The question of whether the magnetic field rotates in the faraday disc generator is a question that is related to aether theories in particular or any theory of privileged reference frames in general. It got me wondering if there are alternate ways to test for the presence of an aether or a privileged frame of reference that do not involve interferometers and radiation. I am not sure why interferometers became the experiment de jour for detecting such things, but they have been studied to death and the null result is still open to interpretation.
Hendrik Lorentz argued on the basis of Maxwell's theory of EM that a stationary magnet has no electric field and that a moving magnet does have an electric field. When he says a moving magnet he clearly states the magnet is moving with uniform velocity. The appearance of this electric field bothered Einstein, because it led to conflicting accounts of how a magnet induces a current in a coil depending on whether the coil was at rest or the magnet was at rest. He didn't like nature exhibiting laws which changed according to their frame of reference. He developed his special theory of relativity, in part, to avoid this conflict. Mathematical and principled arguments aside, was Lorentz's claim ever directly tested? i.e. Has anyone tried to measure the electric field around a moving magnet without the use of a conducting coil? eg. an electroscope can measure an electric field without moving relative to the field. Or am I missing something about the nature of the produced electric field in this case that would prevent such a measurement? Harry On Thu, Mar 14, 2024 at 12:25 PM Jürg Wyttenbach <ju...@datamart.ch> wrote: > As most might know, in physics we only know force fields. Thus so called > field lines (magnet field) are equipotential cuts of the space covered by > fields. Of course you never can draw such a line as all sources are in > constant motion/rotation. > > The static magnetic field is a special case as it is a part of the atoms > mass that form out the field. This field is attached but with the same > restrictions as above. The only real "energy" field is the EM field > produced by an active sender. Here of course no stable lines occur - only > in case of a cavity with a sender-resonance we call receiver. > > > Key is the understanding that in physics a field must have a source and a > sink. From this point of view most so called mathematical physics > (tensor...) field theory simply is nonsense. > > There are far to many simplifications in physics models as historically > only point field equations could be solved. As a consequence of this, one > thing most did miss is: Total potentials almost never are 1/r. Total > because we no longer deal with a single point.... > > > J.W. > > > On 14.03.2024 16:02, H L V wrote: > > Another visualization of the behaviour of magnetic fields without the > concept of lines of force. > When the magnet is moved around it simply changes the orientation of all > the little compass needles. > The notion of lines of force tends to make one think the magnetic field > is somehow mechanically > attached to the magnet so that the centre point of each needle must change > position in order to match > the motion of the magnetic. > > https://www.youtube.com/shorts/HTylDaG5_RY > > Harry > > > > > > On Wed, Mar 6, 2024 at 11:16 AM H L V <hveeder...@gmail.com> wrote: > >> >> >> Here is a physical demonstration of the situation using a ferrofluid. >> https://www.youtube.com/watch?v=Bn41nPOGq-U >> The ferrofluid does not rotate with the cylindrical magnet, >> which supports the idea that the magnet's field does not rotate with the >> magnet. >> (There is a little bit of movement but the narrator explains that this >> movement arises from the field not being perfectly symmetrically.and >> homogeneous). >> >> Harry >> >> On Wed, Mar 6, 2024 at 12:40 AM H L V <hveeder...@gmail.com> wrote: >> >>> It depends what you mean by a field. If you imagine the field is made of >>> wire-like filaments which are fastened to an atom then you would expect the >>> field to translate and rotate whenever the atom translates and rotates. On >>> the other hand if you imagine the field is a vector field then the field >>> never really needs to move. Instead the direction of the magnitude of the >>> vector at each point in space updates as the atom moves through that vector >>> space. The way the vector field changes as the atom rotates and translates >>> gives the appearance of a field that is moving as if it were fastened to >>> the atom. >>> >>> Harry >>> >>> >>> On Tue, Mar 5, 2024 at 1:41 PM Robin <mixent...@aussiebroadband.com.au> >>> wrote: >>> >>>> In reply to H L V's message of Tue, 5 Mar 2024 09:28:31 -0500: >>>> Hi, >>>> >>>> You don't need an experiment to figure this out. The field obviously >>>> rotates with the magnet. >>>> This is because the field is not a single entity. It is the sum of all >>>> the tiny fields created by the electrons attached >>>> to individual atoms, so when the magnet rotates, the atoms all move, >>>> taking their individual fields with them. We know >>>> they do this because when the magnet is moved sideways, instead of >>>> rotating, the field moves sideways as well. IOW, the >>>> atomic fields are attached to their individual atoms. There is no >>>> reason this should change when rotation is involved >>>> rather than translation. >>>> >>>> [snip] >>>> >Resolving the paradox of unipolar induction: new experimental evidence >>>> on >>>> >the influence of the test circuit (Free to download. Published 2022) >>>> >https://www.nature.com/articles/s41598-022-21155-x >>>> Regards, >>>> >>>> Robin van Spaandonk >>>> >>>> Drive your electric car every second day and recharge it from solar >>>> panels on your roof on the alternate days. >>>> The other days, drive your spouses car, and do the same with it. >>>> >>>> -- > Jürg Wyttenbach > Bifangstr. 22 > 8910 Affoltern am Albis > > +41 44 760 14 18 > +41 79 246 36 06 > >
