Are basic magnetism laws wrong?

[Mr. Peterman]

I've encountered a little problem with the way magnetic forces are calculated. The forces of magnetism should be approximately the same in different reference frames as long as the speeds are small compared to the speed of light. Am I right? The calculated force between two wires with currents are the same in different reference frames so there is no problem there because both wires are collectively neutrally charged, but what about the force on a positively charged test particle moving relative to a current carrying wire? The calculated forces are different when calculated in different reference frames, so they can't be right. It may be the case that you should take the speed of the test particle relative to the wire's positive charges (nuclei) as if the nuclei represent the speed of the magnet, but then what do you say about the magnetic forces between electrons alone? I've also heard arguments about length contraction but we are not necessarily dealing with speeds comparable to the speed of light and we may only consider just two charges. I've heard that there is no rule for the magnetic force between just two charged particles and I'm wondering if this is the reason why. I've heard explanations that claim to explain it but I've never seen anything calculated by them and I don't see how some of them could be applied in certain situations. The main thing I am trying to get here is the magnetic force from an infinitely straight current carrying wire on a moving positively charged test particle that is calculated to be the same in different reference frames. Interestingly enough the magnetic force can always be calculated to be zero if you choose a reference frame moving with the same velocity as the test particle. Can someone point me in the right direction. Thank you for your input.

[martillo]

Magnetism force laws are right. What is wrong is Relativity Theory.

The magnetic force would be the same if it would be considered that the velocity to be applied actually is the absolute velocity in relation to some referential at rest in the Universe what Relativity denies.

 

Please take a look at: A New Light In Physics

[Mr. Peterman]

If there is an absolute reference position, say the center of mass of the universe, the forces of magnetism calculated in it would still be different from the forces calculated in an earthly reference frame according to the rules we have now and calculations in an earthly reference frame are how everything has always been done. I agree that the rules of magnetism are correct when dealing with things that are collectively more or less neutrally charged like a current carrying wire or a permanent magnet, but do not give consistent results in different reference frames when dealing with charged objects. I can't trust the laws given in textbooks because they give different results when measuring the same thing while standing on earth or standing on a moving train. It also seems a little hard to distinguish between the electrical force and the magnetic force when trying to measure the magnetic forces of charged bodies directly in an experiment. I need to find some ingenious way to do this or find out if textbooks have things a little askew and if true information has been lost in translation.

[stereologist]

Sounds like a math problem, i.e. applying the laws, and not a problems with the magnetic laws.

 

Anybody know who Alejandro Castillo is? He's the author of the book claiming there is a problem with relativity.

 

The laws expressed as the equations in the books are correct. Lots of interesting things have been designed using these laws.

[martillo]

If there is an absolute reference position, say the center of mass of the universe, the forces of magnetism calculated in it would still be different from the forces calculated in an earthly reference frame according to the rules we have now and calculations in an earthly reference frame are how everything has always been done.

The magnetic force can be expressed as F = q.v x B and the variable that could be frame dependent is the velocity v (the distance in B is not frme dependent). I f it is stated that the velocity to be used is the velocity relative to an absolute frame of reference the frame dependency is removed since there would be only one possibility for the scalar value of v ( |v| ). Of course the direction of the velocity is frame dependent and the direction of the force will be frame dependent (although it will be the same in relation to the "system" or objects being considered) but not its scalar value ( |F| ).

Also the B field would be generated by moving charges and again the velocities to be considered must be in relation of an absolute frame of reference and the same reasoning applies.

In your example it must not be taken just the relative velocity between the particle and the Field. Always an absolute frame of reference must be considered.

 

Where or how do you see frame dependency in this case. Please explain.

[Qfwfq]

Classical electromagnetism is what led to Einstein's special relativity (Zur Electrodynamic bewegter Koerper), it is inherenty relativistic; this becomes more obvious if they are set in the most appropriate form. Things match up if done properly.

[martillo]

It must be noted that the Lorentz Force F = q.v x B works for stationary sources of magnetic Fields only. If the Magnetic Field moves or varies then the phenomenon of Magnetic Induction appears ( Faraday's Law of Induction) where the variable Magnetic Field generates an Electric Field and so actually an Electric Force acts.

The case of a stationary Magnetic Field over a moving particle is equivalent to the dual case of moving Magnetic Field over a static particle (static magnet - moving particle and moving magnet - static particle) but the computation of the force follows different paths.

 

In any case the Maxwell's Equations are verified.

[Mr. Peterman]

Imagine an infinitely long line of electrons along the x axis that is moving at 30m/s in the x direction and nearby, 1m away from the line in the y direction, is a single electron traveling at 10m/s in the x direction. Now probably everyone would agree that the line of electrons produce a magnetic field that causes a nonzero magnetic force in addition to the electric force on the single electron. You would probably also say that the magnetic field is stationary and non varying so you would not expect it to create an additional electric field due to this, and the electric field would be constant and so would not produce an additional magnetic field.

