Is a classical electrodynamics law incompatible with special relativity?

May 24, 2012 by Lisa Zyga feature
Charge-magnet paradox: the point electric charge q and the point magnetic dipole to its right are separated by distance d in the x’y’z’ frame. An observer in the x’y’z’ frame sees no torque, but a stationary observer in the xyz frame watching the x’y’z’ system move with constant velocity along the z axis sees the moving electric charge exert a torque on the moving magnet. Image credit: Mansuripur. ©2012 American Physical Society

(Phys.org) -- The laws of classical electromagnetism that were developed in the 19th century are the same laws that scientists use today. They include Maxwell’s four equations along with the Lorentz law, which describes the force exerted by electric and magnetic fields on charged particles. But Masud Mansuripur, a professor of Optical Sciences at The University of Arizona in Tucson, is now arguing that the Lorentz law of force is incompatible with special relativity and momentum conservation, and should be abandoned. In a recent issue of Physical Review Letters, he has suggested replacing the Lorentz law with a more general expression of electromagnetic force density, such as one developed by Albert Einstein and Jakob Laub in 1908.

However, Mansuripur’s bold claim of a paradox with the Lorentz law has generated some intense criticism. One critic, Daniel Vanzella, a physics professor at the University of Sao Paulo in Sao Carlos, Brazil, has submitted a comment to Physical Review Letters arguing that the Lorentz law is perfectly compatible with , and that Mansuripur has misunderstood relativistic mechanics. The only paradox, Vanzella says, is why the high-ranking journal accepted the paper in the first place.

Charge-magnet paradox

The basis of Mansuripur’s argument is that the Lorentz law violates special relativity by producing different results in different reference frames. According to special relativity, the laws of physics – including electromagnetism – must be the same in all non-accelerating reference frames.

He describes a scenario in which a magnetic dipole and a nearby electric charge are located a certain distance apart. When the magnet and the electric charge are at rest, no net force is exchanged between the two. This is because static electric charges only produce electric fields (to which the magnet is oblivious), and static magnets only produce magnetic fields (to which the static electric charge is oblivious). Both the Lorentz law and the Einstein-Laub version give the same result: the magnet experiences neither a force nor a torque from the electric charge.

However, the Lorentz law gives a different result when a stationary observer watches the magnet and electric charge in a moving reference frame. Here, the observer sees the moving electric charge exert a torque on the moving magnet, causing the magnet to rotate as it tries to align itself with the electric field. The presence of this torque differs from the observation in the stationary reference frame where there is no torque.

On the other hand, the Einstein-Laub formula, when combined with a corresponding torque formula, gives zero torque value for observers in both reference frames, complying with special relativity.

The Lorentz law’s incompatibility with special relativity is not its only shortcoming, according to Mansuripur. Another equally important issue is the long-standing problem of “hidden momentum,” in which he shows that the Lorentz law fails to conserve momentum in certain situations involving magnetic media. In contrast, the Einstein-Laub equations show complete consistency with the conservation laws. For Mansuripur, this evidence indicates that the Einstein-Laub formula should be considered as a better way to understand classical electrodynamics.

“This work provides a firm basis for all calculations of force, torque, momentum and angular momentum whenever electromagnetic fields (microwave, light, etc.) interact with material media,” Mansuripur told Phys.org. “The electromagnetic momentum and angular momentum become well-defined universal entities (i.e., the Abraham momentum), the need for ‘hidden momentum’ disappears, and satisfaction of conservation laws as well as conformity with special relativity are guaranteed.

He explains that, during the past century, there has been a proliferation of equations for force and torque in the scientific literature, with scientists using several different formulas for the electromagnetic momentum.

“My paper fixes the foundational equations and allows researchers to compare their experimental results against a single, well-defined theory,” he said.

Quantum nature

According to Mansuripur, the underlying reason for the difference between the Lorentz law and Einstein-Laub formula involves how each equation mathematically describes the quantum nature of electromagnetic fields and media.

