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Intrinsic Magnetic Moment?

  1. Sep 22, 2006 #1
    Hello Everybody,

    Glad to be back again after a year. My main motivation to be back, is precisely the following observation about the existence of an intrinsic magnetic moment at large scale too.

    Observations Supporting the Existence of an Intrinsic Magnetic Moment Inside the Central Compact Object Within the Quasar Q0957+561
    Authors: Rudolph E. Schild, Darryl J. Leiter, Stanley L. Robertson


    We know that the electron has an intrinsic magnetic moment, that for sure must be associated with an intrinsic magnetic field in it, right? But intrinsic means some sort of absolute proposition, not a relative one.

    In his famous paper On the Electrodynamics of Moving Bodies. The Principle of Relativity. Dover Publications, Inc., on pag51. II. Electrodynamical Part. Transformation of the Maxwell-Hertz Equations..., Einstein stablished that the magnetic field was relative, when he wrote: Now the principle of relativity requires that if the Maxwell-Hertz equations for empty space hold good in system K, they also hold good in system k;...

    My questions is: is there any real evidence that a magnetic field can be cancelled by a relative movement? Would this not mean a real chaos, if it were true? Or is this the greatest drawback of the principle of relativity, not of course of the Lorentz transformation group?

    Are not those laws of quantum numbers and the Pauli exclusion principle dependent mostly on this intrinsic magnetic moment?

    Thank you so much for any answer

    My best regards

    Last edited: Sep 22, 2006
  2. jcsd
  3. Sep 23, 2006 #2
    About this, I'm sure there is, because in electrodinamics, it's not necessary to distinguish between electric and magnetic fields, we only refers to electromagnetic field: what is an electric field in a ref. frame is a magnetic field in another one, using Lorentz transformations.

    Example: two electrons are placed at the two ends of a rigid rod and the rod moves with a constant speed v in a direction perpendicular to its lenght. So, between the two electrons there is the coulombian force and a magnetic force (because each of them, moving, generates a magnetic field that affect the other).

    But, in the ref. frame of the rod, only the coulombian force is present.
  4. Sep 23, 2006 #3
    Hi Lightarrow,

    First of all thank you for your time.

    You wrote:

    in electrodinamics, it's not necessary to distinguish between electric and magnetic fields, we only refers to electromagnetic field

    But, is not electrodynamics defined by Maxwell's equations? In them both mathematically and in the reality "out there", there is a clear distintion between a magnetic field and an electric field, all of electrical engineering and its applications is based on that distintion, which was made relative by the way Einstein framed, with the principle of relativity, that Lorentz transformation group and consequently Maxwell's equations, which is my point.

    On the other hand, in the mean while the magnetic field and permanent magnets are found out there and can be verified by anyone, the electric field possess no real physical basis, for physical measurements must always be in terms of the forces on the charges in the detection equipment. An electric does not distort the space around the way a magnetic field does.

    Sorry but I'm sure that if the magnetic field were relative our physical world would be a real chaos, no quantum numbers, no Pauli exclusion principle, and no electrical engineering. The ref. frame of the rod seems to be precisely one thing that cannot be verified in the reality out there, but just as a thought experiment, a reason why I asked about a real evidence of the cancelation of a magnetic field by a relative movement.

    My best regards


  5. Sep 23, 2006 #4
    For what I know, there wouldn't be an asymmetry between electric and magnetic fields in Maxwell's equations if magnetic monopoles would exist, that is, the asymmetry comes only from the fact that "magnetic charges" comes always in couple; I mean, it's not a difference in principle.

