I read somewhere that only electric currents generate magnetic fields.

Where is the electric current in a permanent magnet?

Is a permanent magnet a frozen electric current in matter?

It seems that the electric current in a magnet would like to flow, but
it cant.

PCB wrote:
I read somewhere that only electric currents generate magnetic fields.

Where is the electric current in a permanent magnet?

Is a permanent magnet a frozen electric current in matter?

It seems that the electric current in a magnet would like to flow, but
it cant.

Discus

PCB wrote:
I read somewhere that only electric currents generate magnetic fields.

That is incorrect. The intrinsic spins of elementary particles also
produce magnetic fields.


Where is the electric current in a permanent magnet?

There is none.


Is a permanent magnet a frozen electric current in matter?

No.

It seems that the electric current in a magnet would like to flow, but
it cant.

No. Iron is conductive, as are most other permanent magnets.


The bulk magnetization of a permanent magnet is due to the alignment of
spins in the constituent atoms. This cannot be understood classically,
QM is required.


Tom Roberts

On May 11, 6:02 pm, Tom Roberts wrote:
PCB wrote:
I read somewhere that only electric currents generate magnetic fields.

That is incorrect. The intrinsic spins of elementary particles also
produce magnetic fields.

Where is the electric current in a permanent magnet?

There is none.

Is a permanent magnet a frozen electric current in matter?

No.

It seems that the electric current in a magnet would like to flow, but
it cant.

No. Iron is conductive, as are most other permanent magnets.

The bulk magnetization of a permanent magnet is due to the alignment of
spins in the constituent atoms. This cannot be understood classically,
QM is required.

Tom Roberts

But sir, QM is false, never makes accurate predictions.

QM only probably will make a prediction, but probably not. I learned
that if a theory does not always make a predicted prediction, always,
than that theory is false, or at best useless.

So the question still remains untouched, and I have a permanent magnet
which is not a conductor at all.

What alignment of spins? You mean synchronization of electron spins?

Because the atoms are still round in a permanent magnet, you cant
align somthing which is round.

You need something to be elongated in order to align them.

Am I wrong? Where?

In sci.physics.relativity, PCB

wrote
on Sun, 11 May 2008 07:48:59 -0700 (PDT)
:


PCB wrote:
I read somewhere that only electric currents generate magnetic fields.

Where is the electric current in a permanent magnet?

Is a permanent magnet a frozen electric current in matter?

It seems that the electric current in a magnet would like to flow, but
it cant.

Discus

This is not an obvious relavistic concern;
followups therefore to sci.physics.

Briefly, however, the permanent magnet *is* a manifestation
of an electric current, though it's hard to specify
precisely since I'm not up on my quantum mechanics.
The Bohr model is very discredited by now, but the general
idea is that of a charge orbiting another charge; the
orbiting charge is a current.

Of course in QM things are expressed a little bit
differently, but I've forgotten the details.

Once we've established that an atom has a pair of poles,
it becomes simple, since iron in particular is a series
of magnetic domains, which are crystalline structures
("grains") in the metal; a magnet has more of them lined
up in a preferential direction than not.

--
#191,
Q: "Why is my computer doing that?"
A: "Don't do that and you'll be fine."
** Posted from http://www.teranews.com **

On May 11, 10:34 am, PCB wrote:
I read somewhere that only electric currents generate magnetic fields.

Where is the electric current in a permanent magnet?

Is a permanent magnet a frozen electric current in matter?

It seems that the electric current in a magnet would like to flow, but
it cant.

Origin of Permanent Magnetism
http://farside.ph.utexas.edu/teachin...es/node77.html

Sue...

On May 11, 7:04 pm, The Ghost In The Machine
wrote:
In sci.physics.relativity, PCB

wrote
on Sun, 11 May 2008 07:48:59 -0700 (PDT)
:



PCB wrote:
I read somewhere that only electric currents generate magnetic fields.

Where is the electric current in a permanent magnet?

Is a permanent magnet a frozen electric current in matter?

It seems that the electric current in a magnet would like to flow, but
it cant.

Discus

This is not an obvious relavistic concern;
followups therefore to sci.physics.

