×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Researchers Discover "Magnetic Current"

samzenpus posted more than 4 years ago | from the positive-and-negative-waves dept.

Science 249

fsouto writes "Researchers have discovered a magnetic equivalent to electricity. From the article, 'The phenomenon, dubbed "magnetricity," could be used in magnetic storage or in computing. Magnetic monopoles were first predicted to exist over a century ago, as a perfect analogue to electric charges. Although there are protons and electrons with net positive and negative electric charges, there were no particles in existence which carry magnetic charges. Rather, every magnet has a "north" and "south" pole.'"

cancel ×
This is a preview of your comment

No Comment Title Entered

Anonymous Coward 1 minute ago

No Comment Entered

249 comments

Bad summary (5, Informative)

Brian Gordon (987471) | more than 4 years ago | (#29752723)

The only thing new here is the current, not the "magnetic charge" from the monopole. And it's theoretical physics ridiculously far from being used in magnetic storage or computing.

Re:Bad summary (3, Informative)

Chris Burke (6130) | more than 4 years ago | (#29752883)

That's because the summary is just copypasta of the first paragraph of TFA, which goes on to say that monopole "quasti-particles" had already been observed.

Re:Bad summary (1, Interesting)

Anonymous Coward | more than 4 years ago | (#29753001)

Basically, what they found was a material that looks like two opposite magnetic monopoles. In other words, they found a magnetic dipole.

Wake me up when I can buy a north magnetic monopole, and not get the south magnetic monopole with it.

Re:Bad summary (1)

fractoid (1076465) | more than 4 years ago | (#29754035)

Wake me up when I can buy a north magnetic monopole, and not get the south magnetic monopole with it.

Wake me when I can buy an electron that doesn't have a proton somewhere out there waiting for it.

Magnetic Storage (1, Funny)

Anonymous Coward | more than 4 years ago | (#29753045)

Isn't that how a hard drive operates?

Re:Bad summary (3, Informative)

fractoid (1076465) | more than 4 years ago | (#29754023)

The only thing new here is the current, not the "magnetic charge" from the monopole. And it's theoretical physics ridiculously far from being used in magnetic storage or computing.

The monopole is at most a month old, so it's not like we're talking particularly old news. At worst it's an update on ongoing research.

Maxwell Equations (0)

Veramocor (262800) | more than 4 years ago | (#29752729)

The vaunted Maxwell equations are crying.

Re:Maxwell Equations (5, Interesting)

Chris Burke (6130) | more than 4 years ago | (#29752959)

No, they aren't. Maxwell's equations don't preclude magnetic monopoles or the movement of net magnetic 'charge' (aka 'current'). In fact it's always been a mystery why monopoles didn't appear to exist. There was no theoretical reason why they shouldn't, we have just never found a particle carrying a net magnetic charge. We still haven't exactly, just a crystal structure in which you can find discreet units of net magnetic charge, but that's effectively the same thing. And now we've seen that these units can move through a structure, so magnetic current exists.

In a way this must be a relief. Electricity and magnetism are symmetric in so many ways, it was odd that in this one way they weren't since they're ultimately aspects of the same force (electromagnetism).

Re:Maxwell Equations (3, Interesting)

Antique Geekmeister (740220) | more than 4 years ago | (#29753081)

There was also no theoretical reason for monopoles _to_ exist. If charge exists, and moving electric charges create magnetic fields, who do you _need_ magnetic charges? Making the equations "symmetrical" for both electric and magnetic charges does not make them any more elegant or powerful, any more than not having "negative mass" makes Newton's equations any less valid.

"Discrete units of net magnetic charge" may be a quantum effect of aligned, moving electrical charges. I still see no need for monopoles.

Re:Maxwell Equations (2, Funny)

Shadow of Eternity (795165) | more than 4 years ago | (#29753091)

I just tried to think about negative mass, thanks for the headache.

Re:Maxwell Equations (1)

c6gunner (950153) | more than 4 years ago | (#29753295)

I just tried to think about negative mass, thanks for the headache.

Think of the marketing potential!

"Loose 50lbs without dieting, overnight! Just try our patented NegaBelt for the low low cost of only 40 payments of $19.99!"

We could make billions!

