velocity. When the velocity, relative to the observer is zero, he observes what we call electrostatic field. The electric charges are attracted/repelled by a force given by Coulomb law. If the same electric charges are moving the forces are given by Lorentz law, depending on their relative velocity, without any other “elementary particles with magnetic properties - magnetic monopoles”. That is why they can never be found.
This article has already been two times deleted!!! Why?! 78.45.207.57 ( talk) 14:53, 6 May 2015 (UTC)
I can not agree with the allegation that the „append is unrelated post to an existing thread“. It concernes the question of existence of „manetic monopoles“ as elementary paricles, which is discused in the article! 78.45.207.57 ( talk) 16:22, 6 May 2015 (UTC)
I really do not understand your argumentation. I see no reason to change my view on the problem. What I have written in my append is true and relevant, 78.45.207.57 ( talk) 18:50, 6 May 2015 (UTC)
The article "Magnetic monopole" begins:
A magnetic monopole is a hypothetical elementary particle in particle physics that is an isolated magnet with only one magnetic pole (a north pole without a south pole or vice versa).[1][2] In more technical terms, a magnetic monopole would have a net "magnetic charge". Modern interest in the concept stems from particle theories, notably the grand unified and superstring theories, which predict their existence.[3][4] Magnetism in bar magnets and electromagnets does not arise from magnetic monopoles, and in fact there is no conclusive experimental evidence that magnetic monopoles exist at all in the universe.
So we know that ".... there is no conclusive experimental evidence that magnetic monopoles exist at all in the universe." In addition, we know the Maxwell's theory of electromagnetic phenomena which explains all of them with existence of electrical charges, in practice mainly electrons, without some "special elementary particles! called magnetic monopoles. Why then should we assume the existance of such particles, and try to find them? Can you explain why?
In my append I state the fact that the search of "magnatic monopoles" is fruitless. 78.45.207.57 ( talk) 00:28, 7 May 2015 (UTC)
Dear Иτlk, I do not demand to change the article. I only publish the fact that the "magnetic monopoles" do not exist in the nature and therefore can never be found. 78.45.207.57 ( talk) 11:51, 7 May 2015 (UTC)
I understand finaly: The reality that there are no „magnetic monopoles“,- the fact revealing that the talk about these not-existing „elementary particles“ is the talk about nothing, may not be published on these pages. 78.45.207.57 ( talk) 16:16, 7 May 2015 (UTC)
Evidently, magnetic monopole hunt is finished. No magnetic monopole in the universe found. Amen 78.102.206.211 ( talk) 16:20, 28 October 2015 (UTC)
Hello!
@ Quondum, Maschen, and Sbyrnes321: I've read the article and while parts are good there are a lot of errors creeping in. In particular conflating philosophical considerations with scientific ones. The idea that the discovered monopoles are not "fundamental" is reductionist ideology and it is not a scientifically testable idea or concept. There is no physical measurable property, part of the electromagnetic field's ontology, that can tell you whether you have finally found the ultimate elementary particle. In Quantum spin liquids and the Fractional quantum Hall effect "elementary particles" ( i.e. the electrons) become fractions of themselves - in this case it is the electrons that are the quasiparticles. This is due to a deep mathematical distinction between linear and nonlinear systems. We know know that fundamental aspects of nature can not only be described in terms of symmetries and broken symmetries (Noether) but in terms of topology (The subject of the 2016 Nobel Prize). In fact they form a duality, I'm recently been working on the Montonen–Olive duality article (not perfect and a lots still to do on it but...} it should hopefully give you a better overview as to why point particles (described by Noether charges) and topological solitons (described by topological charges) can be interchanged depending on the duality.
The Dirac monopole contains a point singularity. It is important to note that Dirac was only able to derive his equation for the electron by adding a non-commutative quantities to the equations; it was these non-commutative quantities that turned out to describe the physical spin of a particle. U(1) is a commutative group and the fact it need to contain a non-commutative element for the formal constancy for Dirac's equation (and Maxwell's) is indicative that a higher dimensional generalization allowing this singularity to be removed. This is the 't Hooft–Polyakov monopole and are equivalent to what has been discovered in experiments. Saying, as the article does, that a "fundamental" monopole will violate gauss's law is like saying we will discover a square triangle, it's not going to happen! It is in fact the act of setting ∇⋅B = 0 which restricts monopoles from existing by stating that only divergence-less solenoidal magnetic fields can exist (no nonlinear solitons allowed!)
I'm redrafting the page here - its currently full of mistakes and not even half done - but would welcome your comments on the above points in the paragraphs above.
-- Sparkyscience ( talk) 20:42, 20 February 2017 (UTC)
@ Sbyrnes321:Apologies for getting my wires crossed here: My understanding is that in Ray et al. (2015) a Dirac monopole with no connecting nodal line was confirmed. The experiment the previous year in Ray et al. (2014) does not contain topological point defect in the order parameter and is "almost" a monopole like those in a spin ice (though even here i disagree that these "almost" monopoles can be defined in terms their of "real" particles that surround them. Their existance is distinct. In this regard the Nature articles like this one were not misleading...) The monopole is singular and embedded in U(1) and thus a Dirac version. The 't Hooft–Polyakov monopole, which i thought they found, is U(2) and can be non-abelian (this is where all the maths gets more complex then standard vector analysis and requires gauge theory), here there seems to be a few interesting papers on these in topological insulators....
In answer to your question: Ray et al. (2015) experiment will (1) violate ∇⋅B = 0 as there is no connecting node and is embedded in U(1) (2) it is not a spin ice analogue.
The central point is: Have “fundamental” monopoles been discovered? The only difference i can see here is that the means of discovery are topological rather then by symmetry breaking. Topology is just as fundamental an aspect as geometry. The idea of discrete categorisation into what is "fundamental" is embedded in the idea of reductionism, the point I was trying to get across earlier is that the monopole soliton is just as fundamental as a particle. Roderich Moessner who was part of the team that discovered monopoles in spin ices Castelnovo et al. (2008) explicitly warns against the dangers of reductionism in this piece here and in a journal article here. There seems to be many many different types of possible magnetic monopoles (i.e dyons, anyons etc...) in the same vien there are many different "types" of electron in things like quantum spin liquids. [a]
Reductionism is is hugely successful ideology and which has been the driving force behind the amazing success with the Standard Model. But it has limits: The core tenant of the idea is that we can reduce things into individual fundament parts and if we understand the functioning of these individual parts we can understand the functioning of a whole system; there is no mode of existence which cannot be defined as a composite function of the underlying parts. This works very well in linear situations, as we can isolate variables and define them analytically and make predictions. It does not work when we enter the realm of nonlinearity, because we cannot separate the variables. We cannot define an emergent structure as a linear function of its parts, the whole and the parts are one in the same. [b] Monopoles do not fit into a linear paradigm.
Let us quickly define "fundamental" particles as those discovered in accelerators. If thats our definition, then it definition raises questions: Have we really discovered fundamental particles called quarks? If they only exist as confined pairs, will we ever “reduce” them to something more fundamental?....will we actually gain any knowledge by doing this process? are quarks not a form of quasiparticle? It turns out quarks can be viewed, in some sense, as monopoles(!) with fractional charges [c] There is nothing “fake” about quasiparticles they are just as real as fundamental particles, our best thoeries in physics are not to do with particles or parts but fields: contious forms where everything is connected. When the field is homogenous it behaves linearly, when it isn't it doesn't. The fundamental laws of nature and the particles are can or cant exist are determined entirely by the geometry and topology of the field.
How would you tell the difference between a "mathamatical analogue" and a “real” particle? You can’t! because all properties we can assign physical meaning to are based the objective mathematics alone. The rest is subjective. The idea that we haven’t discovered the monopole is untenable given it behaves exactly as the model predicts. [d] That being said i appreciate both perspectives, the article perhaps should strike more of the tone found in the Majorana fermion article?-- Sparkyscience ( talk) 18:43, 21 February 2017 (UTC)
@ Sbyrnes321:I think we're getting somewhere: On emulate vs. modify point, this source here in Physics Today states "Maxwell's laws of electromagnetism are dramatically altered by an additional topological term". To my mind the word "emulate" is doublespeak and sounds like an immaterial virtual reality: surely the electromagnetic field is either modified or it is not, we can't have the laws of the familiar "real" electromagnetic field running in parallel with the rules of a concocted "emulated" field in the same area of space at the same time: If an electromagnetically interacting particle is traveling through such an area where we have created an "emulation"... which laws of electromagnetism does it follow? both?! Clearly there is only one electromagnetic field and its rules are modified depending on its topology i.e. it may be more general then that usually described in the U(1) case. The description that it is "synthetic" is empty verbiage, it is just as real as the surrounding electromagnetic field in other areas of more normal space...