For its part, the Lorentz law depicts electric and magnetic dipoles as pairs of positive and negative charges or stable loops of current that interact with electromagnetic fields in terms of free and bound charges and currents. In contrast, the Einstein-Laub formula describes material media as spatio-temporal distributions of charge, current, polarization, and magnetization. Mansuripur explains why this distinction is important.

“The fact that the electron orbits inside atoms and molecules are stable is a quantum-mechanical phenomenon,” he said. “Neither Maxwell’s equations nor the Lorentz law of force (and nor, for that matter, the Einstein-Laub force/torque equations) can account for the stability of the electron orbit. The fact that electrons, protons and neutrons have a magnetic moment associated with their spin angular momentum is also a relativistic quantum effect that has no explanation within classical physics. What Maxwell’s equations and the Lorentz law (or the Einstein-Laub law) do is provide formulas that describe the behavior of fields and material media as they are, without attempting to justify that behavior. The Lorentz law, however, simplifies the underlying physics by assuming that electric and magnetic dipoles can be treated as distributions of ordinary electrical charge and current. In contrast, the Einstein-Laub equation and the accompanying torque equation treat free charge, free current, electric dipoles, and magnetic dipoles as four distinct constituents of material media.

“So, for example, the fact that a magnetic dipole is associated with something resembling a loop of current is a quantum mechanical effect. The Lorentz law does not ignore this fact, but it takes the resemblance to a current loop too far, treating the magnetic dipole as if it were actually a loop of ordinary current. In contrast, the Einstein-Laub formula acknowledges that magnetic dipoles exist as distinct entities – what makes them distinct is quantum mechanics, of course, but Einstein-Laub does not attempt to justify the existence of these dipoles or their nature. The Einstein-Laub formulas then provide a ‘recipe’ for calculating the force and torque on these dipoles, which turns out to be different from the ‘recipe’ provided by the Lorentz law.”

No paradox?

One critic of Mansuripur’s ideas, Vanzella, thinks that the paper is so flawed that it should not have been published at all. In his comment submitted to the journal, Vanzella points out that the Lorentz force can be put in a covariant form. In special relativity, a covariant law cannot lead to incompatible descriptions of the same phenomenon in different inertial reference frames. He explains that Mansuripur has incorrectly used relativistic mechanics and ignored a hidden momentum that makes the Lorentz formula predict a torque in one reference frame but not another.

“This has blown way out of proportion,” Vanzella said. “Let me begin by stating the most important point: there is no incompatibility between the Lorentz force and special relativity. This is not a matter of opinion: any relativist knows that this is impossible for any specially-covariant law (as is the Lorentz force). By construction, a specially-covariant law is compatible with special relativity. This means that if it leads to a satisfactory description of a phenomenon in one inertial frame, then it leads to consistent descriptions in any inertial frame; there are no paradoxes.”

He added that apparent paradoxes appear frequently when dealing with special relativity, but these paradoxes are actually due to simply missing or overlooking part of the relativistic argument. He says that a very similar “paradox” to the charge-magnet paradox, called the Trouton-Noble paradox, was presented and resolved more than 100 years ago.

"In this particular case, using a current loop in a perfectly-conducting ring to model the magnet's magnetic moment, one has to use special relativity to show that, even when the ring is at rest, the total momentum of the system is not zero (when subject to an external electric field),” he explained. “This momentum has been termed ‘hidden’ in the literature and this has led to some confusion, but let me stress that it is real momentum. Mansuripur is missing the point that this momentum is not an ad hoc invention only to solve paradoxes; its existence is forced upon us (upon Nature, actually) due to the principles of special relativity alone. In my comment I do not postulate the existence of this momentum. I simply use special relativity to calculate it; no additional hypothesis other than special relativity and the Lorentz force. Therefore, when Mansuripur dismisses this ‘hidden’ momentum he is doing exactly what I said is needed to arrive at a paradox: missing or overlooking part of the relativistic argument.”

Despite his strong disagreement with Mansuripur, he emphasized that his criticism does not suggest anything against Mansuripur’s scientific credibility.

“Please note that I don't think that Mansuripur not knowing the solution of the ‘charge-magnet paradox’ (or not understanding the given solution) is that bad,” Vanzella said. “Special relativity is certainly not his expertise and confuses a lot of people, even physicists.”