Re:Maxwell Equations (1)

Tanktalus (794810) | more than 4 years ago | (#29753655)

"Loose (sic) 50lbs without dieting, overnight! Just try our patented NegaBelt for the low low cost of only 40 payments of $19.99!"

Um, and if those payments were made in coins, your NegaBelt wouldn't have to do a thing. They'd lose 50lbs right there.

Re:Maxwell Equations (2, Funny)

Anonymous Coward | more than 4 years ago | (#29753979)

Why make billions when you could make... millions!

Re:Maxwell Equations (1)

boxxertrumps (1124859) | more than 4 years ago | (#29753433)

It's simple, objects with negative mass would have a negative gravitational force on the surrounding objects. Say, two objects with equal mass, but one is negative. They wouldn't have an affect on one another gravitationally, because the net force is zero.

AKA negative masses would "fall" up.

Re:Maxwell Equations (2, Funny)

Tanktalus (794810) | more than 4 years ago | (#29753657)

AKA negative masses would "fall" up.

Ah, like Helium balloons.

</sarcasm> <-- for the humour impaired, and those that think I might be posting from the Southern US.

Re:Maxwell Equations (3, Informative)

SEE (7681) | more than 4 years ago | (#29753709)

What, you haven't encountered the idea before? It's been around a while. Look here. [wikipedia.org]

Re:Maxwell Equations (1)

Shadow of Eternity (795165) | more than 4 years ago | (#29754185)

The concept isn't foreign but the idea of an object with a negative mass but positive volume starts to have wierd implications for things like trying to hold it.

Re:Maxwell Equations (4, Insightful)

dlenmn (145080) | more than 4 years ago | (#29753135)

There was also no theoretical reason for monopoles _to_ exist.

Well, if there is so much as one magnetic monopole in existance, it would [wikipedia.org] explain the quantization of electric charge. I call that a theoretical reason for monopoles to exist.

Re:Maxwell Equations (1)

catmistake (814204) | more than 4 years ago | (#29753269)

Well, if there is so much as one magnetic monopole in existance

Look no further! I've got one right here in my kitchen (driving my microwave oven).

Re:Maxwell Equations (5, Funny)

fractoid (1076465) | more than 4 years ago | (#29754047)

Look no further! I've got one right here in my kitchen (driving my microwave oven).

I thought magnetic monopole was a way to play monopole during long family roadtrips.

Re:Maxwell Equations (2, Insightful)

emjay88 (1178161) | more than 4 years ago | (#29753195)

There was also no theoretical reason for monopoles _to_ exist.

I think the point the GP was making was that there was no reason that they couldn't exist...

Re:Maxwell Equations (2, Informative)

Chris Burke (6130) | more than 4 years ago | (#29753403)

I think the point the GP was making was that there was no reason that they couldn't exist...

Exactly. It isn't necessary that they exist, but there's no reason they could not exist and it makes a lot of sense for them to exist for various reasons (charge quantization and symmetry between aspects of the same force being big reasons). But we've never observed them, hence the equations as stated do not account for them. Observe one, and you can trivially modify the equations to account for the fact. The theory is pre-built to accept them. Hence they're not "crying".

Re:Maxwell Equations (1)

Bill, Shooter of Bul (629286) | more than 4 years ago | (#29753509)

Won't you feel funny when we do discover negative mass. It would actually make a lot of things easier. The accelerated expansion of the universe cries out for a repulsive force. Throw a negative sign on a mass and voila, repulsion! Also, it would lead to the possibility of negative energy, which we can then use for warp drives. At least according to my creative star trek esque imagination. Science has taught us to never say never until experiments tell us to say never.

Re:Maxwell Equations (1)

Chris Burke (6130) | more than 4 years ago | (#29753719)

There is negative energy. At least, there is negative potential energy.

Re:Maxwell Equations (3, Informative)

MaskedSlacker (911878) | more than 4 years ago | (#29753965)

You just failed physics. Congratulations.

There is no such thing as negative energy (without negative mass anyway).

What you're confusing with negative energy is relative energy--an object can be said to have negative potential energy if it has less potential energy than the arbitrary zero level. This is not the same thing as negative energy (any more than being in debt is having negative dollars, or being below 0 degrees Farenheit is having negative thermal energy).

