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Author Topic: From where do magnets obtain their "energy" ?  (Read 19370 times)

martin elbin

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From where do magnets obtain their "energy" ?
« on: 01/10/2010 19:30:03 »
martin elbin  asked the Naked Scientists:
   
why dont magnets ever "run out of power" to attract or repel?  ferromagnets in specific, i understand why electric current magnets keep working as long as there is a current, but alignment in ferromagnets dont use current, so why do they keep working...isnt this a contradiction to entropy?

What do you think?
« Last Edit: 01/10/2010 19:30:03 by _system »


 

Offline Soul Surfer

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From where do magnets obtain their
« Reply #1 on: 01/10/2010 19:45:56 »
From the bonded ordered structure of the unpaired electron magnetic fields in the atoms.  Using a magnet to create forces that stresses the bonds that enable the fields and so can weaken a magnet  this is why horseshoe magnets have keepers and bar magnets are usually stored in pairs stuck together.
 

Offline syhprum

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« Reply #2 on: 01/10/2010 20:22:09 »
To create a permanent magnet energy must be supplied to suitable materiel by immersing it in a magnetic field normally supplied by an electromagnet
 

Offline Geezer

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« Reply #3 on: 01/10/2010 20:46:15 »
I don't think magnets actually "store" power, nor do they consume power when they are attracting ferrous objects.

As mentioned above, permanent magnets are maded by aligning the atoms in the same general direction so that the fields produced by each atom add together to produce the force we observe. Prior to aligning the atoms, the individual fields are still there, but because they all point in different directions, the fields tend to cancel each other out.

If you turn a steel nail into a magnet in the manner that Syhprum describes, you can randomize the alignment of the atoms again by giving the nail a few good raps with a hammer. Heating it up will have a similar effect.
 

Offline syhprum

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« Reply #4 on: 01/10/2010 21:22:33 »
Permanent magnets do in fact store some energy, place the magnet within a coil and connect a load to it, if you cause the magnet to demagnetize by some means the collapsing field induces a current in the coil and power flows into the load.
 

Offline Geezer

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« Reply #5 on: 01/10/2010 21:54:56 »
Permanent magnets do in fact store some energy, place the magnet within a coil and connect a load to it, if you cause the magnet to demagnetize by some means the collapsing field induces a current in the coil and power flows into the load.

I never knew that! I suppose the alignment process must create some stress in the structure of the magnet.
« Last Edit: 02/10/2010 05:03:39 by Geezer »
 

Offline chris

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From where do magnets obtain their
« Reply #6 on: 02/10/2010 09:22:41 »
Magnets are not consuming energy; the spin of the electrons within the substance of the magnet creates a field around the magnet, similar in some ways to the Earth's gravitational field that arises because the planet has mass. In both cases, an object placed within that field can interact with it, such as a stone taken to the top of a building - it has gravitational potential energy, but the energy had to be supplied by the stone being carried up in the first place. Similarly, a magnet creates a magnetic hill down which ferromagnetic materials can fall.

Chris
 

Offline syhprum

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« Reply #7 on: 02/10/2010 13:08:08 »
The LHC magnets store 3.056 MW hours of energy quite a lot to get loose if the refrigeration were to fail.
 

Offline Geezer

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« Reply #8 on: 02/10/2010 21:40:41 »
I think the real thrust of Martin's question might be more along the lines of

"What produces the force that permanent magnets exert?"

If that is the case, then one answer is the atomic alignment, but that doesn't really explain the source of the fundamental force either.

I think the fundamental force emerges from a property of space itself.
 

Offline syhprum

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« Reply #9 on: 02/10/2010 21:49:18 »
Entropy concerns the flow of energy to maintan a force entails no flow of energy unless movement is produced.
I presume the field is produced by the exchange of virtual photons in much the same way as the force between quarks is produced by Gluons and the force between masses is produced by (gravitons ?).
I think we need a scientist here I am only a technician!
« Last Edit: 02/10/2010 22:14:23 by syhprum »
 

Offline Geezer

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« Reply #10 on: 03/10/2010 05:13:46 »
I think we need a scientist here I am only a technician!

Me too!
 

Offline acsinuk

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From where do magnets obtain their
« Reply #11 on: 06/10/2010 10:23:56 »
Domain theory is what we were taught.  But it fails to explain were the magnetic dark force comes from.  Is it a property of the spare spaces in the outer electron shell do you think? Can you prove or disprove it??
CliveS
 

Offline JP

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« Reply #12 on: 06/10/2010 11:52:47 »
If that is the case, then one answer is the atomic alignment, but that doesn't really explain the source of the fundamental force either.

Moving charges make magnetic fields.  The spins of electrons generally account for "moving" charges on a subatomic level, as Chris said.  The magnet is most stable when it can align these spins, which is why they all add up to produce a field instead of cancelling out. 

The explanation for how a force gets from the magnet to a piece of metal nearby is the usual one for electromagnetic force: classically its a field in space, while quantum mechanically its virtual photons (which arise from the field in space).  Does that help with the question?
 

