Making Magnetic Monopoles and Other Physics Exotica

PhysicsDavid writes "Physicists have been searching for magnetic monopoles pretty much since they knew about magnetism and definitely since Maxwell unified electricity and magnetism. Now some researchers have shown that using some weird mirror materials will allow them to create something indistinguishable from a monopole in a lab experiment. A paper about it was published today in the journal Science as an advance online publication (abstract; full article available only to AAAS members). The technique looks like it could be used to create analog systems of other kinds of exotic particles that haven't yet been observed, such as axions. The theorists who proposed this are working with experimenters to try to create these systems and study them in depth this year."

Comments

Multiple monopoles?

[ErroneousBee]

I thought there was only one magnetic monopole, and one photon, in this universe.

Re:Multiple monopoles?

[digitrev]

Umm, what brought you to that conclusion? We're fairly certain that there are multiple photons, and no evidence of magnetic monopoles.

Re:Multiple monopoles?

[Anonymous Coward]

I can see how you might confuse photons with zune users.

Re:Multiple monopoles?

[SQLGuru]

Given the state of today's English language usage, I assume that there was confusion between Monopole and Monopoly. But I'm with you on the "WTF about only one photon" part.

Re:Multiple monopoles?

[geckipede]

I think he is referring to the way that Feynmann diagrams allow you to represent an antiparticle as being a particle moving backwards in time. A particle/antiparticle pair then just becomes one particle going forwards and backwards in a loop. There was some talk that this way of looking at it may be physically real and that all particles are one, but taking a really circuitious route through time. It doesn't hold up well because there isn't enough antimatter around to allow it as far as we can see. I'm not sure it was ever supposed to apply to photons in any case.

Re:Multiple monopoles?

[MikTheUser]

I'm not sure it was ever supposed to apply to photons in any case.

Probably not, since photons, being their own antiparticles, never had arrows attached to them in Feynman graphs to begin with.

Re:Multiple monopoles?

[ErroneousBee]

I thought it still sort of worked for photons, cos they are their own anti-particle.

My party piece is to bore anyone who will listen with an argument that the universe only needs one photon travelling backwards and forwards in time.

But the WTFs are usually reserved for the followup where I set fire to my head.

Re:Multiple monopoles?

[morgan_greywolf]

But the WTFs are usually reserved for the followup where I set fire to my head.

Which won't actually hurt since there's only one photon in the universe anyway.

Re:Multiple monopoles?

[Anonymous Coward]

Suppose the big-bang happened n years ago. Perhaps all the missing anti-matter is located in time at 2*n years ago and moving backwards at the same rate that we are moving forward. Is there some reason to assume that it would all be distributed uniformly through space-time? It seems more likely to me that it would all exist in clusters because if matter touches anti-matter, we all know what happens.

Re:Multiple monopoles?

[Anonymous Coward]

cos they are their own anti-particle

Photons: My anti-particle.

Re:Multiple monopoles?

[Anonymous Coward]

there's only one photon in the universe anyway.

I guess now we know which poster Gene Ray isn't.

Re:Multiple monopoles?

[Anonymous Coward]

All the anti-matter in the universe is moving backwards in time and therefore indistinguishable from ordinary matter. Obviously.

nobel

[tritonman]

I think this would be a no-brainer for the nobel prize if they can really make something equivalent to a magnetic monopole.

Re:nobel

[digitrev]

Absolutely. The better part is what this would mean for Maxwell's equations. If it turns out that you can create something indistinguishable from a magnetic monopole, then we have to start some very serious research into the implications.

Re:nobel

[corsec67]

then we have to start some very serious research into the implications.

Traveling north or south becomes much cheaper than heading east or west?

Re:nobel

[MikTheUser]

It wouldn't matter much at all to Maxwell's equations. The model is well fit to accommodate magnetic monopoles, if the

div B = 0

equation were modified to read, say

div B = rho_m / mu_0

in analogy to Gauss' law. The defining qualities of Maxwell's model, such as the compliance with relativity, would remain intact.

For further reading on this, David J. Griffiths' 'Introduction to Electrodynamics' is many a professor's first recommendation to students.

Re:nobel

[SciBrad]

Well in a sense it is already known how the Maxwell equations would transform with hypothetical monopoles (you get the divergence of B to look like the divergence of E and there is a "monopole current" term in the curl of E equation). In any region where there isn't a monopole everything would remain the same, so nothing already known changes. But for regions where we'd have these monopole like things quite a few equations where you wind up with div B would become more interesting to say the least!