Re:Maxwell Equations (4, Informative)

Ghostworks (991012) | more than 4 years ago | (#29753651)

Making the equations "symmetrical" for both electric and magnetic charges does not make them any more elegant or powerful

Discussion of the existence of monopoles or true magneto current -- seriously, people -- this sentence is glaringly false. In fact, the use of magnetic charge and magneto have been integral* to electromagnetic analysis for more than 50 years now. Using the symmetric form of Maxwell's equations. The fields created by all sources and media inside an arbitrary closed surface can be analogously modeled as charge and current distributions over the surface. This is what allows you to equivalently model the open end of a driven waveguide as a rectangular patch of magneto current, an electric dipole antenna as a "cigar band" of magneto current wrapping around the feed gap. All of which, I should add, makes the equations much easier to solve. Hell if nothing else the addition of a magnetic boundary conditions can allow numeric models to converge much more quickly.

Arguing that the phenomenon discovered does not truly uncover a magnetic monopole is one thing. Arguing that there is no benefit to symmetrical equations is as silly as that there is no benefit to expressing the equations in the "bastardly" phasor vector notation when a simple set of 12 differential equations of 12 variables would suffice.

*No pun intended.

Re:Maxwell Equations (0)

Anonymous Coward | more than 4 years ago | (#29753151)

Yeah, it's gauge theory and all the techniques used to actually solve Maxwell's equations that suffer. It would be the physicists crying.

Re:Maxwell Equations (3, Informative)

dlenmn (145080) | more than 4 years ago | (#29753173)

Maxwell's equations don't preclude magnetic monopoles

False. As you find them in a standard text book, they do exactly that. Div B = 0 [wikipedia.org] means no magnetic monopoles. That said, the standard equations can be easily modified [wikipedia.org] to accomodate magnetic monopoles (a few books do this -- Classical Electrodynamics by Julian Schwinger might be one).

ttp://en.wikipedia.org/wiki/Magnetic_monopole#Dirac.27s_quantization

Re:Maxwell Equations (3, Interesting)

Chris Burke (6130) | more than 4 years ago | (#29753257)

Okay, yes, I almost replied to myself to point out that the one equation based on the lack of the observation of magnetic monopoles would change. But none of the rest of the theory would change, and as you point out Maxwell's theory perfectly accommodates this change, so yeah, Maxwell's equations(plural) aren't "crying", except maybe with joy that now the expected symmetry has been discovered.

Re:Maxwell Equations (2, Informative)

Anonymous Coward | more than 4 years ago | (#29753431)

The reason you don't see Maxwell's Equations with magnetic charge in textbooks is because it's pointless to leave them in unless you're specifically looking at the problem of "how would X change if magnetic charge existed?". I happen to have a textbook that assumes magnetic charge throughout the entirety of the text (Balanis, Advanced Engineering Electromagnetics) It doesn't mean that the equations preclude it. Heck, in antenna analysis we model antennas using magnetic current/charge.

Re:Maxwell Equations (1)

MioTheGreat (926975) | more than 4 years ago | (#29753181)

Maxwell's equations don't preclude magnetic monopoles

Excuse me? Last time I checked, Maxwell's equations said that Delta B = 0.

Re:Maxwell Equations (1)

Chris Burke (6130) | more than 4 years ago | (#29753291)

That's an equation, note lack of plural, and it's based on the lack of observation of a monopole. Observe one, change that one equation, and the rest of the equations compensate nicely. Neither Maxwell nor his equations are "crying" because of the discovery of monopoles and magnetic current. The theory doesn't preclude them, it was simply based on observation (as science should be). It's not like we observed that c was different in a vacuum for different inertial observers, which would undo the entire theory of Special Relativity. Maxwell's theory is compatible with magnetic monopoles. That was my point.

Re:Maxwell Equations (2, Interesting)

seeker_1us (1203072) | more than 4 years ago | (#29753279)

No, they aren't. Maxwell's equations don't preclude magnetic monopoles or the movement of net magnetic 'charge' (aka 'current'). In fact it's always been a mystery why monopoles didn't appear to exist. There was no theoretical reason why they shouldn't, .

Yes and no. Its true that if you look at maxwells equations in the traditional form (with div and grad) the statement of no monopoles (Div B) is simply one of empirical observation: monopoles have not been seen.