He also added that he’s not necessarily arguing that the Lorentz law must be the correct law of force, either, but just that special relativity cannot be used to testify against it. The question of which law is correct is an experimental issue. Still, he’s adamant that there is no paradox in this situation.

“I wouldn't even call Mansuripur's idea ‘controversial,’” he said. “Would you call ‘controversial’ the idea that the Earth is flat? It is simply and provably wrong (I mean the claim that the Lorentz force is incompatible with special relativity).”

In a response to Vanzella’s comment, also submitted to Physical Review Letters, Mansuripur has stuck to his original argument, explaining that there is no need to introduce hidden momentum, and that the Trouton-Noble paradox was subtly but significantly different than the charge-magnet paradox.

Future of Einstein-Laub

Despite the advantages of Einstein-Laub formula, Mansuripur acknowledges that it is not without its own problems. In 1979, physicist Iver Brevik performed an extensive review of the Einstein-Laub formula and other possible candidates for an energy-momentum tensor for the electromagnetic field. In some of the experiments, the Einstein-Laub formula did not match actual observations as closely as another formula, the Helmholtz force equation. However, Mansuripur argues that, due to the potential significance of this idea, the contrary evidence deserves a closer examination.

“My colleagues and I are currently trying to identify situations where the distinction between the Lorentz law and the Einstein-Laub formulation is unambiguous, then try to conduct experiments to determine which law is operative in such situations,” he said. “Personally, I don’t attach much significance to the historical evidence against the Einstein-Laub formulation as reviewed in the paper by Brevik. The experiments were all electrostatic experiments, involving the flow of some dielectric fluid into a capacitor. The theoretical methods used to analyze the problem were extremely confusing; many approximations were made, and the Einstein-Laub formula itself was never used directly; instead they used a stress tensor associated with Einstein-Laub, which I have shown elsewhere to be incorrect.

Mansuripur also plans to further investigate what he thinks has been a much overlooked distinction between the two formulas: a term that describes the force density of an electric field acting on the polarization density of a material medium. Whereas the Lorentz law uses –(del.P)E, the Einstein-Laub formula uses (P.del)E. Although the two formulations give exactly the same total force and total torque on any solid object, differences emerge when dealing with soft objects.

“If applied to soft objects such as biological cells under intense illumination or droplets of oil or water in optical tweezers, the two formulas give different force and torque ‘distributions’ throughout the object,” he said. “This difference in force/torque distribution will then manifest itself in different deformations of the object under intense illumination. Our near-term goal, therefore, is to look for deformations of soft objects in optical tweezers experiments. A long-term goal is to look for observable differences between Lorentz and Einstein-Laub in magnetic materials.”

Explore further: Scientists create possible precursor to life

More information: Masud Mansuripur, “Trouble with the Lorentz Law of Force: Incompatibility with Special Relativity and Momentum Conservation.” Physical Review Letters 108, 193901 (2012). DOI: 10.1103/PhysRevLett.108.193901

Journal reference: Physical Review Letters search and more info website

4.7 /5 (21 votes)