Re:nobel

[digitrev]

Ahh, good ol' Griffiths. How I agonized over the problems in that book. I suppose that would work, but it I still think the implications are far reaching. I mean, Maxwell's equations at the core of much of the technology we rely on today. To think that we might be able to do even more is impressive.

Re:nobel

[cc1984_]

Not sure how well a monopole would fit with my view of the world.

Sure, the equations would be symmetrical, but since the field is not necessarily continuous, you could get energy for nothing (imagine that monopole following the field lines around a current carrying wire, getting faster and faster because of the infinite potential in the wire.)

But then again, I don't know any covarient e-mag, so there might be a gap in my knowledge.

Re:nobel

[tenco]

You can do this even without having real monopoles by gauging the equations so that every mass which has electromagnetic charge has a certain amount of electric and magnetic charge (gauge invariance of Maxwell's Equations). For this, the ratio of electric charge to magnetic charge has to be equal for all these masses. This will make the equations symmetrical.

So I'm wondering how the equations will change if there's a real magnetic charge. Does this case distinguish itself from the gauge case in any way?

Re:nobel

[tenco]

(gauge invariance of Maxwell's Equations)

This should be "gauge invariance of electrodynamics". The equations will change for a different gauge, as I wrote later on.

Re:nobel

[pla]

Traveling north or south becomes much cheaper than heading east or west?

Bigger than that... A real magnetic monopole means real over-unity generators (aka "perpetual motion", aka "free energy"). That alone makes me take this "discovery" with a grain of salt the size of Bonneville.

If this amounts to more than sloppy science or outright fraud, I would guess that it comes with the same sort of huge disclaimer that quantum teleportation has regarding FTL information transmission - "It just doesn't work that way".

Re:nobel

[Artraze]

The implications for Maxwell's equations is basically nil. Why? Because div_B=0 works perfectly for every application yet encountered. Thus, regardless of what div_B may end up being once monopoles are accounted for it'll end up being zero basically 100% of the time, unless someone wants to throw a monopole into the situation (on purpose) to spice things up a little.

That being said, it's not really like monopoles do anything much in the context of ME since magnetic fields only matter if they're varying, and it's not like they offer a whole lot of possibilities that dipoles don't. (But I'm sure if they are discovered for real someone will come up with a use for them.)

Re:nobel

[wsherman]

Bigger than that... A real magnetic monopole means real over-unity generators (aka "perpetual motion", aka "free energy").

I had actually been wondering about that myself. Do you have a reference? I did some google searches and looked over the Wikipedia page on magnetic monopoles but didn't see anything about magnetic monopoles violating the laws of thermodynamics.

There's a chance that a magnetic monopole might allow static magnetic levitation (Earnshaw's Theorem) but I haven't actually seen anything definitive on that either so it's pure speculation on my part.

Re:nobel

[wsherman]

Sure, the equations would be symmetrical, but since the field is not necessarily continuous,...

I was wondering similar things myself but then I got to thinking that the field would only be discontinuous in the classical approximation of a point "charge" and that you'd have to mess with quantum and wave functions to really understand what was going on.

... you could get energy for nothing (imagine that monopole following the field lines around a current carrying wire, getting faster and faster because of the infinite potential in the wire.)

The question of how a magnetic monopole would interact with an external magnetic field is quite interesting but also rather tricky. I assume that there are physicists who have worked it all out precisely but, just off the top of my head, it's not obvious to me what would happen.

Whereas an electric field can be thought of as the force on a test (electric) charge, the meaning of a magnetic field is quite a bit more complicated. For one thing, the force depends on the orientation of the test dipole but, more fundamentally, in a certain informal sense, it is actually the gradient of the magnetic field that determines the force on the dipole.

That is, the magnetic field vectors themselves don't actually indicate the direction of force on a test dipole. In particular, a spatially uniform field (for example, inside a solenoid) will not actually exert any force on a test dipole.

So, what happens to a magnetic monopole in an external magnetic field? The more I think about it the more I realize that I have no idea.

Re:nobel

[nospam007]

Sorry for RTFA but it just says, somebody had an idea that a certain theoretically existing matter could help doing such a thing, if it existed and if somebody would identify it.

Re:nobel

[evanbd]

[[citation needed]]

Re:nobel

[logicnazi]

I think the point was that if there were magnetic monopoles then Maxwell's equations would be even more elegant because there would be more symmetry between the electric and magnetic fields.

