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Where Does A Permanent Magnet Get Its Magnetic Field?



 
 
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  #1  
Old March 15th 08 posted to sci.physics.electromag
Bill Miller
external usenet poster
 
Posts: 308
Default Where Does A Permanent Magnet Get Its Magnetic Field?

The title of the post pretty much says it all.

The participants of this list seem to have fairly clear agreement that the
primary *cause* of magnetic fields is the motion of charges.

With a few hold-outs, most folks seem to (finally) understand that an E
field does not *cause* an H field. (Those that disagree: p-l-e-a-s-e read
Jefimenko's "Causality" before jumping in to dispute this statement.)

OK. So far, so good.

A permanent magnet has associated with it a magnetic field whose
characteristics seem to be indistinguishable from those of a magnetic field
that is caused by the motion of charges.

Where the H--- does the H come from? How do we know?

Bill


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  #2  
Old March 15th 08 posted to sci.physics.electromag
FrediFizzx
external usenet poster
 
Posts: 5,404
Default Where Does A Permanent Magnet Get Its Magnetic Field?

"Bill Miller" wrote in message
...
The title of the post pretty much says it all.

The participants of this list seem to have fairly clear agreement that
the primary *cause* of magnetic fields is the motion of charges.

With a few hold-outs, most folks seem to (finally) understand that an
E field does not *cause* an H field. (Those that disagree: p-l-e-a-s-e
read Jefimenko's "Causality" before jumping in to dispute this
statement.)

OK. So far, so good.

A permanent magnet has associated with it a magnetic field whose
characteristics seem to be indistinguishable from those of a magnetic
field that is caused by the motion of charges.

Where the H--- does the H come from? How do we know?


Well, I think we pretty much know that it comes from atomic alignment of
their electron's orbital angular momentum. So there is "local" motion
of charges all coordinated. IOW, the atomic magnetic moments point in
the same direction and all add up. I don't think many physicists would
disagree with that.

Fred

  #3  
Old March 15th 08 posted to sci.physics.electromag
Bill Miller
external usenet poster
 
Posts: 308
Default Where Does A Permanent Magnet Get Its Magnetic Field?


"FrediFizzx" wrote in message
...
"Bill Miller" wrote in message
...
The title of the post pretty much says it all.

The participants of this list seem to have fairly clear agreement that
the primary *cause* of magnetic fields is the motion of charges.

With a few hold-outs, most folks seem to (finally) understand that an E
field does not *cause* an H field. (Those that disagree: p-l-e-a-s-e read
Jefimenko's "Causality" before jumping in to dispute this statement.)

OK. So far, so good.

A permanent magnet has associated with it a magnetic field whose
characteristics seem to be indistinguishable from those of a magnetic
field that is caused by the motion of charges.

Where the H--- does the H come from? How do we know?


Well, I think we pretty much know that it comes from atomic alignment of
their electron's orbital angular momentum. So there is "local" motion of
charges all coordinated.

IOW, the atomic magnetic moments point in
the same direction and all add up. I don't think many physicists would
disagree with that.

Fred

OK

That answers the first part. Kinda

You said that the effect is local.

How local is local? Atoms? Molecules? Magnetic domains? Blobs?

How do we know that the theory that you are postulating is correct? IOW what
measurements have been done to validate the statement you have made?

Bill


  #4  
Old March 15th 08 posted to sci.physics.electromag
Benj
external usenet poster
 
Posts: 1,909
Default Where Does A Permanent Magnet Get Its Magnetic Field?

On Mar 15, 4:09 pm, "FrediFizzx" wrote:

Well, I think we pretty much know that it comes from atomic alignment of
their electron's orbital angular momentum. So there is "local" motion
of charges all coordinated. IOW, the atomic magnetic moments point in
the same direction and all add up. I don't think many physicists would
disagree with that.

Fred


Do we REALLY "know" that there are electrons orbiting around nuclei
like planets around the sun? I thought that theory was more than just
a little bit out of date! I can agree with "magnetic moments" but
where exactly are these "orbiting" charges? I think Bill Miller is
asking the right question!

  #5  
Old March 15th 08 posted to sci.physics.electromag
FrediFizzx
external usenet poster
 
Posts: 5,404
Default Where Does A Permanent Magnet Get Its Magnetic Field?

"Bill Miller" wrote in message
...