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Sonhouse
1 / 5 (1) May 24, 2012
News at 11.
ChangBroot
3.3 / 5 (16) May 24, 2012
Time will tell if Masud Mansuripur is right or wrong, but I admire applaud him for his courage to question century old laws. It's people like Daniel Vanzella who is close minded and who viciously attack those who challenge the norm.
omatwankr
2.1 / 5 (21) May 24, 2012
Dense Æither-Way Theory agrees with both postulated conclusions, proving it ability to transcend the confusion caused by so called "facts" :Þ
rain_atherstone
1.1 / 5 (7) May 24, 2012
"The basis of Mansuripurs argument: the Lorentz law violates special relativity by producing different results in different reference frames. According to special relativity, the laws of physics including electromagnetism must be the same in all non-accelerating reference frames." Unless Magnestism is scaled and manipulated aswell. I think we should be tackling the idea that Magnetism is purer Source, higher on the energy spectrum, oscillating with each lower/slower state of energy. Different energy levels carry different signature waves. Scalers are the fastest yet, no? "The fact that electrons, protons and neutrons have a magnetic moment associated with their spin angular momentum is also a relativistic quantum effect that has no explanation within classical physics.In contrast,Einstein-Laub/torque equation treat freecharge, freecurrent, electric dipoles, and magnetic dipoles as 4 distinct constituents of material media." This may explain its unique relationship w each energy level.
vega12
4.5 / 5 (6) May 24, 2012
The laws of electromagnetism in special relativity are written down in a manifestly coordinate independent way. Although since this article has been accepted at Physical Review Letters, maybe it does have something to it. Odds are against it though I would think.
gwrede
1.2 / 5 (6) May 24, 2012
While the subject in the article is way beyond the grasp of PhysOrg readers (as it should be, since most physicists obviously can't grasp it either), there is a delightfully parallel article on Wikipedia about the history of the Centrifugal force. It took some time there, too, before consensus was reached.
Vendicar_Decarian
4.2 / 5 (10) May 24, 2012
I will clarify.

There can be no prediction in Einsteinian relativity in any reference frame which contradicts (after correction) observation in any other reference frame.

In this instance we observe a charge/magnet system as being stationary and experiencing no torque in a reference frame that is stationary with the charge/magnet.

In a reference frame moving with respect to the charge/magnet - say along the vector drawn between the charge/magnet, we expect to see the charge associated with it's own magnetic field as well as seeing the charge moving inside the magnetic field from the magnet.

The result of these new fields produces a torque on the system which should then begin to rotate in violation of the observations of the observer in the charge/magnet reference frame.

The paradox is resolved by realizing that in the stationary frame there is hidden momentum in the magnet - rotation of charge needed to produce the magnetic field - and that this hidden momentum works cont.
julianpenrod
3.2 / 5 (9) May 24, 2012
Basically, problems in Einsteinian relativity are solved in manners specific to the problems. Essentially, they use new approaches for each situation to erase relativity not agreeing with observation or being internally inconsistent. A minor example is that all "introductions" to relativity begin with measuring supposed time dilation. Not mass, not length. And that is carried out with only one experiment, a mirror reflecting a light signal to the observer. There is no way to begin analyzing relativity, for example, measuring length dilation first on an object moving laterally, or even time dilation on light signals passing between mirrors facing each other, moving laterally.
Vendicar_Decarian
4.6 / 5 (10) May 24, 2012
to exactly counter the torque one would expect to see in the moving reference frame.

So the "hidden" angular momentum in the system - required by relativity - causes the system to experience no net torque.

In all reference frames then the system does not rotate.

Relativity then requires that all magnetic fields be associated with a hidden angular momentum, which is often modeled imprecisely as loops of electric charge.

In this way relativity points to an underlying process to magnetic fields even when those fields are far removed from their point of generation.

Consider a magnetic field located far from it's point of origin. Insufficient time may exist for a charged particle to interact with the magnet that originates the field, and yet the torque must be negated. It can only do so if the field itself carries the hidden angular momentum.

chardo137
1 / 5 (3) May 24, 2012
Anyone interested in this should watch part 2 of the Feynman Messenger Lectures:
http://www.youtub...e=relmfu
Husky
5 / 5 (3) May 24, 2012
Thx Vendicar, now I grasp how the hidden moment is being a real phenomena instead of a fuzz factor bandaid. Still Einstein-Laub by default include this factor and with Lawrence you have to force it into the formula.
CrossMan
3.3 / 5 (4) May 24, 2012
@Vendicar: close. The hidden momentum arises because of the interaction of the magnetic moment (current loop) with the external electric field (here due to the point charge). In the moving frame this gives rise to a non-constant angular momentum r x p, hence the required torque. There is no hidden momentum when there is no external field. When they exist, the angular momentum and the torque are due to the same local external electric field at the dipole.
CrossMan
4.4 / 5 (7) May 24, 2012
@ChangBroot: Vanzella is not being closed minded, though some of his comments are rather snarky. There are two separate issues: 1) Is there a paradox? 2) Is the Lorentz law the right law? As for 1) the answer is no. Like all would-be paradoxes in relativity, when the problem is analyzed correctly it disappears. Almost always the apparent paradox arises from thinking too "Newtonianly," ie not applying relativity consistently. If a covariant law predicts no rotation in one inertial frame, it necessarily predicts no rotation in all inertial frames. If you get a different answer, you did it wrong. As for 2) the article says that Vanzella concedes that this is an experimental equation. He's open to Lorentz being wrong -- but if it's wrong it will be because it disagrees with experiment, not because of a non-existent paradox.
Vendicar_Decarian
5 / 5 (2) May 24, 2012
There is no "external electric field".