Re:nobel

[OldFish]

Actually, there is already a way of hiding the apparent lack of magnetic monopoles in Maxwell's equations. You can write them in a symmetric form and everything works just fine without the distinction between electric and magnetic monopoles. The lack of monopoles implies that the ratio of magnetic "charge" to electric charge is a constant. The observation of a free monopole could be sorta cool.

Re:nobel

[amRadioHed]

How's that? Electric charges and gravity behave like monopoles but they don't result in perpetual motion. How would a magnetic monopole be different?

Re:nobel

[Anonymous Coward]

A moving magnetic charge would induce a current in the wire, eventually equal and counterbalanced to the current initially flowing in it. Much like a electric charge moving in a magnetic field induces its own magnetic field counter to the existing one (think what happens in a transformer as you pull current from it).

Btw, IANAP

Re:nobel

[Anonymous Coward]

Are you implying that the existence of a monopole violates conservation of energy? Because it most certainly isn't the case. The electromagnetic stress tensor will probably change form and stuff like that, but conservation of energy still is there.

When you get down to it, you can see how beautiful a duality symmetry like this would be. By its nature it would mean that electric and magnetic phenomena are indistinguishable. We just call one the E and the other the B field. But magnetic monopoles have not been found and we _have_ a way to distinguish electric and magnetic forces.
Another nice thing if a monopole was found would be that it would account for the quantisation of charge as well, as shown by Dirac (AFAIK this relies on angular momentum conseration).

Re:nobel

[Anonymous Coward]

Even quantum mechanically, even field-theoretically as far as I'm aware, leptons are point particles (i.e. don't abuse uncertainty principle).

Monopoles interacting with a magnetic field is not tricky - it's like a electric charge in an electric field.

Re:nobel

[Anonymous Coward]

That's what the Martians thought until they sucked all the magnetic energy out of their core. Luckily they had enough energy to make it to the blue planet, where they genetically altered the local wildlife to become compatible... oh wait I think I've said too much.

Re:nobel

[Anonymous Coward]

yeah, there was this company (geeze 10 years already?) in grass valley ca called Hydroplus Technologies (hpt research inc.) They showed us some stuff they had accidentally stumbled upon while researching to do acid mine drainage at berkely pit and iron mountain near redding (highest natural ph on earth, super fund site...) i think.

anyway they had 2 strange things. magnetic monopoles and a tech using that to basically assign where valence electrons sit making them behave very strangely... like strong acids or bases. i didn't really belive them until i went up there and saw a off the scale litmus test and then saw the demonstrator (and ceo) pour it on his hand. and played with monopole magnets.... weird as hell. they had been sending samples to Lawerence livermore to find out exactly what they had stumbled upon and the LLL guys basically shit a brick.

shortly after that they started getting shot at (like black-suburbans-in-their-driveway, bullets-through-windshield style) by who knows who and their ceo was living in constant fear. i don't know what happend to them after that. as we'd finished our web design contract with them and then we went out of business shortly after that.. moved etc.

strangely, i was actually just trying to look them up yesterday to see if i could go back up there as they were one of my first web design projects and besides they changed all i ever thought i knew about physics. I cant find hardly a thing left over on the net. basically just some references to their old address...

i know it sounds like a bad sci fi movie but there's a true story for ya. f'ing blew my mind. oh, and mr overton, if you're still out there... i think i just violated our nda. hope you're still alive!
-S (posted anon. obviously.)

Re:nobel

[Anonymous Coward]

Holy shit!!!!
apparently blue sky tech is using their tech...
and Steve Wurzburger is on their board!

page 4 has the reference to HPT on the image lower right///

http://www.blueskytechnologies.biz/HydrocarbonMTBERemoval%20.pdf

-S

Re:nobel

[pla]

How's that? Electric charges and gravity behave like monopoles but they don't result in perpetual motion. How would a magnetic monopole be different?

We do extract work from electric "monopoles", with the annoying problem that they weaken proportional to the amount of energy you extract energy from them - Except at the level of single electrons, which we currently only know how to herd into tiny channels and use in a way not much more elegant than how a waterwheel or pneumatic drill works.

We extract quite a lot of energy from Gravitational "monopoles" (see "Hoover Dam"), which have the perk of not weakening over time (that we know of)... Of course, they also have the down side of requiring a planet-sized body to have any useful strength, and we can't seem to turn them off or attenuate the field in any meaningful way (the "hard" required step for a self-resetting gravity generator).