This paper in Science by Qi et al. (2009) who wrote the above article in Physics Today is particularly enlightening:
“ | Since we started with the Maxwell’s equation, which includes , the magnetic flux integrated over a closed surface must vanish. We can indeed check that this is the case by considering a closed surface, for example a sphere with radius a, which encloses a topological insulator. Inside the closed surface, there is not only a image magnetic monopole charge, but also a line of magnetic charge density whose integral exactly cancels the point image magnetic monopole. However, when the separation between the electric charge and the surface, d, is much smaller than the spherical radius a, the magnetic field is completely dominated by the image magnetic monopole, and the contribution due to the line of magnetic charge density is vanishingly small. Therefore, we propose here to experimentally observe the magnetic monopole in the same sense as we can experimentally observe other fractionalization, or deconfinement, phenomena in condensed matter physics. In any closed electronic system, the total charge must be quantized to be an integer. However, one can separate fractionally charged elementary excitations arbitrarily far from each other, so that fractional charge can have well defined meaning locally. Similar situation occurs in spincharge separation. While the total charge and the total spin of a closed system must be linked to each other, spin and charge can occur as well separated local excitations. In our case, as long as d is much smaller than the radius of curvature of a topological surface a, the local magnetic field is completely determined by a single image magnetic monopole. | ” |
— Qi et al. (2009), pp. 2–3 |
My reading is that outside a closed sphere where the field is homogenous and normal Maxwells laws apply, ∇ · B = 0, but inside this sphere the non-trivial topology prevents us from subdividing it further via simple vector analysis; the monopole is the result of more complex mathematics required of gauge theory ( Witten 1979). Now in the above sources we are talking about a 't Hooft-Polakov monopole, the Ray et al. (2015) is a Dirac monopole which apparently is singular (I'm not sure how) but i imagine that the flux of the synthetic magnetic field is canceled out elsewhere such that any closed linear system will show ∇ · B = 0. But to state that somehow these particles that arise within this more complex "synthetic" space are mathematical fictions with no physical existence is clearly not true - they is really something there... and they are not dipoles...and they are electromagnetic. Surrounding this complex space with homogeneous space enforces ∇ · B = 0 and the flux of monopole is cancelled out [e]...but we can imagine a universe where the EM field is nearly always topologically non-trivial, where monopoles are abundant and only small spheres of synthetic homogeneous space exist: In these strange areas of space we think we have discovered the elusive "electron" that explains the magnetic charge of the monopole, but we conclude that since its charge is canceled out by fractional monopoles (quarks), its only a fake kind of particle and not a real one... this admittedly completely contrived overly simplified example hopefully underlines the nature of duality and the distinction between what is synthetic and what is not is merely relative and arbitrary.-- Sparkyscience ( talk) 14:48, 22 February 2017 (UTC)
@ Sbyrnes321:I think what you're trying to say is that you finally agree that the "synthetic magnetic field" is a indeed actually a magnetic field (not a "order parameter quantum field") that interacts with matter magnetically? If i label one half of the field left and the other half right and this labeling helps me calculate things better then thats fine....if you divide it up another way we can disagree forever over the definition but if both models predict the same thing who cares....the underling physical reality certainly doesn't care about what you labelled it. You can go on believing there are two distinct magnetic fields at each point in space rather then one unified field whose geometry and topology is dynamical if you want...i'm not going to waste time arguing that that view is not valid if it gives correct predictions. Do you agree on the following definitions for the article:
Magnetic field B - a magnetic field that is topologically homogenous
Synthetic magnetic field B* - a magnetic field which is topologically inhomogeneous.
-- Sparkyscience ( talk) 18:16, 23 February 2017 (UTC)
@ Sbyrnes321:Haha... oh wow. You hit the nail on the head! It is exactly analogous to artificial light or artificial insemination!! Couldn't have put it better myself! Happy to put apply WP:IAR and have you down as a cited source on the article itself! Now... I've no doubt there are an infinity of fields in the platonic sense...This diagram here from the first few pages of Roger Penrose's book the The Road to Reality illustrates it perfectly. There is a correspondence between mind, mathematics and matter but not all mathematical fields are manifestly physical. QED is highly accurate, highly successful mathematical model that attempts to explain electromagnetic phenomena we se in reality...it does not mean the mathematical model itself is reality! Consider the Mandelbrot set: if all atoms in the universe were made into one giant quantum computer - would we ever be able to capture the true essence of the infinite complexity of this mathematical object? Or simpler then this, can we ever make a true perfect triangle from elementary particles? No! We can only ever approximate. Reality and mathematics are distinct, both have an exististance, but you are completely conflating the two! You can invent whatever model you want but physics is about the rules of the game in which we play: If you have a model, an idea, that disagrees with what reality says you should change your model, if the the rules don't correspond to the game it is physically meaningless...putting the idea above reality is ideology. Your reverence to the almighty B field is a physically meaningless idea inside the areas of space we are considering! It is both limited and simplistic... it is completely unable to describe the Aharonov–Bohm effect and phenomena found in these experiments. It need to be broadened, as there is no notion of topology in QED.
Any good textbook will tell you the field is defined in terms of its vector potential, and this can be generalised to a situation where it is not a vector but a gauge. A different model, say topological quantum field theory may define the mathematic field that describes the physical phenomena of magnetism very differently to another physics model...but where the two models of TQFT and QED agree with observation they are both valid ...but all mathematical models have limitations no matter how accurate they are... we know that from Gödel's incompleteness theorems! I think it sensible to define the magnetic field as the field that has physically meaningful magnetic effect B present at each point in reality...I could define the real field as B + c...where c is some constant... and it is clear there are an infinity of such fields.. but in general when deciding what value to set the field at we declare merely by fiat the value of the ground state of a vector field be set to zero (this is what Wick ordering is!!) to make things simple. The situation of defining the B field is no different.
It is so clear in Dalibard et al. (2011) (I don't know how you can miss it!) that they are defining the a magnetic B* field in terms of its vector potential A which is not gauge invariant. A cannot be both gauge invariant and not gauge invariant at same set of coordinates, it is or it is not, thus B as defined by you is physically meaningless inside this space. But lets look at the other source referenced in Ray et al. (2014) about synthetic magnetic fields Lin et al. (2009) to get a clearer picture:
“ | To generate a synthetic magnetic field for neutral atoms, we engineered a Hamiltonian with a spatially dependent vector potential producing | ” |
— Lin et al. (2009), p. 628 |
We can elucidate this a little from another cited source:
“ | B is a sum of magnetic field configurations which can be static or dynamic. | ” |
— Ho & Shenoy (1996), p. 3 |
In other words, yet again, this is no different a situation to that of the Aharonov–Bohm effect or Berry phase where the vector potential cannot be trivially defined. The Qi et al. (2009) paper you glossed over earlier doesn't even mention the word artificial/synthetic... they state the "the local magnetic field is completely dominated" by a monopole. Penrose's book recommends Chan & Tsou (1993) as a textbook on monopoles...this book again describes the Aharonov–Bohm effect as equivalent situation, underlying the importance of topology and gauge theory, but not one mention of the word artificial/synthetic. Why? because such a distinction is in practice meaningless...The fact is this: a source of magnetism in a magnetic field that is not a dipole has been discovered, it might not be the magnetic field as defined by the model you are wedded to, but it is a magnetic field nonetheless. Your insistence of living in Flatland blinds to these truths...come out Plato's cave and see the light Steve!
You said your QFT was rusty, but after the "order parameter quantum field" blunder it looks increasingly like you're making it up as you go along!... your unsourced and uncited belief that there is only one true almighty B field whose topology must never vary throughout all of space is completely at odds with cited sources and your argument is increasingly relying on the notion that the academic articles written by the scientific community are some sort of conspiracy against us to mislead and misinform (they must be "nuts" to call it a magnetic field!). This is dangerously close to crackpot territory - don't do it! you're better than this Steve! I want to help!
In short a magnetic monopole has been discovered, reality likely has many types of possible magnetic monopole, but that which we have discovered is not the magnetic monopole that violates Gauss's law due to the inhomogeneity of the field present. Surely you agree with this statement? -- Sparkyscience ( talk) 19:09, 24 February 2017 (UTC)
(1) I don't understand your phrase "that which we have discovered is not the magnetic monopole that violates Gauss's law". I believe that a magnetic monopole by definition is a thing that, if you draw a sphere around it, has an inward or outward net flux of B. So a "magnetic monopole that does not violate Gauss's law for magnetism" is an oxymoron.
(1A): Try reading this whole wikipedia article, but everywhere that you see the phrase "magnetic monopole", starting from the title all the way down, try mentally replacing that phrase with the alternate phrase "source or sink of the magnetic B field". If you do that, then do you endorse the current article and its conclusions (including the statement that such "sources or sinks of the magnetic B field" are believed by particle physicists to exist but have never been seen despite decades of searching, etc. etc.)? If so, that's great! We are graduating from a conceptual disagreement to a terminology disagreement (and article scope disagreement). That would be a big step forward, if true!!
(2) Have you read Nature magazine's own (non-technical) description of Ray et al 2014? [6]. Note how the title is "Quantum cloud simulates magnetic monopole" not "Quantum cloud contains magnetic monopole". Why do you think they phrased it that way? Read the whole article, I think it will help reassure you that my opinion is the dominant mainstream physics opinion, not my own quirky thoughts.
(3) My references to "spin-1 BEC order parameter" were not a "blunder" but a reference to a Ray et al 2015, which we were discussing earlier. Read it yourself. IIRC the spin-1 order parameter is analogous to A, and therefore topological defects (i.e. vortices) in the spin-1 order parameter are analogous to magnetic monopoles. (Note the term "analogous". They are not a manifestation of magnetism but rather an analogue of magnetism, i.e. a different system which is in some respects mathematically similar to magnetism.)