    I'm sorry but I don't know what you mean when you say that a magnetic field distort the space around. Maybe I miss something. Please explain.
    I don't think so. To vanish orbital magnetic momentum of an electron in an atom, for example, you should be in that electron's reference frame. Of course the world would look very different from there.
    Why? I really don't understand this.
  6. Sep 23, 2006 #5
    My dear Lightarrow,

    You wrote:

    Yes, that's exactly my point, there is an asymmetry between electric and magnetic fields, being the former a conservative field and the latter a non-conservative one, and it has to do with the non existence of magnetic monopoles. Meanwhile for conservative fields you have a corresponding Gauss's law, this in not the case for non conservative fields such as the magnetic field. In fact, in magnetic fields, you have an inherent polarity, so the concept of "magnetic charges" do not have any sense, at least the way it has with conservative fields, where you have two opposite charges located in different points of space. In a magnetic field what you have is a unique center for its lines of force, some sort of circularity in its field definition. This is exacly the real asymmetry between them, IMHO.

    Well, it is this experience with a magnetic field and the way its lines of force are clearly seen in the space around the one that took Einstein to think in a curve space for gravitational field. If you put around a permanent magnet some pieces of iron, you just will see this distortion of space.

    Yes, that is why I think it is a thought experiment, because it cannot be done in the real world. If we could do this: to vanish orbital magnetic momentum of an electron, all the laws of QM certainly would not hold anymore, and our physical world would be a real chaos.

    Thank you so much for you time and consistent observations!!!

    My best regards

  7. Sep 23, 2006 #6
    I'm sorry, but I'm still missing something: you are talking about force lines? What do they have to do with a "distortion of space"? Of course you know perfectly that force lines are also created from electric charges, and that an electrically polarized rod creates the same force lines created from a magnet with the rod's shape, for example.
    No, it would be exactly the same;in the ref. frame of that electron, there are other relativistic effects you have to consider, and the result will give the same answers.

    If you don't like the example with two electrons at a rod's end, think about an homogeneously charged disk which rotates with angular speed w. In our ref. frame we see an electric and a magnetic field, in the disk's frame, an electric field only. You can easily perform such an experiment putting your laboratory on the disk, and you will detect an electric field only.
  8. Sep 24, 2006 #7
    Dear Lightarrow,

    You wrote:
    Yes, I'm talking about the circularity of the lines of force observed around a permanet magnet with pieces of iron around. In fact in a non conservative field such as the magnetic field, the magnetic flux lines are closed and do not terminate on a "magnetic charge", a reason why Gauss's law for the magnetic field is zero, that indicates the non existence of magnetic monopoles.
    Between electric charges we have forces that are represented by an inverse square law of the distance such as Coulomb's law; the electric field concept is defined as function of the electric charge but as far as I know the electric field concept does not have existence in the same way a magnetic field does: you have Gaussmeters, but you do not have meters for the electric field. The electric charge is the one that makes it possible to have Gauss's law for the electric field, a conservative field.

    Again, I don't think you can eliminate, physically, the intrinsic magnetic moment of the electron, except by a thought experiment, in which you have replaced the electron, by the disk's frame. How can you detect a field that is not measurable? And furthermore, as far as I've understood, every electron has an intrinsic magnetic moment, or else, a spin.

    My point is again that if we take for granted the principle of relativity and its application to Maxwell's equations, what we obtain in this kind circularity in discussions, as everything can become relative, just by the application of that principle, in spite that reality out there is showing us the contrary.

    No, the magnetic field is not relative, I'm sorry my dear friend, but any thought experiment in which we have to think in a "frame" not accesable, is not a good argument to prove the contrary.

    My best regards


  9. Sep 24, 2006 #8
    What do you mean? Since you certainly are not saying that an electric field cannot be measured with an instrument, I wonder what you could mean.
    Again, I don't understand what you mean. The field exist in a ref. frame but doesn't exist in another. Magnetic "Field" means "presence of a Force in that point of space, on an electric charge or on a magnet", and "Force" means that linear momentum varies with time. It doesn't really matters who or what is responsible for that variation, it could be a "field" in a ref. frame and lenght or time contraction in another, for exampe; taken into account all the effects, the result doesn't change from one ref. frame to another.