But a magnetic monopole! Small enough to work with in a relatively normal environment (but not so small that we can only refer to its position in terms of probability), they don't weaken with use, and we do know how to block (or at least redirect) magnetic fields!

Re:nobel

[Anonymous Coward]

Bigger than that... A real magnetic monopole means real over-unity
generators (aka "perpetual motion", aka "free energy"). That alone makes me take
this "discovery" with a grain of salt the size of Bonneville.

That would only be true in the case where one can control the polarity of the monopole at will (after motion has begun). Doing so, may not be possible.

Re:nobel

[amRadioHed]

These have nothing to do with perpetual motion. For instance, the Hoover Dam harness energy that ultimately came from the sun.

Re:nobel

[vlm]

There's a chance that a magnetic monopole might allow static magnetic levitation (Earnshaw's Theorem)

http://sci-toys.com/scitoys/scitoys/magnets/pyrolytic_graphite.html

Everyone knows about diamagnetic levitation, but Earnshaw specifically doesnt apply to diamagnetic materials.

http://en.wikipedia.org/wiki/Earnshaw's_theorem

This will be great!

[Anonymous Coward]

Whenever I play in the car the pieces end up flying all over, so yeah, magnetic Monopoly would be great!

Not really "indistinguishable"

[Roger W Moore]

If it turns out that you can create something indistinguishable from a magnetic monopole, then we have to start some very serious research into the implications.

This is "indistinguishable" from a monopole in the same way that an image in a mirror is "indistinguishable" from the real object. While extremely interesting there will be bound to be edge effects given the finite size of the mirror and there must physically be a second pole somewhere because the material cannot spontaneously acquire a net magnetic charge...unless there is some significant new physics occuring. Hence I would take "indistinguishable" with a very large grain of salt. It is an extremely interesting result though.

How Maxwell's Equations would change

[Talisein]

My physics teacher used to talk about how the equations would change. del dot B would equal some measure of magnetic charge density rather than zero, while del x E would equal the partial of B wrt t + some measure of magnetic current density.

Basically the equations just become more symmetric; electric charge has monopoles after all. Certainly there will be a wide range of implications.

Re:How Maxwell's Equations would change

[Anonymous Coward]

Most notably, if even a single magnetic monopole exists in the universe, electric charge quantization is the result, as shown by Dirac in 1931. We currently don't really actually know why the hell things are quantized, so that would be ...interesting. If anything, it's a bit peculiar that electric charge is quantized given that we haven't seen magnetic monopoles to date (of course if electric charge wasn't quantized we wouldn't exist... but anyway...)

Quantization in general is weird and inelegant and ugly (the maths is just horrible and shitty compared to the pure background-independent elegance of general relativity or einstein-cartan (general relativity with spin, basically)), but demonstration of the existence of magnetic monopoles would go some way to making it less ugly.

instructables

[gEvil (beta)]

There's an instructable for making magnetic Monopoly right here. As for finding the physics erotica, your on your own--I'm at work right now...

Re:instructables

[Anonymous Coward]

I invoke Rule 34

Re:instructables

[Chris Burke]

Geeze, you're such a monopole.

Searching for magnetic monopoles?

[shawn(at)fsu]

That's easy. Take a regular magnet and cut it in half, gees do I have to do all the heavy thinking around here.

Re:Searching for magnetic monopoles?

[Chris Burke]

Take a regular magnet and cut it in half, gees do I have to do all the heavy thinking around here.

Well I'm handling all the heavy drinking so somebody has got to pick up the slack.

Re:Searching for magnetic monopoles?

[shawn(at)fsu]

comments like that put you on my friend list.

Monopole Magnets at last!

[rk]

Now, do we go for Unified Field Theory and get tachyon bolt weapons, or Nanominiaturization and score the hovertank chassis?

Re:Monopole Magnets at last!

[Anonymous Coward]

I'm just waiting for Centauri Genetics, but I'd settle for Controlled Singularity.

Re:Monopole Magnets at last!

[Anonymous Coward]

Screw having smart robots or flying cars, where's my personal spaceship? Dammit! I'm sure if they can figure out this one, then it shouldn't be too far until they can figure out applied gravitics. Just a matter of figuring out where the dimensional relationships lie, and then applying complex number math to account for some of the quantum behavior stuff. (Stuff that blinks in and out may be hopping dimensional domains rather than just being some probability related anomaly.) If they can make magnetic monopoles, and do stuff like make microsingularities, then figuring out the n-dimensionality of space isn't too far off. Then it should be possible to de-superimpose gravity using the discovered dimensional set from a "monopole" into subdomains. Then you can figure out fun things like having two "null-force" generators creating a negative potential field and things like that. (Perhaps some of that scalar stuff might not be quite as wacky as it had seemed.)