(4) Believing that the gauge fields related to B cannot possibly have topological defects is equivalent to believing that there cannot be any magnetic monopoles. I do not have this belief. I do believe that there cannot be any magnetic monopoles in any region of space in which QED is applicable, because the quantum field structure of QED is indeed topologically trivial. (Do you agree?) Such regions of space include, most likely, everywhere in the solar system, but not everywhere in the universe. (Counterexamples include: around an evaporating black hole, or right after the big bang, or in the vicinity of a GUT monopole...) (Again, a real GUT magnetic monopole would entail a small region of space around the monopole where QED is no longer applicable, because the very very high energy fields which normally simplify / spontaneously-symmetry-break to QED are instead in an unusual configuration.) QED is the most precisely tested theory in the history of physics, with experiments probing it to sub-parts-per-billion levels. Nobody has ever created any experimental apparatus in which any violation of QED could be found. Ray et al and any of these papers are no exceptions. Again, since the field structure of QED admits no topological defects, it follows that there are no real magnetic monopoles in the experiments of Ray et al. or any similar paper. :-D
(5) Did you read Qi et al.? I quote: "Since we started with the Maxwell's equation, which includes ∇·B=0, the magnetic flux integrated over a closed surface must vanish". I don't know how it could be any clearer! :-D
(6) Did you read the Rehn paper? I quote: "Demanding that the field B be divergenceless, implies for its Fourier modes...". I don't know how it could be any clearer! :-D
(7) You said that Dalibard is "defining the a magnetic B* field in terms of its vector potential A". You bolded the term "magnetic". What is your basis for saying and emphasizing that it is magnetic? On the contrary, I find that the paper is extremely clear that the fields under discussion are not magnetic: (A): In the abstract, they say that an atom may "mimic the dynamics of a charged particle in a magnetic field". If it were really a magnetic field, they would have said the atom "has the dynamics of a charged particle in a magnetic field". (B) In the abstract, they call it a "Lorentz-like force". If it were really a magnetic phenomenon, they would have simply said "Lorentz force". (C) Their first example in Section I is based on the AC stark effect, a type of electrical force! (They don't state explicitly that this particular system is based on AC stark, but I can vouch for this as a professional atomic physicist who works every day with this exact type of system.) (D) Their whole long first paragraph sets out how this paper is all about "simulating" a magnetic field. A simulation of an ocean wave is not itself an ocean wave. Similarly, a simulation of magnetism is not itself magnetism! :-D
(8) In QED, there is a single, well-defined, unambiguous quantum field called B. QED is also perfectly capable of describing the Aharonov–Bohm effect. Therefore I think I am entitled to both believe that there is a single unambiguous field called B, which obeys [the QED generalizations of] Maxwell's equations etc., and also simultaneously understand exactly how the Aharonov–Bohm effect works. Can you explain in more detail why you think that these two things are incompatible?? :-D
(9) When you say "all mathematical models have limitations no matter how accurate they are... we know that from Gödel's incompleteness theorems", you are confusing two very different things. The first thing is the Fundamental Laws of the Universe - a set of equations that describe how any physical configuration will evolve in time from one moment to the next. The second thing is the Behavior of Systems Following These Laws. Conway's game of life is a good example of this concept: In Conway's Game of Life, The Fundamental Laws of the Universe can be described completely in one sentence, but the Behavior of Systems Following These Laws is so endlessly complicated that Gödel's incompleteness theorems applies to them. In real-world physics, we do not yet know the Fundamental Laws of the Universe, but we have made remarkable progress. We have found an approximation which is so accurate that it is compatible with literally every experiment that physicists have ever done so far here on Earth!! That approximation is the standard model (QED, QCD, etc.) plus general relativity. So in the present context (again, we are specifically trying to interpret various condensed-matter and atomic physics experiments conducted here on Earth), we cannot possibly go wrong by treating {standard model & GR} as a substitute for the true Fundamental Laws of the Universe. Gödel's incompleteness theorems does not undermine the previous sentence, nor give us any reason to think that the Fundamental Laws of the Universe are forever beyond reach, nor make us doubt that we really understand how {standard model / GR} works. Gödel's incompleteness theorems merely say that there are certain (rather contrived) unanswerable questions about the Behavior of Systems Following the Laws of Physics (e.g. if I set these particles in motion, and wait an infinitely long time, will such-and-such ever happen?) Anyway, there is a real universe, it has real laws, a major goal of physics is to learn about them, we have made remarkable progress towards that goal, and there is no reason to expect that the goal is unreachable (though of course we cannot know for sure unless we do). Anyway, in the standard model there is (among many other things) a specific quantum field that people call the magnetic B field, and since the standard model is an appropriate and predictive model to use in the context of any experiment ever performed on Earth, one can always understand exactly what one means by the magnetic B field. And you will never find an electromagnetism or any other physics textbook that uses the term "magnetic B field" willy-nilly to refer to any old field that has anything to do with magnetism, just like textbooks will never use the term "positron" to refer to anything other than the unique, specific particle species of that name. --Steve (talk) 04:14, 25 February 2017 (UTC)
Ok lets focus this a little! Sorry if my last previous comments have touched a nerve it was all meant in good humour and not to be taken to seriously :-) I know we both want the same thing which is an understanding of what so called "synthetic magnetic fields" are and how they relate to magnetic monopoles.
Lets start with some simplified semiclassical basics: consider a "spinning" charged particle, i.e. an electron, this intrinsic spin gives rise to a tight toroidal magnetic field around the electron. If this electric charge is then locked into an orbit whose axis is orthogonal to the spin, say around an atom such the spin is pointing away from the centre of the orbit, this will give rise to a more complex magnetic field where the toroidal magnetic field of the spin is interlaced with a toroidal magnetic field generated by the orbit. Its not quite as classical as this in a quantum system, as we have complex numbers that describe rotations in Gamma matrices (this is where the quaternion, Clifford algebra stuff comes in! I'm pretty sure the example here is a type of Hopf fibration [8] [9]) but this is the essence of spin-orbit coupling. You can call the magnetic field that arrises from the orbit as "synthetic" or "artificial" compared to that of the intrinsic spin if you want, but it is still very much a magnetic field that arrises from a rotating charge. Both the spin and the orbit are intrinsic to the system and are adiabatic. If i put a compass inside this field, barring special case solutions, in general it would not settle into an equilibrium position because of the nonlinearity of the magnetic field present. The magnetic field in such an area is path dependant thus non-abelian. [10]
Now lets move on to cold atom systems being bombarded by lasers. The essence of these systems is to exploit and manipulate the degrees of freedom present in a magnetic field by engineering the exact nature of the spin-orbit coupling. Atoms are trapping and cooled, and two (or more) lasers are used to create a standing wave soliton that acts as an optical lattice, this process was the subject of the 1997 Nobel prize [11] Using such a system to create a many body state was the subject of the 2001 Nobel prize. [12] Such systems can be used to generalise Rashba effect where the spin-orbit coupling is prolate [13], spherical [14] or oblate [15] [16] [17] etc.
The original idea of using quantum adiabatic system to manipulate gauge structures came well before cold atom systems and was first put forward by Frank Wilczek and Anthony Zee [18] who enigmatically state "It is of course, potentially significant for models of elementary particles that gauge fields can arise "from nowhere" but we shall not attempt specific speculations along that line here". Wilczek later showed how this can be applied to the creation of magnetic monopoles [19]. It was realised that many bodied systems in cold atom give rise to an exact implementation of the situation described by Wilczek [20]. Not an analogy!
It is also interesting to note that time crystal's were made via a cold atom set up at Maryland Uni- none of the press or academic papers said that a time crystal was "simulated" on the contrary they said a real new state of matter had been made for the first time [21] [22] [23]. No different from the monopoles here...
There is no conceivable way anyone can claim that synthetic magnetic fields as implemented above does not arise from the adiabatics of charged particles - they are a "generalised magnetic field" [24] with higher levels of symmetry! Simple!-- Sparkyscience ( talk) 18:08, 26 February 2017 (UTC)
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help)What on Earth has happened to the discussion of the monopole problem on Wikipedia? I seem to recall there actually being a decent article on this topic. But now monopole problem redirects to a page about inflation? And only a handful of poorly explanatory material at that? Seriously? Isn't that a bit POV? Wouldn't this page be a more appropriate place for an NPOV discussion? There is already text referring to the issues here, although it's not a coherent thread. I could have sworn it already had a reasonable page. It certainly merits one, as it could support a number of other articles, such as this one, articles about Grand Unified Theory, unresolved problems in physics, and yes, even inflationary theory. Don't know what's happened, but something definitely seems awry here. 75.139.254.117 ( talk) 06:09, 3 April 2017 (UTC)
For example, it is not good to write in an article that "no evidence exists." Aside from the impossibility of knowing that evidence does not exist (proving a negative), the statement should read like, "As of September 24, 2018, no evidence existed." A present tense statement is likely to become false before long. ( PeacePeace ( talk) 06:42, 25 September 2018 (UTC))
OK, so ... The section titled "Further descriptions in particle physics" appears to be word-for-word identical to the Springer EOM article. That section was added with this edit: [25] which says two confusing things: First, that its restoring some "old deleted text from 2006", and second, that it's claiming to have been written by Nigel Hitchin. If it was actually written by Hitchin, that would be great, as he's a world-expert on this, having created much of the field in the 1980's. However the actual contributor seems to be User:Enyokoyama, who did a similar cut-n-paste from EOM's Hitchin system to Hitchin system, claiming that the original WP article had been AfD'ed. I could not find any AfD logs to back this up, though. Next, the Springer EOM states that new material is covered by the CC-by-SA license, which I think means it's OK to copy this into WP, except that it's not clear if either of these articles are "new" or "old". Or what's up with that. So I've no clue what to do about this copyvio. (I did recently expand the Ginzburg–Landau theory article, which is effectively more-or-less covering the same material as here, and so it would make sense to merge, revise or fork all this off into a generic article on this topic, maybe merging into Yang-Mills-Higgs theory or something like that. Hmm. 67.198.37.17 ( talk) 08:37, 14 May 2019 (UTC)
Prior content in this article duplicated one or more previously published sources. Copied or closely paraphrased material has been rewritten or removed and must not be restored, unless it is duly released under a compatible license. (For more information, please see "using copyrighted works from others" if you are not the copyright holder of this material, or "donating copyrighted materials" if you are.)