    About electronic spin, this is another story. I engaged a discussion on this subject in another forum, because I can't see it as a really "intrinsic" property.
    Last edited: Sep 24, 2006
  10. Sep 25, 2006 #9
    My dear friend Lightarrow,

    Well, the main problem I see is precisely the application of the principle of relativity, that makes it possible to deny the existence of real entities, in this case the magnetic field, just by a relative movement or a ref. frame. I believe this is completely wrong, as I said, electromagnetism and QM, and its quantum numbers are proving the contrary. Please note that most applications on permanent magnets are based on that, you cannot cancelled the information stored in a hard disk just by a relative movement for example.

    No, my dear friend, what I mean is that the magnetic field has a real existence, that's why we have Gaussmeters, you can measure it!.

    And about the electronic spin, it is not relative either, it is a real property of the electron that depends on the intrinsic magnetic moment and as so on inherent magnetic field. Please note that we do not have an inverse square law for magnets, what we have is Lorentz force, which defines the interrelation between electric charge and a magnetic field, as a charged particle in motion in a magnet field of flux density B, is found experimentally to experience a force which is proportional to the charge Q, its velocity V, the flux density B, and the sine of the angle between the vectors V and B, that as a matter of fact, is a real physical definition of the vector product, so there we have a real correspondence between reality out there and the corresponding mathematical representation. It is this kind of correspondence the one that makes possible engineering applications, is it not?

    My best regards

  11. Sep 25, 2006 #10
    The fact magnetic field vanishes in a specific ref. frame, doesn't imply the information would be cancelled. In that ref. frame, there would be something else than magnetic field, which would reproduce the same results.
    Does kinetic energy have a real existence? Of course it has. But in a specific ref. frame, a body's kinetic energy is something, in another one is zero. Where is the difference? The fact it depends on the ref. frame, doesn't mean you couldn't be able to measure it!
  12. Sep 25, 2006 #11
    Dear Lightarrow,

    Here, I really don't understand when you say something else than a magnetic field, don't you realize the fallacy we have to introduce to preserve the principle of relativity when dealing with the magnetic field, a real entity, that as far as I know cannot be vanished by a relative movement?

    Please note that kinetic energy is depending on velocity that can be vanished, but this is not the case for a real magnetic field, sorry, but it's not relative!!!... and what I said is that the electric field is not measurable the same way a magnetic field is, it is confusing to use other types of analogies for the topic we are dealing with! I think, in our dialogues, we must be very precise, to avoid ambiguities.

    My best regards

  13. Sep 26, 2006 #12
    So, what is written in (almost) all physics books is wrong? Richard Feynman, Nobel Prize in physics, was wrong? (The Feynman Lectures on Physics, Volume II-Part1, paragraphs 13-6, 13-7). Having used Special Relativity to prove those results, means that Special Relativity is wrong? So, most of the modern physics is wrong? Particles in a particle accelerator, e.g., moves according to Special Relativity just to make Einstein's fans happy?
    Last edited: Sep 26, 2006
  14. Sep 26, 2006 #13
    My dear friend Lightarrow,

    Now we go to the point. What is wrong with SR is the principle of relativity when applied to Maxwell's equations. One thing is the Lorentz transformation group whose time dilation has been tested in GPS, for example, and another thing is the philosophical framework used by Einstein to frame that Lorentz transformation group. If we take for granted this framework then we have all those drawbacks we have been talking about in this post, that is why I asked about real evidences, not thought experiments about the cancellation of a magnetic field by a relative movement. If there existed such evidences then the principle of relativity would be valid when applied to Maxwell's equations, on the contrary it would be a real evidence of its failure, and there is needed just one failure for a theory to fall, isn't it?

    As a matter of fact my main reference when studying QM is precisely The Feynman Lectures on Physics, thank you!

    By best regards


  15. Sep 30, 2006 #14
    Hello Everybody,

    I really don't understand why you think there is not something wrong about SR, specially when the magnectic field is a not relative field; even NASA could make a real experiment, not a thought one, to prove that two spaceships could communicate to each other without any distortion in the information of their PCs.

    Please note that their hard disk and their information is based on that storing capacity of their magnetic field.

    My best regards

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