However if you cast maxwells equations in differential forms [wikipedia.org] it becomes intuitively obvious why there are no magnetic monopoles. electricity is a one form. Magnetism is a two form. Two forms cannot come from monopoles.

Re:Maxwell Equations (2, Interesting)

Chris Burke (6130) | more than 4 years ago | (#29753339)

That's only an artifact of Maxwell's equations assuming there are no magnetic monopoles. Add them in, and the equations are perfectly symmetrical for electricity and magnetism, the only difference is the name of the variables and the quantities they represent are swapped. Their partial differentials are identical otherwise.

Electricity and magnetism are two aspects of the same force, electromagnetism. They are mediated by the same particle, the photon. The lack of symmetry in this one aspect is theoretically unnecessary, and philosophically kinda weird. That's not proof, of course. Demonstration of net magnetic charges is.

Re:Maxwell Equations (1)

Rick Bentley (988595) | more than 4 years ago | (#29753337)

What? Uhm, no.

Maxwell's 2nd equation, aka "Gauss' law for Magnetism", which is written in differential form as del * B = 0 (divergence of the magnetic field lines is zero). In integral form it's written as the double integral over a closed surface of the magnetic field lines is equal to zero).

Either way you look at it, that says "no magnetic monopoles". The law may need to be rewritten, but as written it does say no monopoles.

Re:Maxwell Equations (2, Interesting)

Chris Burke (6130) | more than 4 years ago | (#29753371)

The law may need to be rewritten, but as written it does say no monopoles.

Which is trivial to do, and doesn't contradict the rest of the theory, and hence they aren't "crying". The possibility of monopoles has been accepted for a very long time. It's simply the lack of experimental observation that ever caused them to be written in the first place. Re-write Maxwell's equations given the existence of 'magnetic charge', set that charge to always be zero, and you get the equations as written.

Maxwell's equations don't preclude the existence of monopoles. They are simply stated in terms that assume there aren't any based on the lack of evidence for them. His theory is fine, his equations are not "crying".

I don't understand why this is so hard to understand. Outside of the fact that you're all just being pedantic. I guess I should have said Maxwell's theory of electromagnetism.

Precludes vs assumes (2, Informative)

Chris Burke (6130) | more than 4 years ago | (#29753601)

Okay, I'm replying to myself as I thought I should immediately after posting the above.

Yes, Gauss's Law of Magnetism, one of Maxwell's Equations, says the magnetic field has zero divergence, meaning there is no net magnetic charge.

That is an assumption based on the lack of experimental evidence for a monopoles.

This does not mean Maxwell's Equations preclude the existence of monopoles, because they don't. What's the difference between precluding their existence, and presuming their non-existence? Well, let's look at something that is both assumed and precluded by theory: the speed of light being different for different inertial observers, and Special Relativity.

Special Relativity assumes c is constant for all inertial observers. It also precludes the possibility of that not being true, because the entire theory is based on that assumption, and falls apart if that assumption does not hold. All the equations of special relativity contradict observer-relative speed of light. If you ever discovered a case where this was not true, you would have to scrap Relativity and re-write the theory from scratch. That's precluding.

Maxwell's Equations assume net magnetic charge is zero, but if that assumption doesn't hold, then you simply have another term in the equations and you don't need to go back to the drawing board. Gauss' Law of Magnetism simply becomes a special case where net magnetic charge is zero (though this 'special' case is the most common case). You don't need to re-write the theory of electromagnetism. These researchers are not claiming to be re-writing the theory of electromagnetism, because the theory does not preclude magnetic monopoles.

Re:Maxwell Equations (1)

TekPolitik (147802) | more than 4 years ago | (#29754149)

Electricity and magnetism are symmetric in so many ways, it was odd that in this one way they weren't since they're ultimately aspects of the same force (electromagnetism).

And that, puny earthling, is why you are stuck on that backward planet. Even the stupid Omicron Persii 8 children know that electricity and magnetism are aspects of gravity. Blorga, it is time to go home.

Re:Maxwell Equations (2, Interesting)

physburn (1095481) | more than 4 years ago | (#29753201)

Maxwells equations are alive, magnetic flux [wikipedia.org] was already pretty much equivalent to a current. It even has its equivalent to Ohms Law, Hopkinson's Law: Magnetomotive force = Flux * Reluctance. A real monopole world add a source term to Maxwell's second equation, the Guass Law for magnetism. But its important to release that this aren't real monopoles, instead its a dipole with a almost invisible thing middle. Even in these Spin Ice crystal, Div B = 0 everywhere. See, Slashdot from earlier in the september [slashdot.org] .