Nothing is external to the experiment. That is why it is employed as an example of what a paradox. The system is closed to both observers and both observers must agree to what the system does.

"The hidden momentum arises because of the interaction of the magnetic moment (current loop) with the external electric field" - CrossMan

You have confused yourself.
CrossMan
5 / 5 (4) May 24, 2012
@Vendicar: I meant the electric field of the point charge, which is external to the magnetic dipole (of course it is internal to the system). If the system is a lone dipole and no other charges, there is no hidden momentum.
Tachyon8491
1 / 5 (4) May 24, 2012
I have lectured in electromagnetics for thirty years and must be suffering from a fundamental conflation - as far as I understand, in the moving ref frame there is no *relative movement* between the electic/magnetic dipoles, therefore no induced current, resulting in no induced magnetic field to torque the magnetic dipole - the dipoles in the moving frame can only induce effects in the stationary frame - these in turn causing induced effects in the moving one. The ambiguity in the article arises from it seemingly implying that there is a direct induction effect between two static dipoles in one subject frame as long as that frame is moving in its entirety.. Fundamentally emf and I induction as modelled in Faraday's and Lenz' laws analogise Newton's third, as well as Le Chatelier's law and many others - all are expressions of a fundamental cosmic phenomenon as the opposition to change. It's relative movement that acts - and there is no relative movement *in* subject frame. Comment?
CrossMan
not rated yet May 24, 2012
@Tachyon8491: A moving magnetic dipole has an induced electric dipole moment. In the moving frame the electric moment interacts with the electric field of the point charge. (The same phenomenon explains the spin-orbit coupling on an atomic electron from the rest frame of the nucleus, though the situation is typically analyzed from the rest frame of the electron.)
celine bag
not rated yet May 24, 2012
Nothing is external to the experiment. That is why it is employed as an example of what a paradox. The system is closed to both observers and both observers must agree to what the system does.
indio007
1 / 5 (6) May 24, 2012
I think it's kind of pathetic that everything is tested against general relativity. "Oh no, it falsifies general relativity, it must be wrong."
Like transit time in quantum tunneling.

That is non-scientific thinking.
Just like "thought experiments". Real world data can not be derived from "thought experiments".
Vendicar_Decarian
5 / 5 (7) May 24, 2012
The exact opposite is the case of course. GR is tested against everything.

This is the nature of science. If GR is wrong then it must be abandoned and replaced with something that does not make the same mistake.

"I think it's kind of pathetic that everything is tested against general relativity." - indiovonpindieo

You don't know how science works.
Vendicar_Decarian
1 / 5 (3) May 24, 2012
Celine bag is a genius.

If only Parker Tard had 1/10,000th the brain power.
Husky
not rated yet May 25, 2012
I woud bet , that if you really zoom in on quantum level there are no static frames at all. dipoles, atoms and even static electric charges are all fluctuating in power/space on the tiniest scale, its only that in a magnet the spins of the electrons are aligned in an orderly fashion that it must be accounted as a force acting on a macroscopic scale, if we are really nitpicking than even the electric charge is vibrating, thus a moving frame, a collection of little diploles that are not alligned and therefore not exert a significant overall moment on the magnet, but even that is not zero.
Husky
5 / 5 (1) May 25, 2012
Indio, why is that pathetic?
Thousands of people have run the most intricate experiments to prove einstein wrong, with the latest technologies they did not have in his time and still the old hack comes out on top time and time again. Its the platinum standards that we can safely measure against, until somebody comes up with something better, just like we still can trust newton to mind your head while sitting under an apple tree.
vacuum-mechanics
1 / 5 (6) May 25, 2012
By the way, it is interesting to note that while we are discussing about electrodynamics, we still do not know how electric charge create electric field. Understand the physical mechanism of electric field (below) may help solving the problem.

