The law of Faraday is very clear any change in magnetic flux induces
charge hence a field.
Many untrained physicists write j (current) instead of q what is wrong.
To measure a current you have to cut the ring (rim) of charges what
leads to dragging forces and movement of charge over e.g. a conductor.
The other things most theoretical physicists get wrong is that they
believe you can make a derivative of charge and flux at the same point
(4 potential) what is total garbage but nevertheless used in QED...Flux
has to fill an area (from a volume) and charge occurs at the edge.
May be once read the good old Jackson that explains tat the vector
potential only can be used in the far field.
J.W.
On 19.03.2024 19:40, H L V wrote:
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
--
Jürg Wyttenbach
Bifangstr. 22
8910 Affoltern am Albis
+41 44 760 14 18
+41 79 246 36 06