 

Now consider a second set of electrons. This time there is again a line of electrons lined up in the direction of the x axis, and all of them are moving in the x direction at 20m/s. Nearby, 1m away in the y direction, is again a single electron that is stationary. Now is the magnetic field produced by this line of electrons stationary? If so, you could calculate the Lorentz force on the single electron. The force would be zero because the velocity of the single electron is zero. Wouldn't you also say that the magnetic field produced would be stationary and non varying as well. So there would be no additional electrical forces. Also the electrical forces would be constant if this were an idealized problem. The change in electric flux would be zero, and even if there was a changing electric field it would produce an additional magnetic field, but this field would also not cause a force on the single electron because again the single electrons velocity is zero. In this case the only force experienced by the single electron would be the same electrical force that it would experience if it were at rest with respect to the line of electrons. That is it would experience no additional magnetic force. You may notice that this is the same as the first problem just in a different reference frame, yet the answers are different. The total force is different in these different reference frames.

 

I see where we could disagree about some things. If you believe in an absolute reference frame, you could say everything has to be calculated in that frame. I also see how someone who believes in Einstein's relativity can suppose that it can be explained by length contraction or something, but both parties must hold the opinion that the single electron accelerates along the direction of the y axis in one reference frame but not in the other. And in regards to relativity, in my example, I don't think 30m/s, 10m/s, or 20m/s approach very near the speed of light. Thank you for listening. Your response is appreciated.

[martillo]

You may notice that this is the same as the first problem just in a different reference frame, yet the answers are different. The total force is different in these different reference frames.

No, your example is not the same phenomenon seen in two different frames of reference but two different physical phenomena. You are changing the absolute velocity of the isolated electron: in one case is 10 m/s and in the other is zero. You mantain the relative velocity between the isolated electron and the electron beam but the absolute velocities are different and the Magnetic Field and Force are dependent on it.

From the perspective of an existing "absolute" frame you are not just changing the frame of observation, you are chanching the "system" or phenomenon.

 

I agree that with the relativistic approach where no "absolute" frame exist the two cases you present should be equivalent and present the same result but not in the classical approach.

May be an experiment could be done with your example and could become another evidence (proof) that Relativity Theory is wrong giving the wrong prediction. And there's no need to reach relativistic speeds to perform it so it is very feasible...

Interesting.

 

Also a problem with the "Galilean Invariance" statement could exist. If forces dependent on absolute velocities in relation to references at rest in the Universe do exist then that principle could not be valid.

Very interesting.

 

I think that the Magnetism laws are right but considering absolute velocities.

Another relation that I think needs the consideration of absolute velocities is De Broglie Law (lambda = h/mv) although it seems to work within Relativity Theory.

[Qfwfq]

the Lorentz Force F = q.v x B works for stationary sources of magnetic Fields only.

Actually you are only saying that the expression is not the total force, just add the other term and you get what you want.

[martillo]

Actually you are only saying that the expression is not the total force, just add the other term and you get what you want.

That term is zero because the Magnetic Field doesn't varies.

[Mr. Peterman]

Well the electric force caused by any changing magnetic field is zero. I'm sure that's what you meant Martillo, but just to be correct the electrical force will be nonzero but still a constant and will still be the same in both systems of particles. The magnetic force will be different in each system. So you will still get different answers.

 

I was working on a theory of my own regarding magnetism, having to do with forces arising from the RELATIVE velocities between charged particles. I was having trouble with it because I had no experimental data, but recently I found out that there is another theory of electrodynamics called Ampere-Gauss-Weber electrodynamics that sounds similar to the theory I was working on, at least from the paragraph I read about it. So I'm going to check it out. I find it hard to believe in an absolute reference frame, so my reasoning is that magnetic forces are a function of relative velocities, I just don't know how yet.

 

An interesting thing I read somewhere about AGW electrodynamics was that some discoveries from this field gave additional insight into the aether regarding its tension or shear or something, I don't know. I don't know if aether exists, but I found that a man named Miller did more accurate experiments for detecting Aether than Michaelson and Morley did, and supposively they found a pattern that followed a sidereal day pattern. I think that means they are in relation to the stars and not the sun. So to me if this is true, that would discredit the heat effect arguments against it, unless it's heat from the rest of the Milky Way I guess. I'm going to check some of this stuff out too. I just thought you might find this stuff interesting.

 

I seem to dabble a bit in fringe and crank science. Some of the stuff I've found is hilarious. I love the spiritual poetic scientific jabberwocky sites. I laughed so hard that I cried.

[Mr. Peterman]

Actually, Ampere-Gauss-Weber electrodynamics doesn't even require an aether. The book I have about Weber electrodynamics says the forces are instantaneous and action-at-a-distance but still let oscillations travel at light velocity. I think that's pretty cool.