For legal reasons, we cannot accept copyrighted text or images borrowed from other web sites or published material; such additions will be deleted. Contributors may use copyrighted publications as a source of information, and, if allowed under fair use, may copy sentences and phrases, provided they are included in quotation marks and referenced properly. The material may also be rewritten, providing it does not infringe on the copyright of the original or plagiarize from that source. Therefore, such paraphrased portions must provide their source. Please see our guideline on non-free text for how to properly implement limited quotations of copyrighted text. Wikipedia takes copyright violations very seriously, and persistent violators will be blocked from editing. While we appreciate contributions, we must require all contributors to understand and comply with these policies. Thank you. — Diannaa 🍁 ( talk) 22:34, 27 September 2019 (UTC)
I've flagged this section as lacking citations. This would include a basic reference on fiber bundles in differential geometry, one applying that to Yang-Mills gauge theory, and one linking that to the 't Hooft-Polyakov monopole. Here's one that address the latter: Monopoles and twisted sigma models. There are probably better sources, but this is one I'm familiar with. NPguy ( talk) 18:47, 17 January 2021 (UTC)
A monopole is a speculative exception to the rule that magnetic fields diverge away from one magnetic pole, say the N pole, then converge again to its paired S pole. But then it is required for the magnetic field to close the loop by returning to the N pole.
Non mathematically inclined physicists see this last requirement as arbitrary, and look for the exception, magnetic monopoles.
But mathematical physicists will look for mathematical reasons, and reasons from physics theory, for not finding monopoles.
The physical theory at stake is the conservation laws. I argue that the conservation of angular momentum and the conservation of energy would be broken by magnetic monopoles.
Make two rings interlinked. Provide rollers so that they can spin, one in the x-y plane and another in the z-x plane. Embed a positive charge in one ring, and embed a magnetic north pole in the other. Now give one a spin. From the law of induction, the other ring will start to rotate, and the one slow. This conserves energy. But angular momentum disappears in one plane, and differently oriented angular momentum appears in the other.
But angular momentum would be conserved if an ordinary magnet were embedded instead of a monopole. No net induction would happen.
Now consider that a crossed E field and B field will provide a net impulse and energy boost to an electric charge that crosses them at right angles to both. This is the principle of an electric motor. To conserve energy, the source of the electrostatic field or the source of the magnetic field would be de-energized to compensate. If the source of the E field is static, then the electromagnet that provides the B field must give up energy and de-magnetize.
Actually, the charge must be coupled to a mass that is trailing it , or otherwise moving at different direction than the charge. This is needed to get work done by the magnetic field.
But a magnetic monopole can not de-magnetize, so the law of conservation of energy would then be broken.
Now, the deeper and non-conventional understanding of this result invokes the basic properties of spacetime. Energy, momentum, and angular momentum are conserved because they are sources of gravity. And sources of gravity are conserved because the Bianchi identities are an intrinsic part of geometry. “The boundary of a boundary is zero.” So the origins and sinks of momentum are naturally zero from this property of spacetime geometry.
If a physicist wants to argue that conservation comes from group theory, the reply is that group theory is also part of geometry.
So electromagnetic energy must be conserved by the existence of the potential A. And then the Bianchi identities applied to A directly require the non existence of magnetic monopoles.
I have written a simulator for a rotating motor powered with free energy from a magnetic monopole. 2602:306:3126:3170:DA1:17AC:3686:FFF1 ( talk) 20:28, 27 November 2022 (UTC)
NPguy, my edit summary says: "well, then, lets just delete it: it is WP:OR, unsourced, and incorrect as stated; in any event, it is only a tangentially interesting observation in this context". With which of these do you disagree? That it is original research, that is is unsourced, that it is incorrect as stated, or that it has little relevance in the context? Any one of these qualifies it for deletion; you will have to remedy all of these if it is to be kept (yes, the onus is on you, since it has been challenged). If you are unable to source this statement in a reliable source, it is reasonable for me to remove it, regardless of your disagreement. — Quondum 22:46, 18 December 2022 (UTC)
Is a topological monopole the same as / similar to / different than a magnetic monopole? Also, are 'Alice rings' a related phenomenon worthy of mention here? Sample source: [30]. Thanks, Last1in ( talk) 15:18, 29 August 2023 (UTC)
Magnetic monopole was created in 2014 with Bosen-Einstein condensate. Could someone update the article. Sources: https://www.tekniikkatalous.fi/tiede/2014-01-30/Aalto-tutkija-l%C3%B6ysi-ensimm%C3%A4isen-synteettisen-hiukkasen-%E2%80%93-80-vuoden-etsinn%C3%A4n-j%C3%A4lkeen-3317491.html and https://www.nature.com/articles/nature12954 -- HenriHa ( talk) 18:21, 21 January 2024 (UTC)
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New minor changes:
F = q(E+v×B) ⇄ ∑ici 07:42, 28 May 2012 (UTC)
Not a single mention to Marko Rodin ( http://www.youtube.com/watch?v=RnjW1zROJPc), one way or another - is there a reason for that? 89.153.150.71 ( talk) 13:00, 1 July 2012 (UTC)
The newly added Appendix section is almost exactly copied from http://www.encyclopediaofmath.org/index.php/Magnetic_monopole, on the site that the poster described. It might be relevant material, but it should definitely be presented in a different format. Also, this article does not have anything like this addition in its 2006 history. Nat2 ( talk) 00:22, 31 July 2012 (UTC)
I wonder that an article like this,"Magnetic monopole" in the present form may still exist. In the light of the fact that there do not exist any real particles justified to be called so, it is confusing, and should be revised, rewritten. Caboz ( talk) 14:10, 1 September 2012 (UTC)
The article should inform the reader that no particle of material substance as a source of magnetic field do exist and therefore can not be found. It should make clear, that all phenomena which we call "magnetic" are the consequence of the motion of electric field (charge). And this it does not. 94.113.59.212 ( talk) 16:55, 2 September 2012 (UTC)
Does this drawing help (from field (physics))?
Apart from the one in the lead there are no other diagrams... Maschen ( talk) 08:24, 3 September 2012 (UTC)
It seems to me that the last discussion brings only more confusion and no clarification of the problem. The fact is that there are no "particle-like" magnetic poles, and this fact should be respected anywhere in this article. The first sentence in the present form: "A magnetic monopole is a hypothetical particle in particle physics that is an isolated magnet with only one magnetic pole...." is confusing. It should state: "Magnetic monopole is a misleading technical term inducing the idea of existence of material particles with magnetic properties (magnetic charge)...." The article should be re-written keeping this fact in mind. http://en.wikipedia.org/?title=Talk:Magnetic_monopole&action=edit# — Preceding unsigned comment added by 94.113.59.212 ( talk) 10:34, 13 September 2012 (UTC)
Note to the new drawings:
In the new drawings the depiction of the electric field is OK, but that of the magnetic field is false, - the lines of magnetic induction B are not "product" of "magnetic monopoles N S" but of moving (orbiting) electrical particles (electrons), i.e. electrical current.
So the drawings are not explaining reality but only the false idea of the author.
94.113.59.212 (
talk) 01:37, 14 September 2012 (UTC)
can you please 94.113.59.212 ( talk) 06:12, 14 September 2012 (UTC)explain why should we talk about "hypothetical particles magnetic monopoles" when we know that they do not exist, and all magnetic phenomena can be explained by real effect of moving electrical particles ? 94.113.59.212 ( talk) 06:12, 14 September 2012 (UTC)
I agree that "...hypotheses may be useful for investigating possibilities in the absence of knowledge..." In the case of magnetic phenomena the knowledge is not absent, so why to use hypotheses when the reality is known ? is my question ?
94.113.59.212 (
talk) 11:01, 14 September 2012 (UTC)
I withdraw from this thread...(Maschen). So do I.( 94.113.59.212 ( talk) 08:51, 15 September 2012 (UTC)) Such a "discussion" leads nowhere. 94.113.59.212 ( talk) 13:41, 14 September 2012 (UTC)
I recommend to read also the discussion to the article Magnetischer monopol Ich empfehle auch die Disskusion : Magbetischer Monopol zu lesen. 94.113.59.212 ( talk) 14:05, 14 September 2012 (UTC)
I strongly disagree with the assertion that "magnetic monopoles do not exist" and that they are a "misleading technical term". I agree,we have not found them,many suspect they dont exist,the difficultly in finding them seems to indicate they may not exist,perhaps even they probably dont exist. All of those might be valid statements,but we dont KNOW they dont exist,until for instance,someone finds a charge thats not quantized like it should be. If charges there are magnetic monopoles,then charges have to be quantized in a certain way,therefore if charges are NOT always quantized that way,there must not be any monopoles. No one has found that charge yet either. Finding either that charge or a magnetic monopole gets you a nobel prize,but so far,we just dont KNOW,all we know is that if there ARE magnetic monopoles,they are hard to find. As for it being a misleading technical term,far from it. You might try to say the same thing about the vector potential. But in fact,like monopoles,the vector potential is a very useful thing when solving problems. Similarly,you can solve magnetic field problems by positing monopoles.In the end though,it turns out the vector potential IS physical,as it can affect a particle in places where its curl vanishes. Makes me a little less certain about the monopoles. — Preceding unsigned comment added by 67.2.240.140 ( talk) 07:59, 13 September 2013 (UTC)
References
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Here [1] is a paper (and here [2] are more related) on the covariant form of Maxwell's equations including monopoles (it's not hard to imagine a monopole 4-current and find a second inhomogeneous equation from the Faraday and electric Gauss equations for monopoles, though obviously OR without citations). The equations are:
in more detail the vector set is:
where:
Units | α | β | γ |
---|---|---|---|
SI | 1/ε0 | μ0 | 1 |
Gaussian | 4π | 4π/c | 1/c |
Heaviside-Lorentz | 1 | 1/c | 1/c |
Any objections to inclusion (aside from those who think monopoles are "impossible"!)? Of course we can change the notation for α, β, γ to something less confusing with notation for the Lorentz factor... Maschen ( talk) 06:41, 22 September 2012 (UTC)
Can you please explain how this contribution: "== Covariant form of Maxwell's monopole equations? == can help to explain the question of existence or non-existence of "magnetic monopoles? 94.113.59.212 ( talk) 13:07, 24 September 2012 (UTC)
Very nicely done (by Sbyrnes321), but there seems to be no mention of the U(1) symmetry, if that is the symmetry group... Also maybe it could be a 2nd level section? Maschen ( talk) 19:36, 24 September 2012 (UTC)
I've never worked this before, so I apologize beforehand if I mess this up. I've found these two intriguing articles and moves magnetic monopoles into the realm of reality (albeit not a very practically useful one at present; still better than hypothetical). I'm not qualified to provide any real text submissions/editions to Wikipedia, so if someone would be kind enough to appropriately create and word the new section, it'd be appreciated.