http://www.vacuum...id=21=en
DarkHorse66
1 / 5 (2) May 25, 2012
Hi VD. I too, appreciate your explanation. I have just one area of confusion.The article switches between "non-accelerating reference frames" and "moving reference frame". Both a stationary reference frame AND a frame moving at a non-zero (but constant) velocity, are NON-ACCELERATING. But, ANY non-stationary frame, regardless of whether it is accelerating or not, can be considered to be a "moving reference frame". So, in the interests of clearing up what does appear to be contradictory terminology within the one article, would you be willing to clarify this? Thanx, DH66
Vendicar_Decarian
3 / 5 (2) May 25, 2012
In quantum-electrodynamics, the field is generated through the polarization of the vacuum.

Electrons are assigned an infinite (positive) charge and vacuum fluctuations are either attracted to or repelled from that charge. The differential which is greatest near the charge and which causes the greatest polarization there diffuses outward from any newly created charge.

"we still do not know how electric charge create electric field." - vacuum

This polarization requires the ependiture of energy, which as it turns out is the energy needed to pull an electron/positron pair apart.

Koen
1.8 / 5 (5) May 25, 2012
Mansuripur tells us that Lorentz force is not invariant with respect to ANY coordinate transform (Galilean or Lorentz or whatever). So his criticism is not against the "special" Lorentz/Minkovski relativity perse, only against the Lorentz force law. Mansipur's criticism can be refuted without shadow of doubt.

But remember this: in general the Lorentz force is in disagreement with Newton's third law of action force and colinear reaction force. That is the best criticism against the Maxwell/Lorentz theory, which was already known to Weber, Von Helmholtz, Pointcare, etc ... There is no cure for this problem, such as also considering the momentum of electromagnetic radiation (which will not 'balance' the Lorentz force such that it agrees with Newton's third principle in all cases).
Koen
1 / 5 (4) May 25, 2012
Mansuripur tells us that Lorentz force is not invariant with respect to ANY coordinate transform (Galilean or Lorentz or whatever). So his criticism is not against the "special" Lorentz/Minkovski relativity perse, only against the Lorentz force law. Mansipur's criticism can be refuted without shadow of doubt.

But remember this: in general the Lorentz force is in disagreement with Newton's third law of action force and colinear reaction force. That is the best criticism against the Maxwell/Lorentz theory, which was already known to Weber, Von Helmholtz, Pointcare, etc ... There is no cure for this problem without expanding the Maxwell/Lorentz theory (such as the speudo cure of considering the momentum of electromagnetic radiation, which will "balance" the Lorentz force into agreement with Newton's third principle in all cases: this is not true).
indio007
1 / 5 (3) May 25, 2012
Indio, why is that pathetic?
Thousands of people have run the most intricate experiments to prove einstein wrong, with the latest technologies they did not have in his time and still the old hack comes out on top time and time again. Its the platinum standards that we can safely measure against, until somebody comes up with something better, just like we still can trust newton to mind your head while sitting under an apple tree.

The problem I have is that the assumption that Lorentz's law must be wrong because it doesn't agree with a general relativity thought experiment.

Maybe Lorentz is right an Einstein wrong. Maybe Lorentz's law falsifies relativity and not vice versa.

brt
1 / 5 (3) May 25, 2012
"There is no "external electric field".

Nothing is external to the experiment. That is why it is employed as an example of what a paradox. The system is closed to both observers and both observers must agree to what the system does."