---

Magnets and Magnetism [feeddistiller.com] Feed @ Feed Distiller [feeddistiller.com]

Current? (1)

tsotha (720379) | more than 4 years ago | (#29752751)

Magnet current? Like, in a transformer?

Re:Current? (0)

Anonymous Coward | more than 4 years ago | (#29752979)

In a word, no.

Re:Current? (2, Funny)

Tumbleweed (3706) | more than 4 years ago | (#29753031)

Magnet current? Like, in a transformer?

No, that's a 'spark'. Still, it might be disguised as a magnetic current.

Re:Current? (1)

Foobar of Borg (690622) | more than 4 years ago | (#29753391)

No, that's a 'spark'. Still, it might be disguised as a magnetic current.

GP may be thinking about magnetic circuits [wikipedia.org] which are used in electrical power system design. Magnetic flux is treated as current so you wind up with reluctance = [magneto-motive force]/[magnetic flux].

Re:Current? (0, Offtopic)

ezzthetic (976321) | more than 4 years ago | (#29753059)

No, silly. Transformers are only fictional robots on TV.

They don't exist in the real world.

aren't the 2 linked? (-1, Redundant)

timmarhy (659436) | more than 4 years ago | (#29752763)

isn't this explained by electromagentism already?

Re:aren't the 2 linked? (3, Informative)

Brian Gordon (987471) | more than 4 years ago | (#29752865)

Nope. Gauss's law [wikipedia.org] (electricity) has some nice formula while the corresponding Gauss's law for magnetism has a big fat zero.

If magnetic monopoles were taken into account, the magnetism one will have a nontrivial div like the electricity one.

Thank you wikipedia. Now I know to ask for for christmas: A Student's Guide to Maxwell's Equations! The amazon reviews are good. Let's learn together, slashdot. div grad curl too, in case old Maxwell's a little heavy with the vector calc

Re:aren't the 2 linked? (2, Insightful)

Anonymous Coward | more than 4 years ago | (#29753183)

The "Gauss' Law" for magnetism (in quotes because this isn't a universally accepted name) is commonly taken to be div(B) = 0, but that's not always the case. The law can be div(B) = rho_m (Gaussian units), where rho_m is the magnetic charge density, analogous to the rho_e electric charge density in Gauss' law. In this case there is also a non-zero J_m, magnetic current.

Basically, Maxwell's equations and the rest of EM theory accept a magnetic monopole freely, but as far as we have seen, none exist in nature. Paul Dirac has shown that the existence of magnetic monopoles would explain the quantization of electric charge.

Re:aren't the 2 linked? (3, Interesting)

mikael (484) | more than 4 years ago | (#29752943)

I think so. It sounds more like "electron holes" in semiconductors. The spin ice [wikipedia.org] contains tetrahedrons formed from ions. Because of this arrangement, adjacent ions must form a positive-negative pair, which then affects the way electrons spin and the resulting magnetic field. Bring in an external magnetic field and that runs the process in the opposite direction. That's where the storage idea comes from.

Magnetricity (0)

Anonymous Coward | more than 4 years ago | (#29752785)

Shouldn't it be magneticity?

Article Abstract (5, Informative)

Issildur03 (1173487) | more than 4 years ago | (#29752791)

Abstract from the actual paper [nature.com] :
"Electrically charged particles, such as the electron, are ubiquitous. In contrast, no elementary particles with a net magnetic charge have ever been observed, despite intensive and prolonged searches (see ref. 1 for example). We pursue an alternative strategy, namely that of realizing them not as elementary but rather as emergent particles—that is, as manifestations of the correlations present in a strongly interacting many-body system. The most prominent examples of emergent quasiparticles are the ones with fractional electric charge e/3 in quantum Hall physics. Here we propose that magnetic monopoles emerge in a class of exotic magnets known collectively as spin ice: the dipole moment of the underlying electronic degrees of freedom fractionalises into monopoles. This would account for a mysterious phase transition observed experimentally in spin ice in a magnetic field, which is a liquid–gas transition of the magnetic monopoles. These monopoles can also be detected by other means, for example, in an experiment modelled after the Stanford magnetic monopole search."