Briefly, however, the permanent magnet *is* a manifestation
of an electric current, though it's hard to specify

Thanks, this is what I said, and Tom said I was wrong.

precisely since I'm not up on my quantum mechanics.
The Bohr model is very discredited by now, but the general
idea is that of a charge orbiting another charge; the
orbiting charge is a current.

Thanks again, so is a frozen currrent indeed.


Of course in QM things are expressed a little bit
differently, but I've forgotten the details.

Once we've established that an atom has a pair of poles,

Cant see how a single atom can have poles


it becomes simple, since iron in particular is a series
of magnetic domains, which are crystalline structures
("grains") in the metal; a magnet has more of them lined
up in a preferential direction than not.

A grain yes, you can align them, but not a single atom as Tom said.

You cant align individually atoms, or I cant see how


--
#191,
Q: "Why is my computer doing that?"
A: "Don't do that and you'll be fine."
** Posted fromhttp://www.teranews.com**

Thanks

Seems that you know more about this concern than anybody else here and
there, so this must be the proper group.

In sci.physics.relativity, PCB

wrote
on Sun, 11 May 2008 10:59:23 -0700 (PDT)
:
On May 11, 7:04 pm, The Ghost In The Machine
wrote:
In sci.physics.relativity, PCB

wrote
on Sun, 11 May 2008 07:48:59 -0700 (PDT)
:



PCB wrote:
I read somewhere that only electric currents generate magnetic fields.

Where is the electric current in a permanent magnet?

Is a permanent magnet a frozen electric current in matter?

It seems that the electric current in a magnet would like to flow, but
it cant.

Discus

This is not an obvious relavistic concern;
followups therefore to sci.physics.

Briefly, however, the permanent magnet *is* a manifestation
of an electric current, though it's hard to specify

Thanks, this is what I said, and Tom said I was wrong.

I'd have to look back through the thread to see what Tom
(and, for that matter, *which* Tom) said.


precisely since I'm not up on my quantum mechanics.
The Bohr model is very discredited by now, but the general
idea is that of a charge orbiting another charge; the
orbiting charge is a current.

Thanks again, so is a frozen currrent indeed.

Not frozen at all. It's moving. Granted, in QM one
doesn't see the movement, but instead a probability
distribution of states.



Of course in QM things are expressed a little bit
differently, but I've forgotten the details.

Once we've established that an atom has a pair of poles,

Cant see how a single atom can have poles

Easy. The electric current around the atom generates a
magnetic field, much like a one-loop solenoid (or in the
case of the iron atom, 26 electrons trying to compete with
one another).



it becomes simple, since iron in particular is a series
of magnetic domains, which are crystalline structures
("grains") in the metal; a magnet has more of them lined
up in a preferential direction than not.

A grain yes, you can align them, but not a single atom as Tom said.

You cant align individually atoms, or I cant see how

Crystals align the atoms within them. These are the "grains".
The size thereof depends on how one manufactures the item.



--
#191,
Q: "Why is my computer doing that?"
A: "Don't do that and you'll be fine."
** Posted fromhttp://www.teranews.com**

Thanks

Seems that you know more about this concern than anybody else here and
there, so this must be the proper group.


--
#191,
/dev/brain: Permission denied
** Posted from http://www.teranews.com **

On 11 mai, 12:36, PCB wrote:
On May 11, 6:02 pm, Tom Roberts wrote:



PCB wrote:
I read somewhere that only electric currents generate magnetic fields.

That is incorrect. The intrinsic spins of elementary particles also
produce magnetic fields.

Where is the electric current in a permanent magnet?

There is none.

Is a permanent magnet a frozen electric current in matter?

No.

It seems that the electric current in a magnet would like to flow, but
it cant.

No. Iron is conductive, as are most other permanent magnets.

The bulk magnetization of a permanent magnet is due to the alignment of
spins in the constituent atoms. This cannot be understood classically,
QM is required.

Tom Roberts

But sir, QM is false, never makes accurate predictions.

QM only probably will make a prediction, but probably not. I learned
that if a theory does not always make a predicted prediction, always,
than that theory is false, or at best useless.

So the question still remains untouched, and I have a permanent magnet
which is not a conductor at all.

No electrical conduction is required. Ceramic magnets for example
are not conductive.