Offline Soul Surfer

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« Reply #13 on: 06/10/2010 17:34:27 »
When considering questions like this it is very important to remember that all materials are very dynamic and contain energy over and above the mass energy of the particles that make them up.  let me describe them in ascending order of magnitude

The smallest is the thermal energy of the atoms and molecules in the structure as a result of the not being at the absolute zero of temperature.

Then there is the bonding energy for solids and liquids which hods the molecules together. When the thermal energy exceeds this solids melt and liquids boil.

Then there is the energy that holds the electrons in their orbitals around the nuclei.  This is where the magnetic effects reside in unpaired electrons in the structure of the material. When the thermal energy exceeds this gases ionise to become a plasma like the outer regions of a star at thousands of degrees K.

Then there is the binding energy of the nucleons in the nucleus.  When the temperature exceeds millions of degrees K as in the centre of a star or fusion reactor nucleosynthesis is possible.

Finally there is the binding energy of the quarks inside the nucleons themselves.  These have so much energy inside their minute confined area that their velocities are relativistic and the mass energy is less than the kinetic energy.  To release these you have to go back to before the first second of the big bang or use equipment like the LHC to create a quark gluon plasma.
« Last Edit: 06/10/2010 17:36:51 by Soul Surfer »
 

Offline syhprum

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« Reply #14 on: 06/10/2010 18:50:09 »
I think we need a scientist here I am only a technician!

Me too!
Thanks JP
 

Offline yor_on

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« Reply #15 on: 06/10/2010 20:16:00 »
Maybe this one might shed some light on it? Magnets and fractals.
As well as this one superconductor-fractals.

And this one too, maybe? Origin of magnetic fields may lie in special relativity's SpaceTime distortions. This one is, as far as I can see, a pure hypothesis though, not experimentally verified. And in that way differing from the ones I linked above, considering the fractal nature of magnets/superconductors that are experimentally verified, as I understands it.

In it the journalist comments. "To get around this constraint, scientists have more recently turned to non-ideal dynamics. Researchers have looked at non-ideal mechanisms ranging from something called the baroclinic effect to processes stemming from inflation" So what are those non-ideal dynamics? Simply non-linearity, the way our SpaceTime actually 'works'.

Interesting 'move of perspective' that one. "Among fluids, two rough broad divisions can be made: ideal and non-ideal fluids. An ideal fluid really does not exist, but in some calculations, the assumption is justifiable. An Ideal fluid is non viscous- offers no resistance whatsoever to a shearing force." From the wiki:Fluid mechanics

So, are we at last starting to accept non-linearity then?
Wonder what that will do to our 'normalizations' and 'cut offs'? 
As for there existing no 'ideal fluid' as seen from that definition?
How about the 'vacuum', or rather what hides in it?
Or maybe not?



When we speak of a magnetic 'force' applied to the idea of an 'permanent magnet' I'm not sure what it is we talk about? When we talk about 'electro magnetism' and the way different charges can show more or less magnetic 'forces' I can see the relation though. But magnets are very strange, and interesting. :)

=== Add this one.

"PROVIDENCE, R.I. [Brown University] — At the quantum level, the forces of magnetism and superconductivity exist in an uneasy relationship. Superconducting materials repel a magnetic field, so to create a superconducting current, the magnetic forces must be strong enough to overcome the natural repulsion and penetrate the body of the superconductor. But there's a limit: Apply too much magnetic force, and the superconductor’s capability is destroyed. This relationship is pretty well known. But why it is so remains mysterious. Now physicists at Brown University have documented for the first time a quantum-level phenomenon that occurs to electrons subjected to magnetism in a superconducting material. In a paper published in Physical Review Letters, Vesna Mitrovic, joined by other researchers at Brown and in France, report that at under certain conditions, electrons in a superconducting material form odd, fluctuating magnetic waves. Apply a little more magnetic force, and those fluctuations cease: The electronic magnets form repeated wave-like patterns promoted by superconductivity.

The discovery may help scientists understand more fully the relationship between magnetism and superconductivity at the quantum level. The insight also may help advance research into superconducting magnets, which are used in magnetic resonance imaging (MRI) and a host of other applications. “If you don’t understand [what is happening at] the quantum [level], how can you design a more powerful magnet?” asked Mitrovic, assistant professor of physics. When a magnetic field is applied to a superconducting material, vortices measured in nanometers (1 billionth of a meter) pop up. These vortices, like super-miniature tornadoes, are areas where the magnetic field has overpowered the superconducting field state, essentially suppressing it. Crank up the magnetic field and more vortices appear. At some point, the vortices are so widespread the material loses its superconducting ability altogether.