"FrediFizzx" wrote in message
...
"Bill Miller" wrote in message
...
The title of the post pretty much says it all.

The participants of this list seem to have fairly clear agreement
that the primary *cause* of magnetic fields is the motion of
charges.

With a few hold-outs, most folks seem to (finally) understand that
an E field does not *cause* an H field. (Those that disagree:
p-l-e-a-s-e read Jefimenko's "Causality" before jumping in to
dispute this statement.)

OK. So far, so good.

A permanent magnet has associated with it a magnetic field whose
characteristics seem to be indistinguishable from those of a
magnetic field that is caused by the motion of charges.

Where the H--- does the H come from? How do we know?


Well, I think we pretty much know that it comes from atomic alignment
of their electron's orbital angular momentum. So there is "local"
motion of charges all coordinated.
IOW, the atomic magnetic moments point in
the same direction and all add up. I don't think many physicists
would disagree with that.

Fred


OK

That answers the first part. Kinda


What is the second part that it doesn't answer?

You said that the effect is local.

How local is local? Atoms? Molecules? Magnetic domains? Blobs?


I do believe I said "atomic" above. However, keep in mind that atomic
"motion" of electrons is dealt with by quantum physics.

How do we know that the theory that you are postulating is correct?
IOW what measurements have been done to validate the statement you
have made?


It's not my theory and I would imagine you could find experimental
references in a good solid state physics book. And I would also imagine
that hard drive companies especially IBM should have some experimental
evidence for you.

Best,

Fred Diether
Co-moderator sci.physics.foundations

  #6  
Old March 16th 08 posted to sci.physics.electromag
Timo A. Nieminen
external usenet poster
 
Posts: 1,159
Default Where Does A Permanent Magnet Get Its Magnetic Field?

On Sat, 15 Mar 2008, Bill Miller wrote:

The title of the post pretty much says it all.

The participants of this list seem to have fairly clear agreement that the
primary *cause* of magnetic fields is the motion of charges.

With a few hold-outs, most folks seem to (finally) understand that an E
field does not *cause* an H field. (Those that disagree: p-l-e-a-s-e read
Jefimenko's "Causality" before jumping in to dispute this statement.)

OK. So far, so good.

A permanent magnet has associated with it a magnetic field whose
characteristics seem to be indistinguishable from those of a magnetic field
that is caused by the motion of charges.

Where the H--- does the H come from? How do we know?


This is a nice little mystery in (classical) physics! Sure, we can say
there is an "Amperian equivalent current" around the magnet, but ???

But I think it comes down to: experimentally/observationally, we find that
there is no magnetic (monopole) charge to be found, but many materials
have a non-zero magnetic dipole moment. Even diving into quantum
mechanics, all we get is the magnetic dipole moment as some magic physical
quantity tacked onto "electron".

Well, we see that the universe is stranger than we expected! Sorry to not
be of more help.

--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
E-prints: http://eprint.uq.edu.au/view/person/...,_Timo_A..html
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html

  #7  
Old March 16th 08 posted to sci.physics.electromag
FrediFizzx
external usenet poster
 
Posts: 5,404
Default Where Does A Permanent Magnet Get Its Magnetic Field?

"Timo A. Nieminen" wrote in message
...
On Sat, 15 Mar 2008, Bill Miller wrote:

The title of the post pretty much says it all.

The participants of this list seem to have fairly clear agreement
that the
primary *cause* of magnetic fields is the motion of charges.

With a few hold-outs, most folks seem to (finally) understand that an
E
field does not *cause* an H field. (Those that disagree: p-l-e-a-s-e
read
Jefimenko's "Causality" before jumping in to dispute this statement.)

OK. So far, so good.

A permanent magnet has associated with it a magnetic field whose
characteristics seem to be indistinguishable from those of a magnetic
field
that is caused by the motion of charges.

Where the H--- does the H come from? How do we know?


This is a nice little mystery in (classical) physics! Sure, we can say
there is an "Amperian equivalent current" around the magnet, but ???


Bound current in a magnet happens because there is a boundary edge.

But I think it comes down to: experimentally/observationally, we find
that there is no magnetic (monopole) charge to be found, but many
materials have a non-zero magnetic dipole moment. Even diving into
quantum mechanics, all we get is the magnetic dipole moment as some
magic physical quantity tacked onto "electron".