But mainly, it would be fun to get out there, just to see just how good or bad earth has it. Until I get my spaceship, that's not an option yet.

This was one of the issues with the SSC...

[inviolet]

The Superconducting Super-Collider to be built in Texas fifteen years ago used magnetic monopoles in its design. In my physics class in 1991 we received a lecture visit from an SSC representative who casually hand-waved the matter of inventing such a thing.

In hindsight I see that perhaps the SSC project really was as overpromised as Congress, in cancelling it, suspected.

Re:This was one of the issues with the SSC...

[meringuoid]

The Superconducting Super-Collider to be built in Texas fifteen years ago used magnetic monopoles in its design. In my physics class in 1991 we received a lecture visit from an SSC representative who casually hand-waved the matter of inventing such a thing.

Er, wow. Citation? The SSC was pushing the boundaries all right - the clue's in the name, superconducting, and that's difficult to do even now as witness the LHC explosion - but I hadn't heard that it would have used magnetic monopoles. Possibly it might have hoped to create magnetic monopoles in some exotic collision, but not to have them as part of its structure.

Re:This was one of the issues with the SSC...

[Hartree]

The guy from the SSC was probably mentioning magnetic quadrupoles which are an assembly of electromagnets used to confine the beam.

The SSC certainly didn't use magnetic monopoles in its design.

Conservation of energy is broken?

[mpoon]

I was reading TFA that was linked, and the author said something about the monopole inducing a current "without dying out." So I presume that he is using some sort of metal in a device to test this current. If the current doesn't die out, isn't there constant heat loss in the metal due to resistance from the current? Where is that heat loss made up, concerning conservation of energy?

Re:Conservation of energy is broken?

[OolimPhon]

That would be why it's called a superconductor.

Re:Conservation of energy is broken?

[Anonymous Coward]

I was reading TFA that was linked, and the author said something about the monopole inducing a current "without dying out."

So I presume that he is using some sort of metal in a device to test this current. If the current doesn't die out, isn't there constant heat loss in the metal due to resistance from the current? Where is that heat loss made up, concerning conservation of energy?

I'm guessing the material superconducts, or that that's the way the reporter interprets all the electron's spins going in the same direction.

I'm guessing the electrons/currents arrange themselves in some sort of microscopical coil, or maybe a spherical coil (south charge inside, north oustide). It'd be interesting what use can come of this, and how transient the effect is (does the image magnet attract the real electron and make it fall in/out? In how long?)

thinking about magnets...

[hort_wort]

I never really got the idea of magnetic monopoles. I studied them for a couple weeks, but they just seem so intuitively wrong. Magnetic fields are caused by electrons moving... but if you have a monopole, that's like saying that you have electrons going somewhere but coming from nowhere. Or coming from somewhere and going to nowhere. This isn't possible though because energy is conserved -- even if you blew up the electron, it'd still just turn into waves that are still there. It is a fundamentally flawed idea.

I'm not saying mag monopoles are impossible, but it would take a drastic rewrite of everything we "know" to get it to work. Yes, yes, I know Maxwell's equations can be modified to get them to work, but so what? Remember when you studied aether as an undergrad before relativity? Same thing here -- an idea that is most likely wrong, but you can still play with it for mental exercise. Plus a bunch of physicists just love to try to find it because it's an automatic Nobel prize if they pull it off.

Re:thinking about magnets...

[DahGhostfacedFiddlah]

Magnetic fields are caused by electrons moving

Are you sure? Maybe the point-"particle" phenomenon known as "the electron" is simply the result of a self-perpetuating magnetic field.

Re:thinking about magnets...

[hort_wort]

Yes, electrons could be thought of as a field. I'm trying to keep things simple for the non-physicists in the audience. Electricity and magnetism is always covered together. One is always the result of the movement of the other. Look up "right-hand-rule" if you want to see how they relate....

How I managed to get a "troll" mod by pointing out the highschool level understanding of magnetic fields is beyond me though. Notice whoever modded me couldn't make an argument against what I said though. Lame. You guys could at least troll me for actually saying something offensive, like "Beta tapes used magnetic monopoles -- but they suck so we just ignore them."

