Magnet Myths and Misconceptions

[vineet_kiran]

someone said in TA thread that magnetic field is move at ~60x speed of light, magnetic field is not static but i dont know he said that for PM or electromagnet (coil) or both. i can not recall his name.

Does it mean that massless entities can travel with a speed faster than light?   Even liquids and gases are  static when held in a container but individual molecules will be moving in all directions hitting the wall of container and we call it as 'pressure'.    Analogically is there anything like 'magnetic field pressure?'   

[sparks]

     Does a conductor moving through a uniform magnetic field develop voltage between the ends of the conductor?  In a unipolar generator you can spin the magnets along with the disk.  What I believe is happening is that  the magnetic field aligns the electrons.   This counteracts the coulomb force trying to disperse the electrons.   The electrons on the inner part of the disk experience less change of position than the electrons on the periphery.   This creates a negative charged pole on the inner parts of the disk.  As you move to the periphery of the disk the electrons are moving and residing in that space for less time.  Entropy takes over and electrons move from the higher state of order to the lower state of order.   I would like to build one of these with an inner ring and an outer ring seperated by an insulator to prove this.

[DreamThinkBuild]

Hi All,

Hi Sparks,

Here are some sources for what your describing. If a dielectric is spun between a charged capacitor plate the dielectric will become magnetic.

Henry Augustus Rowland, Rowland Effect (1887) - "...carried out a well-known research on the effect of an electrically charged body in motion, showing it give rise to a magnetic field."

reference: On The Electromagnetic Effect of Convection-Currents (1889)
https://archive.org/details/onelectromagneti00rowl

Wilhelm Roetgens Experiment (1888) - "...discovered in 1888 that a dielectric became magnetized when moving in a uniform electric field."

Paper: Electromagnetic Fields in Moving and Inhomogeneous Dielectrics, 2001

http://kth.diva-portal.org/smash/get/diva2:9054/FULLTEXT01

Rowland-Vasilescu Karpen's Effect

"A modern reproduction of this experiment consists in connecting a disk of hard rubber or an old phonograph record to the shaft of an electric motor. The disk is electro-statically charged by rubbing it with a piece of woolen cloth. Then, it is set in rotation and a magnetic compass is approached close to it. The needle is deflected; the faster the rotation, the greater the deflection."

source pg8: http://www.pprime.fr/sites/default/files/pictures/pages-individuelles/D2/germain/EPJP2013.pdf

Now there is also the reverse of this which if a dielectric is spun between a uniform magnetic field a +/- charge is built on the disc (linear polarization).

references:
On the Electric Effect of Rotating a Magnetic Insulator in a Magnetic Field, 1913
https://archive.org/details/philtrans08602085

Reverse W.C. Roetgens Experiment: Electrodynamics, Academic Press, 1955

This leads to more questions though.

We have an electrostatic generator which has a high voltage (large E-field) but low current (limited B-field).

Then a homopolar generator with high current (large B-field) but low voltage (limited E-field).

Is there a missing "Electropolar" generator which allows the B and E field to be balanced?

[MileHigh]

     Does a conductor moving through a uniform magnetic field develop voltage between the ends of the conductor?  In a unipolar generator you can spin the magnets along with the disk.  What I believe is happening is that  the magnetic field aligns the electrons.   This counteracts the coulomb force trying to disperse the electrons.   The electrons on the inner part of the disk experience less change of position than the electrons on the periphery.   This creates a negative charged pole on the inner parts of the disk.  As you move to the periphery of the disk the electrons are moving and residing in that space for less time.  Entropy takes over and electrons move from the higher state of order to the lower state of order.   I would like to build one of these with an inner ring and an outer ring seperated by an insulator to prove this.

Sparks:

You are posing an interesting question but you are not posing the question properly.  You are not taking into account the direction of of the magnetic field and the orientation and direction of the conductor.  When it comes to magnetic fields, everything has to take direction into account.  Note that this has already been mentioned several times on this thread.  The implications are as follows:  That means that you have to start at square one, and learn the basics before you can seriously discuss and experiment with magnetic fields.  I have to assume that many people read your posting had the same issue and it did not occur to them either.  Some of those people have probably been discussing magnetic fields and magnetic interactions for years.

This is an opportunity for some of you to "hit the reset button" and discard all of your mostly incorrect preconceptions, misconceptions,  and superstitions about magnetic fields.  You can reread this thread and spend a week or two hunting around online for basic and intermediate course material on magnetic fields and pull yourselves up by your own bootstraps and educate yourselves.  It's all there for free.  In my opinion this is the real way to do it.  When you are "spoon fed" information  by passively reading it simply doesn't stick.

MileHigh

[MileHigh]

Cangas:

I read your posting, and you repeated the point that I took issue with:

<<<
My post blatantly stated that FIELD LINES may or may not be real, and cannot be proved to either exist or to not exist per se.
>>>

But you have no evidence that they exist.  Anything "cannot be proved to either exist or not exist."  You are stating that anything is possible.  That is a hollow argument that goes nowhere.  It's like QEG fans saying that people have to "prove that the clainm does not work" when nobody has proved the claim does work.  The burden of proof is on Fix the Worldd and the QEG replicators to prove that it DOES work.  This is an old argument that has been around forever on the forums.  People have to prove that things actually work or that things actually exist.  Without that throught process, then things degenerate into a useless free-for-all.  Again, you can look at the example of the QEG.  Getting energy from the atmosphwere with an antenna, spark gaps, special separaate LC resonator, mechanical resonance with the core, 400 Hz, you must have good psychiological vibrations, it just goes on and on and it's just an exercise in futility and nonsense.

So I am NOT trying to be disagreeable, I am just making a firm point.

MileHigh