http://www.nature.com/news/2009/090903/full/news.2009.881.html http://www.sciencedaily.com/releases/2009/09/090903163725.htm http://arxiv.org/abs/0908.3568v2 — Preceding unsigned comment added by 111.68.108.82 ( talk) 05:02, 1 March 2013 (UTC)
"Nearly 85 years after pioneering theoretical physicist Paul Dirac predicted the possibility of their existence, an international collaboration led by Amherst College Physics Professor David S. Hall '91 and Aalto University (Finland) Academy Research Fellow Mikko Möttönen has created, identified and photographed synthetic magnetic monopoles in Hall's laboratory on the Amherst campus. The groundbreaking accomplishment paves the way for the detection of the particles in nature, which would be a revolutionary development comparable to the discovery of the electron." http://phys.org/news/2014-01-physicists-synthetic-magnetic-monopole-years.html Thangalin ( talk) 10:17, 30 January 2014 (UTC)
Here we have a demonstration of monopoles being created; and here is a more thorough demonstration of their monopole nature (a compass is circulated completely around the object, showing that it has only a south pole and no north).
Is it the opinion of the editors of this article that these videos are a hoax? 71.219.201.182 ( talk) 20:59, 18 May 2013 (UTC)
It must be a hoax, as no "magnetic monopoles" do exist ! I shall try to find out where the dupery is. 62.245.107.32 ( talk) 13:30, 13 July 2013 (UTC)
The video seemingly demonstrating the "creation south poles" on one drip tray, and "north poles" on the other by passing the drops of melted metal through two coils of wire is nothing but fake abusing the visual similarity with Lord Kelvin Generator (see Wikipedia). Prove of the fake: 1. In "the demonstration" video no connection of the coils to electric current source is shown, so no magnetic field which should influence the melted metal passing through the coils exists. 2. The fact, that the needle of the compass when moved under the tray points always in the direction to the tray is no proof of "monopole". Such an effect has a small permanent magnet pasted to the bottom underneath the tray.(notice, that the compass was moved only under the tray, not also above it, where the magnetic field has opposite direction). The video is nothing but poor fake. 62.245.107.32 ( talk) 07:05, 14 July 2013 (UTC)
Many years ago this article had an "In popular culture" section. It was entirely deleted, which is a pretty common fate for these kinds of sections -- See WP:POPCULTURE! But now it has been recreated and is steadily growing.
For what it's worth, here is the old version, immediately before it was deleted: [3].
I personally think that these sections can be nice when they are done well (not a list), but they tend to get flooded with trivia, and it's so much trouble to maintain that it's better to delete the section altogether. -- Steve ( talk) 17:11, 12 November 2013 (UTC)
The new paper is: Observation of Dirac monopoles in a synthetic magnetic field
in Nature
http://www.nature.com/nature/journal/v505/n7485/full/nature12954.html
This is just... they exist?? arghhhhhhhh — Preceding unsigned comment added by Waylah ( talk • contribs) 14:11, 30 January 2014 (UTC)
Should the article perhaps contain a brief explanation of why monopoles are not possible within normal matter? Perhaps with reference to magnetic domains, and/or to magnetic moment as an extensive property? (Please forgive any vocabulary glitches; my degree is in chemistry, not physics) DS ( talk) 14:57, 18 February 2014 (UTC)
This article is currently the target of a redirect of Magnetricity, and yet does not appear to be mentioned, let alone defined, explained, or bolded as a redirect. I found a layman's description of this term (which has apparently been gracing the headlines of both science and pop-sci articles for years) as "the magnetic equivalent of electricity", which sounds fascinating without being at all illuminating.
Someone apparently believes that "magnetricity" or its related concepts are discussed here. Could that someone or other informed party make this connection explicit? Thank you in advance. ~ Jeff Q (talk) 22:33, 12 March 2014 (UTC)
I wonder how the evident nonsenses about nonexisting "magnetic monopoles" can be "upgraded" by new expressions, like "magnetricity". All "electromagnetic phenomenon" in the universe are explaned by properties of electrons. Exisitence of "magnetic monopoles" as elelemntary particles is not "needed", so why are they supposed to exist and searched for? Can someone explaine ?
14:14, 18 November 2014 (UTC) 94.113.58.149 ( talk)
Hello Steve. here I am again with my doubts about any sense of looking for "magnetic monopoles" or "magnetricity". May be it is so because I am not, and I even do not want to be, a theoretical physicist, looking for something the nature did not find to be necessary for the existence of the universe. And so it is with the "magnetic monopoles". Evidentaly the nature does with electrones, without "magnetrons". It makes without the kind help of theoretical physicists living on a planet in the universe. Nevertheless they, the physicists, should be thanked for their good will. 94.113.58.149 ( talk) 10:53, 4 December 2014 (UTC)
A magnetic monopole is a hypothetical elementary particle in particle physics that is an isolated magnet with only one magnetic pole (a north pole without a south pole or vice versa).[1][2] In more technical terms, a magnetic monopole would have a net "magnetic charge". In fact, all electro-magnetic phenomena are the result of natural properties of electrons, depending on their relative velocity. When the velocity, relative to the observer is zero, he observes what we call electrostatic field. The electric charges are attracted/repelled by a force given by Coulomb law. If the same electric charges are moving the forces are given by Lorentz law, depending on their relative velocity, without any other “elementary particles with magnetic properties - magnetic monopoles”. That is why they can never be found.
This article has already been two times deleted!!! Why?! 78.45.207.57 ( talk) 14:53, 6 May 2015 (UTC)
I can not agree with the allegation that the „append is unrelated post to an existing thread“. It concernes the question of existence of „manetic monopoles“ as elementary paricles, which is discused in the article! 78.45.207.57 ( talk) 16:22, 6 May 2015 (UTC)
I really do not understand your argumentation. I see no reason to change my view on the problem. What I have written in my append is true and relevant, 78.45.207.57 ( talk) 18:50, 6 May 2015 (UTC)
The article "Magnetic monopole" begins:
A magnetic monopole is a hypothetical elementary particle in particle physics that is an isolated magnet with only one magnetic pole (a north pole without a south pole or vice versa).[1][2] In more technical terms, a magnetic monopole would have a net "magnetic charge". Modern interest in the concept stems from particle theories, notably the grand unified and superstring theories, which predict their existence.[3][4] Magnetism in bar magnets and electromagnets does not arise from magnetic monopoles, and in fact there is no conclusive experimental evidence that magnetic monopoles exist at all in the universe.
So we know that ".... there is no conclusive experimental evidence that magnetic monopoles exist at all in the universe." In addition, we know the Maxwell's theory of electromagnetic phenomena which explains all of them with existence of electrical charges, in practice mainly electrons, without some "special elementary particles! called magnetic monopoles. Why then should we assume the existance of such particles, and try to find them? Can you explain why?
In my append I state the fact that the search of "magnatic monopoles" is fruitless. 78.45.207.57 ( talk) 00:28, 7 May 2015 (UTC)
Dear Иτlk, I do not demand to change the article. I only publish the fact that the "magnetic monopoles" do not exist in the nature and therefore can never be found. 78.45.207.57 ( talk) 11:51, 7 May 2015 (UTC)
I understand finaly: The reality that there are no „magnetic monopoles“,- the fact revealing that the talk about these not-existing „elementary particles“ is the talk about nothing, may not be published on these pages. 78.45.207.57 ( talk) 16:16, 7 May 2015 (UTC)
Evidently, magnetic monopole hunt is finished. No magnetic monopole in the universe found. Amen 78.102.206.211 ( talk) 16:20, 28 October 2015 (UTC)
Hello!
@ Quondum, Maschen, and Sbyrnes321: I've read the article and while parts are good there are a lot of errors creeping in. In particular conflating philosophical considerations with scientific ones. The idea that the discovered monopoles are not "fundamental" is reductionist ideology and it is not a scientifically testable idea or concept. There is no physical measurable property, part of the electromagnetic field's ontology, that can tell you whether you have finally found the ultimate elementary particle. In Quantum spin liquids and the Fractional quantum Hall effect "elementary particles" ( i.e. the electrons) become fractions of themselves - in this case it is the electrons that are the quasiparticles. This is due to a deep mathematical distinction between linear and nonlinear systems. We know know that fundamental aspects of nature can not only be described in terms of symmetries and broken symmetries (Noether) but in terms of topology (The subject of the 2016 Nobel Prize). In fact they form a duality, I'm recently been working on the Montonen–Olive duality article (not perfect and a lots still to do on it but...} it should hopefully give you a better overview as to why point particles (described by Noether charges) and topological solitons (described by topological charges) can be interchanged depending on the duality.