Re:thinking about magnets...

[omnichad]

So the electrons are coming from an alternate universe? Free energy for everyone! Until it totally destroys a solar system.

Re:thinking about magnets...

[bar-agent]

Yes, electrons could be thought of as a field. I'm trying to keep things simple for the non-physicists in the audience.

Perhaps it isn't that electrons can be thought of as a magnetic field, so much as they are a magnetic field. I don't have doctorate-level physics, but I think that's what the GP was saying.

Monopoles Are Easy

[camperdave]

Magnetic monopoles are easy. Take an iron sphere, cut it in half. Cut those hemispheres in half, then cut those lunes in half. Magnetize them all the same way, say N at the point and S at the surface, then reassemble the sphere. Voila, a S monopole.

Re:Monopoles Are Easy

[zehaeva]

except that you couldn't keep the sphere together, all the norths in the center would repel and blow the sphere apart.

Re:Monopoles Are Easy

[Chris Burke]

Not if the magnetic field is weaker than whatever you use to hold them together.

Re:Monopoles Are Easy

[camperdave]

I'll just get Chuck Norris to hold them together.

Re:Monopoles Are Easy

[Victor Liu]

That most certainly does not result in a monopole. You'd get a quadrupole I think.

Re:Monopoles Are Easy

[MorePower]

I'm no physicist, but my instincts as an electrical engineer tell me that the flux lines from the north poles would wedge themselves into the cracks between each of the pieces in an effort to close the loop. Probably this very dense flux would forcibly re-magnetize the edges of each iron piece so that the surface of the assembled sphere would be S in the middle of each piece and N all around the edges.

Any physicists want to chip in and confirm or debunk this?

Re:Monopoles Are Easy

[wsherman]

I'm no physicist either but what you say sounds right at a practical level.

At a theoretical level, I strongly suspect that everything would cancel out. That is, as long as the magnetization is spherically symmetric, there will be no magnetic field outside the sphere.

Re:Monopoles Are Easy

[Anonymous Coward]

I'll just get Chuck Norris to hold them together.

You're un-fucking funny.

Re:Monopoles Are Easy

[cryptocom]

Not true at all. I've done something similar. I took two ring shaped magnets and superglued the repelling poles together using a plastic clamp. After the glue had set, the entire assembly was attractive on all sides, but the space in the center repelled objects inserted there. Bingo. Monopole. No exploding necessary.

Monopole magnets are not hard

[philspear]

I can't believe people are having a hard time with this. It's easy! Just cut off the pole you don't want!

Geez!

Re:Monopole magnets are not hard

[Anonymous Coward]

Somehow, I think all of the slashdot readers from Poland are a bit uneasy about being cut off...

Re:Monopole magnets are not hard

[Mindwarp]

Hey - you're not meant to complain about Slashdot Pole options!

Re:Monopole magnets are not hard

[Anonymous Coward]

Lorena Bobbitt was a physicist ???

Re:Monopole magnets are not hard

[Anonymous Coward]

No need. Just wrap the other pole in tinfoil.

I used to use magnetic monopoles

[goombah99]

Back when I was designing magnetic bubble memory we used to use monopole equations to represent the bubbles.

No violation of physics here because they were always paired. But the pairs in the media are well separated so it's a btter approximation to use two monopoles than a dipole.

That is to say, each bubble is really a cyllinder running from the bottom of the thin film to the top just like it is in vertical recording HD. You can treat the top as a monopole and the bottom as an opposite monopole and get a very good model of bubble-to-bubble interactions.

But how good an objection is that?

[Giant Electronic Bra]

I mean it is true we do not OBSERVE much antimatter in this universe, but that doesn't mean it is not present in some sense:

A) It could be in some other part of the universe beyond our effective observational horizon. Granted there are some reasons to think not, but it is a possibility.

B) It could be that the antimatter simply exists in some 'other place'. Given that we haven't at all settled the actual architecture of spacetime, it could be that the antimatter is in a location which is either topologically distant/inaccessible or in dimensions not readily visible to us.

C) Antimatter could be segregated in a different part of time itself. If we imagined that the arrow of time in our universe reverses every now and then, some form of oscillating universe, then perhaps we would find that when time runs backwards, matter looks like antimatter and that may balance the books.