It is impossible to have a system closed to both observers. If you are capable of observing the system, then you are receiving energy from it.
Standing Bear
1.2 / 5 (6) May 26, 2012
Sounds like a last ditch effort to save Albert's work of over a century ago from the dustbin of history....and maybe save a job or a retirement stipend or two ..or maybe threee
chardo137
1 / 5 (4) May 26, 2012
It seems to me that the problem is not with relativity, but with all of the layers of equations and forms of calculation that have been layered on top of it to make it useful. If we spot an error in the way that we have been doing things, it might be useful in our approach to many things.
GinoCe
1 / 5 (1) May 26, 2012
After reading the news and the comments here, it seems that CrossMan was the only one to really grasp it all. I had it wrong after the first reading too, but CrossMan comments helped a lot. Vanzella really says he is open to Lorentz law being wrong, but that this is up to the experiments do decide. In face of that, I tend to take more seriously his opinion regarding not existing any real paradox. It helps too to see that there are other "relativists" who are saying the same thing (published in the so-called arxiv xxx.lanl.gov). People who think that there is a "big plot" to conceal relativity not being consistent with experiments amuse me. Funny this position is usually held by those who have not really had a course on relativity.
GinoCe
1 / 5 (2) May 26, 2012
After reading the news and the comments here, it seems that CrossMan was the only one to really grasp it all. I had it wrong after the first reading too, but CrossMan comments helped a lot. Vanzella really says he is open to Lorentz law being wrong, but that this is up to the experiments do decide. In face of that, I tend to take more seriously his opinion regarding not existing any real paradox. It helps too to see that there are other "relativists" who are saying the same thing (published in the so-called arxiv xxx.lanl.gov). People who think that there is a "big plot" to conceal relativity not being consistent with experiments amuse me. Funny this position is usually held by those who have not really had a course on relativity.
indio007
1 / 5 (4) May 26, 2012
but that this is up to the experiments do decide.

^^^^^^^
THIS

People who think that there is a "big plot" to conceal relativity not being consistent with experiments amuse me.


Get real there are plenty of experiments that don't jibe with relativity and they are just cast aside.

I think the future will tell us that relativity's equations are an approximation.
Smashin_Z_1885
1 / 5 (4) May 26, 2012
They are all becoming increasingly lost within the complexity of their own creation. In time, both the Lorentz Law and ALL of Einstein's work will be completely abandoned in favor of 3 basic constructs of physical law which are all inter-related and unified. The time period involved is 118 years in the 'forward' direction from your observed reality of 'now'. I am not at liberty to discuss further details. And, it is possible that just by my presence here (whether fully observable and tangible or only partially so), and sharing this information, that I am helping to make it a 'future' reality. We really have not yet sorted out just how it all works, but, we are on phase IV of the experiments, meaning we have been given the 'ok' for more specific information sharing processes within the project. Now, get to work and let's see what happens here.
Terriva
1 / 5 (4) May 27, 2012
The true is, nobody knows, how the charge and magnet dipole should interact at high speeds - we still haven't tested it experimentally. But IMO the Mansuripur is, who leaved greater gap in analysis here. He considers, the relative motion will change the charge into magnet partially, which will exert the torque into magnet dipole. This is correct, but incomplete thought.

The main point here is, this relativistic effect is completely symmetric. The motion of magnet dipole will change it partially into charge dipole of the opposite sign. The Coulomb forces exerted with this partial dipole could compensate the torque exerted with partial magnet generated from charge with relative motion, so that the net force will remain very same, i.e. zero in the same way, like at the rest inertial frame. Therefore the Mansuripur's analysis wasn't wrong, but it was non-consequential and the Lorentz law will remain working even at the relativistic speeds in accordance with its covariant form.
Terriva
1 / 5 (3) May 27, 2012
My praise goes to most of commenters of this article, who remained exceptionally on-topic and focused to problem with their comments here. This is how the discussions bellow PO articles should appear.
Terriva
1 / 5 (3) May 27, 2012
Note that the symmetry of charge and magnetic dipoles actions would be violated with distance, separating the charge and magnet in their rest state. With increasing relative speed toward the observers the phase shift between the relativistic torques generated with co-moving charge and magnet dipoles couldn't be neglected anymore, which is why the consequential relativistic analysis requires the relativistic contraction of this distance to eliminate the effect of the limited speed of EM wave, which would prohibit the establishing of zero net force between both co-moving dipoles. At the relative speed of light both dipoles would coincide and they would change into their dual counterparts from the perspective of their observer: the magnet dipole would shrink like pure charge and the charge would change into pure magnet dipole oriented perpendicularly to the motion direction. Their net force/torque would therefore still remain zero.
megas08
5 / 5 (1) May 27, 2012
Time will tell if Masud Mansuripur is right or wrong, but I admire applaud him for his courage to question century old laws. It's people like Daniel Vanzella who is close minded and who viciously attack those who challenge the norm.