The Dirac monopole contains a point singularity. It is important to note that Dirac was only able to derive his equation for the electron by adding a non-commutative quantities to the equations; it was these non-commutative quantities that turned out to describe the physical spin of a particle. U(1) is a commutative group and the fact it need to contain a non-commutative element for the formal constancy for Dirac's equation (and Maxwell's) is indicative that a higher dimensional generalization allowing this singularity to be removed. This is the 't Hooft–Polyakov monopole and are equivalent to what has been discovered in experiments. Saying, as the article does, that a "fundamental" monopole will violate gauss's law is like saying we will discover a square triangle, it's not going to happen! It is in fact the act of setting ∇⋅B = 0 which restricts monopoles from existing by stating that only divergence-less solenoidal magnetic fields can exist (no nonlinear solitons allowed!)
I'm redrafting the page here - its currently full of mistakes and not even half done - but would welcome your comments on the above points in the paragraphs above.
-- Sparkyscience ( talk) 20:42, 20 February 2017 (UTC)
@ Sbyrnes321:Apologies for getting my wires crossed here: My understanding is that in Ray et al. (2015) a Dirac monopole with no connecting nodal line was confirmed. The experiment the previous year in Ray et al. (2014) does not contain topological point defect in the order parameter and is "almost" a monopole like those in a spin ice (though even here i disagree that these "almost" monopoles can be defined in terms their of "real" particles that surround them. Their existance is distinct. In this regard the Nature articles like this one were not misleading...) The monopole is singular and embedded in U(1) and thus a Dirac version. The 't Hooft–Polyakov monopole, which i thought they found, is U(2) and can be non-abelian (this is where all the maths gets more complex then standard vector analysis and requires gauge theory), here there seems to be a few interesting papers on these in topological insulators....
In answer to your question: Ray et al. (2015) experiment will (1) violate ∇⋅B = 0 as there is no connecting node and is embedded in U(1) (2) it is not a spin ice analogue.
The central point is: Have “fundamental” monopoles been discovered? The only difference i can see here is that the means of discovery are topological rather then by symmetry breaking. Topology is just as fundamental an aspect as geometry. The idea of discrete categorisation into what is "fundamental" is embedded in the idea of reductionism, the point I was trying to get across earlier is that the monopole soliton is just as fundamental as a particle. Roderich Moessner who was part of the team that discovered monopoles in spin ices Castelnovo et al. (2008) explicitly warns against the dangers of reductionism in this piece here and in a journal article here. There seems to be many many different types of possible magnetic monopoles (i.e dyons, anyons etc...) in the same vien there are many different "types" of electron in things like quantum spin liquids. [a]
Reductionism is is hugely successful ideology and which has been the driving force behind the amazing success with the Standard Model. But it has limits: The core tenant of the idea is that we can reduce things into individual fundament parts and if we understand the functioning of these individual parts we can understand the functioning of a whole system; there is no mode of existence which cannot be defined as a composite function of the underlying parts. This works very well in linear situations, as we can isolate variables and define them analytically and make predictions. It does not work when we enter the realm of nonlinearity, because we cannot separate the variables. We cannot define an emergent structure as a linear function of its parts, the whole and the parts are one in the same. [b] Monopoles do not fit into a linear paradigm.
Let us quickly define "fundamental" particles as those discovered in accelerators. If thats our definition, then it definition raises questions: Have we really discovered fundamental particles called quarks? If they only exist as confined pairs, will we ever “reduce” them to something more fundamental?....will we actually gain any knowledge by doing this process? are quarks not a form of quasiparticle? It turns out quarks can be viewed, in some sense, as monopoles(!) with fractional charges [c] There is nothing “fake” about quasiparticles they are just as real as fundamental particles, our best thoeries in physics are not to do with particles or parts but fields: contious forms where everything is connected. When the field is homogenous it behaves linearly, when it isn't it doesn't. The fundamental laws of nature and the particles are can or cant exist are determined entirely by the geometry and topology of the field.
How would you tell the difference between a "mathamatical analogue" and a “real” particle? You can’t! because all properties we can assign physical meaning to are based the objective mathematics alone. The rest is subjective. The idea that we haven’t discovered the monopole is untenable given it behaves exactly as the model predicts. [d] That being said i appreciate both perspectives, the article perhaps should strike more of the tone found in the Majorana fermion article?-- Sparkyscience ( talk) 18:43, 21 February 2017 (UTC)
@ Sbyrnes321:I think we're getting somewhere: On emulate vs. modify point, this source here in Physics Today states "Maxwell's laws of electromagnetism are dramatically altered by an additional topological term". To my mind the word "emulate" is doublespeak and sounds like an immaterial virtual reality: surely the electromagnetic field is either modified or it is not, we can't have the laws of the familiar "real" electromagnetic field running in parallel with the rules of a concocted "emulated" field in the same area of space at the same time: If an electromagnetically interacting particle is traveling through such an area where we have created an "emulation"... which laws of electromagnetism does it follow? both?! Clearly there is only one electromagnetic field and its rules are modified depending on its topology i.e. it may be more general then that usually described in the U(1) case. The description that it is "synthetic" is empty verbiage, it is just as real as the surrounding electromagnetic field in other areas of more normal space...
This paper in Science by Qi et al. (2009) who wrote the above article in Physics Today is particularly enlightening:
“ | Since we started with the Maxwell’s equation, which includes , the magnetic flux integrated over a closed surface must vanish. We can indeed check that this is the case by considering a closed surface, for example a sphere with radius a, which encloses a topological insulator. Inside the closed surface, there is not only a image magnetic monopole charge, but also a line of magnetic charge density whose integral exactly cancels the point image magnetic monopole. However, when the separation between the electric charge and the surface, d, is much smaller than the spherical radius a, the magnetic field is completely dominated by the image magnetic monopole, and the contribution due to the line of magnetic charge density is vanishingly small. Therefore, we propose here to experimentally observe the magnetic monopole in the same sense as we can experimentally observe other fractionalization, or deconfinement, phenomena in condensed matter physics. In any closed electronic system, the total charge must be quantized to be an integer. However, one can separate fractionally charged elementary excitations arbitrarily far from each other, so that fractional charge can have well defined meaning locally. Similar situation occurs in spincharge separation. While the total charge and the total spin of a closed system must be linked to each other, spin and charge can occur as well separated local excitations. In our case, as long as d is much smaller than the radius of curvature of a topological surface a, the local magnetic field is completely determined by a single image magnetic monopole. | ” |
— Qi et al. (2009), pp. 2–3 |
My reading is that outside a closed sphere where the field is homogenous and normal Maxwells laws apply, ∇ · B = 0, but inside this sphere the non-trivial topology prevents us from subdividing it further via simple vector analysis; the monopole is the result of more complex mathematics required of gauge theory ( Witten 1979). Now in the above sources we are talking about a 't Hooft-Polakov monopole, the Ray et al. (2015) is a Dirac monopole which apparently is singular (I'm not sure how) but i imagine that the flux of the synthetic magnetic field is canceled out elsewhere such that any closed linear system will show ∇ · B = 0. But to state that somehow these particles that arise within this more complex "synthetic" space are mathematical fictions with no physical existence is clearly not true - they is really something there... and they are not dipoles...and they are electromagnetic. Surrounding this complex space with homogeneous space enforces ∇ · B = 0 and the flux of monopole is cancelled out [e]...but we can imagine a universe where the EM field is nearly always topologically non-trivial, where monopoles are abundant and only small spheres of synthetic homogeneous space exist: In these strange areas of space we think we have discovered the elusive "electron" that explains the magnetic charge of the monopole, but we conclude that since its charge is canceled out by fractional monopoles (quarks), its only a fake kind of particle and not a real one... this admittedly completely contrived overly simplified example hopefully underlines the nature of duality and the distinction between what is synthetic and what is not is merely relative and arbitrary.-- Sparkyscience ( talk) 14:48, 22 February 2017 (UTC)
@ Sbyrnes321:I think what you're trying to say is that you finally agree that the "synthetic magnetic field" is a indeed actually a magnetic field (not a "order parameter quantum field") that interacts with matter magnetically? If i label one half of the field left and the other half right and this labeling helps me calculate things better then thats fine....if you divide it up another way we can disagree forever over the definition but if both models predict the same thing who cares....the underling physical reality certainly doesn't care about what you labelled it. You can go on believing there are two distinct magnetic fields at each point in space rather then one unified field whose geometry and topology is dynamical if you want...i'm not going to waste time arguing that that view is not valid if it gives correct predictions. Do you agree on the following definitions for the article:
Magnetic field B - a magnetic field that is topologically homogenous
Synthetic magnetic field B* - a magnetic field which is topologically inhomogeneous.
-- Sparkyscience ( talk) 18:16, 23 February 2017 (UTC)
@ Sbyrnes321:Haha... oh wow. You hit the nail on the head! It is exactly analogous to artificial light or artificial insemination!! Couldn't have put it better myself! Happy to put apply WP:IAR and have you down as a cited source on the article itself! Now... I've no doubt there are an infinity of fields in the platonic sense...This diagram here from the first few pages of Roger Penrose's book the The Road to Reality illustrates it perfectly. There is a correspondence between mind, mathematics and matter but not all mathematical fields are manifestly physical. QED is highly accurate, highly successful mathematical model that attempts to explain electromagnetic phenomena we se in reality...it does not mean the mathematical model itself is reality! Consider the Mandelbrot set: if all atoms in the universe were made into one giant quantum computer - would we ever be able to capture the true essence of the infinite complexity of this mathematical object? Or simpler then this, can we ever make a true perfect triangle from elementary particles? No! We can only ever approximate. Reality and mathematics are distinct, both have an exististance, but you are completely conflating the two! You can invent whatever model you want but physics is about the rules of the game in which we play: If you have a model, an idea, that disagrees with what reality says you should change your model, if the the rules don't correspond to the game it is physically meaningless...putting the idea above reality is ideology. Your reverence to the almighty B field is a physically meaningless idea inside the areas of space we are considering! It is both limited and simplistic... it is completely unable to describe the Aharonov–Bohm effect and phenomena found in these experiments. It need to be broadened, as there is no notion of topology in QED.