Not being a cosmologist or high energy physicist I don't have the wherewithal to analyze these various possibilities, maybe some of them are ridiculous on the face of them or there may be other more obvious or simple solutions, but it seems there are probably ample unknowns out of which to construct hypotheses along these lines.

Given that we could answer the 'where's the antimatter' question, then how would it even be meaningful to say there is 'more than one electron' in the universe vs 'there is one electron/antielectron with a very convolved history'? It would likely be a case of 6 of one and half a dozen of the other.

Re:But how good an objection is that?

[hesiod]

I mean it is true we do not OBSERVE much antimatter in this universe, but that doesn't mean it is not present in some sense:

Perhaps it's all clumped together at another point on the time loop. Once the largest antimatter clump and largest matter clump come back together in the time loop, there's a big bang.

What? No, I don't have any idea what I'm talking about, thank you.

Re:But how good an objection is that?

[Nazlfrag]

Why not? When the big bang banged, it sent the universe hurling in every other direction, so why not both forward in time and backward in time. Of course, antimatter running backwards through time is identical to matter running forwards, thereby creating the parallel universe where everything is the same except that evil is good and they all have goatee beards.

Re:But how good an objection is that?

[nusuth]

I mean it is true we do not OBSERVE much antimatter in this universe, but that doesn't mean it is not present in some sense:

A) It could be in some other part of the universe beyond our effective observational horizon. Granted there are some reasons to think not, but it is a possibility.

B) It could be that the antimatter simply exists in some 'other place'. Given that we haven't at all settled the actual architecture of spacetime, it could be that the antimatter is in a location which is either topologically distant/inaccessible or in dimensions not readily visible to us.

C) Antimatter could be segregated in a different part of time itself. If we imagined that the arrow of time in our universe reverses every now and then, some form of oscillating universe, then perhaps we would find that when time runs backwards, matter looks like antimatter and that may balance the books.

All of that could happen. Perhaps it is just that our assumptions about how antimatter looks from distance is flawed. Or it may be just that we have a matter bias in our minds and refuse to see evidence of antimatter around us. Or mighty invisible aliens controlling our experiments may be rigging them to conceal the fact antimatter is plenty... Once you start making hypotheses based on what we don't know, don't observe or can't observe, matter-antimatter asymmetry ceases to be a problem, but I hope you realize your explanations also cease to have any scientific value whatsoever.

Re:But how good an objection is that?

[hesiod]

parallel universe where everything is the same except that evil is good and they all have goatee beards.

At first I read that as "goatse beards" and though "Boy, that is evil!"

Valentine Day's particle

[hsunami]

Just in time for Valentine's Day!

I still don't get the concept of a Monopole

[pugugly]

I'm sure I'm ascribing an incorrect visualization to the phenomena, but my image of a magnetic pole is that of a motion in liquid - like a propeller in water - line two propeller in a row, and they will work in sync pulling water from the input to the output, put two propellors face to face, and they will 'repulse' each other, i.e. create a high pressure region.

I've always visualized the lines of force in magnets as the same thing, with electrons. Which can't really be right, because if that were the case, then a monopole would be an obvious paradox - a 'one way' line of force with an output but no input - which makes no sense whatsoever.

Obviously either I'm just smarter than Paul Dirac, or there's something obvious about magnetism I just don't get - and even I am not egotistical to pretend that I have those listed in order of likelihood -{G}.

Pug

Re:I still don't get the concept of a Monopole

[wsherman]

I'm sure I'm ascribing an incorrect visualization to the phenomena, but my image of a magnetic pole is that of a motion in liquid - like a propeller in water - ...

Just to add my two cents, I visualize a magnetic field as three superimposed scalar fields of potential energy.

Classically, potential energy is the integral of force with respect to distance or, equivalently, force is the derivative of potential energy with respect to distance. To use slightly more sophisticated language, force is the gradient of the potential. In three dimensions, imagine a room with hot spots and cold spots. The temperature would correspond to the (scalar) potential energy (field) and arrows indicating changes from hot to cold would correspond to the (vector) force field.

Anyway, an electric field is a force field (rather than a potential (energy) field). The vectors of an electric field give the force on a test charge.

In contrast, a magnetic field is (the superposition of) three potential (energy) fields. Essentially, the orientation of the test magnetic dipole selects which of the three potential energy fields the dipole is interacting with. Further, to rotate the magnetic dipole requires exactly as much energy as the difference between the potential energy fields that are selected.