Re:Article Abstract (2, Funny)

Anonymous Coward | more than 4 years ago | (#29752849)

Ow, my head.

Re:Article Abstract (3, Funny)

cjfs (1253208) | more than 4 years ago | (#29752893)

Ow, my head.

Just put some spin ice on it.

Re:Article Abstract (0)

Anonymous Coward | more than 4 years ago | (#29752977)

But he's already got cold feet...

Re:Article Abstract (1, Funny)

Anonymous Coward | more than 4 years ago | (#29753021)

Great. Now his head will stop hurting and start spinning. It's like getting drunk and getting a hangover in reverse.

Startrek theory of science (-1, Troll)

Anonymous Coward | more than 4 years ago | (#29752927)

Oh, this is easy. Just some Technobabble explaining Technobabble

Re:Article Abstract (5, Informative)

bkpark (1253468) | more than 4 years ago | (#29753033)

Um. I think that's the wrong article. Look at the date: it's published in 2008; that's hardly news.

Here's the correct one [nature.com] published ... um, on 15th—probably in U.K., since it's still 14th here.

Re:Article Abstract (4, Interesting)

Interoperable (1651953) | more than 4 years ago | (#29753115)

Oh quasi-particles; on one hand you you think "well they're just mathematical constructs rather than physical things" but then you realize that regular particles fall into the same category. I heard of an interesting experiment where a Stern-Gerlach experiment [wikipedia.org] was conducted on a dark-state polariton [wikipedia.org] and resulted in the same effect as for nuclei. You can really only talk about how something behaves when a particular measurement is performed when treating it within whichever theory you're using, calling something a particle or a quasi-particle doesn't really matter.

"Discovered" magnetic current? (4, Interesting)

Anonymous Coward | more than 4 years ago | (#29752835)

If this is a discovery then why did I learn about this in my electromagnetics class I took a semester ago? And why did I have to work on problems with magnetic circuits if this phenomenom wasn't discovered yet?

Re:"Discovered" magnetic current? (1)

cjfs (1253208) | more than 4 years ago | (#29752965)

If this is a discovery then why did I learn about this in my electromagnetics class I took a semester ago? And why did I have to work on problems with magnetic circuits if this phenomenom wasn't discovered yet?

I think you know why [youtube.com] .

Re:"Discovered" magnetic current? (2, Interesting)

Rising Ape (1620461) | more than 4 years ago | (#29752985)

I'm pretty sure you didn't learn about a current of magnetic monopoles in electromagnetics class.

This is not the same as a normal current of electric monopoles (charges) producing a magnetic field.

Re:"Discovered" magnetic current? (1)

Garble Snarky (715674) | more than 4 years ago | (#29753555)

http://en.wikipedia.org/wiki/Maxwell's_equations#With_magnetic_monopoles [wikipedia.org]

based on the course I'm taking right now, its a pretty standard exercise in EM duality. It's extremely straightforward mathematically, and apparently the fictitious magnetic current sources can be useful for simplifying complicated electrical current geometries.

so... definitely not unreasonable to think that he learned about this.

Re:"Discovered" magnetic current? (4, Informative)

ReneeJade (1649107) | more than 4 years ago | (#29752989)

Magnetic circuit analysis deals with magnetic fields and magnetic flux etc. Not magnetic current in the sense that there is a displacement of magnetic monopoles analogous with the displacement of electric monopoles (e.g. delocalised electrons in a metal) that is electricity. It's a different idea. Yes, a magnetic field and a conductive "circuit" in a magnetic field can be analysed using a loose analogy to electricity, but the actual physical phenomena are not the same thing, unless these guys are on to something.

magnetic flux vs magnetic current (3, Informative)

slew (2918) | more than 4 years ago | (#29753817)

Well, in the interest of closing the loop, these aren't totally disjoint ideas ;^)

In the standard magnetic circuit with flux and field, the analogy between a magnetic circuit and an electrial circuit is

MMF = PATHINTEGRAL (H dot dl) vs EMF = PATHINTEGRAL(E dot dl)

Without any magnetic monopoles, this path integral that represents the magnetic circuit is merely analogous to a magnetic charge making a loop in the circuit creating a potential around the loop. Although this MMF is now taught as being generated by transformer/inductor coils wrapped around the magnetic circuit using the relationship MMF = N*i, but instead in a world with magnetic monopole current (i.e., magnetic current), in principle the same MMF relationships can be used.