No it is Not. It's people who checked their facts. That's what scientists do. That's what gallileo, Einstein and others did. Simply stating that something feels wrong is not challenging the norm.
Terriva
1 / 5 (3) May 27, 2012
The true is, special relativity is restricted to the inertial reference frames and as such is incomplete. This is why the more general theory, i.e. general relativity has been developed. In addition, the special relativity (and even the general relativity) neglects the influence of the CMBR noise, i.e. background photon field in the vacuum. This field generates EM field in the vacuum, which could interact with charge of electron or magnetic field and it will cause a drag force, which general relativity doesn't account to (this theory accounts to the Lense-Thirring drag of gravitating bodies only). This theory is logical, but problematic at the case of uncharged bodies (neutron, atoms and large bodies), which are all composed of many mutually compensating charges. Will such composite bodies remain a subject of this drag too? We actually didn't observe it, even the Lense-Thirring drag is difficult to detect.
Terriva
1 / 5 (3) May 27, 2012
As a first evidence of such violation of special relativity could serve the observation of "antigravity beams" generated with co-moving charges within superconductors by Eugene Podkletnov. The charged electrons are already moving with high speed there, but they're sparse enough for not to move collectively. This enables the dragging effect of vacuum fluctuations to manifest itself at larger distance. The so-called EM-drive, Dean drive and Woodward effect could belong into this category too.

A common characteristic of all these effects is, they do maintain the special relativity locally and temporarily - but because these effects aren't additive, they manifest itself with violation of special relativity at the macroscopic scale in similar way, like the gravitational lensing.
JIMBO
1 / 5 (2) May 27, 2012
Vanzella is of course correct: Any covariant law cannot give different results for any physics in different reference frames: fu = Jv*Fuv. The plot thickens as U.Ariz. has an expert on EM, Prof.Melia. Why was he not consulted first ? Jackson is smirking right now.
PoombaDo
not rated yet Jun 01, 2012
Maxwell never wrote the four equations he is famous for... Thanks to Heaviside and Gibbs who hacked his orginal twenty equations to death. Maxwells original quarternion formulas actually answer this problem better than the Einstein-Laub formulation.
Origin
1 / 5 (4) Jun 01, 2012
Maxwells original quarternion formulas actually answer this problem better than the Einstein-Laub formulation.
IMO Maxwells formulas doesn't enable to predict the Lorentz force at all, which is why the Lorentz law is added to it as a fifth law of classical electrodynamics. In dense aether model the Lorentz force in an analogy of Magnus-Robins force.
Infinum
1 / 5 (4) Jun 03, 2012
I'm 100% on Masud Mansuripur side.

Even if there was no paradox (and there is) Occam's razor suggest that the simpler of the two laws should be used and it's the Einstein-Laub formulation. No "hidden" forces are needed to make it work.
Dave K
1 / 5 (2) Jun 05, 2012
I'v been working on something for a while and now I'm a little stuck.
This is what I have so far.

F = M * E < pie.Y2 C > E = M * F
< pie . Y/c >
< 2sq / pie . Y/C >
F = M * E < 2sq/pie . Y/C > E = M * F
F/ F = M * E < 2sq/pie . Y/C > E = M * F/-F

if someone knows what I have here e-mail me and let's talk. thetracker1099@hotmail.com And I know this is off topic I'm sorry.
Dave K
1 / 5 (1) Jun 05, 2012
I'm sorry I tryed a few times to fix the equation but it wont let me. thats F over F = M * E < 2sq over pie * Y over C > E = M * F over -F