Any good textbook will tell you the field is defined in terms of its vector potential, and this can be generalised to a situation where it is not a vector but a gauge. A different model, say topological quantum field theory may define the mathematic field that describes the physical phenomena of magnetism very differently to another physics model...but where the two models of TQFT and QED agree with observation they are both valid ...but all mathematical models have limitations no matter how accurate they are... we know that from Gödel's incompleteness theorems! I think it sensible to define the magnetic field as the field that has physically meaningful magnetic effect B present at each point in reality...I could define the real field as B + c...where c is some constant... and it is clear there are an infinity of such fields.. but in general when deciding what value to set the field at we declare merely by fiat the value of the ground state of a vector field be set to zero (this is what Wick ordering is!!) to make things simple. The situation of defining the B field is no different.
It is so clear in Dalibard et al. (2011) (I don't know how you can miss it!) that they are defining the a magnetic B* field in terms of its vector potential A which is not gauge invariant. A cannot be both gauge invariant and not gauge invariant at same set of coordinates, it is or it is not, thus B as defined by you is physically meaningless inside this space. But lets look at the other source referenced in Ray et al. (2014) about synthetic magnetic fields Lin et al. (2009) to get a clearer picture:
“ | To generate a synthetic magnetic field for neutral atoms, we engineered a Hamiltonian with a spatially dependent vector potential producing | ” |
— Lin et al. (2009), p. 628 |
We can elucidate this a little from another cited source:
“ | B is a sum of magnetic field configurations which can be static or dynamic. | ” |
— Ho & Shenoy (1996), p. 3 |
In other words, yet again, this is no different a situation to that of the Aharonov–Bohm effect or Berry phase where the vector potential cannot be trivially defined. The Qi et al. (2009) paper you glossed over earlier doesn't even mention the word artificial/synthetic... they state the "the local magnetic field is completely dominated" by a monopole. Penrose's book recommends Chan & Tsou (1993) as a textbook on monopoles...this book again describes the Aharonov–Bohm effect as equivalent situation, underlying the importance of topology and gauge theory, but not one mention of the word artificial/synthetic. Why? because such a distinction is in practice meaningless...The fact is this: a source of magnetism in a magnetic field that is not a dipole has been discovered, it might not be the magnetic field as defined by the model you are wedded to, but it is a magnetic field nonetheless. Your insistence of living in Flatland blinds to these truths...come out Plato's cave and see the light Steve!
You said your QFT was rusty, but after the "order parameter quantum field" blunder it looks increasingly like you're making it up as you go along!... your unsourced and uncited belief that there is only one true almighty B field whose topology must never vary throughout all of space is completely at odds with cited sources and your argument is increasingly relying on the notion that the academic articles written by the scientific community are some sort of conspiracy against us to mislead and misinform (they must be "nuts" to call it a magnetic field!). This is dangerously close to crackpot territory - don't do it! you're better than this Steve! I want to help!
In short a magnetic monopole has been discovered, reality likely has many types of possible magnetic monopole, but that which we have discovered is not the magnetic monopole that violates Gauss's law due to the inhomogeneity of the field present. Surely you agree with this statement? -- Sparkyscience ( talk) 19:09, 24 February 2017 (UTC)
(1) I don't understand your phrase "that which we have discovered is not the magnetic monopole that violates Gauss's law". I believe that a magnetic monopole by definition is a thing that, if you draw a sphere around it, has an inward or outward net flux of B. So a "magnetic monopole that does not violate Gauss's law for magnetism" is an oxymoron.
(1A): Try reading this whole wikipedia article, but everywhere that you see the phrase "magnetic monopole", starting from the title all the way down, try mentally replacing that phrase with the alternate phrase "source or sink of the magnetic B field". If you do that, then do you endorse the current article and its conclusions (including the statement that such "sources or sinks of the magnetic B field" are believed by particle physicists to exist but have never been seen despite decades of searching, etc. etc.)? If so, that's great! We are graduating from a conceptual disagreement to a terminology disagreement (and article scope disagreement). That would be a big step forward, if true!!
(2) Have you read Nature magazine's own (non-technical) description of Ray et al 2014? [6]. Note how the title is "Quantum cloud simulates magnetic monopole" not "Quantum cloud contains magnetic monopole". Why do you think they phrased it that way? Read the whole article, I think it will help reassure you that my opinion is the dominant mainstream physics opinion, not my own quirky thoughts.
(3) My references to "spin-1 BEC order parameter" were not a "blunder" but a reference to a Ray et al 2015, which we were discussing earlier. Read it yourself. IIRC the spin-1 order parameter is analogous to A, and therefore topological defects (i.e. vortices) in the spin-1 order parameter are analogous to magnetic monopoles. (Note the term "analogous". They are not a manifestation of magnetism but rather an analogue of magnetism, i.e. a different system which is in some respects mathematically similar to magnetism.)
(4) Believing that the gauge fields related to B cannot possibly have topological defects is equivalent to believing that there cannot be any magnetic monopoles. I do not have this belief. I do believe that there cannot be any magnetic monopoles in any region of space in which QED is applicable, because the quantum field structure of QED is indeed topologically trivial. (Do you agree?) Such regions of space include, most likely, everywhere in the solar system, but not everywhere in the universe. (Counterexamples include: around an evaporating black hole, or right after the big bang, or in the vicinity of a GUT monopole...) (Again, a real GUT magnetic monopole would entail a small region of space around the monopole where QED is no longer applicable, because the very very high energy fields which normally simplify / spontaneously-symmetry-break to QED are instead in an unusual configuration.) QED is the most precisely tested theory in the history of physics, with experiments probing it to sub-parts-per-billion levels. Nobody has ever created any experimental apparatus in which any violation of QED could be found. Ray et al and any of these papers are no exceptions. Again, since the field structure of QED admits no topological defects, it follows that there are no real magnetic monopoles in the experiments of Ray et al. or any similar paper. :-D
(5) Did you read Qi et al.? I quote: "Since we started with the Maxwell's equation, which includes ∇·B=0, the magnetic flux integrated over a closed surface must vanish". I don't know how it could be any clearer! :-D
(6) Did you read the Rehn paper? I quote: "Demanding that the field B be divergenceless, implies for its Fourier modes...". I don't know how it could be any clearer! :-D
(7) You said that Dalibard is "defining the a magnetic B* field in terms of its vector potential A". You bolded the term "magnetic". What is your basis for saying and emphasizing that it is magnetic? On the contrary, I find that the paper is extremely clear that the fields under discussion are not magnetic: (A): In the abstract, they say that an atom may "mimic the dynamics of a charged particle in a magnetic field". If it were really a magnetic field, they would have said the atom "has the dynamics of a charged particle in a magnetic field". (B) In the abstract, they call it a "Lorentz-like force". If it were really a magnetic phenomenon, they would have simply said "Lorentz force". (C) Their first example in Section I is based on the AC stark effect, a type of electrical force! (They don't state explicitly that this particular system is based on AC stark, but I can vouch for this as a professional atomic physicist who works every day with this exact type of system.) (D) Their whole long first paragraph sets out how this paper is all about "simulating" a magnetic field. A simulation of an ocean wave is not itself an ocean wave. Similarly, a simulation of magnetism is not itself magnetism! :-D
(8) In QED, there is a single, well-defined, unambiguous quantum field called B. QED is also perfectly capable of describing the Aharonov–Bohm effect. Therefore I think I am entitled to both believe that there is a single unambiguous field called B, which obeys [the QED generalizations of] Maxwell's equations etc., and also simultaneously understand exactly how the Aharonov–Bohm effect works. Can you explain in more detail why you think that these two things are incompatible?? :-D
(9) When you say "all mathematical models have limitations no matter how accurate they are... we know that from Gödel's incompleteness theorems", you are confusing two very different things. The first thing is the Fundamental Laws of the Universe - a set of equations that describe how any physical configuration will evolve in time from one moment to the next. The second thing is the Behavior of Systems Following These Laws. Conway's game of life is a good example of this concept: In Conway's Game of Life, The Fundamental Laws of the Universe can be described completely in one sentence, but the Behavior of Systems Following These Laws is so endlessly complicated that Gödel's incompleteness theorems applies to them. In real-world physics, we do not yet know the Fundamental Laws of the Universe, but we have made remarkable progress. We have found an approximation which is so accurate that it is compatible with literally every experiment that physicists have ever done so far here on Earth!! That approximation is the standard model (QED, QCD, etc.) plus general relativity. So in the present context (again, we are specifically trying to interpret various condensed-matter and atomic physics experiments conducted here on Earth), we cannot possibly go wrong by treating {standard model & GR} as a substitute for the true Fundamental Laws of the Universe. Gödel's incompleteness theorems does not undermine the previous sentence, nor give us any reason to think that the Fundamental Laws of the Universe are forever beyond reach, nor make us doubt that we really understand how {standard model / GR} works. Gödel's incompleteness theorems merely say that there are certain (rather contrived) unanswerable questions about the Behavior of Systems Following the Laws of Physics (e.g. if I set these particles in motion, and wait an infinitely long time, will such-and-such ever happen?) Anyway, there is a real universe, it has real laws, a major goal of physics is to learn about them, we have made remarkable progress towards that goal, and there is no reason to expect that the goal is unreachable (though of course we cannot know for sure unless we do). Anyway, in the standard model there is (among many other things) a specific quantum field that people call the magnetic B field, and since the standard model is an appropriate and predictive model to use in the context of any experiment ever performed on Earth, one can always understand exactly what one means by the magnetic B field. And you will never find an electromagnetism or any other physics textbook that uses the term "magnetic B field" willy-nilly to refer to any old field that has anything to do with magnetism, just like textbooks will never use the term "positron" to refer to anything other than the unique, specific particle species of that name. --Steve (talk) 04:14, 25 February 2017 (UTC)
Ok lets focus this a little! Sorry if my last previous comments have touched a nerve it was all meant in good humour and not to be taken to seriously :-) I know we both want the same thing which is an understanding of what so called "synthetic magnetic fields" are and how they relate to magnetic monopoles.