You will find all the particular of what interests you here in the
CRC handbook of Chemistry & Physics, p 12-117

What alignment of spins? You mean synchronization of electron spins?

In all atoms, each orbital becomes complete when two electrons
associate by inverse parallel spin. Electrons behave like small
magnets having two magnetic poles. The magnetic pole duality
is named spin (a strange misnomer cooked up before spin was
clearly identified as being the magnetic aspect of electrons.)

To put it simply, in some atoms, some layers close to the
outermost do not get filled completely and contain isolated
electrons that are partially free to rotate locally.

When circumstance allow (typically an external strong magnetic
field will force a lot of these electrons to align contrary
to the direction of the external field. When the external
field is removed, local electromagnetic equilibrium will
tend to keep them align parellel which will cause their
fields to add up to make up the macroscopically detectable
field that we can use.

This has been understood for more than 80 years, even though
QM trained physicists tend not to learn about it since this
observed fact is in contradiction with QM.

Because the atoms are still round in a permanent magnet, you cant
align somthing which is round.

You need something to be elongated in order to align them.

Am I wrong? Where?

Atoms are not really "balls" you know. They are mostly
vacuum with the electrons captive at certain locations
in the volume detemined by the whole atom. Electrons
keep their individual characteristics, including their
spin orientation, which can only be anti-parallel for
orbital filling and for covalent bound (between atoms)

Only electrons isolated alone on their orbital can
be part of a larger magnetic field. See the CRC ref
I mentioned for the complete story.

André Michaud

On May 11, 12:46*pm, wrote:
On 11 mai, 12:36, PCB wrote:





On May 11, 6:02 pm, Tom Roberts wrote:

PCB wrote:
I read somewhere that only electric currents generate magnetic fields.

That is incorrect. The intrinsic spins of elementary particles also
produce magnetic fields.

Where is the electric current in a permanent magnet?

There is none.

You cannot have a magnetic field without an electric flow.

Mitch Raemsch; Twice Nobel Laureate 2008

Is a permanent magnet a frozen electric current *in matter?

No.

It seems that the electric current in a magnet would like to flow, but
it cant.

No. Iron is conductive, as are most other permanent magnets.

The bulk magnetization of a permanent magnet is due to the alignment of
spins in the constituent atoms. This cannot be understood classically,
QM is required.

Tom Roberts

But sir, QM is false, never makes accurate predictions.

QM only probably will make a prediction, but probably not. I learned
that if a theory does not always make a predicted prediction, always,
than that theory is false, or at best useless.

So the question still remains untouched, and I have a permanent magnet
which is not a conductor at all.

No electrical conduction is required. Ceramic magnets for example
are not conductive.

You will find all the particular of what interests you here in the
CRC handbook of Chemistry & Physics, p 12-117

What alignment of spins? You mean synchronization of electron spins?

In all atoms, each orbital becomes complete when two electrons
associate by inverse parallel spin. Electrons behave like small
magnets having two magnetic poles. The magnetic pole duality
is named spin (a strange misnomer cooked up before spin was
clearly identified as being the magnetic aspect of electrons.)

To put it simply, in some atoms, some layers close to the
outermost do not get filled completely and contain isolated
electrons that are partially free to rotate locally.

When circumstance allow (typically an external strong magnetic
field will force a lot of these electrons to align contrary
to the direction of the external field. When the external
field is removed, local electromagnetic equilibrium will
tend to keep them align parellel which will cause their
fields to add up to make up the macroscopically detectable
field that we can use.

This has been understood for more than 80 years, even though
QM trained physicists tend not to learn about it since this
observed fact is in contradiction with QM.

Because the atoms are still round in a permanent magnet, you cant
align somthing which is round.

You need something to be elongated in order to align them.

Am I wrong? Where?

Atoms are not really "balls" you know. They are mostly
vacuum with the electrons captive at certain locations
in the volume detemined by the whole atom. Electrons
keep their individual characteristics, including their
spin orientation, which can only be anti-parallel for
orbital filling and for covalent bound (between atoms)

Only electrons isolated alone on their orbital can
be part of a larger magnetic field. See the CRC ref
I mentioned for the complete story.

André Michaud- Hide quoted text -

- Show quoted text -