I am sure that atomic magnetic moments have been measured and that is
mainly the source for the H field in permanent magnets. In the
viewpoint of the quantum "vacuum" (QV) as a relativistic medium, there
is not much "magical" about an electron's magnetic moment. ;-) Keep in
mind that in the QV medium picture, virtual fermionic pairs interact
directly with a fermion such as an electron constantly. It takes a bit
of different thinking to visualize it as most people are so used to
interactions as pictured in Feynman diagrams.

Best,

Fred Diether
Co-moderator sci.physics.foundations

  #8  
Old March 17th 08 posted to sci.physics.electromag
Bill Miller
external usenet poster
 
Posts: 308
Default Where Does A Permanent Magnet Get Its Magnetic Field?


"FrediFizzx" wrote in message
...
"Bill Miller" wrote in message
...

"FrediFizzx" wrote in message
...
"Bill Miller" wrote in message
...
The title of the post pretty much says it all.

The participants of this list seem to have fairly clear agreement that
the primary *cause* of magnetic fields is the motion of charges.

With a few hold-outs, most folks seem to (finally) understand that an E
field does not *cause* an H field. (Those that disagree: p-l-e-a-s-e
read Jefimenko's "Causality" before jumping in to dispute this
statement.)

OK. So far, so good.

A permanent magnet has associated with it a magnetic field whose
characteristics seem to be indistinguishable from those of a magnetic
field that is caused by the motion of charges.

Where the H--- does the H come from? How do we know?

Well, I think we pretty much know that it comes from atomic alignment of
their electron's orbital angular momentum. So there is "local" motion
of charges all coordinated.
IOW, the atomic magnetic moments point in
the same direction and all add up. I don't think many physicists would
disagree with that.

Fred


OK

That answers the first part. Kinda


What is the second part that it doesn't answer?

You said that the effect is local.

How local is local? Atoms? Molecules? Magnetic domains? Blobs?


I do believe I said "atomic" above. However, keep in mind that atomic
"motion" of electrons is dealt with by quantum physics.


I'm perfectly happy to have someone use quantum physics to explain this.
Also, my question still stands.

To clarify. I can imagine a magnetic material in which every atom has
somehow gone into "lock step" with every other other one. I would expect
that would be a pretty powerful magnet. I can imagine a magnetic material
that contains just a pair. Pretty weak.

How are these alignments arrayed? What causes them to become arrayed?

Some permanent magnets appear to, indeed, be permanent. It is
hard-to-impossible to degauss them. Others, like soft steel, are
self-degaussing and their field (there's THAT word again) "decays" with
time. Presumably if we know what mechanisms cause the permanence, we can
understand and why they decay and vice-versa. Do we know why they decay (or
don't)?

How do we know that the theory that you are postulating is correct? IOW
what measurements have been done to validate the statement you have made?


It's not my theory


I did not say it was your theory. I carefully tried to avoid that situation
by saying "the theory that you are postulating."

and I would imagine


*imagine?!*

I'm sorry, Fred, but this is not an answer that is even close to acceptable!
Over the last year or two, I have made some kinda outrageous claims about EM
theory on this list. In every instance, I believe I have backed up those
claims with references to documentation that is clear and readily available.
(In fact, I hope you are reading one of those references now!)

you could find experimental references in a good solid state physics book.


Which ones? Author's names? Page references?

And I would also imagine


THAT word again!

that hard drive companies especially IBM should have some experimental
evidence for you.


If they do, how likely is it that I could write them and they would send it?

What about some_available_ references that show in a clear and unambiguous
way that the theory you postualted is valid?

Otherwise, its about as valid as phlogiston!

Cheers,

Bill

Best,

Fred Diether
Co-moderator sci.physics.foundations



  #9  
Old March 17th 08 posted to sci.physics.electromag
Bill Miller
external usenet poster
 
Posts: 308
Default Where Does A Permanent Magnet Get Its Magnetic Field?


"Timo A. Nieminen" wrote in message
...
On Sat, 15 Mar 2008, Bill Miller wrote:

The title of the post pretty much says it all.

The participants of this list seem to have fairly clear agreement that
the
primary *cause* of magnetic fields is the motion of charges.

With a few hold-outs, most folks seem to (finally) understand that an E
field does not *cause* an H field. (Those that disagree: p-l-e-a-s-e read
Jefimenko's "Causality" before jumping in to dispute this statement.)