Interestingly with magnetic monopoles this can also be extended like "electrical" circuit element.

R = dv/di, C = dq/dv, L = dF/di, M = dF/dq, i = dq/dt, and v = dF/dt

Historicall, only Resistance ~ Reluctance was the only one of the analogs that made sense w/o magnetic monopoles.
Now that we have magnetic monopoles, the other electrical circuit elements now have possible analogs in a magnetic circuit.

So this is actually a similar idea that shouldn't be dismissed out of hand.

Re:"Discovered" magnetic current? (1)

Korbeau (913903) | more than 4 years ago | (#29752999)

I learned about this TWO years ago.
And I'm FOURTEEN years old!

Re:"Discovered" magnetic current? (1)

black3d (1648913) | more than 4 years ago | (#29753099)

Then you weren't paying attention two years ago and don't realise this is the inverse to what you were learning about then.

Re:"Discovered" magnetic current? (1)

black3d (1648913) | more than 4 years ago | (#29753111)

To elaborate, what you learned about was ELECTRICAL currents being induced by MAGNETISM. The fundamentals of transformers, generators, electromagnets, etc. That is not what his article is about. Perhaps it is because you are 14 that you can't be bothered reading it.

Re:"Discovered" magnetic current? (1)

some_guy_88 (1306769) | more than 4 years ago | (#29753261)

Perhaps it is because you are 14 that you can't be bothered reading it.

That and he's a slashdotter

Re:"Discovered" magnetic current? (1)

socceroos (1374367) | more than 4 years ago | (#29753361)

You're fourteen and you've got a six digit account number?

.......

no, i won't say that...

Re:"Discovered" magnetic current? (1)

hoggoth (414195) | more than 4 years ago | (#29753629)

> I learned about this TWO years ago.
> And I'm FOURTEEN years old!

Well I'm TWELVE years old, and er um what is this?

Re:"Discovered" magnetic current? (0)

Anonymous Coward | more than 4 years ago | (#29753003)

If this is a discovery then why did I learn about this in my electromagnetics class I took a semester ago? And why did I have to work on problems with magnetic circuits if this phenomenom wasn't discovered yet?

your magnetic circuits most likely consisted of a high-mu toroid with some number of turns on one side, and some number of air gaps on the other side. then you set mu1 * H1 = mu2 * H2, and calculate all sorts of different values, right?

Nowhere does this simple model take into account magnetic charge. You just used plain old maxwell's equations, the constitutive relations, and maybe the lorentz force law.

Re:"Discovered" magnetic current? (0)

Anonymous Coward | more than 4 years ago | (#29753461)

I think you will fail your class if you think this article is related to your homework!

Haha your t-shirt is wrong (1, Funny)

Anonymous Coward | more than 4 years ago | (#29752919)

div B = rho_b

Magnetricity? (1)

transiit (33489) | more than 4 years ago | (#29752945)

Seriously? Magnetricity? That's the best name they could come up with? Really?

I hope if they can't do better figuring out what term to measure in it, they at least pander to the attention it would gather and call the unit "Colbert"

Re:Magnetricity? (1)

Chris Burke (6130) | more than 4 years ago | (#29752991)

Yeah I agree it sucks.

I think they should call it "Magnetocurrent", since whether he was aware of it or not Magneto has been creating magnetic currents since WWII. :)

Re:Magnetricity? (1)

ceoyoyo (59147) | more than 4 years ago | (#29753213)

Elect-ricity is moving elect-ric charges. Magnet-ricity is moving magnet-ic charges. Seems about as logical as you can get, while making the word actually pronounceable.

Oh no, Rick Berman just came in his pants... (4, Funny)

Mr. Roadkill (731328) | more than 4 years ago | (#29752993)

More buzzwords and concepts for Trek to abuse.


...that whizzing sound is my karma, flying out the window.

Whoa! (5, Funny)

neiras (723124) | more than 4 years ago | (#29753383)

...that whizzing sound is my karma, flying out the window.