Lets start with some simplified semiclassical basics: consider a "spinning" charged particle, i.e. an electron, this intrinsic spin gives rise to a tight toroidal magnetic field around the electron. If this electric charge is then locked into an orbit whose axis is orthogonal to the spin, say around an atom such the spin is pointing away from the centre of the orbit, this will give rise to a more complex magnetic field where the toroidal magnetic field of the spin is interlaced with a toroidal magnetic field generated by the orbit. Its not quite as classical as this in a quantum system, as we have complex numbers that describe rotations in Gamma matrices (this is where the quaternion, Clifford algebra stuff comes in! I'm pretty sure the example here is a type of Hopf fibration [8] [9]) but this is the essence of spin-orbit coupling. You can call the magnetic field that arrises from the orbit as "synthetic" or "artificial" compared to that of the intrinsic spin if you want, but it is still very much a magnetic field that arrises from a rotating charge. Both the spin and the orbit are intrinsic to the system and are adiabatic. If i put a compass inside this field, barring special case solutions, in general it would not settle into an equilibrium position because of the nonlinearity of the magnetic field present. The magnetic field in such an area is path dependant thus non-abelian. [10]
Now lets move on to cold atom systems being bombarded by lasers. The essence of these systems is to exploit and manipulate the degrees of freedom present in a magnetic field by engineering the exact nature of the spin-orbit coupling. Atoms are trapping and cooled, and two (or more) lasers are used to create a standing wave soliton that acts as an optical lattice, this process was the subject of the 1997 Nobel prize [11] Using such a system to create a many body state was the subject of the 2001 Nobel prize. [12] Such systems can be used to generalise Rashba effect where the spin-orbit coupling is prolate [13], spherical [14] or oblate [15] [16] [17] etc.
The original idea of using quantum adiabatic system to manipulate gauge structures came well before cold atom systems and was first put forward by Frank Wilczek and Anthony Zee [18] who enigmatically state "It is of course, potentially significant for models of elementary particles that gauge fields can arise "from nowhere" but we shall not attempt specific speculations along that line here". Wilczek later showed how this can be applied to the creation of magnetic monopoles [19]. It was realised that many bodied systems in cold atom give rise to an exact implementation of the situation described by Wilczek [20]. Not an analogy!
It is also interesting to note that time crystal's were made via a cold atom set up at Maryland Uni- none of the press or academic papers said that a time crystal was "simulated" on the contrary they said a real new state of matter had been made for the first time [21] [22] [23]. No different from the monopoles here...
There is no conceivable way anyone can claim that synthetic magnetic fields as implemented above does not arise from the adiabatics of charged particles - they are a "generalised magnetic field" [24] with higher levels of symmetry! Simple!-- Sparkyscience ( talk) 18:08, 26 February 2017 (UTC)
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help)What on Earth has happened to the discussion of the monopole problem on Wikipedia? I seem to recall there actually being a decent article on this topic. But now monopole problem redirects to a page about inflation? And only a handful of poorly explanatory material at that? Seriously? Isn't that a bit POV? Wouldn't this page be a more appropriate place for an NPOV discussion? There is already text referring to the issues here, although it's not a coherent thread. I could have sworn it already had a reasonable page. It certainly merits one, as it could support a number of other articles, such as this one, articles about Grand Unified Theory, unresolved problems in physics, and yes, even inflationary theory. Don't know what's happened, but something definitely seems awry here. 75.139.254.117 ( talk) 06:09, 3 April 2017 (UTC)
For example, it is not good to write in an article that "no evidence exists." Aside from the impossibility of knowing that evidence does not exist (proving a negative), the statement should read like, "As of September 24, 2018, no evidence existed." A present tense statement is likely to become false before long. ( PeacePeace ( talk) 06:42, 25 September 2018 (UTC))
OK, so ... The section titled "Further descriptions in particle physics" appears to be word-for-word identical to the Springer EOM article. That section was added with this edit: [25] which says two confusing things: First, that its restoring some "old deleted text from 2006", and second, that it's claiming to have been written by Nigel Hitchin. If it was actually written by Hitchin, that would be great, as he's a world-expert on this, having created much of the field in the 1980's. However the actual contributor seems to be User:Enyokoyama, who did a similar cut-n-paste from EOM's Hitchin system to Hitchin system, claiming that the original WP article had been AfD'ed. I could not find any AfD logs to back this up, though. Next, the Springer EOM states that new material is covered by the CC-by-SA license, which I think means it's OK to copy this into WP, except that it's not clear if either of these articles are "new" or "old". Or what's up with that. So I've no clue what to do about this copyvio. (I did recently expand the Ginzburg–Landau theory article, which is effectively more-or-less covering the same material as here, and so it would make sense to merge, revise or fork all this off into a generic article on this topic, maybe merging into Yang-Mills-Higgs theory or something like that. Hmm. 67.198.37.17 ( talk) 08:37, 14 May 2019 (UTC)
Prior content in this article duplicated one or more previously published sources. Copied or closely paraphrased material has been rewritten or removed and must not be restored, unless it is duly released under a compatible license. (For more information, please see "using copyrighted works from others" if you are not the copyright holder of this material, or "donating copyrighted materials" if you are.)
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I've flagged this section as lacking citations. This would include a basic reference on fiber bundles in differential geometry, one applying that to Yang-Mills gauge theory, and one linking that to the 't Hooft-Polyakov monopole. Here's one that address the latter: Monopoles and twisted sigma models. There are probably better sources, but this is one I'm familiar with. NPguy ( talk) 18:47, 17 January 2021 (UTC)
A monopole is a speculative exception to the rule that magnetic fields diverge away from one magnetic pole, say the N pole, then converge again to its paired S pole. But then it is required for the magnetic field to close the loop by returning to the N pole.
Non mathematically inclined physicists see this last requirement as arbitrary, and look for the exception, magnetic monopoles.
But mathematical physicists will look for mathematical reasons, and reasons from physics theory, for not finding monopoles.
The physical theory at stake is the conservation laws. I argue that the conservation of angular momentum and the conservation of energy would be broken by magnetic monopoles.
Make two rings interlinked. Provide rollers so that they can spin, one in the x-y plane and another in the z-x plane. Embed a positive charge in one ring, and embed a magnetic north pole in the other. Now give one a spin. From the law of induction, the other ring will start to rotate, and the one slow. This conserves energy. But angular momentum disappears in one plane, and differently oriented angular momentum appears in the other.
But angular momentum would be conserved if an ordinary magnet were embedded instead of a monopole. No net induction would happen.
Now consider that a crossed E field and B field will provide a net impulse and energy boost to an electric charge that crosses them at right angles to both. This is the principle of an electric motor. To conserve energy, the source of the electrostatic field or the source of the magnetic field would be de-energized to compensate. If the source of the E field is static, then the electromagnet that provides the B field must give up energy and de-magnetize.
Actually, the charge must be coupled to a mass that is trailing it , or otherwise moving at different direction than the charge. This is needed to get work done by the magnetic field.
But a magnetic monopole can not de-magnetize, so the law of conservation of energy would then be broken.
Now, the deeper and non-conventional understanding of this result invokes the basic properties of spacetime. Energy, momentum, and angular momentum are conserved because they are sources of gravity. And sources of gravity are conserved because the Bianchi identities are an intrinsic part of geometry. “The boundary of a boundary is zero.” So the origins and sinks of momentum are naturally zero from this property of spacetime geometry.
If a physicist wants to argue that conservation comes from group theory, the reply is that group theory is also part of geometry.
So electromagnetic energy must be conserved by the existence of the potential A. And then the Bianchi identities applied to A directly require the non existence of magnetic monopoles.
I have written a simulator for a rotating motor powered with free energy from a magnetic monopole. 2602:306:3126:3170:DA1:17AC:3686:FFF1 ( talk) 20:28, 27 November 2022 (UTC)
NPguy, my edit summary says: "well, then, lets just delete it: it is WP:OR, unsourced, and incorrect as stated; in any event, it is only a tangentially interesting observation in this context". With which of these do you disagree? That it is original research, that is is unsourced, that it is incorrect as stated, or that it has little relevance in the context? Any one of these qualifies it for deletion; you will have to remedy all of these if it is to be kept (yes, the onus is on you, since it has been challenged). If you are unable to source this statement in a reliable source, it is reasonable for me to remove it, regardless of your disagreement. — Quondum 22:46, 18 December 2022 (UTC)
Is a topological monopole the same as / similar to / different than a magnetic monopole? Also, are 'Alice rings' a related phenomenon worthy of mention here? Sample source: [30]. Thanks, Last1in ( talk) 15:18, 29 August 2023 (UTC)
Magnetic monopole was created in 2014 with Bosen-Einstein condensate. Could someone update the article. Sources: https://www.tekniikkatalous.fi/tiede/2014-01-30/Aalto-tutkija-l%C3%B6ysi-ensimm%C3%A4isen-synteettisen-hiukkasen-%E2%80%93-80-vuoden-etsinn%C3%A4n-j%C3%A4lkeen-3317491.html and https://www.nature.com/articles/nature12954 -- HenriHa ( talk) 18:21, 21 January 2024 (UTC)