OK. So far, so good.

A permanent magnet has associated with it a magnetic field whose
characteristics seem to be indistinguishable from those of a magnetic
field
that is caused by the motion of charges.

Where the H--- does the H come from? How do we know?


This is a nice little mystery in (classical) physics! Sure, we can say
there is an "Amperian equivalent current" around the magnet, but ???

But I think it comes down to: experimentally/observationally, we find that
there is no magnetic (monopole) charge to be found, but many materials
have a non-zero magnetic dipole moment. Even diving into quantum
mechanics, all we get is the magnetic dipole moment as some magic physical
quantity tacked onto "electron".

Well, we see that the universe is stranger than we expected! Sorry to not
be of more help.


That's OK! An honest "I don't know" is kinda refreshing on this list!

Bill


--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
E-prints: http://eprint.uq.edu.au/view/person/...,_Timo_A..html
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html



  #10  
Old March 18th 08 posted to sci.physics.electromag
FrediFizzx
external usenet poster
 
Posts: 5,404
Default Where Does A Permanent Magnet Get Its Magnetic Field?

"Bill Miller" wrote in message
...

"FrediFizzx" wrote in message
...
"Bill Miller" wrote in message
...

"FrediFizzx" wrote in message
...


[...]
Well, I think we pretty much know that it comes from atomic
alignment of their electron's orbital angular momentum. So there
is "local" motion of charges all coordinated.
IOW, the atomic magnetic moments point in
the same direction and all add up. I don't think many physicists
would disagree with that.

Fred


OK

That answers the first part. Kinda


What is the second part that it doesn't answer?

You said that the effect is local.

How local is local? Atoms? Molecules? Magnetic domains? Blobs?


I do believe I said "atomic" above. However, keep in mind that
atomic "motion" of electrons is dealt with by quantum physics.


I'm perfectly happy to have someone use quantum physics to explain
this. Also, my question still stands.

To clarify. I can imagine a magnetic material in which every atom has
somehow gone into "lock step" with every other other one. I would
expect that would be a pretty powerful magnet. I can imagine a
magnetic material that contains just a pair. Pretty weak.

How are these alignments arrayed? What causes them to become arrayed?

Some permanent magnets appear to, indeed, be permanent. It is
hard-to-impossible to degauss them. Others, like soft steel, are
self-degaussing and their field (there's THAT word again) "decays"
with time. Presumably if we know what mechanisms cause the permanence,
we can understand and why they decay and vice-versa. Do we know why
they decay (or don't)?

How do we know that the theory that you are postulating is correct?
IOW what measurements have been done to validate the statement you
have made?


It's not my theory


I did not say it was your theory. I carefully tried to avoid that
situation by saying "the theory that you are postulating."


When you say "the theory that you are postulating" implies to me that
you think it is my theory. "The theory that you are stating" would be a
better way to put it. I am not really postulating anything.

and I would imagine


*imagine?!*

I'm sorry, Fred, but this is not an answer that is even close to
acceptable! Over the last year or two, I have made some kinda
outrageous claims about EM theory on this list. In every instance, I
believe I have backed up those claims with references to documentation
that is clear and readily available. (In fact, I hope you are reading
one of those references now!)


Sorry, this really isn't interesting enough for me to do your research
for you. ;-) I'm not really claiming anything special here. Just
repeating the very widely accepted explanation that can be easily found
in books and various websites.

you could find experimental references in a good solid state physics
book.


Which ones? Author's names? Page references?


A seach on Amazon for Solid State Physics books should do you well.
Just read the various customer reviews and look thru the contents to see
if a particular book might suit your research. Here is a link to make
it easier,

http://www.amazon.com/s/ref=nb_ss_gw...+state+physics

And I would also imagine


THAT word again!

that hard drive companies especially IBM should have some
experimental evidence for you.


If they do, how likely is it that I could write them and they would
send it?

What about some_available_ references that show in a clear and
unambiguous way that the theory you postualted is valid?


Again, I am not really postulating anything new or unusual. And I fully
accept the atomic / quantum physics explanation so it really is not all
that interesting to know more about where the H field of a permanent
magnetic comes from. Sorry. Hope this might help anywise.

Best,

Fred Diether
Co-moderator sci.physics.foundations

 




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