You've discovered the karmic equivalent to electricity!

The phenomenon, dubbed "karmicity", could be used in meta-moderation or in troll suppression. There were previously no known particles in existence which carried karmic charges. A net-positive karmic particle is known as a karmon; a net-negative particle, a moron.

LHC, eat my shorts.

Re:Whoa! (1)

gmrath (751453) | more than 4 years ago | (#29753519)

How about calling the negative karmic particle a "less"-on since calling it a "mor"-on give it too much credit. . .

Re:Whoa! (2, Funny)

Thanshin (1188877) | more than 4 years ago | (#29753941)

"...And so, the development of karmon storage marks the end of the Just Age; where consequences always hit the originator of the action. i.e.: The karmiker and the karmiked where always one and the same."

"Mr. Johnson. What were khores paid for, then?"

"As you may know, the term "khore" comes from "karma whore". At that time, they were called just "whores" and they were paid in exchange for sexual favours."

"Like computers?"

"Yes, Jimmy. Exactly like computers."

Re:Oh no, Rick Berman just came in his pants... (0)

Anonymous Coward | more than 4 years ago | (#29753549)

Thankfully, that fuckwad has nothing to do with Star Trek! He's a fucking dolt. So's Brannon Bragga.

My CAPTCHA said "wreckers". How appropriate!

So this means (3, Funny)

Tablizer (95088) | more than 4 years ago | (#29753423)

...we're 0.00317% closer to flying cars!
 

Re:So this means (0, Offtopic)

buchner.johannes (1139593) | more than 4 years ago | (#29753609)

Remind me: Why do helicopters not qualify as flying cars?

Re:So this means (1, Insightful)

Anonymous Coward | more than 4 years ago | (#29753727)

Hey! I've an idea! Let's take an average car driver and stick 'em in a heli and see what happens!

Re:So this means (0)

Anonymous Coward | more than 4 years ago | (#29753795)

They don't make the sound.

Re:So this means (1)

DrSpock11 (993950) | more than 4 years ago | (#29754017)

Now we can look forward to the definitive source on scientific accuracy to test if they're really possible...

Mythbusters.

We're going up the tech tree! (4, Funny)

Anonymous Coward | more than 4 years ago | (#29753479)

So, what's the next breakthrough? According to the Alpha Centauri tech tree I'm reading, we can now research Unified Field Theory and Nanominiaturization now that we have Monopole Magnets!

so... (0)

Anonymous Coward | more than 4 years ago | (#29753627)

flying cars?

a tiny magnet is monopole (1)

bgd73 (1300953) | more than 4 years ago | (#29753797)

if a magnet is large enough to detect north and south, we can tell, but what if it isn't?

So what do the field lines look like? (2, Interesting)

Pfhorrest (545131) | more than 4 years ago | (#29753971)

The classic illustration of magnetic field lines is to put a big bar magnet on a table and sprinkle iron filings on and around it; they will end up tracing the magnetic field lines of the bar magnet.

So say they could construct the monopole equivalent of such a bar magnet, just one big lump of North or South. If we put that on a table and sprinkled iron filings on and around it, what (if any) lines would they end up tracing? Just rays away from the monopole?

spin ice doesnt violate div B =0 (0)

Anonymous Coward | more than 4 years ago | (#29754215)

In spin ice "monopoles" lines of "molecular bar magnets" line up head-to-tail to form a tetrahedral network of "pipes" along which a flux much less than h/e can be said to flow,

Usually, at each lattice point of the spin-ice pyrochlore structure two pipes have inward flowing flux, and two have outward flowing flux.
At a "monopole-like" defect, three flow in and one flows out (or vice versa) and the excess flux sprays out from the defect in all directions, looking like there
was a monopole there. This radial flux is not quantized and much less than the dirac monopole flux

  The monopole looks like

                                                                SNSN*NSNSNS

                                                                                .
(from an anonymous physicist who knows about the spin-ice/pyrochlore work)

macroscopic? (0)

Anonymous Coward | more than 4 years ago | (#29754249)

if it's only working inside some material (spin ice), then it appears to me that the magnetic charge it is not truly a fundamental particle, but some macroscopic effect is at work...
anyone who can explain what is really going on? why can this magnetic effect only be shown inside spin ice?

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account

Loading...