So, anyway once the orientation of the magnetic dipole has selected a particular combination of the three potential fields to interact with, the translational (as opposed to rotational) force on the dipole will actually be a combination of the gradients of those three potential fields.

To summarize, electric fields give the force on a test particle while a magnetic fields give the (potential) energy of a test particle.

Re:I still don't get the concept of a Monopole

[paulgrant]

Picture putting your propeller against a solid wall (negative pressure region towards the wall)
Picture your propeller developing such a high pull that it literally sucks material through the wall (or in the proposed case above, from surrounding regions of the wall similar to ground effect in aerodynamics)

Magnetic monopole ;)

Magnetism (the movement of electrons) is usually limited to the surface of a material (or some penetration depth thereof depending on field strength). in essence what you want is a positive (or negative) pressure differential without experiencing both at the same time ;) this could be accomplished with the theoretical wall structure listed above (positive pressure exists only because the negative pressure is eliminated bya constant source of free electrons).

Re:I still don't get the concept of a Monopole

[Anonymous Coward]

But if there was a monopole, it would be a force field.

div B = 0 means there are no point sources of magnetic fields. I interpret this as an extra restriction on magnetic fields. Electric fields can have div D = 0 if there are no charges nearby, and would have the same restrictions that are always imposed on magnetic fields.

Re:I still don't get the concept of a Monopole

[Anonymous Coward]

what the heck are you trying to express?

magnetic monopole, Dirac, charge quantization

[Anonymous Coward]

I think Dirac also showed that the existence of a single magnetic monopole would explain charge quantization.

Alpha Centauri

[Arancaytar]

So does that mean we can expect to travel around by mag tube any time soon? :D

Link to full article

[Pope Raymond Lama]

I guess /.'rs aren't that excied about these news, or I am certain the legal link for the full PDF paper would have been posted already, as it lies right there in Google

Re:Link to full article

[n6kuy]

That's for the supplementary stuff.

This link works for me for the main article. But that may be because of where I work.

monopole?

[ILuvRamen]

I heard a rumor that the first person to make a true monopole gets a get out of jail free card...what? that's spelled differently? Eh, whatever

MOD PARENT -1, UNFUNNY

[Anonymous Coward]

chuck norris? really? in 2009. it's not funny any more loser.

Re:MOD PARENT -1, UNFUNNY

[rhombic]

Obviously only Barak Obama can hold them together.

And then only Ted Nugent could blow them apart again.

Re:MOD PARENT -1, UNFUNNY

[Anonymous Coward]

Are you trying to say that Chuck Norris is to old to hold a monopole together?

I'm confused

[Anonymous Coward]

Aren't monopoles illegal?

Maybe cannot observe now

[Giant Electronic Bra]

Any hypothesis would have to make predictions which could be observed, it would have to be falsifiable. I am not suggesting any of my basically idle speculations are anything like solid theories. Nor am I one of those deluded posters you see on so many forums who somehow believe their random thoughts are amazing new groundbreaking scientific insights (which of course the "hide bound" ultra-conventional scientists simply "cannot see"), lol.

My main point was that if a theory is advanced which can explain where the antimatter is, or explain its absence away, then it starts to look like a moot point as to how many elementary particles there are in the universe.

Re:Maybe cannot observe now

[nusuth]

I fully agree with parent. My gripe with ggp was none of your speculations (except "not readily visible dimensions" of B, where "readily" suggests they might be visible with enough understanding of theory and more advanced technology) had observable qualities, at all. No one can ever know if there is antimatter trapped in causally disconnected parts of the universe, residing in inaccessible dimensions or in a shadow universe going back in time since bing bang.

Perhaps

[Giant Electronic Bra]

But I would wager that many people 100 years ago would have said that some of the things we observe today would remain forever hidden as well. Obviously if some part of the universe really is fundamentally unobservable and causally disconnected from the part we can observe then any theorizing (to use the term loosely) we might engage in relative to that is no more scientifically valuable than a fantasy novel.

But it may turn out that there are some subtle effects we can measure. Some formulations of quantum gravity seem to suggest we might be able to observe some effects of the configuration of the universe previous to the big bang for instance. Likewise if there is some sort of 'shadow universe' it might leave some mark on what we do observe. The two could have some very slight effect on each other or they might have influenced each other at a much earlier epoch in our universe's history that has left some trace.

Given that it seems our understanding of the architecture of the universe itself is still at a fairly elementary level there is a lot of terra incognita out there still. It will be interesting to see what sorts of discoveries we make in the next 100 years.