At an even more basic level, sets of electrons called Cooper pairs (named for Brown physicist Leon Cooper, who shared a Nobel Prize for the discovery) form superconductivity. But scientists believe there also are other electrons that are magnetically oriented and spin on their own axes like little globes; these electrons are tilted at various angles on their imaginary axes and move in a repeating, linear pattern that resembles waves, Mitrovic and her colleagues have observed. “These funny waves most likely appear because of superconductivity, but the reason why is still unsettled,” Mitrovic said.

Adding to the mystery, Mitrovic and fellow researchers, including Brown graduate student Georgios Koutroulakis and former Brown postdoctoral associate Michael Stewart, saw that the waves fluctuated under certain conditions. After nearly three years of experiments at Brown and at the national magnetic field laboratory in Grenoble, France, Mitrovic’s team was able to produce the odd waves consistently when testing a superconducting material — cerium-cobalt-indium5 (CeCoIn5) — at temperatures close to absolute zero and at about 10 Tesla of magnetic force. The waves appeared to be sliding, Mitrovic said. “It’s as if people are yanking on the wave,” she added. Mitrovic and her colleagues also observed that when more magnetic energy is added, the fluctuations disappear and the waves resume their repeating, linear patterns.

The researchers next want to understand why these fluctuations occur and whether they crop up in other superconducting material. The research was funded by the National Science Foundation and a European Community grant, as well as the Alfred P. Sloan Foundation."

===
« Last Edit: 06/10/2010 21:58:58 by yor_on »
 

Offline yor_on

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« Reply #16 on: 06/10/2010 22:28:04 »
To get an idea at what I'm aiming at here you can research Mitchell J. Feigenbaum. and his Feigenbaum Constant.

That constant is one of the most remarkable phenomena I know of, and it's a purely mathematical concept, even if relating to almost anything physical in our 'real world'. And he got to it researching clouds :) Well, that's what he called it I think? Taking trips with various commercial airlines looking through that small window, wondering how those clouds could be so similar and yet so different. For some other constants, mainly for those 'mathematically inclined' needing their daily feed, have a look here. Food for U 'mathgeeks' :)

And here is a cool pdf Introduction to Chaos in Deterministic Systems. presenting the ideas.
« Last Edit: 06/10/2010 22:44:10 by yor_on »
 

Offline Geezer

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« Reply #17 on: 07/10/2010 07:22:56 »
There's not a lot of dispute that magnetic materials are somehow drawn towards each other. Is this because of an attractive force, or is it due to the absence of some repulsive force?

Either way, what is it that's doing the attracting, or not doing the repulsing?
 

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« Reply #18 on: 07/10/2010 21:27:05 »
Well, that seems to have pretty much put the kibosh on this thread  :D
 

Offline JP

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« Reply #19 on: 08/10/2010 04:36:46 »
You done killed it.

There's not a lot of dispute that magnetic materials are somehow drawn towards each other. Is this because of an attractive force, or is it due to the absence of some repulsive force?
It's the electromagnetic field interacting with charges that either pushes things apart or pulls them together.  This field can either attract or repel--something that's due to the fact that the field is generated by, and interacts with two kinds of charges, +/-.  A field acting on uncharged matter will produce no force, and you'll also get no force if you have charged matter, but no field.  Is that what you were asking about?
 

Offline Geezer

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« Reply #20 on: 08/10/2010 08:01:42 »

It's the electromagnetic field interacting with charges that either pushes things apart or pulls them together.  This field can either attract or repel--something that's due to the fact that the field is generated by, and interacts with two kinds of charges, +/-.  A field acting on uncharged matter will produce no force, and you'll also get no force if you have charged matter, but no field.  Is that what you were asking about?


You really didn't think it was going to be that easy, did you? I'm interested in understanding what it is that actually communicates the force.

Are there particles involved, or is there some distortion of space-time? The forces produced are considerable, so whatever it is that communicates the force must be working quite hard.
 

Offline syhprum

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« Reply #21 on: 08/10/2010 08:23:44 »
I think JP has already confirmed my hunch that the force is mediated by virtual photons.
 

Offline Geezer

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« Reply #22 on: 08/10/2010 08:35:40 »
I think JP has already confirmed my hunch that the force is mediated by virtual photons.

Ah! Well, they must be busy little characters then, so we ought to be able to observe them doing their stuff.

Might I also posit that the force is mediated by virtual bungee cords?
 
 

Offline syhprum

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« Reply #23 on: 08/10/2010 08:42:52 »
Bungee cords would also use virtual photons to transmit the forces between their atoms.

See http://en.wikipedia.org/wiki/Electromagnetism
« Last Edit: 08/10/2010 08:48:29 by syhprum »
 

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« Reply #24 on: 08/10/2010 08:55:15 »
Bungee cords would also use virtual photons to transmit the forces between their atoms.

Please pardon my skepticism Syhprum, but whenever I hear "virtual" anything, I subconsciously substitute "we really don't know what the heck's going on, but hopefully this will blind 'em with science".

We seem to be sufficiently clueless about the nature of actual photons, so it seems to me like a bit of a stretch (any allusion to bungee cords being purely accidental) to invoke virtual photons to explain anything.
 

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